Focusing Screen R9

[ryee3]

Advertisement (gone after registration)

I was wondering why one of the split rings on the focusing screen of the R9/DMR is sometimes so dark that the split images can not be easily focused through the viewfinder. This occurs even during the middle of the day in bright sunlight. Are there ways to minimize this occurrence?

[pop]

Speaking from experience with similar devices, I would think that the brightness depends on (a) the focal length and aperture being used and ( the angle under which the eye sees the prisms on the focusing screen, Does the brightness change when you tilt the camera slightly in front of your eye? Is the focusing screen rated for the focal lens and aperture you are using it with?

[masjah]

Speaking from experience with similar devices, I would think that the brightness depends on (a) the focal length and aperture being used and ( the angle under which the eye sees the prisms on the focusing screen, Does the brightness change when you tilt the camera slightly in front of your eye? Is the focusing screen rated for the focal lens and aperture you are using it with?

 

Likely to be ( - you are looking through a wide open aperture and you say the light is good. Try moving your view slightly left and right. If you are looking too far off centre, either the top or the bottom semicircle may black out.

[psquared]

This usually happens at f/5.6 or smaller. So, if you're using a long telephoto lens, this phenomenon would happen even wide open, if the maximum aperture is f/5.6 or smaller. The same goes for microprism focusing aids as well. I stick with matte focusing screen for this reason, as I use long telephotos often.