Shutter Speed testing with Android Phone and Photoplug

[Cor]

Came recently across a fairly old (2013) thread on this forum:

https://www.largeformatphotography.info/forum/showthread.php?104402-Shutter-Speed-Tester-for-the-iPhone

So I downloaded the Android version:

https://www.filmomat.eu/photoplug

Although the app is relatively old, and could be improved, it basically works quite nice in audio mode for speeds up to 1/30. And it helps if you have a loud shutter..:).. Placing the shutter on a table, and the mic of your smartphone as close as possible, use a cable release & no other sounds.

Than I read about the Photoplug and I released that I had made something similar in the past (well an acquaintance did actually): a photo diode which plugs in a PC, and you can measure behind the shutter when having a light source on the other side, opening and closing gives you a wave form on an Audio program such as Audicity.

The scheme:
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It involves a AA battery of 1.5 Volt.

No my question is: can I plug in this sensor in my Android phone (the 2mm Jack Plug for headphones) ?

I am not very knowledgeable on electronics, and I wonder about the 1.5 volt battery could damage my phone ?

thanks in advance,

best,

Cor

[Tin Can]

I used my original light sensor many times to test a bunch of shutters including Packards

I lost the sensor in my move

Just ordered another

[Tin Can]

Read this

https://www.largeformatphotography.info/forum/showthread.php?56786-High-shutter-speed-accuracy&p=536366&viewfull=1#post536366

[Cor]

I am aware of the pitfalls, but I am only interested in measuring upto 1/30, cannot remember I ever used a faster speed. So my question remains: will my home made sensor damage my phone ?

Cor

[Tin Can]

Who knows until someone tries

I doubt the plugin has a battery, as the 'light' sensor will produce a tiny amount of electricity as 'signal'

Soon phones won't have an input socket. but I have 3 old ones to test with

I can answer in a month

remind me

[gnd2]

You don't need a battery (nor a switch). You need to connect it to the correct terminals of the jack.
http://www.artdecocameras.com/resources/shutterspeed/

[Ron (Netherlands)]

Have one that I directly plug into the jack of my Ipad....works perfect

[chris73]

I made something like this and works perfect at least up to 1/1000
http://www.willegal.net/photo/repair/shuttertester.htm

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218620

Or just use directly a solar panel from a garden light
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In both cases i didnt have any problem with the sound card of my laptop.

[r.e.]

There was a thread just last week that discussed this app and testing shutter speed generally: Copal 0 Shutter Speed Accuracy (https://www.largeformatphotography.info/forum/showthread.php?164825-Copal-0-shutter-speed-accuracy&highlight=shutter+speed)

I don't believe that an optical assist is necessary to test to 1/30. See the first full paragraph in post #7 of that thread. It discusses Tom Johnstone's test with a lens that had just received a CLA from SK Grimes and had known shutter speeds. Unlike Johnstone, the people who claim that a sound recording isn't good enough haven't actually tried it. A search will find the full Photo.net thread.

I'd also suggest that you import your audio recording into an app that will give you a better waveform image than you'll get on a phone. For an example, see post #13.

[lassethomas]

There was a thread just last week that discussed this app and testing shutter speed generally: Copal 0 Shutter Speed Accuracy (https://www.largeformatphotography.info/forum/showthread.php?164825-Copal-0-shutter-speed-accuracy&highlight=shutter+speed)

I don't believe that an optical assist is necessary to test to 1/30. See the first full paragraph in post #7 of that thread. It discusses Tom Johnstone's test with a lens that had just received a CLA from SK Grimes and had known shutter speeds. Unlike Johnstone, the people who claim that a sound recording isn't good enough haven't actually tried it. A search will find the full Photo.net thread.

I'd also suggest that you import your audio recording into an app that will give you a better waveform image than you'll get on a phone. For an example, see post #13.

I'll go as far as to say that audio is accurate enough even up to 1/60. After that it's really hard to identify the start and end as there is so much noise from the shutter. All this from a lot of experience of using the app both with audio and the suggested optical hardware.
Perhaps audio measurements are not 100% exact, but good enough to give a reading within 1/3 of a stop. Who needs more precision anyway for most situations?