Bronice ETR lens mount different to SQ?

Discussion in 'Medium Format' started by peter_yardley, Oct 17, 2009.

  1. can someone tell me if the bronica SQ lens series has a different mount to the ETR series lenses?
    would an SQ lens fit an an ETR and vice-versa, coverage not withstanding?
  2. No way - they are a completely different mount. I havent heard of anyone doing an adaptor.
  3. In theory it could work. If you think about it, the image circle must be big enough since it covers at least one side of the negative that is 6cm (as the Etr lenses are made for a 6x4.5cm camera). But why make or buy an (in most cases expensive) adapter when the lenses themselves are relatively cheap nowadays. I'm not aware of any adapter in existence although this would not be difficult to make.
  4. Simple answer is, use SQ lens on SQ and ETRS lens on ETRS.
  5. The image circle has to cover the diagonal and according to my numbers:
    6x4.5 diagonal is 7.5
    6x6 diagonal is 8.5
    6x7 is 9.2
    So the image circles are considerably different. Only having an SQ-a, I'm not sure what the exact mounting differences are, but it has always been my understanding the lenses will not interchange between series.
  6. If you want to be able to choose between formats you can get an SQ series camera with both 6X6 and 6X45 backs. You will want the correct focusing screen to go with the 6X45 back so you can compose correctly. There is very little difference when shooting in the 6X45 format between the image obtained with a 75mm Zenzanon on an ETR/S/Si and the one obtained with an 80mm Zenzanon on an SQ/A/Ai.

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