Lens adapters (QBM to Nikon F or Canon RF)

[Anaxagore]

Dear all, I would like to use my old QBM lenses on more recent digital cameras to which I have access (one has a Nikon F mount, the other is a Canon R series).
When googling for adapters, I see many different choices in terms of manufacturers: fotodiox, K&F, Kipon, maybe Novoflex also has some.
What would be the most reliable of all those, for each of the aforementioned mounts? Thanks in advance for any hint.

 

[abruzzi]

When adapting lenses one critical bit is the flange focal distance of the camera and the same of the adapted lens. If the host camera’s FFD it larger than the lens you’re trying to adapt the adapter will need to have additional optics to adjust the infinity point so the lens can focus to infinity. For example the Rollei QBM FFD is 44.5mm while the Nikon F is 46.5mm. So there is no way to focus to infinity if you adapt a QBM lens to Nikon F unless the adapter has it own glass.

It’s why adapting old lenses to new mirrorless cameras are so popular—as mirrorless they don’t need, and don’t have lung FFDs. The Canon RF mount is 20mm which is short enough to easily handle any old SLR lens with a glass less adapter.