Close focus RF coupling

[pvdhaar]

I've been having loads of fun with my recently acquired Bessa-T. Nearly all shots are spot on with respect to focus, but noticed a couple that weren't. I could track it down to where I wanted to focus closer than about 0.9m/3ft.

Using an object placed on a ruler and checking the lens barrel markings, I could see that at just under 0.9m the rangefinder seems to disengage. I dug out the manual, but there was no mention of this.

Now here's the question (finally): does anyone know an authoritative source on the RF coupling range for the Bessa's?

 

[pvdhaar]

Ok, I think I've found it on the Japanese Cosina site: http://www.cosina.co.jp/seihin/voigt/v-camera/bessa-t/index.html

Using bablefish I could indeed deduce that RF coupling is from 0.9m to infinity.

 

[peter_n]

Peter even Leicas can be a bit dodgy at the closest focusing distance. The modern ones are supposed to go down to 0.7M but I'm not so sure about that.

 

[Doug]

I will often move the lens to its near-focus limit and then bring the subject into focus by examining the RF image in the viewfinder, then moving closer or further. When the lens can focus closer than the RF, this results in a frustrating focus error. I just ran into this with the new 28 Summicron on my CLE, which decouples at about 0.8m. 🙁 Sounds like we will regularly encounter this with ZM lenses.

 

[dougi]

The new R2As and R3As couple to 0.7m and is a handy improvement over the earlier ones which stopped around 0.9m. Note that this never seemed documented in the R2 instructions.