i read here that some people are verifying/checking the backfocus every morning on his red, and some check on every change of location and change of temperature. this sounds to a very broadcast style. http://www.reduser.net/forum/showthread.php?t=8899
i mean if i got a collimated prime set(all lenses on 52,000mm)
1) does somebody had problems with the variable backfocus on red? in different temperated locations or just by moving/working with the camera. so does the pl-mount from red with his variable backfocus is rock solid? is it in pre-production test once collimated(also the lenses) neccesary to collimate it every day like in broadcast? or is like normaly with filmcameras.
what ever the answer is, i know an AC must keep in mind that something could move in micrometers, innerside.
2)somebody showed me an article in the newest "TV und Filmkameramann" an article about si-2k camera.
this production which was reported about, said that if you got a collimated pl-lens prime set (all collimated to the same 52,000mm distance) you have to collimate/change the backfocus on camera everytime you change the lens.
all those lenses for analog fotocameras or cine-pl-lenses got a focus distance for filmemulsion. with digital cameras we got now a glass in front of the chip/sensor.
so what the articel says is, that with every different focal lenght lens, you would get different distances in backfocus (also if all lenses are really collimated correctly by 52,000mm).
this should happen by the glass in front of the sensor which breaks the light, so every lens with different focal lenght should get different angle to the chip.
the article said, that "digital lenses" like zeiss digiprimes(only 2/3 chip) and fotolenses for digital fotocameras got it solved, in manufacturing a more parallel light pass trough the last lens elements. so you don't have to adjust the backfocus by changing the lenses.
i don't know if i should trust this article, i mean all "digital lenses" got an backfocus adjustment on lens, not on camera. in fotolenses it doesnt sound so important, because fotographers decide the sharpness by the eye, not the printed marks on lens.
so perhaps somebody could explain me, afirm or negate me, if i have to correct my backfocus on the red-one camera by every change of lens.
a) does the variable backfockus on red-one camera is rocksolid?
b) does i get problems in different temperated locations with the backfocus?
c) does i have to correct the variable backfocus by changing a lens(if all lenses are collimated at same distance, perhaps 52,000mm)
d) does i get different flange back of the lenses because i got a glass in front of the sensor?
e):sorcerer: what would this mean for the new prime lenses from red