[Leica] Screen Secret

[Lucian Chis <chis@ece.orst.edu>]

Well,

According to Minolta, the secret for their AcuteMatte screens is the fact
that the microscopic surface, unlike in a regular screen, where it is
randomly shaped, in their screens it resembles tiny pyramids.
You may think of it as a microprism ring which is 100 or 1000 times finer
and it extends all over the screen.
So I would expect all of these screens to have some sort of ordered
polishing to reach the same result. And that's why NOBODY makes screens
for Minolta, as I have said previously!

Lucian 

No archive!

On Thu, 20 May 1999, Kotsinadelis, Peter (Peter) wrote:

> Jeff,
> 
> Each manufacturer has a patented process that captures and funnels light.
> THe guy at Brightscreen incidentally was once employed at Beattie, his
> process is similar but perhaps slightly improved.  I really did not get into
> the scientific reason as to why one if better than the other, but can only
> tell you the result.  Perhaps some others on the list know more of this and
> the intricate process used.  I know Maxwell was in discussion with Leica,
> and did send his screens to Germany for review.  But to date, he has
> received no response.  Right now Alpa and some other manufacturers are
> working with him and their new screens may very wellbe Hi-Lux screens.
> 
> Peter K
> 
> > ----------
> > From: 	4Season[SMTP:4Season@boulder.net]
> > Reply To: 	leica-users@mejac.palo-alto.ca.us
> > Sent: 	Wednesday, May 19, 1999 8:45 PM
> > To: 	leica-users@mejac.palo-alto.ca.us
> > Subject: 	Re: [Leica] Re:  Beattie Intenscreen for Leica R4-7
> > 
> > I've had terrific results with the Beattle screens for Rolleiflex SL66 and
> > Hasselblad--absolutely delighted with everything except the fact that not
> > even B+H seems to stock them for immediate delivery. I didn't buy an
> > Accu-Matte because my favorite full-grid pattern with no split-image or
> > microprism wasn't available. Even with the SL66 bellows racked out almost
> > fully, with the lens closed down to f/16 *and*a polarizer in use, I could
> > generally still make out details pretty good using the Beattie
> > screen--enough to gauge the effects of lens tilt. I haven't tried the
> > other
> > brands, but seem to recall paying around $125 for a Beattie, which I
> > presume
> > is far cheaper than the others. Compared to the circa-1987 stock
> > Hasselblad
> > screen, the Beattie screen is about 4 stops brighter. Of course, the stock
> > Rollei and Hasselblad screens were bad by today's standards, whereas I
> > find
> > the Leica R screens pretty good as-is.
> > 
> > What makes one viewscreen brighter than another, anyhow? I'm under the
> > impression that they present the viewer with a narrower but more
> > concentrated cone of light, but it hasn't been a problem at all on the 6x6
> > SLRs.
> > 
> > Jeff
> > 
> > -----Original Message-----
> > From: Kotsinadelis, Peter (Peter) <peterk@lucent.com>
> > >The absolute best focusing screen is also made by the same person who
> > makes
> > >the loupes.  Maxwell Precision Optics.
> > 
>