3rd November 2004, 07:35 PM
Building up multiple exposures...
ok...got a basic question here about photoshop...
how do i build up multiple exposures from digital images in photoshop? (want to achieve the equivalent in traditional film cameras...where multiple exposures on the same frame are made by exposing the film several times without advancing the film itself.)
*not referring to simply putting layers on top of one another and adjusting the opacity*
im sure there is a simple answer to this simple question...just that i have not figured out how it can be done. thanks for any tips in advance!
4th November 2004, 08:55 PM
any tips and hints, guys?
4th November 2004, 09:27 PM
i could tell u how to do it out of photoshop...
strobe firing at regular intervals....else the only way i know of in photoshop is using the overlay...
5th November 2004, 10:16 AM
Last edited by sammy888; 5th November 2004 at 10:42 AM.
5th November 2004, 11:14 AM
In Photoshop, you paste the new picture over the old one as a new layer. Then you create a layer mask (specifying Hide All). Then you use the brush and "paint" in only those areas you want to include.
Last edited by StreetShooter; 5th November 2004 at 11:22 AM.
5th November 2004, 01:04 PM
thanks for the info guys, including the very exhaustive and informative manual written by sammy888 on "painting with light" with flash strobes. lovely picture you have there streetshooter!
ok..let me clarify the purpose of asking such a question. let me simulate a shooting scenario, in order to put the question into context.
let's say i have a tall sculpture, over 1.8 metre tall, and one flash strobe. in order to capture the art piece in its entirety, i would probably need to light it from several different angles (side, back, top, bottom etc.) to bring out its form, shape and texture. obviously 1 flash exposure won't do the trick, and setting the camera on long exposure and 'paint' the sculpture with flashes from the strobe as sammy888 described presents a few problems for me.
1) during the entire exposure, any movement within the frame would be captured. hence, i can't move around the subject lighting it from different angles, unless i move really really fast.
2) painting it with light this way is unpredictable as i won't be able to see the effects beforehand...how the light falls, any stray shadows, unwanted flare, strength of flash etc.
it will be good if i want to do an experimental picture with unpredictable results. in this hypothetical scenario however, i would like WYSIWYG and a carefully choreographed lighting situation.
with a traditional 35mm film camera, careful calculations can be made before each exposure on the same frame. set up lighting -> open shutter, flash -> close shutter -> repeat step 1 as needed.
with a DSLR, the benefits are immediately obvious. the effects of each flash exposure can be reviewed and changes made accordingly. i can appear in the picture holding the flash, but i can be easily erased out later, as described by Streetshooter.
however, this is the part where i got stumped. how i do combine the several images i have into one coherent picture? certain light rays will overlap each other, in essence, naturally adding on exposure to the previous (aka 'brighter'). simply adjusting the opacity of layers on top of another won't achieve that effect, nor erasing away layers. i know some software that comes with digital backs can achieve that automatically, but obviously i don't have access to that.
i am sure photoshop can achieve that same effect of "building up" exposures, albeit a bit more manually. and i'm quite confident it's a matter of adjusting layer modes etc...but i haven't figure that out yet.
5th November 2004, 06:57 PM
I painted this with a torchlight and a few minutes exposure time:
Is this what you had in mind? f22 ISO 100 i think.
5th November 2004, 07:01 PM
maybe...is it a series of multiple exposures combined in photoshop? mind sharing your workflow? thanks!!
5th November 2004, 07:32 PM
No, it is a single exposure (about 5 mins) at f22 ISO 100.
I used a torchlight to illuminate the subject from many different angles. I shone the light for a longer duration on those areas I wanted to highlight.
5th November 2004, 08:03 PM
ok..then it's not it then. it's similar to what sammy888 had written on, light painting... the quest continues!
thanks for all the info anyway, it has been useful!
7th November 2004, 06:52 PM
7th November 2004, 07:30 PM
Well there you go.... There is nothing you can't do with a bit more time spent thinking about it.. knowing where the strengths of your camera equipment are and also learning abit about post-picture production like Photoshop. Now you are moving into the realm that is my favorite..mixed media production. Your concept is something most graphic designers uses ever so often. Looks like you are on your way to more complex shooting now.
7th November 2004, 07:31 PM
Hi, pardon my ignorance but what is the purpose of this exercise?
7th November 2004, 08:00 PM
saberlancer> it will be useful if one need to capture a scene which require multiple flash lighting setup, and you have less than what you require.
actually i learnt this trick from interior photographers who use this method when capturing a super wide view. why?
1> big room, and you might not have enough lighting equipment at hand. hence, need to duplicate lighting setups
2> big room, unable to hide all lighting equipment without appearing in the scene.
of course, they have access to proprietary software that comes with the digital back to combine the various exposures easily and automatically (ie. can duplicate the effects of building up exposures on film). was trying to find a roundabout way to do it in photoshop
8th November 2004, 10:52 AM
OIC,so thats what this is for...
Originally Posted by imaginevisuals
Hmm,actually,'dodge' brightens/saturates up ur image but u may wanna try 'lighten' instead as it most closely matches ur original photos?