Technique Question; Multiple captures same frame - How is this done?

[syd]

I don't know where else to place this question because it's a

technique based question relative to Sports/Adventure photography

which happens to involve travel so travel it is!

 

I'm very sound in all other forms of trick photography but am now

looking at doing some snow sports shots and just wondered what is the

process for those shots of skiers or snowboarders where there are

multiple moments of a skier making a jump in staggered stages

throughout the frame? Can anyone break this down for me and tell me

how it's done?

 

Here is my guess ... it's obviously shot on a camera with rapid fire

or power winder, most likely set to shoot so many frames per whatever.

What I am curious about is the exposure situation since it's shot on

the same frame of film? Some of these shots show something like 15

stages of the skier from take off to mid air and then landing with

perfect exposure for the landscape etc. How is this metered and sorted

out in terms of exposure and shutter speeds?

 

Thanks, Simon.

[maiken]

If someone asked me to do a shot like this, I would stick a DSLR on a tripod, dial in the appropriate exposure on Manual so it wouldn't shift during the shoot, and use its motor-drive mode, or rapid shutter presses, to capture multiple frames of the stunt. Then I would use Photoshop to overlay the frames. One way to do this would be to pile them all up as layers with their mask set to conceal-all to start out with, then paint onto the layer mask to reveal just the skier from each layer. This should be very easy since the background is always identical.

 

It seems like accomplishing this without a computer would be quite hard. The only thing I could think of if you were trying to get this onto a single film frame would be to reduce your exposure for the background so the repeated exposures would end up, cumulatively, correct, and using a flashgun to illuminate the skier. That sounds a lot trickier than just using Photoshop, though.

[greglyon]

For all those shots you see in bright daylight...it's typically a photoshop trick. YES, the photographer is using a camera with high frames/second but it's a digital camera making multiple images. (There are only a few digital cameras that are capable of single frame multiple exposures anyway).

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Basically you figure out where the action is going to take place, put the camera on a tripod with correct location/lens to capture the whole thing without moving the camera. Then when the athlete does the stunt or whatever you just fire away.

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Then in photoshop you overlay all the images together and use masking to reveal the athlete in each frame. Since everything else is stationary it goes together quite nicely.

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It can be done using film camera and scanning slides, or by panning with the athlete, but it's more hit and miss that way.

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Other things that can make it tricky are fast moving clouds, wind moving trees/foliage...basically anything in the background that moves too makes the merging of images more tricky.

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It's fun to do! The only example I have right now is with a bird that I panned with but you'll get the idea...<a href="http://www.photo.net/photo/1899539&size=lg">http://www.photo.net/photo/1899539&size=lg</a>

[greglyon]

ACK - of course Mark gave you some key info I forgot...shoot in manual so exposure doesn't change between frames. Also, prefocus and turn of autofocus!

[syd]

Thanks guys ... I wasn't sure if it was a modern SLR or Digital SLR trick or not because I shoot only manual camera's ... the most modern camera I have is a 1979 Contax 139Q! I have a Crown Graphic and an RB67 Pro-S so for me it wasn't clear how this was done since I'm not up to date with the funtions of the more modern whiz bang cameras.

 

What I was curious about was this ... say with an EOS 1N or something of that nature, would it be possible to pre program ( I am guessing at all this mind you since I have never used this camera ) the camera for so many frames per second on multi exposure having worked out the fractions of cumulative exposure first to reach the final correct overall exposure - with a film camera and no PS?

 

Just curious because if so I'd love to try this ...

[greglyon]

Assuming that the EOS1N would allow you to use continuous motor drive on one frame (I don't know, I'm almost certain I CAN'T do it with my Nikon F5) there would still be 2 big problems with that idea:

 

1) the athlete would be quite underexposed and ghostly in each shot. Say you took an 8 shot sequence. For each shot you'd be aggregating 1/8 of the total exposure which means that each image of the athlete would have 1/8 the necessary exp.

 

2) Any movement of the camera would ruin the whole shot, making it look blurry most lilely.

 

You MIGHT be able to get away with it in a case where the subject was much brighter than the background, or in the sun with the background shaded, etc...but there would have to be a big difference!

 

Even more out there...an elaborate flash setup where you'd take one exposure and the flashes would be triggered by the athlete's movement (Yikes! to set up though.) The one long exposure would cover the background, the flashes would only illuminate the athelete. Once again it would probably only work well with a relatively dark background.

[syd]

Good point regarding the lagging exposure of the athlete Greg! I forgot that small issue. I always shoot on tripod anyway so it was a given that in snow near a jump I would set up with a 24mm to cover the entry and exit points of the trick and then fire away with stability. I even thought about using multiple flash bursts to take care of the athlete as you said but again it would be tough to set up! So it seems the only way , even with a film camera with rapid fire is to just shoot multiple fast frames and then create the final image in PS. Atleast I know how they do that now though.

[jeffrey_lan]

there are also toy cameras with multiple lenses and shutters that will record 4-12 shots (depending on the camera) onto one frame of film.

[ellis_vener_photography]

The Nikon D2x has two multiple exposure modes-- one sequential, one non-sequential--

which both can be programed to compensate for the cumulative exposure build up.

 

Other than that: multiple exposures on separate frames montaged in Photoshop using

layers.

[syd]

Ellis,

 

For sure, but regarding the correct exposure of an athlete in a scene it wouldn't solve that problem. I could work it out on my Contax with the power winder perhaps and get multiples of a scene built up to correct exposure but the exposure of a moving skier would not be correct ... it's an interesting problem which I am sure could be solved with multiple flash setup and film but it would be too elaborate.

[ellis_vener_photography]

With the D2X I tried it with slowly moving subject matter - floating foam leters in a bubble

bath -- and it worked out pretty well for the background exposure but there was bleed

though in the letters. I really suspect these types of athletic in full sunlight with non black

backgrounds imagesare done with a high fps camera and composited (montaged) in

Photoshop. It

could be done pre-Photoshop but was difficult and expensive.

[ellis_vener_photography]

An alt aproach would be to set the camera on B or T, open the in camera shutter and have

a slit type shutter in front of the lens this shutter would be synchronized with the

movement of the subject exposing just slices of your frame across the width of the frame .

You'd need to know the speed of the subject, the relative size of the subject to determine

the minimum width of the slit, and come up with an aperture setting based on the fixed

width of the slit, its velocity and the sensitivity of the film. Essentially you are just

exposing one small stripe of the frame at a time.