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Showing results for tags 'flange distance'.
Hi all, I recently did some minor tests with a handful of Super 16 zoom lenses on my BMPCC4K in the 2.6K S16 crop mode. I was finding that whilst sharping up at the longer focal lengths is no problem, when I pulled out to the wider end everything became a bit soft and I couldn't find the focus. At first I thought that it was just that the focus was so deep at the softness was part of the look of the lens but in hindsight I tested mostly at T5.6 so I'm starting to think the flange distance was just off. I have shims for my PL-MFT adapter but I didn't get the chance to try them out. Any lens specialists that know a bit more on this subject - from what I'm describing, does this just sound like a flange distance issue? And if so - how do you know if the lens needs to be closer or further away from the sensor? Obviously my shims will allow me to make minor extensions of the flange distance but I have no way of bring the back element closer. If you've made it this far, thanks for taking the time to read! Any feedback is appreciated.
I was wondering if there was any way to convert a C/Y mount to PL mount without a full rehousing. I would love to have a set of MMJ Contax Zeiss lenses in PL mount but so far I haven't seen little to any information regarding this subject. I know it's possible to convert a C/Y mount to M42 so maybe it would be possible to convert it to M2 first, then screw on an M42 to PL adapter which might work on few C/Y lenses but I know for sure the diameter of the particular Contax lenses I want would be too wide to fit inside of the adapter. And I I know It wouldn't be possible to make the flange of the PL mount adapter flush with the flange of the C/Y Mount because the flange focal distance of a C/Y mount needs to be 45.50 mm from the film plane and a PL mount needs to be 52.00mm from the film plane so in theory would need to remove 6.5mm worth of material from the rear of the lens to accommodate for the difference in FFD (Which wouldn't normally be TOO hard), however of course on majority of the C/Y lenses the aperture ring is pretty much right up against the flange of the mount. I guess I could remove the aperture ring but then what? Maybe someone has any input as to how I could possibly pull this off but I believe I've hit a dead end.