seany65
Well-known
Hello all,
I'm aware that doing multi-exposures on a single frame will lead to over exposure if you use the original exposure reading for each shot, which means you should deliberately under-expose, but if we want to do two shots on one frame do we under-expose both shots by one top or just the second shot? What about a third or even fourth shot?
Any help would be much appreciated.
I'm aware that doing multi-exposures on a single frame will lead to over exposure if you use the original exposure reading for each shot, which means you should deliberately under-expose, but if we want to do two shots on one frame do we under-expose both shots by one top or just the second shot? What about a third or even fourth shot?
Any help would be much appreciated.
Joao
Negativistic forever
Trichromy (sort of)
Trichromy (sort of)
Triple exposure of Portra 160 (with red, blue and green filters). Mamiya C330. Standard commercial development, some resizing, no colour changes.
Regards
Joao
Joao
Negativistic forever
To get the above image I just exposed each shot 1/3 of the total required exposure time.
This is quite empiric but I get the results I want.
Joao
This is quite empiric but I get the results I want.
Joao
Richard G
Veteran
I’ve done ok with accidents with the same exposure as for one image with black and white.
seany65
Well-known
Hmm, seems pretty much to be what I think I vaguely remember of what I think I've read about it many years ago, but the memory was so vague I thought I'd better check. Thank you.
Richard, nearly all my shots look like accidents and I've not done any multi-exposures yet, lol.
seany65
Well-known
Joao, I'd better double check, as I'd generally be thinking in apertures when adjusting exposures for M.E.'s:
The meter suggest f4 for 1 shot, so for a double exposure I'd be exposing both shots at f5.6 and for a triple exposure I'd be exposing all three shots at f8?
The meter suggest f4 for 1 shot, so for a double exposure I'd be exposing both shots at f5.6 and for a triple exposure I'd be exposing all three shots at f8?
pvdhaar
Peter
f8 would be for four shots (two times two). For 3 shots it would be halfway between f5.6 and f8. So at f6.7.
It's a valid question though, because at the extreme, you're running into the limitations of the film. There's a minimum exposure required to push the film's response above its threshold. But that's only an issue when you're really doing something extreme, like stacking tens of exposures on a single frame. In such cases, pre-flashing the film up to threshold level may be required.
It's a valid question though, because at the extreme, you're running into the limitations of the film. There's a minimum exposure required to push the film's response above its threshold. But that's only an issue when you're really doing something extreme, like stacking tens of exposures on a single frame. In such cases, pre-flashing the film up to threshold level may be required.
Joao
Negativistic forever
@sean65 A quick search finds several links with techniques for ME. Most deal with tricks to get doble exposures in cameras that prevent it.
A Multiple Exposure Experiment: 20+ Exposures in a Single Film Image » Shoot It With Film
Emma Lloyd in “Analogue Wonderland” sumarizes the technique (Quote)
It would be interesting if you post your results mentioning what you have done
Regards
Joao
A Multiple Exposure Experiment: 20+ Exposures in a Single Film Image » Shoot It With Film
Emma Lloyd in “Analogue Wonderland” sumarizes the technique (Quote)
- Correct exposure at shutter speed 1/125 would need to be set to 1/250 for a double exposure (2 exposures, each 1 stop underexposed), and 1/500 for a quadruple exposure (4 exposures, each 2 stops underexposed)
- Correct exposure at aperture f8 would need to be changed to f11 for a double exposure (2 exposures, each 1 stop underexposed) and f16 for a quadruple exposure (4 exposures, each 2 stops underexposed).
It would be interesting if you post your results mentioning what you have done
Regards
Joao
seany65
Well-known
Thank you Peter and Joao for the further replies and info.
a single f4 would be at f5.6 for a double, (1 stop down from a single) but a triple would be f6.7 (1 and a 1/2 stops down from a single), and f8 for a quadruple (2 stops down from a single).
But to my two braincells, if the exposure for a triple is only 1 and 1/2 down and not 2 as I'd thought, then each successive shot should be cut by a smaller amount each time, eg. if the first decrease is 1 full stop, and the second half a stop, then the third decrease (fourth shot) should be cut by 1/4 of a stop.
To any readers: don't mind this stuff, it's just my ramblings, which may or may not help me get my head around the decreases being less than I thought they'd be for each shot after the second.
Anyway, the photos I have in mind will only be having three shots on each frame at most, that is if I ever get to do them. Unfortuantely the camera I want to use only has 3 apertures and no between settings, though I have a set of ND's I can use. Would using a 1 stop ND on the third shot have any effect?
a single f4 would be at f5.6 for a double, (1 stop down from a single) but a triple would be f6.7 (1 and a 1/2 stops down from a single), and f8 for a quadruple (2 stops down from a single).
But to my two braincells, if the exposure for a triple is only 1 and 1/2 down and not 2 as I'd thought, then each successive shot should be cut by a smaller amount each time, eg. if the first decrease is 1 full stop, and the second half a stop, then the third decrease (fourth shot) should be cut by 1/4 of a stop.
To any readers: don't mind this stuff, it's just my ramblings, which may or may not help me get my head around the decreases being less than I thought they'd be for each shot after the second.
Anyway, the photos I have in mind will only be having three shots on each frame at most, that is if I ever get to do them. Unfortuantely the camera I want to use only has 3 apertures and no between settings, though I have a set of ND's I can use. Would using a 1 stop ND on the third shot have any effect?
pvdhaar
Peter
The same compensation is applied to all exposures. In the example with a base single exposure at f4, all three would be shot with the same shutter speed and all three at f6.7. Don't confuse multiple exposures with layers in a photo editing program where each higher layer needs higher transparency to build up the total image.
seany65
Well-known
Thanks Peter. Yes, I understand that, but I didn't explain myself very well (as per usual, when "thinking" is involved, due to the fact that I'd started writing before the full idea of what I wanted say to had formed. 
). Instead of "each successive shot" I should've written "each successive set of shots for one frame", going from a "set of 2" which has both shots 1 stop under, I now find a "set of 3" has all three at 1.5 stops under (instead of 2 stops under as I'd expected) through to a "set of 4", which to me, I'd expected a "set of 4" to be three stops under. Looking at the second of Joao's "Emma Lloyd" examples, a "set of 4" would only be 2 stops under, meaning the decrease gets smaller for each "set". eg. 1stop each for a "set of 2", a further decrease on that of a 1/2 stop for each for a "set of 3" and a further decrease on that of a 1/4 quarter stop for each of a "set of 4".
I think that's what I mean.
). Instead of "each successive shot" I should've written "each successive set of shots for one frame", going from a "set of 2" which has both shots 1 stop under, I now find a "set of 3" has all three at 1.5 stops under (instead of 2 stops under as I'd expected) through to a "set of 4", which to me, I'd expected a "set of 4" to be three stops under. Looking at the second of Joao's "Emma Lloyd" examples, a "set of 4" would only be 2 stops under, meaning the decrease gets smaller for each "set". eg. 1stop each for a "set of 2", a further decrease on that of a 1/2 stop for each for a "set of 3" and a further decrease on that of a 1/4 quarter stop for each of a "set of 4".I think that's what I mean.