SNIP
I've used a pellicle mirror camera. They're fragile, they suffer
mirror rot, they're so hard to clean that they make sensor cleaning
look like a snap, and they cause vertical image smear, even with
the pellicle is only a few microns thick.
SNIP
Joe
http://www.swissarmyfork.com
As you said here, in your kind response to my question about AF in
EVF only cameras:
'First, pop up a semi-transparent mirror for AF. It doesn't have to
cover the entire sensor, so it can be smaller, lighter (therefore
lower mass and less vibration) than a full SLR mirror. And it can
be closer to the sensor, to not eat up so much back focus.'
This sounds as though the same probs as with pellicle mirrors might
apply.
I'm not trying to be difficult, just interested in what you are saying
My observations on the small pop up mirror were based on personal
experiences with pellicle mirror cameras.
Canon made two autofocus pellicle mirror cameras. The EOS RT (an
EOS 630 varient) and the EOS-1n RS (an EOS 1, surprisingly) had
pop up mirrors for the AF sensor. The RT had a single, central
sensor that didn't make much demand of the mirror. The RT had
multiple sensors, but its mirror was still 1/3 the size (1/9 the
area) of a normal mirror, and with a shorter arc. Overall, you're
talking 1/8 the moment of inertia, so proportionally less
vibration. Instead of being suspended from two pivot points at the
sides of the mirror box, it comes up from the bottom, on a shaft
like a little fly swatter.
These are real "cult cameras" these days. I repaired an RS recently
for a wedding photographer, who absolutly loves seeing the flash go
off through the viewfinder. He said the flash image "burns" itself
into your retina, you get a couple od seconds of "review", sort of
like using a DSLR.
The wild thing is that I was trying to find some good pictures of
the mechanism and I came across three different reviews that
claimed the lack of mirror slap substantially improved hand holding
shutter speeds, giving them a stop of advantage. I think it may
have been a placebo effect, but that's the cool thing about hand
holding a camera: it's neuromuscular, so placebos work!
--
Salvage troll posts! When you see a thread started by a troll, post
something useful to it. It will drive the trolls up the wall.
Ciao!
Joe
http://www.swissarmyfork.com
