dtcls100
Well-known
I have been itching to try my extensive OM Zuiko lens collection on digital. I understand that the best full frame digital cameras for using such lenses appear to be Canon's full frame bodies or one of the Sony A7 type camera bodies, because with those cameras' short register distances, you can use the Zuikos with a glassless adapter, thus supposedly avoiding image degradation caused by extra adapter glass.
However, I don't have a full frame Canon or Sony A7 series body. I do have a Nikon d750, modified with a custom K3 type split image microprism/split image focusing screen. With this screen, the camera focuses very accurately with Nikon AIS manual focus lenses and works perfectly with the Nikon AF f2.8 lenses I have (17-35, 28-70, and 70-200 VRII). Used with the native Nikon lenses, the viewfinder and live view focus pretty much agree on my d750.
To use the OM Zuikos on the d750, requires an adapter with glass in it to achieve infinity focus. I ended up buying a Fotodiox Pro OM-Nikon adapter (about $40). It is very nicely and solidly made and it mounts onto the Nikon body and OM lenses smoothly and solidly with no play. Unfortunately, using the d750 viewfinder and focusing screen (also using focus confirmation) to focus yielded hazy, soft-focus images with lots of spherical and chromatic aberrations (possibly useful for women's portraits). I initially believed that this image degradation was due to the glass elements in the adapter, consistent with popular belief. However, before returning the adapter, I tried focusing the Zuikos using the d750's live view and magnification functions. Used this way, the adapter yielded surprisingly sharp images with the lenses shot wide open, which images became sharper as the lenses were stopped down.
Comparing the live view focus point against the viewfinder's focus point (and focus confirmation point) -- with the d750 mounted on a tripod -- revealed that the viewfinder was backfocusing with the Fotodiox adapter about six inches to one foot compared to the live view. Interestingly, using live view, one can see what appears to be spherical and chromatic aberrations greatly diminish as the subject matter comes into critical focus.
So, contrary to what goes for general knowledge, it appears that most of the image quality degradation that comes from using this adapter with additional glass elements isn't so much from the additional glass itself per se (although it may play some role), but rather from the fact that those additional glass elements appear to cause a decided focus shift.
One last point: some superwide OM Zuikos (like the 18mm) will not mount on the Fotodiox Pro adapter, possibly because of the rear baffle on such lenses.
However, I don't have a full frame Canon or Sony A7 series body. I do have a Nikon d750, modified with a custom K3 type split image microprism/split image focusing screen. With this screen, the camera focuses very accurately with Nikon AIS manual focus lenses and works perfectly with the Nikon AF f2.8 lenses I have (17-35, 28-70, and 70-200 VRII). Used with the native Nikon lenses, the viewfinder and live view focus pretty much agree on my d750.
To use the OM Zuikos on the d750, requires an adapter with glass in it to achieve infinity focus. I ended up buying a Fotodiox Pro OM-Nikon adapter (about $40). It is very nicely and solidly made and it mounts onto the Nikon body and OM lenses smoothly and solidly with no play. Unfortunately, using the d750 viewfinder and focusing screen (also using focus confirmation) to focus yielded hazy, soft-focus images with lots of spherical and chromatic aberrations (possibly useful for women's portraits). I initially believed that this image degradation was due to the glass elements in the adapter, consistent with popular belief. However, before returning the adapter, I tried focusing the Zuikos using the d750's live view and magnification functions. Used this way, the adapter yielded surprisingly sharp images with the lenses shot wide open, which images became sharper as the lenses were stopped down.
Comparing the live view focus point against the viewfinder's focus point (and focus confirmation point) -- with the d750 mounted on a tripod -- revealed that the viewfinder was backfocusing with the Fotodiox adapter about six inches to one foot compared to the live view. Interestingly, using live view, one can see what appears to be spherical and chromatic aberrations greatly diminish as the subject matter comes into critical focus.
So, contrary to what goes for general knowledge, it appears that most of the image quality degradation that comes from using this adapter with additional glass elements isn't so much from the additional glass itself per se (although it may play some role), but rather from the fact that those additional glass elements appear to cause a decided focus shift.
One last point: some superwide OM Zuikos (like the 18mm) will not mount on the Fotodiox Pro adapter, possibly because of the rear baffle on such lenses.