Exposure compensation for Reciprocity Failure

[rafarojas44]

Hello everybody :)
First of all, i will apologize since surely i will say a lot or rubbish since i am a digital guy trying to make his way through film nowadays (panoramic 617).

I was just wondering one thing: If you use a modern light meter (sekonic, for instance), can you introduce (program) directly into the meter the reciprocity failure law given by the fabricant of the film you use?

I have discovered that film fabricants provide the "law" of compensation depending on the exposure time, i was just wondering if you need to make the calculations mentally when using light meters or whether you can introduce those laws into the machine so that it gives you the correct exposition already "corrected".

As i said before, surely my question will be no sense at all...:) but i had to ask.:)

Thanks very much in advance!!!
Rafael
Switzerland

[Doremus Scudder]

I am not aware of a light meter that is able to be programmed to compensate for reciprocity failure. Most of us refer to a table to determine the adjusted exposure. There are many online and in manufacturers' literature. You don't have to do the calculations in your head, but you will need to carry a table for each film you use.

Best and good luck,

Doremus Scudder

[Brian Ellis]

I'm not aware of a light meter that automatically takes reciprocity failure into account but IIRC the BTZS expo-dev program for the Palm Pilot sold in the U.S. by The View Camera Store does this (and a lot of other things as well). But the expo-dev program would be an expensive purchase if you used it only for that purpose. Much less expensive just to carry around a table of reciprocity-adjusted exposure times for the film you're using.

[Benno Jones]

Since I use a Windows Mobile PDA and can't find a program similar to the BTZS one that works on it, I just have the charts in spreadsheets for the films I use and then use the calculator.

[rafarojas44]

Thanks very much for the info :)
That means the traditional method will do very well ;)

Thanks again
Rafael

[Greg Lockrey]

There is a program that you can download that's called Pinhole Designer that has a function to calculate reciprocity for various named films. We pinholers deal with this sort of thing all the time. ;) http://www.pinhole.cz/en/pinholedesigner/

[Gary L. Quay]

I carry a small notebook with all of the various reciprocity charts, and do the math in my head. It's low tech, but the batteries never run out.

--Gary