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RocketScientist90
28-Apr-2017, 07:24
As a long time lurker of these forums, I was encouraged by koraks to participate more in the discussions here. I recently got started in LF with a Toyo 45A and am still in the process of finding my own workflow. Part of this was having to correct for bellows extension and reciprocity failure. Doing it by heart get annoying quickly. Being a bit of a nerd, I decided to give app development a go and what better than make an app that is useful to me in the field too :).

The end result is a free Android app called Inverso (Android 4.0.3 and up) that helps in correcting for bellows extension, filters and reciprocity failure for continuous light, flash and a combination of both. It also includes a timer function that offers an optional delayed start and audible start/stop warnings, so you don't have to start the timer and fire the shutter at the same time.

http://printerattic.com/wordpress/wp-content/uploads/2017/04/MainScreen_Normal-169x300.png http://printerattic.com/wordpress/wp-content/uploads/2017/04/Timer-169x300.png

The full description of the functionality and a list of the included film stocks can be found here: http://printerattic.com/inverso/

You can find it in the Play Store here (https://play.google.com/store/apps/details?id=com.printerattic.inversoapp).

I am in the process of expanding it further and trying to find reliable data for Ilford films. If you have some, I'd be happy to incorporate it!

Let me know what you think and how you think it can be improved further.

Roy

David Karp
28-Apr-2017, 10:23
Thanks!

Pali K
3-May-2017, 17:28
This looks nice Roy - thanks!

I ventured into something very similar a while ago and have been using my app for personal use. Never got to the point of releasing it for public use so it's nice that you are able to do this for the community.

Here is link to my discussion (http://www.largeformatphotography.info/forum/showthread.php?124360-Android-APP-for-Reciprocity-Bellows-Manual-Exposure-Calculations) about it that might have some useful information for you.

Pali

RocketScientist90
3-May-2017, 23:19
Thanks Pali! I will read that discussion to see what I can take from it.

Roy

koraks
4-May-2017, 01:29
Ah, so you've announced it to the world, great!
I've been using this app since the first beta you released and I feel it's very useful indeed. It omits all the clutter I don't need, but that is present in some other apps. I highly recommend it!

RocketScientist90
12-May-2017, 13:48
Over the next few days version 1.2 will be rolled out, which contains data for Bergger Pancro, Kentmere 100 and 400 and the Ilford films. The Ilford data is preliminary, as they are yet to officially publish the definitive data.

Roy

Jac@stafford.net
12-May-2017, 14:07
Why depend upon an app when simple mental arithmetic works? Dunno about y'all, but my brain does not need a smart phone.
.

Bob Salomon
12-May-2017, 14:48
Why depend upon an app when simple mental arithmetic works? Dunno about y'all, but my brain does not need a smart phone.
.

Since I use an iPhone, so I remember that 1:1 needs 2 stops, 1:2 needs 1 stop, life size needs stop so I don't use a phone to calculate it. I just put a ruler in the scene and measure how big 1" on the ruler is on the go and then use the above corrections.

RocketScientist90
12-May-2017, 23:15
What ever works for you! All roads lead to Rome, eventually, and I just find this one more convenient. :)

Roy

Sweep
13-May-2017, 01:58
I have never been able to do mental arithmetic which is why I always avoided playing darts in the pub. Adding triple 17 to double 15, adding a single 19 and taking that all away from 501 was just too much for my small brain.
I would find this very useful, particularly as I am new to LF, but please develop for iPhone.

Sweep

RocketScientist90
13-May-2017, 02:42
Sorry, as of yet no plans for an iPhone version. Developing for Android is 25 usd once, while developing for iPhone is 100 usd/year, last time I checked. For an app I make for free and distribute for free, that is too much. Rather spend that money on film instead ;) Perhaps I will make a webversion to solve this. Give me some time. I do this stuff in my spare time.

Roy

Sweep
13-May-2017, 05:25
Ouch! Sorry Roy, foolishly, I didn't realise there was any cost involved in dealing with Apple. Silly me. ��

RocketScientist90
14-May-2017, 11:55
The web-app idea had me intrigued, so I started working on it last night. The weather was a bit iffy today, so now I have the UI working and now need to start porting the actual calculations. Will let you know when it is available for use.

Roy

Delfi_r
14-May-2017, 14:16
Thanks for developing this app for Android, there is something for iOS as well and it`s a pity that there is no new development (Reciprocity Timer, a nice app). I understand the costs involved, and for sure it's easy if you are develoing a lot of apps. If you ever want to try the iOS route, there's room for improvement and a way to monetize the work done with the in-app purchases.

Jac@stafford.net
14-May-2017, 15:56
Would it not be good if there were some kind of upgrade from our 5th grade arithmetic so we did not need an app?

Edit: Make that 4th grade.
.

RocketScientist90
19-May-2017, 10:41
For those not using Android: a beta-version of the web-app is now online at http://inversoweb.printerattic.com. I'd love to hear your comments and experiences. It is completely clientside, so after loading, you shouldn't need wifi/internet connection. I don't have any other devices to test on, so if you find something strange let me know.

Roy

Jim Andrada
20-May-2017, 23:11
Nice idea - but I've never been able to read anything on the Android screen in the midday Arizona sunshinse.

RocketScientist90
21-May-2017, 05:20
Can imagine. Over here it suffices to just turn up the screen brightness a bit, but we get more clouds than we get sunshine ;-).

Roy

seezee
21-May-2017, 13:40
This. (http://www.salzgeber.at/disc/)

RocketScientist90
21-May-2017, 13:45
This. (http://www.salzgeber.at/disc/)

Thanks for the suggestion, seezee. Looks like one of many variations on the same theme. Something similar is described in Beyond Monochrome. It works well for bellows extension compensation, but not for reciprocity failure.

Many roads to Rome. :)

Roy

BIT Saddle
22-May-2017, 14:30
Roy, thank you for this! It's awesome, and you offering it for free is fantastic! :)

martinf5
17-Aug-2017, 00:54
This app is brilliant. Use it for every shoot when bellow extensions or reciprocity is needed.
If I could I'de spend a beer :-)
Btw. I yet only use Fomapan 100 and your maths work perfect for this rural films.

Pere Casals
17-Aug-2017, 02:02
Since I use an iPhone, so I remember that 1:1 needs 2 stops, 1:2 needs 1 stop, life size needs stop so I don't use a phone to calculate it. I just put a ruler in the scene and measure how big 1" on the ruler is on the go and then use the above corrections.

Hello Bob, does this work for any focal lenght ?

hoffy
17-Aug-2017, 02:41
Just found this. Simple and quick . I like it!

RocketScientist90
18-Aug-2017, 00:51
Good to hear it is of good use! :) If you are using an iPhone or other non-Android device, you can also give the web version a try at http://inversoweb.printerattic.com/. It has the same reciprocity functions implemented, but is a bit limited in functionality. For example, I have implemented the countdown timer for longer exposures, but not the countdown sounds (yet).

Roy