P3D Re: Photographing Slides From Computer Monitor

[Gregg Podnar <Gregg_Podnar@xxxxxxxxxxxxxxxxx>]

There is a slight possibility of misunderstanding a few aspects of
monitor resolution by some readings of the recent post by Mr. Al
Knecht <aknecht@xxxxxxxxxxxxx>:

   >... the screen resolution of most monitors is 96dpi for Windows 
   > and 72dpi for the Mac, regardless of the video resolution setting.
   
For "normal" resolution settings for various size monitors this is
certainly true of pixel size.  But by changing the video resolution
setting of a 19" monitor to say 1600x1200 you can have a pixel pitch
of about 118 per inch (about 0.22 mm/pixel).  Now if one uses a less
expensive monitor, it may only have an aperature grille pitch of 0.26 mm.
Clearly, because the aperature grille is lower resolution than the 
image resolution (pixels) this monitor cannot render each pixel
accurately.  (Bandwidth of the electronics also plays a part.).

On the other hand, if you have a high-end monitor with an aperature
grille pitch of say, 0.22 mm, this image should be quite a bit sharper.


   Tips on photographing a computer monitor:

1) Darken the room to eliminate reflections off the screen.
2) Lower the brightness to minimize 'blooming'.
3) Use a long lens to minimize effects of screen curvature.
4) Use a long exposure (>1 sec.) to minimize refresh (raster) overlap.
5) Use a tripod (see 2, 3, and 4 above).
6) Adjusting screen size may improve sharpness due to aperature grille
   pitch vs. image pixel pitch interaction (see discussion above).
   
   


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