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11-29-2015, 11:34 PM   #16
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I tested deeper, no impact on metering at all, I don't have any AF lens ATM but will soon have a K-5 II with a 18-55 AF, but as an engineer I'm pretty shure that centered AF should be very accurate, as the center disk is cristal clear (no mate) and the slicing should improve AF process (based on small image sample sharpness analysis algorithms if I'm right), but other not centered AF could be altered as the mate zone of this screen is more granular than on the genuine screen.

12-01-2015, 06:46 PM   #17
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QuoteOriginally posted by bygp Quote
I tested deeper, no impact on metering at all
Spot metering is what suffers when focus aides at center are present. KatzEye found 0.6 EV overexposure with f/2.8 maximum aperture increasing to 2.5 EV at f/8. Matrix and Center-weighted modes are minimally impacted.


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12-01-2015, 06:48 PM - 1 Like   #18
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QuoteOriginally posted by bygp Quote
the slicing should improve AF process (based on small image sample sharpness analysis algorithms if I'm right), but other not centered AF could be altered as the mate zone of this screen is more granular than on the genuine screen.
The focus screen does not affect the AF system or manual focus confirm. That is done using a separate light path with the sensor at the bottom of the mirror box.


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12-01-2015, 07:00 PM   #19
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QuoteOriginally posted by stevebrot Quote
The focus screen does not affect the AF system or manual focus confirm. That is done using a separate light path with the sensor at the bottom of the mirror box.


Steve
Thanks a lot, this is a very precious tech. information

So if only metering may be affected, in this situation it does not seem to be, at least in daylight situations, in low light, it appears in Av mode that the camera often choose 1/8s when it can easily hold 1/20s but I'm not sure if this is due to the screen, I noticed that already with the genuine screen...

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