Live view of prime lenses on a7II?

Diano

• 4. Oktober 2015 06:55

Camera : Sony a7II
Lenses : Vintage primes 20MM - 300mm all manual focusing lenses.

Ours is a photography class learning how to use vintage primes on mirrorless cameras.
We need a live view setup for the class.

Question:
Can Capture One display live view (focal length, f-stops, depth of field etc. and the features of the lenses, bokeh effects, for example) on PC monitor and simultaneously projected to a large screen IF THE LENSES MOUNTED ON CAMERA ARE VINTAGE MANUAL FOCUS PRIMES?

Thanks.

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  SFA

  • 4. Oktober 2015 10:01

  Capture One can only use the information provided by the camera.
  
  For your needs the camera would have to rely on information provided by the lens.
  
  It is very unlikely that the old lenses you mention will be able to provide any technical information.
  
  Using an old Prime Telephoto lens with my Canon equipment I do see a suggested lens length and default f-stop identified but only because the lens requires an adapter to fit a modern dSLR (FD to EOS mount) and the adapter is fitted with a programmable chip that provides that specific information. Nothing else is available from the lens although the camera can, or course, report ISO setting and Shutter speed. I would assume that there is some possibility that one could retrofit some sort of chip facility for a lens via an intermediate mount device to report values but I really cannot imagine this would be helpful or practical for your purpose as described, especially since an adaptive mount would likely change the lens characteristics - or worse. However I am not familiar with the world of Sony options for using old lenses so you might want to investigate that further.
  
  As for bokeh - stop the lens down (as you would probably have to to use it) and you may see the effect on screen but the video delivery of the camera for live view requirements may not offer a particularly complete impression of the end result.
  
  For a DoF estimate you would probably have to look at the lens barrel (assuming it has markings as used to be provided on old lenses) or, for a visual impression, take what you can from the live view feed when the lens is stopped down to its f-number. (That would be the equivalent of using the D-o-F preview button.)
  
  The answer to your projection question is likely to be something controlled by the computer's hardware configuration.
  
  
  HTH.
  
  
  
  Grant

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  Diano

  • 5. Oktober 2015 13:06

  "Capture One can only use the information provided by the camera.
  For your needs the camera would have to rely on information provided by the lens.
  It is very unlikely that the old lenses you mention will be able to provide any technical information."
  
  Thank you very much.
  Well explained and completely understood. We'll have to look for some other methods for teaching the class.
  
  Thanks again.

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  SFA

  • 5. Oktober 2015 14:07

  One thought occurs to me here.
  
  On older lenses one sees a lot of information marked on the barrel of the lens - basically the sort of information you are looking for so long as absolute precision of the measurement is not of primary importance (for DoF for example). In fact one of my old "Pro" grade film SLRs came with an optional adapter that would display the lens f-stop setting in the viewfinder by reading the value off the lens adjustment ring. (An interesting proposition in the dark ....)
  
  I could sort of envisage a situation where your video feed output (i.e. the projector itself?) might allow dual inputs and viewing windows such that you could take a video feed from a small camera focused on the markings on the lens barrel and display them in a second on-screen window. However that might be more technically difficult than it would be worth.
  
  I have never experimented with such a set up but I would imagine that you would probably need a high resolution projector to make a beneficial presentation of D-o-F (for example).
  
  As an alternative there are several web sites that offer interactive presentations of the sort of material you need to cover. www.cambridgeincolour.com for example is one I find most useful and refer people to for illustrated explanations.
  
  Now the point of your course is probably not well served by pointing people at web sites! However visiting the sites may give you some ideas about how you could address your needs in ways that have not yet appealed to you.
  
  See a graphical presentation of what should happen ought to make it easier for people to see what does happen when they get a chance to look at their "hands-on" experiences.
  
  HTH.
  
  
  
  Grant

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