Film for 4 - hour night exposures
I'm looking for a film that can hold up to 4 hour night exposures. Basically, there is an activity with people and lights that I want to photograph that will take between 3-4 hours. I want to be able to capture the people's movement like you would star trails. There will be no artificial light other than lanterns held by the people moving. Moonlight will hopefully fill in the landscape.
Has anyone successfully done night exposures on that scale? (3-4 hours)
What film did you use? I was thinking of doing some tests with Provia 100 as a starting point. I want to shoot the final shot on 4x5 film. I'm thinking slide film of some sort.
I have done night exposures of up to about an hour using TMax 100. I have also been thinking about working up a system for Acros 100, but have gotten distracted by other endeavors. Both TMax 100 and Acros 100 have far better reciprocity characteristics than more traditional films, so for this kind of exposure, they are faster than most 400 speed films. I think that Acros is the better of the two for reciprocity.
You might actually want film that will slow you down somewhat, for such long exposures. If there is any kind of ambient light, street lights or the like, four hour exposures are very long. You might find that something slower, or with more reciprocity failure, than Tmax or Acros would be in order.
Color film, not b&w. Provia is a fine choice. Yes, i've done it.
ahh, I should read more carefully.
No opinion on color.
This is an "urban myth" that really needs to be put to rest...
Originally Posted by Paul Sorensen
Yes, exposure compensations grow sligthly quicker with higher ISO films, but in most instances and with current 100 and 400 ISO films, this does NOT compensate for the two stop extra sensitivity of the 400 ISO film.
So, if with "they are faster than most 400 speed film" you also mean you will have shorter exposure times with 100 ISO films to GET CORRECT EXPOSURE ON THE FILM than with 400 ISO film for very long exposures, than in most cases THIS IS NOT TRUE.
I have done some controlled real world testing with very long exposures by shooting film and visually examining the density of the resultant negatives using TMax 100, TMax 400, TXP320 and Acros 100.
TMax 400 did beat all other films up to exposures of 8 hours, meaning after an 8 hour exposure, the TMax 400 had the densest negative. Correspondingly, it means TMax 400 had the shortest needed exposure times.
Actually, only at this 8 hour point, Acros 100, known for the good reciprocity characteristics, started to "catch up" with the TMax 400, meaning the density of the negative almost equalled TMax 400 after both films were exposed for 8 hours.
But for any exposure below 8 hours, you will have the shortest exposure times with TMax 400 to get to a certain predefined film density. But yes, sure, if you intend to do day(s) long exposures, than by all means, throw in Acros 100 or so. It is likely to give shorter exposure times, but this is going to the extremes and I stopped testing at 8 hours as a practical limit...
Interestingly, although an "old type" emulsion, TXP320 did surprisingly well too. It wasn't that far behind TMax 400, and beat the 100 ISO films too for most exposures less than 8 hours.
2 stops ISO difference is just a lot to compensate for with better reciprocity characteristics... Buy TMax 400 if you don't want to wait for hours in the cold...
I still intend to post the results with all the scans here once on APUG. It is just a damned amount of work that I'd rather spent working in my darkroom...
Last edited by Marco B; 12-31-2010 at 06:18 AM. Click to view previous post history.
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I am not sure that I understand exactly what your objective is. If you truly need a 3 to 4 hour exposure and your scene includes people moving while carrying some sort of lanterns, I cannot see how the people will record. It seems that you will have many streaks of light on the film from the moving lanterns, but no evidence of what is moving them.
I'm guessing that's exactly his point!
Originally Posted by Dan Henderson
But if he's really doing a 4 hours exposure, at an f-stop small enough to make the background need 4 hours to expose properly, those people are going to have to be moving very slowly, and/or carrying some exceptionally bright lights, to get them to show up well also. I've seen pictures along these lines before (but never 4 hours long!) and the effects you can get are pretty neat. I can't wait to see the results here.
Marco, when you say that you "visually" checked the densities, are you saying that you did measurements of the tonal ranges, not just how dense the neg looked, with a densitometer? Checked the total range, including FB&F, not just zone I? Higher speed films tend to look denser than slower speed films regardless of reciprocity. I am willing to bet that the FB&F of the T-Max400 is already higher than that of the Acros, and would lend a look of greater density to begin with.
In looking at the reciprocity failure data reported by Kodak and Fuji, for exposures of 100 seconds in length, Kodak does not indicate ANY times longer, the correction for Tmax 400 is 1 1/2 stops. So the effective EI drops to about 150 for a less than 2 minute exposure.
For Fuji Acros the data given is for exposures up to 1000 seconds, or nearly 17 minutes, and the correction recommended by Fuji is only 1/2 stop, or an effective EI of 50. However the data also indicates that NO compensation is required for exposures shorter than 2 minutes. Whereas the T-Max 400 a +1/3 at 1 sec, a +1/2 at 10 seconds, and a plus 1 1/2 at 1000 seconds. This indicates to me that compared to the fuji, there is a more rapid decrease in film sensitivity as exposure time increases, whereas the fuji seems to stabilize. One could argue that on exposures of hours length, that the trend of increased reciprocity failure of the T-Max 400 would increase and could catch up to the Fuji Acros in actual sensitivity. If that were the case or even if there was still a slight edge in speed in favor of the T-Max 400, one still has to consider is the image quality of T-max400 worth the slight increase in effective speed?
Fuji Acros has a RMS granularity value of 7, and a resolution of 60 LP/mm, T-max400 has an RMS of 10 and a resolution of 50 LP/mm. Personally, I'd rather wait a little longer, or open up a half a stop, to use a superior film.
I've got to agree here. If a tree is properly exposed at 4 hours, then a person's walking motion for even 4 minutes in the scene will be negligible. A bright light in their hand may record, but the person is unlikely to be visible.
Originally Posted by Dan Henderson
Long exposures can give some very interesting results, but until you've done a few they surprise you. Or at least they surprised me.
Somewhere in my junk I've got a picture of a firetruck that's leaving after duty for a fireworks show. (No fires that night! Just standing by.) The exposure is about 40 seconds as I recall, and the people standing still on the sides are properly exposed. There is no recognizable fire truck in the image - only blurred lights, and even though I took the picture it still took me a minute to figure out what it was when I first saw the image days later. Had it been months later, and I had forgotten the "last frame" on the fireworks roll I doubt I would have ever been able to figure out what that blur was.
I do encourage you to do the experiment, but I expect you'll need to refine the technique to get the image you've envisioned.
From an artistic perspective, the photographer's job is to capture the preconceived mental image. (A. Adam's gospel there; you can disagree if you like.) So try a few experiments before you set up the 4 hour exposure. That way you can get some faster feedback on your technique before you set up the long exposure.
I suspect you're after trails following a figure. (Just a guess, so don't beat me if I'm wrong.) If so then take a look at the difference between the images here. http://www.shortcourses.com/use/using6-2.html
I know that may not be what you asked, but it might be what you're looking for. And if not then just ignore it.
Tests would be a good idea. Back when I did a lot of astrophotography I used Kodak Ektachrome 200 and 400 and Fuji Provia 400F for long exposures and all worked well. They each have their own color shift characteristics which happen with long exposures which have undoubtedly changed with the current reformulations.