Exposure Recommendation for Color Night Photography

[tgtaylor]

If a 7 to 8 minute exposure on Fuji Acros gives you an acceptable negative, what might be a good starting point for Fuji/Kodak 160 Color negative film? (Fuji recommends a 1/2 stop compensation for Acros exposures reaching 16-2/3 minutes.)

What about for color transparency film - say ISO 100?

Thanks,

Thomas

[Walter Calahan]

All depends. Best to test various transparency films on your own to see what works for you.

Color negative film is easier to use due to color balance issues.

[Richard Wall]

I think Walter is right. You need to do some test exposures with the film in the light you will be shooting under. I have exposed transparency film at night under a full moon where the moon was my only light source. My exposures were 106mins at f8 using fuji velvia 50. I have also shot the same film in the city when I had the lights of the city and shot at 4 min at f6.8. Do some experiments and keep good notes about your exposures and lighting conditions. As for print film, you will always have greater latitude with these films, so exposure times become less critical. But, you should still be as accurate as possible.

Richard

[tgtaylor]

Early Saturday morning at 4:30am me and two other photo buddies went to shoot the Sutro Baths ruins which fronts the Pacific Ocean in San Francisco. The moon was high overhead at 1/2 phase and a little light was falling from the street lamps at the adjacent Cliff House onto nifty looking ruins in the mid foreground giving them a neat orange/yellow cast. Seal Rock(s) with their white caping of bird po comprised the background with good wave action around the rocks and to the shoreline which resulted in a milky white sea on the negatives.

I was shooting ISO 100 film (Acros) and couldn't get anything but a "0" with the spot meter. I got an exposure estimate from one of the digital guys and started off with 5, 6, 7 and 8 minute exposures taken at f8. All came out as Acros is films version of a CCD chip at exposures up to about 15 minutes.

I want to go back and shoot this location with color negative as the colors (muted deep blue/black sky, white and grey sea mounts, white milky water and an earthy landscape dotted with ruins makes for a great image. The data sheet on Fuji 160C and 160S don't say anything beyond 32 seconds.

If Richards exposure with Velvia 50 was 108 minutes, then what would be a reasonable starting time with ISO 160 negative film?

[Richard Wall]

The reason that 5, 6, 7 and 8 minute came out nearly the same is because you were within one stop difference of exposure values. A one stop increase from 5 minutes would be 10 minutes, a two stop difference would be 20 minutes and three stop difference would be 40 minutes, so going from 5 minutes to 8 minutes is not a huge exposure difference. It is just over 1/2 a stop. You will always have to either double the time or halve the time to get one stop difference in exposure value.
This works the same with ASA. ASA 50 is one stop slower than ASA 100. So, ASA 160 would be around +1.5 stops difference from ASA 50. +1 stop from 108 minutes @ f8 would be 54minutes, and then +.5 stops would give a time of about 36-40 minutes @ f8.

I hope I'm not telling you things you already know, but this tends to catch people by surprise when dealing with such long times.

There is a website dealing with night photography that might provide more info: http://thenocturnes.com/

Post some images when you get them.

Richard

[tgtaylor]

Thanks Richard. I got my initial exposure start from one of the guys that that shooting with a Canon 40D or 50D: 11 minutes resulted in a somewhat blown-out image.

As you may have surmised, I am familiar with computing the f-stop from the ISO. However, I am not certain that the reciprocity curve for Velvia is the same or similar to that of Fuji 160C or 160S. Nor, for that matter, do I know if the reciprocity curves for 160C and 160S similiar. I'm going to find out, though, on the next full moon!!

BTW, its finally raining here in NCal. No much, but at least there is a trace of moisture on a very dry ground.

Thomas

PS: Thanks for posting the link to the nocturnes. It's been a long time since I visited the site and it provides a wealth of information for those interested in night photography like myself.

[sgelb]

106 minutes f/8 under full moon? sounds overexposed to me.

I shot a moonlit scene with moonlight coming from behind the clouds, I think at f/22 and exposure was 16 mins. provia100F of course i messed up the focussing but the light looks like it did when I shot it.

often i take readings at 6400 iso at night and work backwards.. seems to work well judging from some of my 4x5 shots.

btw: I am a big provia fan for nighttime..

[Richard Wall]

106 minutes f/8 under full moon? sounds overexposed to me.

That was exactly my point. It sounds overexposed, but it wasn't. I was arguing that experimentation was needed to get a proper exposure as there are so many variables each situation is different.

r.

[Rory_5244]

Not overexposed: the extra time is required to compensate for Velvia's reciprocity failure.