Re: Who's not so bright..........

[Jim Brick <jim@brick.org>]

At 11:47 AM 10/8/97 -0500, you wrote:
>
>I have used split image rangefinder screens in my Leica R4s, R4s', R4sP and
>R7. They work fine for me, but obviously not as accurate as the M6, which
>is why I just bought an M6 with 35mm 1.4 Aspheric rather than an R8 and
>35mm 1.4 Summilux R, even though the aspheric is only slightly better.
>
>=============
>Eric Welch

The split image on the ground glass screen in R cameras is not a true
rangefinder. There is no distance between the images. It's an aerial image
focus phenomenon. Compared with the M6 rangefinder, the R split image has a
zero base and zero accuracy. When an M rangefinder/lens is aligned
properly, with it's wide base, it is dead-on. This was one of Walter Heun's
hot buttons. I suspect he was instrumental in getting interchangable GG
screens into the R4. He hated the non-changable R3 Universal screen. With
wide angle lenses, the wide base of the M rangefinder makes a big
difference. Since the R's dual ground glass prism is only simulating a
rangefinder, I find it useless and in the way. I'm a big big fan of
previewing depth of field on the ground glass. This was drilled into me at
Brooks. It's almost impossible for me to shoot if I haven't "looked" at the
DOF. Believe me... the split prism and other garbage in the center of the R
camera Universal Focusing screen is truly in the way. I had a couple of
R3's It goes black during DOF preview. And it's nearly black without DOF
preview with my 350 f/4.8 Telyt-R, and absolutely black using an extender.
And it disrupts one's ability to see good composition on the GG screen.
Which is why my R cameras, as well as all of my colleagues R's and other
SLR's, are all fitted with the plain GG with grid (helps keep the horizon
straight) and no warts in the center. Even my Alpa 10D has an absolutely
plain flat GG screen.

My Rolleis, Hasselblads, and view cameras did not and do not have such
interruptions. So why does Leica continue to do this? Is this because they
think that either amateur (don't know how to use a GG) or old (cannot see
to focus on a GG) photographers are the main market? Shouldn't it be the
other way around? Buy the universal screen if you have a problem focussing
on a plain GG. Maybe it's like selling a UV "protection" filter for every
lens sold at the camera store... selling Leica R purchasers a new GG
screen... just extra profit.

The above is my personal opinion, but of course, if you find the zero base
split image useful for your purposes, that's really all that counts.

Happy shooting,

Jim