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Night Photography and Reciprocity Failure

S L , Dec 30, 2000; 12:33 a.m.

Bear with me please, because I'm wandering into unchartered territory...

I'm interested in shooting some nighttime urban architectural scenes and I am pretty sure I have all the goods. I've got my Canon AE1, tripod, Minolta Autometer IIIF and some print film ISO100. My question is regarding reciprocity failure because I'm not quite sure I understand it. I've seen nighttime prints where the exposures were extremely long - 20 minutes(?!). I'm still wet behind the ears, but this sounds impossibly long to me, and given what I know about reciprocity failure, I don't understand how people produce such immaculate/accurate/ pristine colors on these prints. Typically, the slower the shutter (say, slower than a 1/8), the more the reciprocity law breaks down, right? And isn't that when the film starts to get a bit funky? I feel like I am missing something really obvious here, but I don't know what... Please enlighten me - I would be really grateful.


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Jeff Drew , Dec 30, 2000; 02:15 a.m.

You seem to be connecting pieces of pertinent info into a confusing conclusion. Was the 20 minute exposure taken with your gear and ISO 100 film? I rarely have seen reciprocity issues at 1/8 or slower with 35mm ISO100 print film, unless we are talking real long exposures here. The 20 minute exposure possibly did account for reciprocity failure, but are we comparing "apples to apples?" Check Kodak.com for film specs and reciprocity compensation for each film - that may help.

Jerry Litynski , Dec 30, 2000; 02:25 a.m.

You might consider a notebook to track your exposures.

Kodak Company's recommended exposure table of reciprocity:

If the calculated exposure time Multiply the is between: exposure by:

1/5 - 2 seconds x 1.4

2 - 6 seconds x 2.0

6 - 15 seconds x 2.8

15 - 35 seconds x 4.0

35 - 70 seconds x 5.6

Example: a 40 second exposure x 5.6 would actually require: 3 minutes 44 seconds

If you use the table above, your meter (in the camera) should provide a ballpark exposure. Then bracket 10 seconds more and less. Once the film is processed, you can check the negatives. (If you are shooting slides -- you do not have the luxury of plus/minus exposures.)

This was a 30-second exposure (Nikon F5 metering)

Terry Carraway , Dec 30, 2000; 08:06 a.m.

Also the film data sheets may have filtration recommendations for long exposures to compensate for different reciprocity characteristics in different color layers.

So the shots you have seen probably had the calculations done and the proper filtration applied. Although print film does have an advantage of filtration during printing.

j d c , Dec 30, 2000; 03:08 p.m.

Try this...

When lights get truly low, most in-camera meters are useless. I use an old Luna Pro it is the only meter I know of that will get a reading in really low light (alleys, warehouses, city streets without street lights etc...). In addition Kodak and fuji do not supply useful information in these conditions (or I lack the knowledge to understand). You need to pick a film take notes test the hell out of it. Reciprocity failure is not what I think your concerned with but the associated color shift. As the exposure gets longer the colors begin to be absorbed at different rates resulting in an overly green, red or yellow image. Film sees color, especially in low light differently than your I. What appears to be neutral grey to you may be very warm or cold to the film. Predominate lighting or colors can heavily influence this as well.

So it appears you need to learn a few things:
how long and
what kind of color correction for a particular film,
What impact the existing color/light environment will have on the image/film.

I have some images in my photo.net gallery as well as others on my website that might be help you understand what to expect.

j d c , Dec 30, 2000; 03:12 p.m.

Excuse my bad proofing!

<i>'your"</i> should have been <b>you're</b><br> <i>"differently than your I."</i> should have been <b>eye</b><br> Public schools and an education in art -- what can i say!?

Peter T , Dec 30, 2000; 04:14 p.m.

The term "reciprocity failure" scared me...it seemed for so long to be so technical. LOL. Until I figured out what the phrase meant. The relationship between stops, that is f-stops vs. shutter speeds, is reciprocal. IE; a change in the f-stop by one stop is corrected for in a corresponding one-stop change in shutter speed. They have a "reciprocal (helping) relationship". Same as for full stop changes in film speed settings. We do it all the time in photography, as we utilize various shutter speeds and f-stops and ISO film. No big deal. Everything stays in balance. Double your shutter time? ;...just halve the f stop. The exception is you reach a certain point in shutter speeds where that relationship breaks down (fails). Usually somewhere about 1 second. Recipricity fails. That friendly relationship between f stops and shutter speeds fails.

Just go the the maufactuers web page or check the film data sheet/box, look up the adjustment for that films reciprocity failure adjustment, add it in, and shoot normally. I just "rate" my film at the adjusted rate, and meter normally. So 100 speed film ends up being rated at 50 or 25 etc. Depending on how many stops is recommeneded.

It's a big phrase but it's a very simple problem. Don't be intimidated.

Green Ears , Dec 30, 2000; 04:15 p.m.

Cheaper & easier way to get perfect shots

Ok, all of the above is true. But, if you are an "amateur" or a young photographer (like me) and don't have truckloads full of ca$h, here's a way you can effectively measure and calculate the appropriate exposure time:

1) Set your aperture to the desired opening (F8, etc..) and a basic exposure time (I try about 1/16 of a second for this) 2) Obviously, your camera meter is probably way way down by now... 3) Change your FILM SPEED setting till you get a good light meter reading (this is the cheating part of it) 4) Divide the exposure time you have on now by 2 for every step up you did when changing the FILM SPEED or multiply by 2 for every step down you did. (ie: ISO 100 to ISO 25 would be EXPOSURE TIME X 4 )

This is what I remember about this trick...

GOOD LUCK! ; ) P.S. Remember to put your FILM SPEED back to where it should be before shooting!!!

S L , Dec 30, 2000; 10:04 p.m.

Hey thanks guys, for all the info. I think what I need to do is take all your advice and experiment like a madwoman. What's the deal with Type L film? Can someone who's used this tell me if it's worth it to switch to medium format just for the sake of using this film?

Marika Buchberger , Dec 31, 2000; 07:34 a.m.

I won't give you any advise other than to purchase the following books as these books have the answer to your question and cover not only view cameras but 35mm as well:

How to Photograph Buildings and Interiors. Author, Gerry Kopelow. Published by, Princeton Architectural Press, 1998. ISBN: 1-56898-097-3.

Professional Architectural Photography. Author, Michael G. Harris. Published by, Focal Press, Second Edition, 1998. ISBN: 0 240 51532 3.

(I will however add that you may need to actually make a double-exposure, but you'll learn about this once you buy the books.)

Hope this helps.

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