Reciprocity Timer 1.0

[Allen in Montreal]

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]

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]

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]

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]

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]

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

[Allen in Montreal]

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

T400
T100
TMZ

Are supported.

[Steve Hamley]

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

Cheers, Steve

[Russell Regnery]

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/efke...0/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]

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!