Originally posted by stevebrot I have contacted KatzEye regarding this and will post their response.
Steve
I got a response from Rachael Katz about an hour ago. The short answer is that there
is a decrease in contrast for the OptiBrite treated KatzEye vs. the non-treated screen. This results in somewhat less focus "snap" for the matte (ground glass) portion of the field. Below is the full text of the KatzEye response (emphasis added by me):
------------------------------
Thank you very much for your inquiry. The short answer to your question is
"yes, that is basically true". However, there is considerable nuance to the
whole reality of it. Physics does demand a certain tradeoff between
focusing acuity (sometimes called 'contrast') and brightness. A brighter
screen usually has less contrast, meaning less difference between the
appearance of in focus objects and OOF objects, as well as a less accurate
depth of field presentation. KatzEye is, alas, subject to the laws of
nature and we cannot completely avoid that tradeoff. However, since we work
in much smaller batches than the big camera makers, and because we have
proprietary processes which would be too expensive to implement in the sort
of quantities Pentax, Nikon, Canon, et al make, we are able to refine that
tradeoff quite considerably.
The net result is that the KatzEye screen,
both with and without the OptiBrite enhancement, will provide better
focusing acuity and depth of field presentation than almost all OEM screens.
So there is no tradeoff when compared to the original focusing screen. But,
when comparing strictly the two KatzEye versions, yes, brighter does mean a
bit less accurate depth of field and a little less "pop" when focusing using
the matte field. Thanks again for your interest in KatzEye Optics products
and if you have any other questions, please feel free to ask.
Best regards,
Rachael Katz, Owner
KatzEyeT Optics
Toll Free: 855-KatzEye (528-9393)
Outside USA: +1.413.743.2523
KatzEye