Reciprocity Timer 1.0 [Archive] - Large Format Photography Forum

Boinzo

31-Aug-2011, 19:50

Hi All. I have just had Apple accept my first iPhone App into the store! It is a simple little app I originally made for my own use that I thought others might also get some value from.

It allows you to select from a list of available films and a metered exposure duration - from there it will calculate an actual exposure including reciprocity. The maths is based on as many formaulas I could find for some common films. You can currently select from Ilford B+W, Velvia (color filtered and unfiltered), Provia, Tri-X and Ektar. I will be more than happy to add new films if anyone has the mathematics and can send it to me.

The app also includes a slider to let you add or remove stops of initial exposure (for example if you add an ND) and gives you a count-down timer to time-out your shutter.

It's pretty simple - but I have found it really useful.These (http://www.largeformatphotography.info/forum/showthread.php?t=79804) shots were made using it.

I have it listed at $1.99 - but will obviously review that depending on feedback and workload.

You can get it here (http://itunes.apple.com/au/app/reciprocity-timer/id459691262?mt=8).

SMBooth

1-Sep-2011, 19:44

Been hoping for something like this, will download and give it a try.

jeroldharter

1-Sep-2011, 20:37

It would be useful to know all of the films included.

Boinzo

1-Sep-2011, 20:43

The included films are listed in my post. I am also happy to add new films as the maths comes to hand!

jeroldharter

1-Sep-2011, 20:52

OK. I did not notice that. What I should have said is that I wish it had TMY2!

Boinzo

1-Sep-2011, 22:35

Have you got a chart of times? I can try to calculate a best fit formula for it and add it if you have. If you have some useful data for other films just pm me!

sultanofcognac

2-Sep-2011, 06:20

Just downloaded it – looks very interesting and will put it to the test this weekend ;-)

How about Acros 100 and Efke films?

Good luck in the future and thanks for what looks like a good tool!

David Aimone

2-Sep-2011, 06:56

tmax 100 and 400; Efke 25 and 100; Acros 100 are those I use the most. Looks good.

Steve Goldstein

2-Sep-2011, 09:33

Nice-looking and useful app, well done.

Is there any value in some sort of zoom function on the filter slider to trade less range for finer resolution, like 1/2 or 1/3 stop? I don't use filters that need 9 stops of compensation, but usually use 1-1/3 stop for my polarizer. So maybe the full +-9 stop range in 1-stop steps as now, and a second with +-3 stop range in 1/3 stops???

Light Guru

2-Sep-2011, 11:38

Any chance of adding Velvia 100?

Steve Goldstein

2-Sep-2011, 12:11

Hi Stef,

The times you list in the "Metered Exposure" column differ slightly from those that you'd read off a light meter dial, for example 15sec instead of 16sec. How did you choose the times?

SW Rick

2-Sep-2011, 12:49

I think the "bell" at the end is WAY too loud- the iphone volume doesn't lower it. I'm embarrassed to use it in public. Please either drop it or make it user-controllable.

jeroldharter

2-Sep-2011, 13:00

Does anyone have a table of verified reciprocity times for various films (e.g. TMY2)?

I have not yet downloaded the app because it does not include my primary film. I wonder if it could include user programmable tables that feed the controls/dials on the app?

Boinzo

2-Sep-2011, 15:48

Thanks for all the suggested improvements guys. I will certainly take those suggestions on board and make some changes. You can expect an update soon.
The times I selected for metered exposure were really just arbitrary so I will look at making them more closely match a spot meter.
I'll turn down the bell. Sorry! I'm a bit deaf....:)
I will also look at changing the slider to provide some finer control. I have a lee big-stopper. Hence the 10 stops...
I did want to make it possible to add your table but this is complex and might be a while away.
I will also try to add some more film types while I am doing an update. If anyone has reliable references for formulas I am keen to see them. One issue I have found is that there are many conflicting tables and formulas...
Thanks for the feedback guys and thanks for trying it out. I'll see what I can do to address the suggestions!

jeroldharter

2-Sep-2011, 16:36

I went ahead and downloaded the app. I think it has good potential.

Apart from adding additional films, some additional features might include:

A toggle switch to calibrate the slider in 1/10, 1/3, 1/2, 1 stop increments

A link to tables with filter factors and stops including the math for combining filters

A link to bellows compensation information, and perhaps a second slider for bellows extension adjustments that could be enabled/disabled.

If it had Tmax films plus the above features I would be willing to pay more also.

Allen in Montreal

3-Sep-2011, 07:53

I bought the app too.

What would be a great addition is the development compensation that matches the chosen exposure.
ie: A 12 second metered exposure requires X time and -8% dev. etc.
That would be perfect.

I like Jeroldharter's idea about a bellows extension table.

I think in North America, it has to have T-Max tables to fly, T-max really seems to the number once choice of film here.

I agree the bell is a little loud if you are in a public place. I imagine shooting the interior of a cathedral. :eek:
For now, you can hold the phone so the speaker rests on the tip of your baby finger and it cuts the noise by 80 percent.

Boinzo

4-Sep-2011, 21:44

Hi all. I have submitted an update to the app to Apple for approval. Hopefully it will hit your phones in the next week or so.

I have added a bunch of films - including Kodak TMY, TMX, Velvia 100, and Efke. Among others. The maths for the black and white films is now largely based on the Gainer method as discussed here (http://www.apug.org/forums/forum37/11566-reciprocity-misbehavior-12.html) (thanks to SMBooth for putting me onto that article).

The Efke calculations are based on adding 1/3 rd of a stop to 10 secs, 1/2 stop to 100 secs and 2/3 of a stop after that.

I also messed with the Ilford math (splitting it out into separate films and using the Gainer method). The returned data for HP5+ is now a very close match to Ilfords published charts.

Please be aware that I don't personally shoot all of these films so I have no way to verify the calculations will result in correct exposure or negative density. If the numbers you get don't meet your real-world experience please send me your data tables and I'll try to make the required adjustments.

I have also added the ability to adjust the slider by 1/3, 1/2 or 1 Stop increments.

I also tamed the loud bell and made sure it adjusts with the volume control as expected.

I like the bellow extension suggestion - but I only shoot wide angle and have never needed to calculate it. If someone can give me a definitive reference I'll look into it.

Thanks again for giving the app a try. And for all the great suggestions. Some of the more complex ones might take a little longer to implement but I have certainly taken them on board.

jeroldharter

4-Sep-2011, 22:09

Those are excellent and quick updates.

For extension factor:

Bellows length squared/focal length squared=exposure factor

Example:

Extension = 300 mm
Focal length = 210 mm
Extension factor = 90000/44100=2.04

So the extension factor is ~2, or 1 stop.

A metered exposure of 1/4 sec would then be 1/2 second.

Boinzo

5-Sep-2011, 03:34

Thx! I have implemented 2 sliders. One for extension and one for focal length. This seems to work well but I am wondering what the highest values should be? I have implemented it with 10mm to 500mm range. Does that seem right?
I can have this feature included in the current release which should then cover off on all the main requests so far.

jeroldharter

5-Sep-2011, 09:26

For large format, 90 - 600 mm should cover. I think Olympus made a 35mm macro for 35mm film.

So 35-600 should cover film based scenarios.

SW Rick

5-Sep-2011, 09:51

Thanks for your prompt action on our suggestions, esp. the bell :) - makes for a better product and happy user base! Will note this in itunes.

Boinzo

5-Sep-2011, 18:07

Hi Again! So I have implemented bellows extension with 2 sliders between 30mm and 600mm as you can see in the screen grab below.

Now - my concern is that the sliders are a bit difficult to adjust accurately over such a large range. Eventually I might push focal length out into a setup page where you enter your and select your lens. But right now I want to get this updated for you guys that have already downloaded it.

My question is - what accuracy do you guys use when measuring this stuff? The sliders would be easier to use if I made them move in 5mm increments (for example). But will this make the accuracy of the exposure calculation unacceptable? I am thinking about making the sliders go 30,35,40,45 etc... in my tests it seems to take a change of around 5mm to change exposure by 1 second on a 10 second exposure.

I am a bit concerned that anyone with big fingers might struggle to set the sliders right where they want them.

Any thoughts?

jeroldharter

5-Sep-2011, 19:24

That looks much better. For me, the 5mm increments would be fine.

Is the first slider in the picture a filter factor adjustment?

If possible, it would be nice to have a link to a table of common filter factors.

jeroldharter

5-Sep-2011, 19:27

By the way, is the updated version available? I can't find it. Thanks.

Boinzo

5-Sep-2011, 19:47

Ok - I'll roll it up at 5mm increments. It just makes it easier to use.

The first slider is filter factor -yes. I agree a table would be nice. Some of those features will be part of a bigger app I have in mind that will incorporate this functionality. It'll take a bit longer to do though!

The updated version wont be available until Apple approves it. That usually takes 5-7 days. Once it's approved it'll just appear as an update within App Store on your phone and you'll be able to install it from there.

Will Whitaker

5-Sep-2011, 20:49

Glad to see the support. I've just purchased it.

SMBooth

5-Sep-2011, 23:12

Can you explain how this works, do you now need to set the bellows at the the len focal length each time you use it? So 90 for a 90mm lens when there is no bellow ext to worry about?

Sorry my bad another look at the image and I see that the len / bellow is separate and just gives a stop value to add

Boinzo

6-Sep-2011, 01:25

Ok guys. After spending all day on this... here's where I am at.

I have added a table of filter values - some may need a bit of editing. I based the data on this (http://en.wikipedia.org/wiki/Filter_factor#Filter_factors_for_common_filters) page at Wikipedia.

Someone let me know if they are no good - I rarely use any of these so aren't sure. Some of the values look a bit high to me.

Effectively you will now be able to hit the little circular blue arrow button to access a list of filters. These can be added (as many as you like) to the exposure calculation. You can clear them all out as well.

The slider is now just an additional compensation device for times when your filter isn't in the list - like my Lee Big Stopper!

So basically there are 4 things that impact the exposure time. Film and Metered Time selection, the adjustment slider (in Whole, Half or Third Stops), the Filters you add and the Bellows Compensation you set.

I need to do some more testing before I release this to Apple for approval but thought you might like to see the progress so far. It's now a pretty complex app so I need to re-make-sure I don't have any memory leaks etc.

Hopefully Apple will have it tomorrow so you guys should get an update about a week or so later.

Future additions will include ability to add and manage your own filters and lenses but I might need to do some work for some actual clients tomorrow! :rolleyes:

Here's some pix...

Steve Goldstein

6-Sep-2011, 04:11

This is a really useful app, thanks for undertaking it.

The new additions look great. I'm not sure you really need to carry around the UV and Skylight filters.

What would be really cool, and a lot more work, would be a light meter (spot, of course) with this functionality. As good as this app is, metering is still a 2-step process - read the exposure, then compensate for reciprocity. It's always been thus. But imagine one of those Sekonic meters, that already contains a micro, that gives direct exposure time when you're in fixed-aperture mode. That would be sweet!

Hmmm, I have a friend with contacts at Sekonic...

rdenney

6-Sep-2011, 06:53

This is perfect. Don't clutter it up with a personal lens library or anything like that--no need to have to maintain a database that then can't be transferred to a new phone.

For those focused in the far field who don't need a bellows extension factor, one can just leave the sliders all the way to the left with no need to worry about the focal length.

And if someone doesn't want to use the timer, they don't have to. I like software that provides features that stay out of the way when not needed.

And as for me, I don't need this capability in a meter. I want the meter to be simple and predictable, with the fewest number of buttons to push. I think that desire is pretty common, and the reason the classic Pentax spot meters are still so popular.

Rick "who bought it already and is looking forward to the upgrade" Denney

Steve Goldstein

6-Sep-2011, 08:58

rdenney

6-Sep-2011, 12:39

As I've given a little more thought to a reciprocity-compensated meter, I've realize that to be really useful the meter would need to be much more sensitive than any on the market today. I don't see that happening, but will pursue with Sekonic nevertheless.

I'm also a big fan of simple meters, and have both analog and digital Pentax models. But if I have to make a reading with gadget A, then transfer the info and push some buttons on gadget B, I don't see that life would be worse if gadget A had the optional capability to do the work of gadget B.

I don't want to get into an argument, I'm just saying...

No argument--just an aspect you might not have considered. It seems to me that reciprocity failure varies quite a lot over different films, and including it in a meter would require some way to enter the film type as well. Keeping that sort of data on the meter seems to me a hassle.

If you have pull with Sekonic, get them to reissue the L-488 with a low price tag.:)

(By the way, in looking at the meter in my Canon 5D, it does seem to have built in the reciprocity failure of the sensor in its calculation. I discovered this comparing it to a traditional meter. But it should tell you that your idea makes a lot of sense--if you know what film you are using.)

Rick "who'd rather have two simple and fool-proof gadgets than one that can be easily programmed wrong" Denney

ljsegil

6-Sep-2011, 16:06

Just happy to have bought your app and support all your good work.
LJS
?Porta 160 and 400?

Allen in Montreal

6-Sep-2011, 20:13

Great work, thank you.
I have been toying with mine for ideas to improve but you have beat me to them!:)
Looking forward to the bellows draw addition and the T films.

Ok - I'll roll it up at 5mm increments. It just makes it easier to use.

The first slider is filter factor -yes. I agree a table would be nice. Some of those features will be part of a bigger app I have in mind that will incorporate this functionality. It'll take a bit longer to do though!

The updated version wont be available until Apple approves it. That usually takes 5-7 days. Once it's approved it'll just appear as an update within App Store on your phone and you'll be able to install it from there.

Boinzo

8-Sep-2011, 21:31

Hi Again! I just wanted to let everyone know that it's taken me a little longer to get the update submitted to Apple than I had hoped. The app got a lot more complicated this week and it took me some time to finish and to completely test it. It is now submitted to Apple so I hope you will be getting the update soon.

The new version now includes an editable table of common photographic filters. This is accessed by touching the little notepad icon. You can select a filter and edit its details to suit your needs. So if you know that your CPL requires 1.4 stops of compensation you can enter that in and the app will remember that value. You can then apply your CPL to the reciprocity calculation. You can move back and forth between the main screen and the table adding as many filters as you want (or to clear them all out of the calculation).

As I said it also now includes bellows extension, lots more films and the ability to add manual compensation in whole, 1/2 or 1/3 stops increments.

Thanks again for all the suggestions and the supportive comments.

BTW: With respect to Portra films - I couldn't find much on reciprocity for these. But what I did find seemed to indicate that you could probably use the calculation for Efke B+W film and come out pretty close.

Here's some screen grabs of the new app....

leetmode

9-Sep-2011, 12:07

thanks a lot for this boinzo, please let us know when apple accepts it!

Steve Goldstein

13-Sep-2011, 18:32

I just downloaded rev 1.1 from Apple. It looks great. Thank you.

Are the arrow, plus, and times buttons supposed to have different functions on the filter page? They all seem to revert back to the main timer.

Boinzo

13-Sep-2011, 19:26

Hi Steve.
Yeah - I just saw Apple had approved it. Hooray.

The Back Arrow button just takes you back to the main page. It does nothing else.

The Plus button adds the currently selected filter's exposure factor into your maths and then goes back. You will see the filter and its factor appear on the main page. If you go back and forth between the filter list and the main screen pressing the plus you can add more than one filter to the exposure.

The X Button removes all filters from your exposure calculation so you can start over.

When you have a filter selected you can hit the pencil icon to make edits to it. So you can rename the filters and modify their exposure factors to more closely match what you use.

Enjoy.

Lachlan 717

13-Sep-2011, 20:03

Boinzo,

Thanks for the App.

One (hopefully not too stupid) question: What is the difference in the Velvia 50 tabs (filtered/unfiltered)?

Thanks.

Boinzo

13-Sep-2011, 20:12

Hi Lachlan. You're welcome!
There are no stupid questions!

I had 2 sets of maths and figures. One (filtered) is if you have a colour-correction filter attached to deal with Velvia's known colour shift on long exposures. The other is if you don't.
Hope that makes sense!

Steve Goldstein

14-Sep-2011, 02:56

Thanks for the filters explanation. I only noticed that all buttons took me back, but missed the time changes. Feeling a bit dumb about that, the numbers are certainly big enough!

jeroldharter

14-Sep-2011, 05:01

I am using it on an iPad. Is it hard to "upsize" the app for iPad?

Boinzo

14-Sep-2011, 05:17

Hi Jerold. Unfortunately it's basically a separate app. It would take a lot of effort to make it fill the iPad screen.
My original design was to have something I could use out hiking in the mountains or next to the sea. Something I could fit in my pocket. I never take my iPad on those trips!

jeroldharter

14-Sep-2011, 07:58

SW Rick

14-Sep-2011, 08:07

Just wondered. It works fine on my iPad.

On the larger screen I was envisioning sliders for f stop, shutter speed, then the adjustments, a field for notes, a field for exposure number, and a save feature. Ability to attach an iPad photo would be ideal. Kind of like the BTZS software disengaged from film development data, but appealing to a broader audience. I would pay a lot more for that.

While I understand the desire for an all-in-one, things tend to get complicated and wind up with bloated dslr-like menus and sub-menus. Have you looked at Lenny Eiger's PhotoToolsPro app, which does most, if not all, of what you're describing?

There's virtue in doing a few things well, which is why the Pentax spotmeters have an advantage over the Sekonic in terms of ease of use and not needing to carry the manual with you.

Rick

jeroldharter

14-Sep-2011, 10:50

Good point.

However I assume it could be designed with smart toggle to disable unwanted features and make for a simpler interface.

For someone with no Mac skills, I have a lot of ideas.

SW Rick

14-Sep-2011, 12:53

Good point.

For someone with no Mac skills, I have a lot of ideas.

Hey, you're an Artist, not a coder :)

Boinzo

14-Sep-2011, 13:57

I do have another app I am working on that will do much more than this one but it's still some time away. It will come at things from a different perspective and provide many more features to support the film workflow.

But I agree I will need to be careful not to make a "sekonic" where a Pentax would do.

In any case I hope the new version meets most people's needs for the task of getting more accurate and repeatable long exposures. And thanks again for all the suggestions and comments. Tell your friends to buy it!

I firmly believe it's possible to be both an artist and a coder! :)

Erik Larsen

14-Sep-2011, 15:09

I'm not sure if it's possible, but it would be nice if the reset button would reset the filter factor so you do not have to go to the filter screen to do it. Just a thought. I think I will be using your app a lot, Thanks!
regards
Erik

Boinzo

14-Sep-2011, 15:31

Hi Erik. I know what you mean and I just couldn't decide between the two options. On one hand if you are going to make another exposure you may well leave the same filters in place and just bracket or something. On the other hand you might change lenses and/filters and shoot another frame.

I figured which ever way I did it it was going to not work for someone... Sorry.

If the consensus of comments is that reset should zero the filters I'll make the change in the next update.

Thanks for the input. And glad the app is working for you.

jeroldharter

14-Sep-2011, 18:20

I have been playing around with the TMAX 400 and filter sliders. As far as I can tell, the filter factors shown on the sliders become the f stop corrections on the main page. For example, when I add a red filter with a filter factor of 8, the exposure is then adjusted by 8 stops instead of 3 stops.

Boinzo

14-Sep-2011, 19:00

Oh no! :eek:

Sorry - I just checked and I had omitted the log maths for the filter factors. I think I was too fixated on making the filters editable! :mad:

I have fixed this and re-submitted to Apple. Once again the update will take a few days.

When it arrives the filter maths will be correct based on multiplication factors. In the mean time if you edit the filters to show actual stops of compensation required you will get the correct exposure. So if you change the Red filter's factor from 8.0 to 3.0 you'll get correct times.

Sorry for the error.... :o

jeroldharter

14-Sep-2011, 19:34

That's ok. Thanks for being so quick with the changes.

SMBooth

15-Sep-2011, 14:38

While your fixing thing you cannot make changes to the lower filter factors as the keyboard get in the way and you cannot scroll the display up far enough.

Boinzo

15-Sep-2011, 17:43

Ok. I have made some changes to allow for editing of the bottom rows of the filter table. Thanks for pointing that out.
I also made it so that the sliders all disable when you start the timer. This is just to prevent accidentally moving them during an exposure and throwing the time out.
This is all submitted to Apple so you should have an update in due course.

SMBooth

15-Sep-2011, 21:24

I bet you wish you never started this now don't you :)

Boinzo

15-Sep-2011, 21:32

Hahaha. No. It's all good. :-)
I am hoping everyone is happy now though! ;-)

Allen in Montreal

20-Sep-2011, 10:50

There is a new update posted today

Boinzo

20-Sep-2011, 16:05

That's right! Apple have approved the latest update. Hopefully this release will address everyone's requests. :-)

I'd appreciate it if those that have bought the app and found it useful could take a few seconds to review and/or rate it on the app store. Supporting this little app will help me to move forward on developing some more photography tools I have in mind!

Thanks again everyone for all your suggestions and support.

jeroldharter

2-Oct-2011, 16:40

I have another suggestion. I understand that the purpose of the app is to figure out the exposure time corrected for reciprocity taking into account the variables. But sometimes, you don't know in advance that reciprocity will be an issue.

For example, if you use TMY2 (TMAX400), with a 1/8 second base exposure, a filter and some bellows compensation the resulting exposure might be 1/2 second. But the program won't show you that.

So the suggested change is to add a field above the Reset button that shows the actual shutter speed that the program calculates formatted in usual photographic notation, e.g. 1/4, 1/2, 1", 1.5", 2"...

Boinzo

6-Oct-2011, 16:56

Thanks for the input.
I have looked at implementing this but it is a little complex because the app can easily generate shutter speeds with small fractions of a stop. To achieve sensible "standard" shutter speed notations is a bit difficult - I end up with shutter speeds like 1/33, 1/62, 1/12 for example...
In any case - I am looking into it but the primary purpose of the app is to calculate and time reasonable shutter speeds for longer exposures where reciprocity is an issue.

Dcohio

20-Nov-2011, 09:19

Just purchased the app this week and got to use it this morning. Very usefull! Times listed where very close to my highly refined total guesstimations that I typically use. Thanks for giving me something I can actually use on my phone other than playing games.
Thanks,
Doug

Boinzo

26-Nov-2011, 04:34

I'd just like to say thanks for the positive comment! I appreciate it. I'm really pleased you are finding my little app useful.
I'd really love it if people who are using the app would take a moment to submit a review on the app store...
Thanks again to all that have purchased the app!

jb7

4-Dec-2011, 09:18

Hello-

I downloaded this ages ago, haven't used it yet-

One thing, I've searched through the thread, but haven't seen this as an issue-
the app timer doesn't seem to work in the background- which might be useful for my current setup- Efke 25, dark interior, 72XL, centre filter, f/16. Computed time is around 15 mins...

When the phone goes to sleep, which I think is reasonable, for battery conservation, the timer just pauses, until it is woken up again. Any chance of making it run in the background, or am I missing something?

Other than that, good app, well done-

Erik Larsen

4-Dec-2011, 09:31

Boinzo

4-Dec-2011, 14:03

Guys. I am looking into the timer issue. It did not used to do this ... Playing a sound should be enough to keep the app from deep sleeping...but it certainly seems to be an issue now. I will try to implement a fix for this ASAP. Thanks for bringing it to my attention.

Boinzo

4-Dec-2011, 22:57

It used to be fine on IOS4 because it was playing a sound.... (this is supposed to stop the device from going in to sleep mode).

Ok. So making the timer stay alive was not an option (this violates Apple's Development Guidlelines - something to do with battery life). :(

So. Instead I have managed to make it time how long it is asleep for and compensate accordingly when it wakes up. Also - if it goes to sleep with more than 30 seconds left it will create a system alert at 20 seconds to go to remind you to wake it up. If your exposure has less then 10 seconds to go when it goes to sleep - it'll throw an alert at the end of the exposure time to tell you to shut your ... umm.. shutter.

Thanks for bringing this to my attention. Most of my use has been at times of under 30 seconds so it had not come up for me.

I am pleased you are getting good use out of the app. The new version with this fix will automatically appear once Apple have approved it. This usually takes about 7 days.

I'd appreciate it if those using the app would take the time to jump on iTunes and rate it for me. Every bit helps.... :)

SW Rick

5-Dec-2011, 07:15

Thanks for your continuing interest in keeping your product current and useful!

jb7

5-Dec-2011, 08:16

Very good, thank you, appreciate your continued support of the app-

Boinzo

8-Dec-2011, 15:41

Apple have approved the update. So your App Store icon should have a little red number on it!
Thanks all. I hope this fix makes the app more useful for you.

Steve Goldstein

9-Dec-2011, 03:13

Just downloaded version 1.5. Thanks for your continuing efforts on this slick and useful app.

Ken Lee

9-Dec-2011, 04:07

I just got the app - brilliant!

Here are 2 suggestions from a software engineer/photographer :rolleyes:

1) The focal length and bellows extension sliders are great for moving a large distance, but once you get close to your desired number, they are hard to adjust with fine control, on an iPhone at least. In cold weather, I imagine it would be even harder. If there were > and < arrows (or +/- buttons) then we could finely increment/decrement the numbers simply by clicking. So don't remove the sliders, just augment them with a finer control that is easy to adjust with fat fingers.

2) Perhaps I'm alone in this, but I generally think about my lens first, and bellows draw second. ("I'm using a 210mm lens. Done. Now what is the bellows extension ? 250mm. Done") not ("I've got 273mm of bellows extension. Now what lens am I shooting with again ?"). So I'd like to have the lens selection appear before the bellows extension. That's less important of course, and I may be in the minority.

jb7

9-Dec-2011, 05:12

Thanks for doing that-

There's still a bit of an issue with the timer- if I switch to the app when I receive the alert, the timer counts down from the last two seconds- effectively cutting the time by nearly twenty seconds. Not a big deal, but if I have to manually count out the last few seconds, then a 5 second alert might be more accurate than 20. Or rather, more convenient- If the alert contained the end of the countdown timer, that would be perfect.

However, in the grand scheme of things, and considering the application of the app, at those sort of times, perhaps a 20 second difference might be unmeasurable on film anyway.

It just results in me standing around for a bit longer, lips moving, mumbling, not really a great look...

Boinzo

9-Dec-2011, 13:11

Thanks for doing that-

There's still a bit of an issue with the timer- if I switch to the app when I receive the alert, the timer counts down from the last two seconds- effectively cutting the time by nearly twenty seconds.

How long does it takes you to unlock the phone? The timer keeps running as this is happening. The 20 second notification is not second accurate because the phone will queue this alert. It's meant to simply give you time to get back into the app. Perhaps it should just say "exposure is ending soon" to more accurately reflect that.

There is another issue Ken found where just starting and sleeping the app is enough to get you an exposure alert sometime later. I am looking into this.

It serves me right for trying to get the update out too quickly!

jb7

9-Dec-2011, 13:38

It only takes a couple of seconds to get back into the app. I've checked the overall time against a stopwatch, and the difference is around 20 seconds-

Boinzo

9-Dec-2011, 18:02

Ok. So I have done another update.

The timer is definitely accurate to within a second or two on long exposures! Even after phone call interruptions and sleeping. I have done many tests over and over at various durations.

I fixed Ken's issue with the notifications. And I have added fine adjustment buttons for focal length and bellows extension. I have also swapped the position of the two sliders as per Ken's suggestion. This makes sense and I don't know why I didn't do it in the first place!

While I was in there - I added the Big Stopper to the list of available ND Grads.

As always it's now with Apple. Should hit your phones by the end of the week.

Apologies for messing up the previous update. Was in a bit too much of a hurry I think.

And again thanks for the support!

jb7

10-Dec-2011, 03:54

Ken Lee

10-Dec-2011, 03:58

And again thanks for the support!

You should get an award for world-class customer support. :)

Boinzo

10-Dec-2011, 04:09

Yes, sorry for the panic, the alerts were late, but the times were accurate- however, the lateness of the alerts seemed to also slow the stopwatch app, which I was using to time the timer, not being near any other timing device at the time-

Altogether a bit confusing, but I'm glad it works, and that I can be confident it works-

Sorry for the wobble...

All good jb7. You only cost me $4 million in sales. My lawyers will be in touch... ;)

You should get an award for world-class customer support. :)

Haha. Thanks Ken. It's how I run my real software business. If I didn't I wouldn't be able to afford LF!

SW Rick

10-Dec-2011, 07:17

Haha. Thanks Ken. It's how I run my real software business. If I didn't I wouldn't be able to afford LF![/QUOTE]

Too bad you don't run most of the software companies I have to deal with.... :)

J. Fada

11-Dec-2011, 18:33

Wow, you have my two bucks. I look forward to trying it out! Almost all of the exposures I do with LF have reciprocity issues. I usually just eeny meeny it, but this app (hopefully) will let me be more accurate. Thanks.

MWitmann

12-Dec-2011, 13:55

Bought yesterday; will try it tomorrow.

Any chanche to have listed also the Portra 160?

Many thx

Boinzo

12-Dec-2011, 14:15

Bought yesterday; will try it tomorrow.

Any chanche to have listed also the Portra 160?

Many thx

I have always said I am happy to add new films if people can provide me with an appropriate formula or at least a list of times they find reliable.
It takes many hours of research to find the best data for each film and I can't make the time at the moment.
My initial research on Portra did not turn up much of value though which is why it isn't listed.
Hope you enjoy yet app and it works well for you. There is another update due this week.

MWitmann

12-Dec-2011, 15:54

I have always said I am happy to add new films if people can provide me with an appropriate formula or at least a list of times they find reliable.
It takes many hours of research to find the best data for each film and I can't make the time at the moment.
My initial research on Portra did not turn up much of value though which is why it isn't listed.
Hope you enjoy yet app and it works well for you. There is another update due this week.

many thanks

SMBooth

12-Dec-2011, 21:36

Regarding filter, I find when adding a yellow(8) filter (1 stop) makes no difference to the time, however if I add a red (25) filter (2 stop) it only adds one stop of time , eg 1/500 > 1/250

Boinzo

12-Dec-2011, 21:43

Regarding filter, I find when adding a yellow(8) filter (1 stop) makes no difference to the time, however if I add a red (25) filter (2 stop) it only adds one stop of time , eg 1/500 > 1/250

Check what you have as the filter factors. The value listed next to each filter is filter-factor not stops. So a 1 Stop Filter has a factor of 2.0x . A 10 Stop filter has a factor of 1024.0x. The skylight filter is 1.0x and so does not change exposure.

The default value for a Yellow filter is 2x when the app is installed. This is 1 stop. It changes a 1/500 exposure to 1/250 as expected in all my tests.

Of course you are free to edit these factors to more closely represent what you have in your kit. They are not over-written by an update.

SMBooth

12-Dec-2011, 22:06

OK that's the problem, my yellow was set to x1.0 which I assume to be 1 stop not as you say filter factor. I go through and fix. Thanks

For reference: http://myphotohome.com/pto/filters4.html

Boinzo

12-Dec-2011, 23:40

Apple have approved the latest update. This should improve the notifications and a couple of other little things (as suggested by Ken). It also adds the Lee Big Stopper 10 Stop ND to the filter list.
Enjoy!

Ken Lee

13-Dec-2011, 15:12

I installed the update. Now it's even better !

r.e.

13-Dec-2011, 18:47

The new + & - controls for 5mm changes in focal length and bellows extension are a good idea.

Dcohio

14-Dec-2011, 08:04

Like the updates. Makes it easier to adjust lense and bellows slider. Thank you

Ken Lee

18-Dec-2011, 10:15

I used it again this weekend. What a treat. It has paid for itself many times over ;)

John Wiemer

20-Dec-2011, 12:05

Thanks for all the work on this very useful app. Since you are using Filter Factors to determine the exposure changes, it seems to me that the FF for the polarizers should be between 3 and 4, not 1.6 (2/3 of a stop) as you have listed them. My experience in reading exposures through the filter is that polarizers generally have between 1 1/2 to 2 stop differences.

Boinzo

20-Dec-2011, 15:46

Hi John. Glad you are finding the app useful. The filter factors are editable to meet your requirements. Just select a filter and touch the pencil icon and enter the required factor as a decimal such as 3.0.
There is such a variation in different filters that people carry so I felt it best to allow you to enter your own and simply provide a starting point.
All the best Stef.

John Wiemer

20-Dec-2011, 16:29

Good point. I have done just that with my most used filters. I guess my point was that there are those who will use your filter factors as they are listed on the app as being totally correct. Rather than use a filter factor of 1.6 for the polarizer why not list it as 3 or 4 which is more accurate. A FF of 1.6 is about a one stop difference from 3 or 4. Wilkepedia has a good chart under "Filter Factors." Again, thank you for an excellent app. I have used it several times and find it very useful.

Boinzo

20-Dec-2011, 16:31

No problem. I'll change the default in the next release. That wiki page was one of my sources so perhaps I copied it wrongly!
Thanks again.

Ken Lee

27-Dec-2011, 05:05

Here's a set of Large Format photos (http://www.kenleegallery.com/html/tech/NineInchKershaw.php) made at close range with long exposures - all timed using the app.

Michael W

1-Jan-2012, 02:56

I have this app and it looks to be useful. I have noticed one thing that doesn't appear to be correct. If I set the exposure reading to 10 seconds and bring up Kodak Tri-X the app says the exposure should be 12 seconds. However according to the Kodak pdf for Tri-X the adjusted exposure should be 50 seconds.

taulen

1-Jan-2012, 05:13

Seems to be right about tri-x, at least that should be a quick fix =) If apple approves it ;)

Boinzo

2-Jan-2012, 03:48

Hey Guys. I'm away on a family holiday at the moment. I'll look into this when I get back to the office in 2 weeks.

Allen in Montreal

2-Jan-2012, 16:51

I was wonder about the bellows draw feature.
I really appreciate it and use it, but it falls a little short allowing only plus one stop. I ran out of calculations and had to dig up my homemade chart once it went beyond 1 stop.

Thanks for a great app!
Allen

Ken Lee

2-Jan-2012, 17:17

The bellows compensation is not limited to 1 f/stop.

Try a focal length of 30mm and a bellows extension of 600mm: the app tells you to apply a compensation of 8 2/3 stops.

What may be limiting, is the upper bound of 600mm. You're starting out with a long lens (410mm), and you have reached the upper bound.

An 8x10 camera with a 300mm normal lens, needs 600mm of extension just to reach 1:1 magnification.

An upper limit of 2000mm or greater might be overkill for most users, but it would put an end to requests to increase the number.

Boinzo

3-Jan-2012, 14:36

Thanks Ken. It's funny how it works. When I implemented the bellows extension feature I actually posted here for suggestions on an upper limit! 600mm seemed to be the suggestion (I have no experience with this because I shoot wide angle only). :)
I can push up the limit easily but it is a trade off between using the slider and the limit.
Would 1200mm work for most?

Allen in Montreal

3-Jan-2012, 15:36

Hi Ken,

I was actually shooting people, with a 16.5 red dot, which I really like. It is razor sharp and a length I like for portraits. I know many prefer the 14", which allows 1 2/3 for 23.6 inches of draw.

The rail on my 8x10 camera is 30 inches (762mm) but if anyone adds a second standard to that (which I do once in a while), it can hit 1143mm.
I really can't see myself ever going beyond that, but if the app went to outer limits, I could stop carrying my reference book. ;)

Ken Lee

3-Jan-2012, 16:40

I think beyond 1200, anyone can just drop the unit of measure altogether (mm/cm/inch, etc.)

After all, a 12mm lens at 24mm extension gets the same bellows compensation as a 1200mm lens extended to 2400mm - or a 12 inch lens extended to 24 inches.

It's the relationship between the two which matters, not the absolute unit of measure.

corgan4321

5-Jan-2012, 19:23

As soon as TMAX films are added, I'll buy it!

Allen in Montreal

5-Jan-2012, 19:29

As soon as TMAX films are added, I'll buy it!

T400
T100
TMZ

Are supported.

Steve Hamley

8-Jan-2012, 14:25

I just bought it - let's see how it works. Thanks Boinzo!

Cheers, Steve

Russell Regnery

26-Jan-2012, 19:14

Boinzo,

I noticed the app store description does not mention the Efke films as currently supported by your well reviewed application. And I also note that you offer to include additional films when data is provided. I found a link for reciprocity failure and Efke films that can be readily translated if necessary from the German:

http://www.fotoimpex.de/Technik/efkefilms/efke100/efke100.html

As large format Kodak films have become either essentially unavailable (e.g., Tmax 5x7) the Efke sheet film data should become more relevant to many of us. I hope this is useful...inclusion of Efke info in your app would be much appreciated.

Thanks much, Russ

Boinzo

26-Jan-2012, 22:12

Hi Russell.
Thanks. The app does support efke film already. Although I think it is not adding the 6th of a stop at 1 sec to 2 secs. In any case efke 25 is a film I use a lot and have certainly made many long exposures timed with the app on efke!
I am not at my desk ATM (away for the weekend). But I'll check exactly what math I am doing on efke and post it for you. If it needs some change I'll look into it.
Thanks again for the post!

Allen in Montreal

30-Jan-2012, 15:28

You could probably make a killing on a basic darkroom timer,

Just a basic timer, autorun is a must, 10 stages would be best, programmable and be able to name the steps and save.

Simple but no one has made the ideal simple timer yet.

http://www.largeformatphotography.info/forum/showthread.php?t=86345

http://www.largeformatphotography.info/forum/showthread.php?t=86345&page=4