home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.graphics
- Path: sparky!uunet!spool.mu.edu!caen!destroyer!ubc-cs!unixg.ubc.ca!reg.triumf.ca!noel
- From: noel@reg.triumf.ca (NOEL)
- Subject: Re: slide shots of computer graphics using an SLR camera
- Message-ID: <15SEP199211315975@reg.triumf.ca>
- News-Software: VAX/VMS VNEWS 1.41
- Sender: news@unixg.ubc.ca (Usenet News Maintenance)
- Nntp-Posting-Host: reg.triumf.ca
- Organization: TRIUMF: Tri-University Meson Facility
- References: <92255.173915U21709@uicvm.uic.edu>
- Date: Tue, 15 Sep 1992 18:31:00 GMT
- Lines: 87
-
- In article <92255.173915U21709@uicvm.uic.edu>, Prasad Ravi <U21709@uicvm.uic.edu> writes...
- >
- >Hi folks,
- >
- >I am trying to find out various issues involved in taking
- >pictures of a computer screen for molecular modeling graphics.
- >Some of the details of the computer screen:
- >
- > 19" screen (IBM 6091-19)
- > scan rate: 60 frames/sec
- > resolution: 1024x1280
- >
- >I have an SLR camera (Pentax P30T) with a 28-80mm zoom lens with
- >a minimum focus distance of 1 meter. I would like to know the
- >following details:
- >
- > film type
- > film speed
- > aperture size/shutter speed
- > flash/no flash
- > lighting conditions, etc.
- >
- >I greatly appreciate your help. Please send any responses to
- >u21709@uicvm.cc.uic.edu. I'll post a summary if there is enough
- >interest.
- >
- >Prasad Ravi.
- >u21709@uicvm.cc.uic.edu
-
- Tried mail got an invalid address so I thought interest might warrent a post.
- NMG.
-
-
- I take this kind of photo all the time and I feel I have the technique
- down quite well. I use an old pentax spotmatic II camera and right now
- I'm taking photos from an Idek llyama 17" 5217 colour monitor 1024x768 res.
- It has a vertical scan rate of 72 Hz and has a reasonably flat screen.
-
- So this is what I find gives the best results.
-
- Film 100 asa Kodak gold (print) 64 asa kodak (slide)
-
- aperature screen is flat so depth of field doesn't matter
- wide open for more light is best but just make sure
- focus is crisp. I use f4 setting.
-
- shutter speed must be longer than monitors vertical frame rate or
- you won't get a complete image. With normal monitor
- brightness ie. colours bright but not blurred or
- blooming and good contrast I use 1/4 second exp
-
- lens I use a 100 millimeter macro telephoto lens and with
- this focal length and image size a camera mounted
- about 1 metre from the screen fills the frame.
-
- flash impossible, don't even try, think about it, you
- must be joking.
-
- misc conditions
-
- With these shutter speeds it is imperative to mount the
- camera on a good solid tripod. Use a cable release
- or the self timer button. The camera should be mounted
- directly on axis with the centre of screen to minimize
- distortion and keep image square. A long lens is
- better than a short one for minimizing pin-cushion
- and also a flat screen monitor. Take all photos
- at night in a completely blackened room. I really
- mean black. No lights! This allows the least amount
- of stray reflected light to bounce off the screen and
- all light is coming directly from your image. This
- will give nice black borders around your image and
- not silly looking monitor frame and logo. To optimize
- image squareness you can adjust the image size on the
- monitor down away from the edges where the screen
- glass is thicker and least flat but you will have to
- move the camera closer or zoom to compensate. Moving
- closer will introduce angular distortion from the lens
- so there is a trade off here.
-
-
- That should produce good quality images
-
- Good Luck
-
- Noel Giffin "noel@reg.triumf.ca"
-
-