I have extensive experience on focusing screens, I had one of the special
split screen (I think it was for the T90), the split was seems to be
composed with some vertical straps and it doesn't give very clear alignment
like the normal split. I had reworked one to be used on a OM2n but it was
sold with the camera.
The early laser matte on the C*non was not that bright but finer than the OM
1-series screen. The later one for the EOS6xx series is brighter and further
finer but make sure it is the standard EC-C screen, some others are not as
bright.
Just dig out an old email I sent to the list in April 1999, the EOS screen I
tested at that time was a non EC-C (I had damaged the only EC-C I had at
that time) so it was not very bright but later I found another EC-C and
found its brightness was between the OM 2-series and M*nolta.
=============================================
>There were some threads concerning the brightness of focusing screen before
>without any conclusion, here I have some data just measured with my OM4Ti
>and 50/3.5, target to a light color wall, place a light meter behind the
>viewfinder and take some readings with four different FS (with comments on
>the smoothness of screen) :
>
>OM4Ti with
>
>OM 2-4 --- 4 +0.6EV (extremely fine)
>Minolta 7000 --- 4 +0.3EV (fine)
>Canon EOS 620 --- 3 +0.7EV (very fine)
>OM 1-4n --- 3 +0.1EV (coarse)
>
>OM2n with Canon EOS 620 screen --- 4 +0.2EV
>
>Other observations:
>
>- With large aperture lenses, the brightness between different FS is less.
>Some people said the OM series 1 and 2 screen look no different, they might
>have used a 50/1.4 and compared with OM4 and OM2n.
>- Minolta 7000 FS is not as bright and fine as OM 2 series FS but focus
>better with large aperture wide angle lenses.
>- I own a Beattie screen before, (by memory) it is very similar to Minolta
>FS, but it vignette with my 16mm fisheye. If you can find a used Minolta
>FS, it is a more cost effective approach.
>- The finer the screen the better it works with small aperture lenses, a
>200/f4 with 2X-A works very well with the OM 2 series screen, but not so
>good with large aperture wide angle.
>
>The Canon screen I damaged is the best I have ever seen, it is extreme
>fine, the brightness is close to the OM 2 series screen but focus equally
>well with wide or tele lenses, I will try to find out what it is later.
>
>C.H.Ling
===================================================
----- Original Message -----
From: "John Hermanson" <omtech@xxxxxxxxx>
> How much different are C*n!n screens? They hold a patent on the only
split
> image that doesn't black out with slow lenses.
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