Previous versions of Tariq Gibran's message #13293026 « Zeiss 35mm f1.4 ZM or Voigtlander 35mm f1.7 Ultron for Landscape with deep DOF for A7rM and A7rII »
Re: Zeiss 35mm f1.4 ZM or Voigtlander 35mm f1.7 Ultron for Landscape with deep DOF for A7rM and A7rII
Steve Spencer wrote:
A 5 or 10 percent drop or curve probably isn\'t going to matter much (and probably individual lenses vary this much anyways). A 20 or especially a 40 percent drop or curve will definitely matter, however, but you are absolutely right we need to know more about how the tests are done to draw the most useful conclusions.
The problem, particularly with comparing say that ZM 35/1.4 (at least wide open, where differences would be the greatest), is that off-axis we see a whole lot more than just a small variation based on the cover glass thickness. It is in the 20 - 40% range over more than half of the frame. That delta almost certainly shrinks as we stop down but I bet it\'s still very high between the mid-zone and borders even there with this lens.
Back to the Leica M 28 cron vs lux. The off-axis performance difference of the Lux on the SL vs Leica M240 was not so subtle. It was noticeably better on the SL in Sean Reid\'s test. Conversely, some of the more traditional M wides were noticeably worse on the SL. This does raise a question (relevant for you I suppose as I think you are considering the ZM 35/1.4 for use on the SL?) as to just how will the ZM 35/1.4 do on the SL - a lens which has been optimized for the M240. Until other evidence, I highly suspect that indeed the SL has thicker cover glass than the M240 (the differences in performance with the SL vs M240 is not about micro-lens differences for instance).
Re: Zeiss 35mm f1.4 ZM or Voigtlander 35mm f1.7 Ultron for Landscape with deep DOF for A7rM and A7rII
Steve Spencer wrote:
A 5 or 10 percent drop or curve probably isn\'t going to matter much (and probably individual lenses vary this much anyways). A 20 or especially a 40 percent drop or curve will definitely matter, however, but you are absolutely right we need to know more about how the tests are done to draw the most useful conclusions.
The problem, particularly with comparing say that ZM 35/1.4 (at least wide open, where differences would be the greatest), is that off-axis we see a whole lot more than just a small variation based on the cover glass thickness. It is in the 20 - 40% range over more than half of the frame. That delta almost certainly shrinks as we stop down but I bet it\'s still very high between the mid-zone and borders even there with this lens.
Back to the Leica M 28 cron vs lux. The off-axes performance difference of the Lux on the SL vs Leica M240 was not so subtle. It was noticeably better on the SL in Sean Reid\'s test. Conversely, some of the more traditional M wides were noticeably worse on the SL. This does raise a question (relevant for you I suppose as I think you are considering the ZM 35/1.4 for use on the SL?) as to just how will the ZM 35/1.4 do on the SL - a lens which has been optimized for the M240. Until other evidence, I highly suspect that indeed the SL has thicker cover glass than the M240 (the differences in performance with the SL vs M240 is not about micro-lens differences for instance).
Re: Zeiss 35mm f1.4 ZM or Voigtlander 35mm f1.7 Ultron for Landscape with deep DOF for A7rM and A7rII
Steve Spencer wrote:
A 5 or 10 percent drop or curve probably isn\'t going to matter much (and probably individual lenses vary this much anyways). A 20 or especially a 40 percent drop or curve will definitely matter, however, but you are absolutely right we need to know more about how the tests are done to draw the most useful conclusions.
The problem, particularly with comparing say that ZM 35/1.4 (at least wide open, where differences would be the greatest), is that off-axis we see a whole lot more than just a small variation based on the cover glass thickness. It is in the 20 - 40% range over more than half of the frame. That delta almost certainly shrinks as we stop down but I bet it\'s still very high between the mid-zone and borders even there with this lens.
Nov 17, 2015 at 11:00 AM
Previous versions of Tariq Gibran's message #13293026 « Zeiss 35mm f1.4 ZM or Voigtlander 35mm f1.7 Ultron for Landscape with deep DOF for A7rM and A7rII »
