Taking photos of displays...

[Tony Duell]

> 
> 
> Recent discussion about photographing machines prompted this one.
> 
> Has anyone got any useful tips for photographing (with a digital camera)
> running machines such that whatever's on the screen is captured with
> some kind of decent quality?

I can't comment on digital cameras, I've never used one. But I guess the 
problems of using a film camera are much the same. 

There are basically 2 problems. Reflections in the screen and the fact 
that the image is scanned, it's not all there at once.

The best way to eliminate reflections is to put the camera at an angle 
(and off to one side) and correct the perspctive with a swinging back. 
Problem is that no digital camera that I've seen has a swinging back 
(actually, few modern film cameras do either, but...)

You might be able to correct the perspective by manipulating the digital 
image o na computer. I've never tried this.

The second problem is easier to get round. You need a relatively long 
exposure time -- I normally say at least twice the refresh time of the 
display. 1/8 of a second should be fine. Set the aperture to give the 
right exposer, use a neutral density filter if your lens won't stop down 
far enough. With a digital camera you should be able to do some test 
exposures and fiddle the aperture setting until it comes out right.

If you want to get both the machine and the image in the same picture, I 
would suggest taking 2 exposures. One of the screen image (in a darkened 
room), the other of the machine (turned off?) under normal lighting. 
Maybe you can combine the resulting digital images on a computer (I'd do 
it by multiple exposure on the same film, but...)

Obviously you should put the camera on a solid tripod, and don't use 
flash at all. 



-tony