Reciprocity failure

[Leigh]

...up on the shoulder of the curve, which is the region for the longest exposures, any incremental additional exposure results in only a comparatively small increase in density.

While that's true, it's not relevant.

Long exposures are done because the light level is too low to start with.
Even with extended exposure the mid-tones will be on the linear portion of the curve.
Only the highlights (street lights and such) will be on the shoulder.

- Leigh

[Pfiltz]

Back Story: I worked for a printing company for 30 years before they shut the plant. I decided over night to become a photographer, and start up a studio. Bought Camera's, lighting, backgrounds, etc... with NO experience in Photography. Everything I know about it, has been hands on. I never read a book. I never attended a seminar. Back then, 10 years ago, I didn't even know about forums.

Having said that, the reason for my question coming up, was I mentioned on a another forum about wanting to shoot streams with long exposures, and the subject came up briefly.

I can't capture anything technical by reading. It's not in me. I'm more of a hands on guy. When I ask someone for help, all I need is the basic info. Laymens terms.

Someone just today mentioned about a 6x7 format being good for portraits on some street photography I did. OK? I guess. I just take 'em. I've never gotten into the technical background of Photography. I don't plan on creating a darkroom and doing any printing, or at least not in the foreseeable future.

If this reciprocity thing means that I have to tell the lab, that I shot it a x- seconds, and they should develope it based on that, well, OK I guess.
We don't have streams here, so i don't see me doing any milky water looking shots. Having said that, I'm trying to learn 4x5 work, prior to me going up to the Pacific NW in September to visit a friend, and hoping to shoot landscapes, which is not more Forte.

I don't get to travel much, so I hope to get at least 1 good landscape with my 4x5 camera in September on my trip. I know I'll be taking my RB with me, as a backup.

I plan on talking with the lab that is currently developing my color film, so I can get on the right page with them, if there is a need.

Thanks to all that gave me some nibblets to digest on the subject.

[Leigh]

I never read a book. I never attended a seminar.

So you expect us to do all the work for you.

It's probably no in your best interest to brag about that.

- Leigh

[Brian C. Miller]

I can't capture anything technical by reading. It's not in me. I'm more of a hands on guy. When I ask someone for help, all I need is the basic info. Laymens terms.
...
If this reciprocity thing means that I have to tell the lab, that I shot it a x- seconds, and they should develope it based on that, well, OK I guess.

Laymen's terms: Reciprocity failure = you need more exposure. How much more exposure depends on the film. If the film development needs to be changed, it's noted in the film data.

When you say, "I can't capture anything technical by reading," how can you expect to understand a manufacturer's film reciprocity information?? You need to read! Most film has information about reciprocity. You need to just go and look it up. The information is usually presented as a simple table, so it's very easy to understand. But you won't know what it is if you don't go and read it.

[Helen Bach]

I plan on talking with the lab that is currently developing my color film, so I can get on the right page with them, if there is a need.

If you are sticking to colour neg then there's probably no need to tell the lab anything. I've used Portra 160 (with standard C-41 processing) for exposures of around 20 minutes with no problems. Colour shifts can be corrected at the printing stage.

Best,
Helen

[E. von Hoegh]

Education is what you get from reading the small print. Wasted time is what you get from ignoring the small print.

It is impossible to learn in any efficient manner about a complex field such as photography without doing at least some technical research. Do you read a chart to learn what time and which developer to use for a given film? The reciprocity charts are no more complex.
And, you are reading the responses in this thread. If you can read this thread, you can do basic research.

[cyrus]

I should also point out that extending exposure time is only part of dealing with reciprocity failure. You may have to reduce development time too, to deal with the excess contrast that can result.

[Pfiltz]

Ok, folks.

I get it.

[Steve Smith]

If this reciprocity thing means that I have to tell the lab, that I shot it a x- seconds, and they should develope it based on that, well, OK I guess.

You don't need to do that. You compensate for it during exposure so that you can give the film standard development.


Steve.

[E. von Hoegh]

You don't need to do that. You compensate for it during exposure so that you can give the film standard development.


Steve.

That depends upon the film. You can be certain by reading the data sheet which comes with the film.....