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Lukas
16-Jun-2013, 11:13
Hi,

my name is Lukas and I wrote a little app for the iPhone that allows you to check the shutter speeds of your cameras or your LF-lenses.
I thought this might be helpful for one or two, so I'm telling you about this :)

The App itself uses a acoustic measuring method to determine the shutter speed: You can record the shutter release sound, and the App displays the waveform of this sound. Because the shutter makes a noise, when it opens and closes you can see two peaks in the signal. The time between those peaks is the shutter speed of your lens/your camera.
97141

Of course, this acoustic way of measurement has it's limits. That's why I invented a small extension for this app: A phototransistor-plug. With a small phototransistor at the top, it allows you to measure the actual light passing through the lens:
97147

It's pretty simple to use, just point the camera or the lens against a bright lamp, position the fototransistor-plug behind it, and release the shutter:
97143

What you get is a waveform like this:
97145

You will see two clear peaks, and you can easily determine the shutter speed from this.

The App plus the phototransistor-plug is a very powerful tool that allows you to check the accuracy of your lenses/your cameras quickly and without wasting money for film. I already sold several of them and I only get positive reviews about the plug.

If you are interested and if you have an iPhone/iPod Touch/iPad, I would be glad if you give it a try:https://itunes.apple.com/us/app/shutter-speed/id560154244?l=de&ls=1&mt=8
And if you like the idea and want to get more precise measurements, especially at faster speeds, you may want to try the phototransistor-plug as an extension: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251288249805?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a81f265cd

Thank you :)

Best,
Lukas

VPooler
16-Jun-2013, 11:20
My hat goes off to you, my friend!

Tin Can
16-Jun-2013, 11:58
On it NOW!

Thanks!

Testing will begin shortly!




Hi,

my name is Lukas and I wrote a little app for the iPhone that allows you to check the shutter speeds of your cameras or your LF-lenses.
I thought this might be helpful for one or two, so I'm telling you about this :)

The App itself uses a acoustic measuring method to determine the shutter speed: You can record the shutter release sound, and the App displays the waveform of this sound. Because the shutter makes a noise, when it opens and closes you can see two peaks in the signal. The time between those peaks is the shutter speed of your lens/your camera.
97141

Of course, this acoustic way of measurement has it's limits. That's why I invented a small extension for this app: A phototransistor-plug. With a small phototransistor at the top, it allows you to measure the actual light passing through the lens:
97147

It's pretty simple to use, just point the camera or the lens against a bright lamp, position the fototransistor-plug behind it, and release the shutter:
97143

What you get is a waveform like this:
97145

You will see two clear peaks, and you can easily determine the shutter speed from this.

The App plus the phototransistor-plug is a very powerful tool that allows you to check the accuracy of your lenses/your cameras quickly and without wasting money for film. I already sold several of them and I only get positive reviews about the plug.

If you are interested and if you have an iPhone/iPod Touch/iPad, I would be glad if you give it a try:https://itunes.apple.com/us/app/shutter-speed/id560154244?l=de&ls=1&mt=8
And if you like the idea and want to get more precise measurements, especially at faster speeds, you may want to try the phototransistor-plug as an extension: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251288249805?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a81f265cd

Thank you :)

Best,
Lukas

Tin Can
16-Jun-2013, 12:57
Seems to work nicely with audio only on a Copal 3. I second is 0.8 sec. Faster than 1/30 gets tricky with the manual setting required. I feel it is worth the $3 and I ordered the optional light measuring device.

Such a simple thing but so handy for many of use.

Tim Meisburger
16-Jun-2013, 15:16
Hi Lukas. Any plans to write for the Android?

Bill_4606
16-Jun-2013, 17:34
It works pretty well on the iPad. I really like the user interface... Simple and easy to figure out.
Two things.
1. It would be nice to be able to print the camera results table. Not a big deal cause you can do a screen capture and print the picture... Minor issue.
2. A little more annoying was that the app froze up when I tried to shut down without saving a camera first. Not a huge deal cause once I saved the first camera, it worked fine.

I've done similar tests using audacity on my Windows computer. For speeds slower than 1/250 or so that works fine. This app provides the convenience of calculating a one third stop deviation table and formatting a table on the screen. For that convenience alone, it's well worth the $3.

I have an opitical shutter tester too. For my use, I actually like the audible test better for the slower speeds. The audible tester can see (hear) the shutter start open, stop open, start close, and stop close.

97159

Very good and thanks for design effort.
Bill

Tin Can
16-Jun-2013, 17:44
I would think it would be easier to adjust the sliders on an iPad.

I am resisting an iPad until my iPod Touch 4 fails. And I hope it doesn't, the darn thing now does everything.

I never use it for music.

The trick will be not losing the photo eye dongle...

I agree, thanks for the app.




It works pretty well on the iPad. I really like the user interface... Simple and easy to figure out.
Two things.
1. It would be nice to be able to print the camera results table. Not a big deal cause you can do a screen capture and print the picture... Minor issue.
2. A little more annoying was that the app froze up when I tried to shut down without saving a camera first. Not a huge deal cause once I saved the first camera, it worked fine.

I've done similar tests using audacity on my Windows computer. For speeds slower than 1/250 or so that works fine. This app provides the convenience of calculating a one third stop deviation table and formatting a table on the screen. For that convenience alone, it's well worth the $3.

I have an opitical shutter tester too. For my use, I actually like the audible test better for the slower speeds. The audible tester can see (hear) the shutter start open, stop open, start close, and stop close.

97159

Very good and thanks for design effort.
Bill

Lukas
18-Jun-2013, 03:07
Hi,

thanks for the positive feedback !
Would be great if those who ordered the photo-plug could post their experiences with it, once you received it (shipped it today).

There won't be an android version so far. It's quite difficult to develop and maintain an app on two platforms, and at the moment I just don't have the time for that. But maybe I will try it someday.

Bill, when exactly did the app crash/freeze ? Would be great if you can describe the error in more detail so I can try to find the issue.

Best,
Lukas

cosmicexplosion
18-Jun-2013, 05:39
Brilliant thank you!!!!

Lukas
19-Jun-2013, 00:01
Thanks :)
I relisted the eBay auction, because all plugs of the previous offering are sold: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251292077485?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a822ccdad
At the moment there are only 4 plugs left, but I will built more soon.

dave_whatever
19-Jun-2013, 02:04
Looks like a great idea, well done for bringing this to market.

I was thinking though, given the iPhone already has a device capable of detecting light (the camera) can the app not be programmed to use that instead of the additional sensor?

Lukas
19-Jun-2013, 02:52
I thought about this at the beginning, but unfortunately it is not possible. The camera has a limited frame rate (about 30fps), so the theoretical fastest speed that could be measured would be 1/30s.

Peter De Smidt
19-Jun-2013, 18:05
I ordered one of the light sensors, and I'll buy and try the app when the sensor arrives.

Tin Can
19-Jun-2013, 18:12
Of course, duh!

I like your app and am glad I did not buy all the other shutter testers over the years.

I think many of us have pretty good ears for the slower speeds.



I thought about this at the beginning, but unfortunately it is not possible. The camera has a limited frame rate (about 30fps), so the theoretical fastest speed that could be measured would be 1/30s.

fecaleagle
20-Jun-2013, 23:52
Thanks for this... I purchased the app and will be ordering the photo-plug soon. I had a freeze the first time I attempted a recording and had to quit the app from task switcher on an iPhone 5. If it helps, my status bar turned red, indicating a recording (which I see it doesn't do when it works correctly), and the recording spinner just went on and on, although the timer never moved. I also have a feature request. I will use this to test my shutters, but I would also like to use it to check my bulb exposure timings. So for instance, I would like to be able to adjust the duration of the recording up to, say, 10 seconds, so I can check my accuracy on a 5-second bulb exposure.

Thanks for the app. I think you will find that there are more than a couple members here who will purchase it.

Lukas
23-Jun-2013, 09:03
The phototransistor-plugs are available again !
http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251294470832?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a825152b0

Yes, I will keep your suggestion to enable longer recording times in mind.

Jim Graves
23-Jun-2013, 10:22
I bought and have been trying out the app on my I-Phone (it's an early version 3G phone ... so later versions may vary.)

App works well and is quite easy to use after a few tries. I have four different versions of home shutter testers and this is by far the most convenient to use ... especially with the on-phone recording of readings and stop adjustments. Well worth the cost.

I tested it on a shutter I had professionally tested and it was right on up through 1/60. I had trouble discerning the exact open-close peaks at any higher speeds.

But I've had problems at higher speeds with all four testers I have.

I have ordered the photo transistor plug ... so I'm looking forward to measuring using light rather than sound. One quirk of a couple of photo transistor testers I have is that they seem to require a specific light level to be accurate so I'm curious to see if that is an issue with this system.

Doremus Scudder
23-Jun-2013, 11:01
Lukas,

I have the app and like it very much. It would be very helpful to me if in a future update you could provide the option to read shutter speeds in milliseconds instead of deviation from a chosen speed. That would be more convenient and more in line with what shutter speed readouts normally are.

Best,

Doremus

Tin Can
25-Jun-2013, 13:44
Just received the plug in light sensor.

Checking a reliable Pentax at 1/30 yielded 1/33.6.

Then using a LED flashlight 1/250 was 1/189th.

Isn't 20% considered the standard?

Aimed it a fluorescent lamp and it can read the AC sine wave!

Thanks Lukas!

Jim Graves
25-Jun-2013, 17:09
Randy ... curious to know how the speeds measured by sound and then by light compare.

Tin Can
25-Jun-2013, 17:40
The inventor states sound is OK for under 1/30th and above that light is better. I agree.








Randy ... curious to know how the speeds measured by sound and then by light compare.

Lukas
27-Jun-2013, 12:17
Nice to hear that the plug works for you :)

Here is a new batch of plugs, 6 are left: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251296367135?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a826e421f

ashley161
28-Jun-2013, 00:33
Hi,

my name is Lukas and I wrote a little app for the iPhone that allows you to check the shutter speeds of your cameras or your LF-lenses.
I thought this might be helpful for one or two, so I'm telling you about this :)

The App itself uses a acoustic measuring method to determine the shutter speed: You can record the shutter release sound, and the App displays the waveform of this sound. Because the shutter makes a noise, when it opens and closes you can see two peaks in the signal. The time between those peaks is the shutter speed of your lens/your camera.
97141

Of course, this acoustic way of measurement has it's limits. That's why I invented a small extension for this app: A phototransistor-plug. With a small phototransistor at the top, it allows you to measure the actual light passing through the lens:
97147

It's pretty simple to use, just point the camera or the lens against a bright lamp, position the fototransistor-plug behind it, and release the shutter:
97143

What you get is a waveform like this:
97145

You will see two clear peaks, and you can easily determine the shutter speed from this.

The App plus the phototransistor-plug is a very powerful tool that allows you to check the accuracy of your lenses/your cameras quickly and without wasting money for film. I already sold several of them and I only get positive reviews about the plug.

If you are interested and if you have an iPhone/iPod Touch/iPad, I would be glad if you give it a try:https://itunes.apple.com/us/app/shutter-speed/id560154244?l=de&ls=1&mt=8
And if you like the idea and want to get more precise measurements, especially at faster speeds, you may want to try the phototransistor-plug as an extension: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251288249805?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a81f265cd

Thank you :)

Best,
Lukas

Hi Lukas,

I have downloaded the app and i will begin to test it shortly but great app and nice sharing keep up the great work :)

Peter De Smidt
28-Jun-2013, 02:16
I tried it out briefly this evening with the phototransistor-plug. So far so good!

Yo' Vinny
28-Jun-2013, 05:22
I also tried the app and it is very convenient to use for a quick audio test. I like how the app can be opened in the field to show pre-tested charts for my lenses. It would be good if the recording time was configurable to be more than three seconds. It is sometimes hard to get the iPhone in the right position before the shutter release starts.

Tin Can
28-Jun-2013, 07:16
I agree, juggling the whole mess in the field could be difficult.

My first uses were fully handheld, and nearly impossible, but if I set-up on a flat surface with a flashlight it becomes possible for me to barely do it in 3 seconds.

5 seconds would be better.

Are those metric seconds?



I also tried the app and it is very convenient to use for a quick audio test. I like how the app can be opened in the field to show pre-tested charts for my lenses. It would be good if the recording time was configurable to be more than three seconds. It is sometimes hard to get the iPhone in the right position before the shutter release starts.

Lukas
28-Jun-2013, 09:23
Ok, I will try if it is possible to extend the recording time to 5sec.

Indeed it is a little bit tricky to hold the camera and the iPhone together in both hands, pressing the record button and releasing the shutter at the same time.
Let me show you how I do it:
Here with a leaf shutter camera:
97720
I hold the camera in my left hand, so that I can release the shutter with my forefinger. In my right hand I hold the iPhone, so I can press on the record button with my thumb.

Analog with a SLR:
97721
Camera in the left hand, with my middle finger on the release. iPhone in my right hand, analog to the leaf shutter camera.

I hope this tips help a little bit :)

Tin Can
28-Jun-2013, 09:32
I have real arthritic hands as many of us old people do, what is simple for you is a miracle for me. I am worried I'll drop something, hence the table and flashlight method.

I do like the APP and the lightmeter dongle, it is sensitive enough to 'see' fluorescent flickering from AC current.

Keep plugging it all over, if it was a Kickstarter you may have raised more money for development.

Peter De Smidt
28-Jun-2013, 10:02
For large format lenses, the easiest thing to do is to mount them in a camera. Stop down the aperture to a working stop, say F22. Remove the camera back and compress the bellows a bit Move a light to in front of the lens. Don't get it too close to the lens if the light produces a lot of heat. I use an Jansco LED. Attach cable release. Set time and then cock shutter. I fire the shutter a few times before taking a reading. It should now be fairly easy to hold the ipod behind the lens while tripping the shutter.

Arne Croell
28-Jun-2013, 10:20
Here is a table of a small test I did, comparing Lukas' tester in acoustic mode and with his optical sensor against a Calumet shutter tester. The shutter was a Copal 1 from a 210mm Nikkor W. The first column shows the nominal time in fractions, the second column the nominal time in milliseconds, the third column the Calumet tester result in milliseconds, the fourth column the iphone tester results with the optical sensor converted to milliseconds, and the fifth column the iphone tester using the microphone converted to milliseconds. The times between the three test units/setups are well in agreement for all practical purposes.
97722

Tin Can
28-Jun-2013, 10:31
Thanks for a complete test. I was too lazy.

You used an iPhone. Which one?

I have some trouble expanding the time chart on my iPod 4 Touch. Most likely my device is not as good as an iPhone.

I would think it works really good on an iPod with it's bigger screen.

I wonder if Mac Lion OS has an IOS emulator so I could run the APP on my AIR 11?



Here is a table of a small test I did, comparing Lukas' tester in acoustic mode and with his optical sensor against a Calumet shutter tester. The shutter was a Copal 1 from a 210mm Nikkor W. The first column shows the nominal time in fractions, the second column the nominal time in milliseconds, the third column the Calumet tester result in milliseconds, the fourth column the iphone tester results with the optical sensor converted to milliseconds, and the fifth column the iphone tester using the microphone converted to milliseconds. The times between the three test units/setups are well in agreement for all practical purposes.
97722

Arne Croell
28-Jun-2013, 10:32
iphone 5

Thanks for a complete test. I was too lazy.

You used an iPhone. Which one?

I have some trouble expanding the time chart on my iPod 4 Touch. Most likely my device is not as good as an iPhone.

I would think it works really good on an iPod with it's bigger screen.

I wonder if Mac Lion OS has an IOS emulator so I could run the APP on my AIR 11?

Lukas
1-Jul-2013, 07:48
Thanks for the test Arne !
Nice to see that the app works as it should be.

Unfortunately, there is no way of running an iOS app on Mac OS. You can emulate an app with Xcode (the developing platform), but even there you can't access the hardware (like the microphone).

rcmartins
2-Jul-2013, 11:14
Thanks for a complete test. I was too lazy.

You used an iPhone. Which one?

I have some trouble expanding the time chart on my iPod 4 Touch. Most likely my device is not as good as an iPhone.

I would think it works really good on an iPod with it's bigger screen.

I wonder if Mac Lion OS has an IOS emulator so I could run the APP on my AIR 11?
Actually you don't need any of that. The device Lukas is selling, from what I could gather, is an open plug which has a photodiode or a phototransistor connected as a photodiode. The photodiode converts photons into electrons. If the photodiode is connected within a closed circuit a current will develop and a voltage will appear at the input of the mic input through the amplifier's input impedance. This in turn is digitized (sampled) and shown with a time base. Thus, the plug converts light into electricity which is input through the mic therefore appearing as being a sound. Now, this means that you can use any program, either in the iOS, OS X or any other operating system which records sound inputs from mics and shows them in an appropriate time base. Then you just have to measure the delay between spikes. The most difficult thing to overcome is the 4 ring plug which is non-standard. I don't know if the mac mic input is compatible or not with this 4 ring plug. I am guessing it might be but depends on the age of the mac, in the assumption that the newer macs followed the trend of the iOS devices. Really don't know.

Tin Can
2-Jul-2013, 11:22
I may try that, when I get some time.

Thanks!



Actually you don't need any of that. The device Lukas is selling, from what I could gather, is an open plug which has a photodiode or a phototransistor connected as a photodiode. The photodiode converts photons into electrons. If the photodiode is connected within a closed circuit a current will develop and a voltage will appear at the input of the mic input through the amplifier's input impedance. This in turn is digitized (sampled) and shown with a time base. Thus, the plug converts light into electricity which is input through the mic therefore appearing as being a sound. Now, this means that you can use any program, either in the iOS, OS X or any other operating system which records sound inputs from mics and shows them in an appropriate time base. Then you just have to measure the delay between spikes. The most difficult thing to overcome is the 4 ring plug which is non-standard. I don't know if the mac mic input is compatible or not with this 4 ring plug. I am guessing it might be but depends on the age of the mac, in the assumption that the newer macs followed the trend of the iOS devices. Really don't know.

fecaleagle
2-Jul-2013, 11:59
Actually you don't need any of that. The device Lukas is selling, from what I could gather, is an open plug which has a photodiode or a phototransistor connected as a photodiode. The photodiode converts photons into electrons. If the photodiode is connected within a closed circuit a current will develop and a voltage will appear at the input of the mic input through the amplifier's input impedance. This in turn is digitized (sampled) and shown with a time base. Thus, the plug converts light into electricity which is input through the mic therefore appearing as being a sound. Now, this means that you can use any program, either in the iOS, OS X or any other operating system which records sound inputs from mics and shows them in an appropriate time base. Then you just have to measure the delay between spikes. The most difficult thing to overcome is the 4 ring plug which is non-standard. I don't know if the mac mic input is compatible or not with this 4 ring plug. I am guessing it might be but depends on the age of the mac, in the assumption that the newer macs followed the trend of the iOS devices. Really don't know.

I bought the app, but Lukas has saved us all the trouble of wiring up a phototransistor to a circuit with these plugs. You can buy an extension stereo (or mono, I haven't gotten my plug yet) audio cable, and plug it into the line-in jack on any computer. Just make sure you use the highest sample-rate your hardware supports when recording the audio file. Then just analyze the waveform as you would with the app. The main advantage of the app is portability and automation of the charts!

Edit: I just read that Lukas is utilizing the iPhone's 4-conductor, 3-ring plug. My research has indicated that you can plug one of these into a standard pc/mac microphone or line-in port without any problems. If you really want to isolate the microphone from the headphones, there are plenty of cheap adapters: 1 (http://www.amazon.com/GTMax-Headset-Adapter-Smartphone-smartphone/dp/B0046FMRGA/ref=cm_cr_pr_product_top), 2 (http://www.ebay.com/itm/iPhone-Headset-PC-Laptop-Speaker-Mic-3-5mm-Adapter-/350759348868) and DIY instructions (http://benttronics.blogspot.com/2009/05/audio-breakout-cable-for-ipodiphone.html) available online.

fecaleagle
2-Jul-2013, 14:05
I actually just ordered the last plug available at the moment, so I will let you know the details when it arrives!

About those adapters... I picked one up on Amazon, because I can imagine wanting to use my phone's headset mic with a pc in a pinch, but I'll also be able to run a 6-foot extension cable from the isolated microphone line so that I don't have to press my computer up to the ground glass. What a world we live in. A few years ago, I had a hardware guy (I'm a software guy) build me one of these on a breadboard, but it was nowhere near as convenient as this little photo-plug. Really brilliant stuff, Lukas. Thanks!

Again, if you want to do this with a computer, it is important that you set the sample rate as high as your audio card/computer can handle for measuring fast shutter speeds. When I talked to Lukas about expanding the recording window, one of his concerns was the high sample rate eating up the iDevice's resources over the course of a long recording, because he has it set so high for the quick shutter speeds.

taulen
2-Jul-2013, 15:34
Same here, just bought the app, and seems tow work great only with sound, but also bought the plug to support you ;) and see how it works, not that I need it for the collodion work I'm mainly doing atm, but still nice to have ;)

rcmartins
2-Jul-2013, 17:22
I also have bought both the plug and the app but I do think that understanding how it works goes a long way towards better using it. In this spirit I'll leave some comments that result from my knowledge of these things and not from having in any way opened mine or tried anything. Not that I could't, I just don't want.
Indeed an adapter might exist, and probably does, that has a socket with four contacts (to where connect the plug) and which provides two other jack plugs, one for stereo headsets and another for a mono microphone. The plug with four contacts has the following signals: electronic common, left channel (out), right channel (out), input channel (mic). What signal corresponds to what ring or contact I don't know, but a simple google search surely will answer that since it is a standard iOS thing. Once you have a plug with just the mic signal to where the photodiode is connected you can insert it into a microphone input or a line in. The results will not be the same because the input impedances of these two inputs are not the same. Don't know what they are in most computers (if memory suits me right the line in typically is around 10 kOhm universally), but I would suggest you try both and use the one with higher amplitude. Both have more than enough bandwidth. And bandwidth takes us to the question of sampling rate. In theory the higher the sampling rate the better. True. But there are other problems to consider. If I am not wrong the iphone can go as high as 96 kSps (kilo Samples per second). Yet, if you sample at, say, 22 kSps, you will have a time resolution per sample of 1/22000 ~ 45 us (micro second). This would be more than enough even for speeds of 1/500. Unfortunately, these 22000 samples cannot be represented directly on the screen of an iPhone which can only show, at best, 960 samples simultaneously (iPhone 4). This means that if you acquire 3 s of data, you will have to downsample 66000 samples into 960. This is where you loose resolution. To circumvent this you can zoom near the high slope sections, put markers and then measure. You could also do this by interpolating the data and finding the high slope zones analytically providing a way to measure it automatically without the need to fiddle with markers and zooming in or out.
On a computer, with a decent sound wave manipulating program, you can do this in a much more efficient way with decent sampling rates or, if preferred, with sub-micron-second resolution sample rates. In the field, which is where I intend to use this application, the resolution is more than enough.
The reason why I will be using this in the field is that I have some temperamental shutters which vary a bit so the printing of a correction table is of little meaning, but each one of us will have a different use for it. Also, for packard shutters this helps train the manual sensibility required :)

fecaleagle
2-Jul-2013, 18:24
Also, for packard shutters this helps train the manual sensibility required :)

I actually don't have a shuttered lens for 5x7, so measuring and training my exposure times with a lens cap/hat/darkslide is exactly how I plan to implement this. In addition to it being a nice piece of equipment to have around for future shutters and my shuttered 4x5 lenses.

Thanks for all the info!

Does the plug indeed have four contact points/rings? The pictures on ebay appeared to be the standard 4-pole, 3-ring iPhone mini-plug. Or is the fouth contact point not a ring? Sorry for my ignorance on these matters.

rcmartins
3-Jul-2013, 00:21
Does the plug indeed have four contact points/rings? The pictures on ebay appeared to be the standard 4-pole, 3-ring iPhone mini-plug. Or is the fouth contact point not a ring? Sorry for my ignorance on these matters.
I am also not used to the english terms associated with the plugs. The iphone/ipod/ipad variations do have four contact points, three rings and a tip or, more correctly, one tip, two rings and the chassis. But I guess it is better if I redirect you to a site which shows photos and suggests solutions for connection :)
http://www.iphone-tips-and-advice.com/iphone-headphone-adapter.html
The plug that Lukas sells has four contact points instead of the usual three that stereo jacks have.

rich815
3-Jul-2013, 06:25
I got one of the sensors from eBay. Works great. A bit awkward at first figuring best way to hold my various cameras and lenses (rangefinders, TLRs, LF lenses, etc) in front of the light source and hit the shutters but in time I get a good process down. Seems to be working very well and the graphs are easier to "read" for placement of the end points vs when I used the program as only analog sound.

Jim Michael
3-Jul-2013, 15:10
The total exposure is a function of the light transmitted during shutter open + shutter open time + shutter close time. Shutter open and close times vary according to the number and mass of the leaves and the force acting to move them etc. So my question is, with the phototransistor might one integrate over the transmission curve and derive a modified equivalent shutter speed? I suppose the benefit would be proportional to the open and closing time as contributor to the total exposure.

Arne Croell
3-Jul-2013, 22:44
The total exposure is a function of the light transmitted during shutter open + shutter open time + shutter close time. Shutter open and close times vary according to the number and mass of the leaves and the force acting to move them etc. So my question is, with the phototransistor might one integrate over the transmission curve and derive a modified equivalent shutter speed? I suppose the benefit would be proportional to the open and closing time as contributor to the total exposure.
That is what is called "shutter efficiency", and can be a problem for testing leaf shutters at the shortest times. The measured time then also depends on the aperture and the light intensity used for the test. Its not specific to Lucas' setup, it is the same problem for all test setups using a single photodiode or -transistor. It can be seen in the values for 1/125, 1/250s, and 1/400s in my comparison table (post #30), where the acoustic measurement gives consistently shorter values than both optical ones (Lucas' sensor and Calumet shutter tester). I used a pretty strong light source, open aperture, and the sensor was positioned close to the back lens. Therefore the photodiode measured the time from the moment when the shutter just started to open to when it is nearly closed, giving a longer time than a correct value, which would use the FWHM (full width at half maximum) of the light intensity curve behind the lens. For the acoustic measurement, on the other hand, I used the two strongest peaks in the signal, which I guessed are the shutter blades hitting the fully open position and then the fully closed position - this gives a shorter time than the optically measured one and is probably closer to reality. For more precise values at high speeds one needs an oscilloscope to really measure the light intensity, preferably with a sensor that integrates the light at the focal plane, and then either integrate the area under the curve or at least use the FWHM. Alternatively, for a given photodiode sensitivity one can specify a specific brightness value and distance of the sensor from the lens for the setup that results in measured values close to the FWHM, but this requires a calibration which can only be done at the manufacturer or by someone having an oscilloscope. Years ago, the company Micro-Tools offered a shutter tester where the instructions specified light intensities and distances to be used for the measurements, but it has been removed from their web site years ago.
In the real world its not much of a problem, since how often do we use those fast times? Its completely negligible for 1/60s and slower and still too small of an error at 1/125 to have any significant effect.

Tin Can
3-Jul-2013, 22:52
Great story, even if it is true!





That is what is called "shutter efficiency", and can be a problem for testing leaf shutters at the shortest times. The measured time then also depends on the aperture and the light intensity used for the test. Its not specific to Lucas' setup, it is the same problem for all test setups using a single photodiode or -transistor. It can be seen in the values for 1/125, 1/250s, and 1/400s in my comparison table (post #30), where the acoustic measurement gives consistently shorter values than both optical ones (Lucas' sensor and Calumet shutter tester). I used a pretty strong light source, open aperture, and the sensor was positioned close to the back lens. Therefore the photodiode measured the time from the moment when the shutter just started to open to when it is nearly closed, giving a longer time than a correct value, which would use the FWHM (full width at half maximum) of the light intensity curve behind the lens. For the acoustic measurement, on the other hand, I used the two strongest peaks in the signal, which I guessed are the shutter blades hitting the fully open position and then the fully closed position - this gives a shorter time than the optically measured one and is probably closer to reality. For more precise values at high speeds one needs an oscilloscope to really measure the light intensity, preferably with a sensor that integrates the light at the focal plane, and then either integrate the area under the curve or at least use the FWHM. Alternatively, for a given photodiode sensitivity one can specify a specific brightness value and distance of the sensor from the lens for the setup that results in measured values close to the FWHM, but this requires a calibration which can only be done at the manufacturer or by someone having an oscilloscope. Years ago, the company Micro-Tools offered a shutter tester where the instructions specified light intensities and distances to be used for the measurements, but it has been removed from their web site years ago.
In the real world its not much of a problem, since how often do we use those fast times? Its completely negligible for 1/60s and slower and still too small of an error at 1/125 to have any significant effect.

rcmartins
4-Jul-2013, 04:37
The total exposure is a function of the light transmitted during shutter open + shutter open time + shutter close time. Shutter open and close times vary according to the number and mass of the leaves and the force acting to move them etc. So my question is, with the phototransistor might one integrate over the transmission curve and derive a modified equivalent shutter speed? I suppose the benefit would be proportional to the open and closing time as contributor to the total exposure.
Yes, indeed. I agree with Arne that given the usual fixed times associated with opening and closing the blades the difference should only be noticeable in mechanical shutters at speeds of 1/125 and higher. For manually operated shutters it is an all completely different story. The opening and closing can be a significant portion for speeds faster than 2 s, depending a lot on the operator. In that case the only solution is to integrate the graphic given by the program. This could be easily accomplished by the program, but Lucas would have to implement it. We can also do it by simply looking at the graph and implementing an approximate visual Riemman Integral approach. What I do is to see i) when the light starts to reach the photodiode, ii) the starting instant of the light plateau (interval during which light is approximately constant), iii) the ending instant of the light plateau and iv) the time instant of when the light completely stops (it's a four point estimate). If the intervals before and after the light plateau, corresponding to the opening and closing, are more or less of the constant slope (triangular shape), I simply divide by two each of those two intervals, sum them together and to the duration of the plateau. This seems more complicated than it actually is.
raul

Carsten Wolff
4-Jul-2013, 19:21
The DIYers amongst you can make your own using e.g. Audacity software and any microphone, or your own simple photoelectric circuit; I made myself one about ten years ago from this:
http://www.davidrichert.com/sound_card_shutter_tester.htm
Still works like a charm, although very short speeds can get a bit hard to read.
(NB: phototransistors also have a response-time, that just an aside)

Jim Graves
4-Jul-2013, 20:19
The DIYers amongst you can make your own using e.g. Audacity software and any microphone, or your own simple photoelectric circuit; I made myself one about ten years ago from this:
http://www.davidrichert.com/sound_card_shutter_tester.htm
Still works like a charm, although very short speeds can get a bit hard to read.
(NB: phototransistors also have a response-time, that just an aside)

Yup ... I've done that and used several that others made and sold ... but the beauty of Lukas' App is how easy it is to use and the built in record for each lens/shutter combination that you can easily carry with you into the field ... and for the price ... that's truly a good deal.

Tin Can
4-Jul-2013, 20:24
I agree, having it as an APP on my iPod is the best. It goes along with my many film based APP's, all of which are very handy and cheap.

Ken Lee
10-Jul-2013, 16:33
I just tested my old #4 Alphax Shutter. Using the sliders to identify the peaks, the shutter is quite close to the "old" speeds of 1/5, 1/10, etc.

Thanks for an excellent app !

C_Remington
11-Jul-2013, 07:33
So, obviously, I'm not catching on and am having a hard time reading "the peaks"

Here are one of my results. What am I supposed to be looking at??? do I have too much background noise?

Ken Lee
11-Jul-2013, 08:57
You may find it helpful to release the shutter with a cable release, and pre-squeeze it - as close to actually triggering as possible - before recording with the app.

Try not to record the sounds made by the cable release, or sounds emitted by the shutter after it fires: don't relax the cable release either, since that introduces yet more clicks.

If you place the iPhone right on the lens itself, it will sense the vibration as directly as possible, rather than through a table via the air from a distance.

Ken Lee
11-Jul-2013, 09:06
For the record, I now recommend the app on the "Technique" page of my web site. See http://www.kenleegallery.com/html/tech/index.php#iPhoneShutterTester

One suggestion I would make is to not distinguish between so-called "old" and "new" shutter-speeds. When looking for 1/5, 1/10 etc I almost didn't find them until I clicked on the old/new button by accident. Why not just place them in the same single list of speeds ?

Lukas
11-Jul-2013, 10:40
Wow, quite a discussion going on here :)
There was a short break, but now the phototransistor-plugs are available for sale again: http://www.ebay.com/itm/ShutterSpeedTester-for-your-iPhone-Verschlusszeitentester-fr-das-iPhone-/251303004538

Thanks for the recommending, Ken !
The problem with those old and new values is, that the speed-table (were all the measured data is listed) has a fixed size (so that it fits to the iPhone screen). If you mix old and new values, it would be hard to put den all in one single table.

@C_Remington: I guess you have to try around a little bit, as Ken suggested. As the measurement is acoustic, the position of the iPhone as well as all kinds of background noices affect the measurement.
Try zooming in a little bit more, and position the two bars at the two highest lines in the signal.

Ken Lee
11-Jul-2013, 11:42
The problem with those old and new values is, that the speed-table (were all the measured data is listed) has a fixed size (so that it fits to the iPhone screen). If you mix old and new values, it would be hard to put den all in one single table.

In that case, perhaps different text would be more descriptive, like Modern Speeds (1/8, 1/15...) and Decimal Speeds (1/5, 1/10...)

Lukas
16-Jul-2013, 11:59
Ok, I will think about this in one of the next updates :)

Tin Can
16-Jul-2013, 12:01
Lukas, did you see the Android LF framing and lens app posted here a few days ago? A great idea also.



Ok, I will think about this in one of the next updates :)

fecaleagle
16-Jul-2013, 12:54
Just to report in, I received my photo-plug, and it works perfectly with both the iPhone and my computer. The bad news is, because the device is powered by the iPhone or computer via the "common electrical" contact of these plugs (and not by a battery), standard stereo extension cables will not power the plug. I am buying one of these extension cables (http://www.amazon.com/Ledhill-3-5-mm-Stereo-Plus-Mic-Reader-Extension/dp/B00BYQ0B6M), because they are purported to work with the iPhone remote/volume controls on standard iPhone headsets, and I assume that the volume/remote signals are sent over the same line that powers Lukas' plugs. Again I will report back with the details when I actually have this thing working with an extension cable, but it does work beautifully when plugged directly into the iPhone or my computer, I just need about six feet of cable to make it ideal for me to use.

Tin Can
16-Jul-2013, 12:58
I put that in my Prime cart, I will wait for your report.

Thanks!



Just to report in, I received my photo-plug, and it works perfectly with both the iPhone and my computer. The bad news is, because the device is powered by the iPhone or computer via the "common electrical" contact of these plugs (and not by a battery), standard stereo extension cables will not power the plug. I am buying one of these extension cables (http://www.amazon.com/Ledhill-3-5-mm-Stereo-Plus-Mic-Reader-Extension/dp/B00BYQ0B6M), because they are purported to work with the iPhone remote/volume controls on standard iPhone headsets. Again I will report back with the details when I actually have this thing working with an extension cable, but it does work beautifully when plugged directly into the iPhone or computer.

fecaleagle
6-Aug-2013, 10:01
I put that in my Prime cart, I will wait for your report.

Thanks!


Hey Randy and others,

I just received my Ledhill extension cable (with support for volume controls/swipe readers/shutter-speed testers). It's only four feet long, so a hair shorter than optimal, but it works beautifully with my computer... I have a newer Dell laptop that accepts a 4-conductor 3-ring jack plug, but everything is functioning as expected. The trick, as I expected, is to get a cable that has support for the volume control/etc., because that appears to be the electrical signal line that powers Lukas' shutter speed plug.

I will test it on an older computer with a dedicated (3-conductor 2-ring) line-in jack in a couple of minutes, but here she is in action.

http://farm8.staticflickr.com/7453/9453366214_7c63decf2f_c.jpghttp://farm8.staticflickr.com/7445/9450580975_4dd0b1c9c7_c.jpghttp://farm6.staticflickr.com/5529/9450582849_67c2d33e61_c.jpg

If anybody would like a detailed tutorial on how to use one of these with a computer and measure the readings, I'd be happy to post a follow-up.

fecaleagle
6-Aug-2013, 10:24
The plug does not work on my older HP laptop, presumably because there's no electrical line to power it. I will check on a couple of desktops around the office, but I would assume that any multi-function jack on a newer computer would work swimmingly, but for analog line-in and mic jacks, it seems as though we're out of luck. Maybe somebody with a Mac in front of them can tell me, but I believe that MacBooks have been outfitted with these jacks for a few years now.

Again, to be continued, but it will work for me given my computer hardware, and it also works as an extension cable for the plug with my iPhone...

Edit: Confirmed. The extension cable (and the plug itself, for that matter) will work on any computer with a TRRS jack (Tip-Ring-Ring-Sleeve). I just tested on a late 2009 MacBook Pro, and it works perfectly, but it does not work on any older computers with analog (TRS) line-in jacks. They obviously aren't powering it. Convenient not to need a battery, but apparently quite inconvenient when trying to use the plug with older devices/computers.

My conclusion: if the plug by itself (without the extension cable) works with your computer, the extension cable from Ledhill will work just fine. If the plug alone does not work, you do not have a compatible jack and the extension cable will be pointless, unless you want to send it to me for the trouble. :)

Tin Can
6-Aug-2013, 10:41
William,

Thanks for the update.

If you can do so easily I am sure a tutorial will be welcome by some here. I would prefer to use a laptop, rather than a iPod Touch. I have OS X, iOS and Win 8.

I'll order the cable later today.


The plug does not work on my older HP laptop, presumably because there's no electrical line to power it. I will check on a couple of desktops around the office, but I would assume that any multi-function jack plug on a newer computer would work swimmingly, but for analog line-in and mic jacks, it seems as though we're out of luck. Maybe somebody with a Mac in front of them can tell me, but I believe that MacBooks have been outfitted with these jack plugs for a few years now.

Again, to be continued, but it will work for me given my computer hardware, and it also works as an extension cable for the plug with my iPhone...

Cletus
6-Aug-2013, 12:04
I must have missed this - now I'll be watching like a hawk for the next batch of 'photoplugs'! What a great idea!

fecaleagle
6-Aug-2013, 12:11
There are more available now, actually. Searching from US eBay is finicky because he's an "international seller" to us. Anyway, here's a direct link: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251313659154?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a83761d12

Tin Can
6-Aug-2013, 12:30
I lost track of that extension cable. which one are you using?



There are more available now, actually. Searching from US eBay is finicky because he's an "international seller" to us. Anyway, here's a direct link: http://www.ebay.com/itm/Shutter-Speed-Tester-for-your-iPhone-Verschlusszeitentester-fur-das-iPhone-/251313659154?pt=DE_Foto_Camcorder_Analogkameras&hash=item3a83761d12

fecaleagle
6-Aug-2013, 12:51
The extension cable is made by Ledhill. http://www.amazon.com/gp/product/B00BYQ0B6M

Shocking how many cables are branded as iPhone headset extension cables, and yet do not carry the electrical signals required by the volume controls and other accessories (like shutter speed tester plugs). Anyway, this one works perfectly. I should have purchased two, and I wish it were available in different lengths, but it certainly gets the job done.

Tin Can
6-Aug-2013, 13:08
Cool and it works with those credit card readers which are handy for making quick sales to 'cashless' people.

Thanks!

ordered



The extension cable is made by Ledhill. http://www.amazon.com/gp/product/B00BYQ0B6M

Shocking how many cables are branded as iPhone headset extension cables, and yet do not carry the electrical signals required by the volume controls and other accessories (like shutter speed tester plugs). Anyway, this one works perfectly. I should have purchased two, and I wish it were available in different lengths, but it certainly gets the job done.

toyotadesigner
7-Aug-2013, 12:19
Incredible!

Unfortunately, I still don't have any smart phone, iPhone or Android phone. But I like the idea, my hats off to you for this great app and device.

So I have to wait until my current mobile phone will quit its service... To be honest, I don't need such a smart phone, but I can imagine the advantage of having a tiny computer with me all the time to use TPE, a calculator for exposure times and filter offsets, as well as a DOF calculator, long exposure calculator, bellows extension calculator and now this nice device to check the shutters of my cameras. This list of benefits justifies the investment into such a 'smart phone'.

Tin Can
7-Aug-2013, 12:27
Don't buy a phone, get an iPod Touch 4 or 5. It does everything without a contract. All apps work and I use Voip to call at any WIFI hotspot. I don't have a 'real' phone. Don't want one.

I don't use it for music, just as a tiny computer. Works great.


Incredible!

Unfortunately, I still don't have any smart phone, iPhone or Android phone. But I like the idea, my hats off to you for this great app and device.

So I have to wait until my current mobile phone will quit its service... To be honest, I don't need such a smart phone, but I can imagine the advantage of having a tiny computer with me all the time to use TPE, a calculator for exposure times and filter offsets, as well as a DOF calculator, long exposure calculator, bellows extension calculator and now this nice device to check the shutters of my cameras. This list of benefits justifies the investment into such a 'smart phone'.

fecaleagle
7-Aug-2013, 14:43
Incredible!

Unfortunately, I still don't have any smart phone, iPhone or Android phone. But I like the idea, my hats off to you for this great app and device.

So I have to wait until my current mobile phone will quit its service... To be honest, I don't need such a smart phone, but I can imagine the advantage of having a tiny computer with me all the time to use TPE, a calculator for exposure times and filter offsets, as well as a DOF calculator, long exposure calculator, bellows extension calculator and now this nice device to check the shutters of my cameras. This list of benefits justifies the investment into such a 'smart phone'.


It is certainly getting easier to justify having one (a smartphone) all the time, but I am planning to use this primarily with a computer. There are some jack considerations that I mentioned above, but in the next few days I'll post a detailed walkthrough for using Lukas' plug with a computer.

It's pretty straightforward once you find a compatible extension cable (also listed above).

ScottPhotoCo
7-Aug-2013, 15:27
This is a great answer to something I often wonder about. I bought the app if for no other reason than to support this effort. I do love entrepreneurs!

I boycotted ebay several years ago after they screwed me (corporate) once too often. If we don't use ebay is there another way to acquire the photoplug?

fecaleagle
7-Aug-2013, 15:40
This is a great answer to something I often wonder about. I bought the app if for no other reason than to support this effort. I do love entrepreneurs!

I boycotted ebay several years ago after they screwed me (corporate) once too often. If we don't use ebay is there another way to acquire the photoplug?

PM sent with Lukas' contact information.

ScottPhotoCo
7-Aug-2013, 15:51
PM sent with Lukas' contact information.

Thank you. :)

Tin Can
8-Aug-2013, 12:40
I just got the Amazon Prime Ledhill cable and mine works great, makes it much easier to use the app with my iPod 4.

Combined with a Fenix E05 micro LED flashlight everything works better and easier. I carry that Fenix on my keychain, simply amazing AAA flashlight.

Now when is Apple going to come out with a 6x9 cm 100 megapixel sensor for an iPod 2020?



The extension cable is made by Ledhill. http://www.amazon.com/gp/product/B00BYQ0B6M

Shocking how many cables are branded as iPhone headset extension cables, and yet do not carry the electrical signals required by the volume controls and other accessories (like shutter speed tester plugs). Anyway, this one works perfectly. I should have purchased two, and I wish it were available in different lengths, but it certainly gets the job done.

toyotadesigner
9-Aug-2013, 10:12
Don't buy a phone, get an iPod Touch 4 or 5. It does everything without a contract. All apps work and I use Voip to call at any WIFI hotspot. I don't have a 'real' phone. Don't want one.

I don't use it for music, just as a tiny computer. Works great.

Thank you for this information - I didn't know the iPod can handle apps. Sounds like a real good alternative, similar to the Palm I had a decade ago.

Tin Can
9-Aug-2013, 10:20
I am a fan of Ken Rockwell. He does has some good ideas. I found the iPod 4 Touch through his site. I use it for everything and as a free WIFI phone. WIFI hot spots are everywhere in Chicago and while traveling in the USA I use McDonalds and Starbucks, often from my car and never even go inside. A hidden plus is I can't call while driving, which is against the law many places.

http://www.kenrockwell.com/apple/ipod-touch-5g.htm#intro

http://www.kenrockwell.com/apple/ipod-touch-4g.htm

ymmv



Thank you for this information - I didn't know the iPod can handle apps. Sounds like a real good alternative, similar to the Palm I had a decade ago.

Lukas
23-Aug-2013, 12:40
Hi,
thanks William for your "research" in those extension cables ! It's very nice to hear that the plug also works with a PC, and not only on iOS-devices. I will try this out myself soon.

Lukas
25-Dec-2014, 07:57
Hello everybody !
It's been a while since my last post, but now I have some good news for all android-users:

"Shutter-Speed" and the PhotoPlug are now available for android on the Google Playstore :)
More information on http://www.photoplug.de

Best regards and happy holidays,
Lukas

Toyon
25-Dec-2014, 08:37
Android operating system please.

Tin Can
25-Dec-2014, 11:28
Hello everybody !
It's been a while since my last post, but now I have some good news for all android-users:

"Shutter-Speed" and the PhotoPlug are now available for android on the Google Playstore :)
More information on http://www.photoplug.de

Best regards and happy holidays,
Lukas

Purchased! I also have the IOS version with light sensor. I use it fairly often. Works fine for me.

Merry Christmas!

David Karp
25-Dec-2014, 13:21
Just bought the android app. Going to use it in a few minutes.

David Karp
25-Dec-2014, 14:54
OK. Some questions. I am using this on my Nexus 7 tablet to get the benefit of the bigger screen. When looking at the graphic presentation of the sound waves, where do I place the sliders? Do I start at the first deviation from straight line and end at the last? Or do I go from tallest spike at the start to tallest spike at the end?

Thanks in advance.

Lukas
26-Dec-2014, 09:58
Hi David,
Thanks for downloading the App.
With the acoustic measurement, there is no exact "rule" for interpreting the Signal, because it looks different for any Camera. When you test a camera with leaf shutter, you most likely will get a signal with two Sharp peaks with high intensity. On the Otter Hand, if you have a SLR, the two peaks will be more broad. Here it is the best way to measure from beginning of the first peak to beginning of the second peak.

I hope this helps a bit !

David Karp
26-Dec-2014, 16:36
Thanks Lukas. I will take another look at it later. I think the light measurement method may be in my future!

fishbulb
15-Jan-2015, 22:41
Got the android app and the plug. Works fine, tested my four lenses. Most were slow at 1/500 and 1/250 but OK at the rest of the speeds.

Here are my suggestions for improvement of the app.

* This app needs some options in a settings panel. Some ideas for options and improvements:

* * Option to remember the last lens you saved data to. For example, if I have five lenses, I have to pick which one each time I save a test result. It would be nice if there was an option to automatically save to the last selected lens, and then pick the lens at the beginning of testing. Most people are going to test all the shutter speeds on one lens before switching to another lens. So, with this option enabled, you would pick the lens at the beginning of testing, then test all the shutter speeds, than go back and pick a different lens. Instead, we are picking the lens a dozen times while testing all the shutter speeds.

* * Option to NOT default to 1 second (1/1) in the testing screen. Like, just leave it blank so I have to pick something. I kept forgetting to set the speed, and kept overwriting the 1 second test results. Then I had to go back and re-test the default of 1 second. An option so that the default was blank would avoid this problem.

* * Option to set a custom shutter speed list. Copal 1 shutters max out at 1/400 for example. A lot of the shutter speeds to pick from aren't commonly used either. It'd be great if we could choose what shutter speeds were on the list to pick from.

* * Option to turn on auto-zoom on the graph. I kept having to zoom in and zoom in and zoom in. It would be great to have an autozoom feature, where the app detects the beginning and end of the wave and zooms in to that to start out.

* * Option to change the zoom speed. It is agonizingly slow! I shouldn't have to pinch to zoom ten times just to get the wave framed up. If there was an options panel, people could set this to how they liked.

Additional app features:

* In-app instructions and documentation for setting up the photo plug - i.e. usage tips, how to read the graphs, etc.

* Data export - at least export a JPG file with the lens's stats for all the shutter speeds as tested. Option to dump either a text file or a JPG would be great. Right now the stats are trapped in the app and I have to write them down or type them out myself. A screenshot would be great for people selling lenses and cameras too - they could put it in their for sale ads. You could even put your logo and URL on the screenshot and maybe get some advertising.

Bugs/issues:

* The correction math isn't working. For example, on my 360mm f/6.5, the 1/125 speed was measured at 1/63.9. 1/60 is one stop slower of 1/125 - it is half the speed. Yet the app says it needs a three-stop correction. This is pervasive through the app, for all my lenses. None of the correction factors are accurate. Unless the correction column isn't in stops, but what else would it be measured in? It would be great to have them show values smaller than 1, such as 1/2 stop, 1/3 stop, 1/4 stop, in fractions not decimals.

Anyway, great job so far, and thank you very much for making this app. Hopefully these suggestions will help you take it to the next level! =)

fishbulb
16-Jan-2015, 09:11
On that last one, I now understand from re-reading this thread that the correction table is in 1/3 stop increments. That would be good to know, with either a better heading of that column (call it "1/3 stop correction" instead of just "corr"), or at least a help file in the app that explains this.

fishbulb
24-Jan-2015, 13:23
One more update from today. Used this app and the plug again to test two more lenses. Here are some things that the app could use for improvements:

* When you view a lens' test results under 'Camera Manager', it doesn't tell you what lens it is. That is, when you are looking at a list of shutter speeds and corrections, it should say the name of the lens at the top so when you screenshot (or in the future, export?) that page, you know what lens it was that you were looking at.

* An added data export feature (described in two posts above) should support exporting all the lenses at once, or just one lens at a time.

* When you are testing a lens, the app should tell you if the waveform was generated from audio, or from the light from the photoplug. I noticed that you can tell by how choppy the waveform is (choppier = audio) and also that the app needs to be restarted if you plug in the photoplug while the app is running. It would be great to just have the app say "photoplug" or "audio" at the top of the waveform screen so that the user can quickly determine how the waveform was created.

* On the lens result page under 'Camera Manager' you have to scroll to view all of the shutter speeds. It would be great to be able to pinch zoom on this page so that I can get all of the shutter speeds on one page for taking a screenshot. Or just for viewing them all. Right now, I can take a screenshot using my phone's operating system (Android KitKat Cyanogenmod using the power button) but I have to take two screenshots and combine the two files with an image editing program to see all the shutter speeds.

Long story short, data export and screenshots desperately needed in this app! :)

That said, it is amazing to see how far off some of my shutters are. Despite all being relatively modern Nikon lenses with Copal shutters, all of them have some issues. The best one is probably the 75mm f/4.5, which is spot on except for the "1/500" speed actually only being about 1/250. The 90mm f/8 was the worst, being open too little at longer shutter speeds, about right at 1/4 to 1/15, and open too long at faster shutter speeds, with 1/500 really being about 1/300. The 120mm f/8 was also slow at 1/500 (actually about 1/340) and the 300mm f/9 too slow at 1/125, 1/250, and 1/400. The 360mm f/6.5 in Copal #3 couldn't even come close to the max speed of 1/125 - it was about 1/60th! In fact, none of the six lenses were able to achieve their max shutter speeds, and typically were slow at the second fastest shutter speed as well. Interesting stuff, and worth knowing.

Tin Can
24-Jan-2015, 13:30
Read this. (http://www.largeformatphotography.info/forum/showthread.php?56786-High-shutter-speed-accuracy&p=536308&viewfull=1#post536308) Perfectly normal.

fishbulb
25-Jan-2015, 11:24
Interesting. In that case here is another feature request:

Add an option to automatically calculate a corrected shutter speed for the faster shutter speeds like 1/125, 1/250, 1/400, 1/500. This could be estimated by having the user enter the focal length and aperture of the tested lens so that the app could get the diameter of the opening. The app would then have to make some assumptions about the behaviour of the leaf shutter and then perform some calculus to estimate the true shutter speed.

Jac@stafford.net
25-Jan-2015, 17:29
Let's make this even more complex. I have an app that records vibration. Place the phone at the lensboard, calculate effect at shutter speed... No! Two phones, one front, one at film plane. No! Three, another to measure wind speed. No! Four, the last to measure how much time was wasted mucking with the other three.

nonuniform
14-May-2015, 09:49
Are you using this app with an iPhone 6 and iOS 8? Because it absolutely doesn't work for me with an iPhone 6.

rich815
21-May-2015, 06:47
Let's make this even more complex. I have an app that records vibration. Place the phone at the lensboard, calculate effect at shutter speed... No! Two phones, one front, one at film plane. No! Three, another to measure wind speed. No! Four, the last to measure how much time was wasted mucking with the other three.

There's one to measure time wasted online.

JerryP
11-Jun-2015, 18:58
I love your app on the iPhone, but I was just given a Kindle Fire 7. Does your app support kindle or do you have plans for future development?

Miguel Coquis
25-Aug-2015, 14:00
This is not working when measuring curtain shutters.
Am I missing something ?
Got the apps and the PhotoPlug for Android version. Have try with my large format Mentor reflex camera, with the Speed Graphic and with a Werra (35mm camera). No way.
No pics as shown on the demo.
Any tips ?
Thanks

Tin Can
25-Aug-2015, 14:28
You need to set up carefully.

I use a small LED flashlight on one side of lens and put light sensor on other side. Tape it all down, open aperture fully and try several times.

I use old iPod 4.

Miguel Coquis
26-Aug-2015, 01:12
Randy, I much appreciate your recommendation, will try the light source mentioned.
My doubt is that perhaps the apps and photoplug are not yet appropiate to function with the Samsung android.
For that reason, I would like to hear about someone who have try with android.
Thanks

Tin Can
26-Aug-2015, 09:25
I have Droid Samsung S2, but I have not wanted to buy 2 copies of the software.

I will look into into it if possible.

Miguel Coquis
28-Aug-2015, 12:36
I have Droid Samsung S2, but I have not wanted to buy 2 copies of the software.

I will look into into it if possible.

That would be great if you could, Randy !
It seems there is no body there that have try it.
Lukas have not found the solution yet !
Thanks,

Drew Bedo
7-Sep-2015, 13:09
Congratulations to you!

I do not have the intellectual tools to do do this myself . . . .and proposed this a year or so ago on this board and another. Evryone told me that it was not feasible, so I did not persue it.

This would allow a photographer to check shutter speeds in the field in real time.

I would suggest mounting the sensor to a lens cap to eliminate taping.

Pretty cool.

Ron (Netherlands)
3-May-2016, 02:04
Reading this quite old thread was quite interesting. Has there been any further development with regard to this shutter speed test app? the advertisements on the internet seem quite old, ...2013

scheinfluger_77
3-May-2016, 19:10
I used this app a few nights ago and it seemed to work fine. I'm running an iPad, 3 I think.

Ron (Netherlands)
4-May-2016, 02:01
Thanks, is it an updated version of the app you are using, or is it still the original one?

Rael
4-May-2016, 03:50
I just tried it (whatever version is in the app store at the moment) on the new iPhone SE and it worked fine there as well. Audio only, I didn't buy the photosensor (yet).

Ron (Netherlands)
5-Aug-2017, 12:18
Bought the sensor some time ago. Gives pretty accurate results with my Ipad.
It seems the app is not further developed anymore, which is a pity, since it does not have:
A. an option to print out the results of the shutter test;
B. has only limited ranges/intervals of shutterspeeds: it has all the modern intervals, but lacks many of the intervals on old shutters, so it is only partially usable when you want to use it with older shutters were it would specifically come in handy.