Jupiter 9mc

[jano]

Sorry to go askew in topic here...

Thanks Jay and Steve. I have two R lenses, 50 lux and 28 something or other here that I want to use.. and I've tried manually focusing with some of my L glass before plopping down on R-EOS, and I couldn't ever get them on focus properly with my 300d. I had read about the split screens, but then, those take away from auto-exposure ability? My leica R4 has the split screen, and I still have difficulty with it. Since I'm planning on upgrading the dribble next year to something better... I may just wait before getting the split screen on EOS?

 

[ZorkiKat]

Sorry to go askew in topic here...

I had read about the split screens, but then, those take away from auto-exposure ability? My leica R4 has the split screen, and I still have difficulty with it. Since I'm planning on upgrading the dribble next year to something better... I may just wait before getting the split screen on EOS?

The only thing lost in the conversion is the little red dots which glow in the viewfinder screen, at least with the 300/350D. Otherwise everything remains the same: AF lenses would still focus automatically, AE functions would be the same. With a non-EOS lens though, AE is limited aperture priority. Shutter priority and program modes won't work.

The focus screens are great. But I think there is something in the low-priced construction of the 300/350D which hampers the screen's full efficiency. In these cameras, the reflex mirror doesn't seem to be too accurate. Its flipping movement would make it rest at times, at slightly different positions. This sort of compromise isn't critical with AF- the EOS AF module is independent of the viewing mirror. It uses a secondary mirror behind the main one. An observation which led to this theory is that in exposures made in rapid sequences (the mirror with flip and flop in quick succession) , 3 to 4 in 10 would be out of focus, despite appearing to be correctly focused, according to the split-screen. This would suggest that the mirror isn't really returning all the time at its designated seating position.

A better alternative I think, is to use an adapter with a 'dandelion' chip which
"wakes" the camera's autofocus system. Normally, adapted, non-EOS lenses are not recognised by the camera. The chip is attached to the adapter and engages with the contacts on the camera. The camera then is 'fooled into thinking' that there is an EOS lens on manual mode mounted on it and activates the electronic rangefinder/focus confirmation LED. The chipped adapters I've seen are mostly for M42, but this may probably be available for other mount adapters as well.


Jay