What the heck is a "digital" LF lens??

Discussion in 'Large Format Cameras and Accessories' started by jovo, Mar 30, 2009.

  1. jovo

    jovo Membership Council

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    No, I don't want to start a digithread here, of course, but there are several "Digitar" lenses for sale in the Recent Classifieds, and I don't even know what they are. As I understand it, digital cameras aren't (or weren't 2 hours ago) able to easily handle the oblique angles of light from the non-central areas of the potential image. Are "digtal" lenses modified in some way that enables this to be better managed? Are such lenses equally able to perform well with film? Were I to buy one for my film camera would there be any advantage or disadvantage to the lens's effect on a traditional film set-up? Inquiring minds (with apparently too many free moments on hand) want to know! :wink:
     
  2. Sirius Glass

    Sirius Glass Subscriber

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    How about LF lenses that use fingers aka digits to make adjustments?

    Steve
     
  3. L Gebhardt

    L Gebhardt Subscriber

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    They have smaller image circles and from the looks of it the flange to infinity focus is longer than the focal length. So they are optimized for smaller sensors and try to keep the light at less oblique angles. They will work just fine on film (coverage limits apply of course).
     
  4. 2F/2F

    2F/2F Member

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    What size sensors are they made to cover with movements? The ones that are approx. 645 size, or the bigger ones that are made for LF cameras?
     
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  5. jnanian

    jnanian Advertiser

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    often times the numeric lf lenses do not have a large back element.
    very much like older wollensak lenses and ilex lenses from the 40s-70s ..
    at least that was what a sales person told me years ago ...
     
  6. L Gebhardt

    L Gebhardt Subscriber

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    I think there really is only one sized sensor and that is the 6x4.5. Actually most are slightly less than a full 6x4.5 frame. There is now one full frame sensor in I think the Phase 65mp back. Look at Badger Graphics to see the specs. Here is a 35mm Apo Sironar http://www.badgergraphic.com/store/cart.php?m=product_detail&p=1528
    They claim coverage of a 37x49mm sensor.

    I bet these things are fantastic with roll film. The longer lenses such as the 55mm should cover 6x7 with movements. I wonder if it matches the Mamiya 7.
     
  7. Tom Duffy

    Tom Duffy Member

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    These lenses offer fantastic resolution compared to "non digital" lenses. Up to 200 lines per millimeter. Comparisons in Photo Techniques show they really blow away medium format lenses using the same digital back. Not sure how many films would really take advantage of these lenses; Acros, TMax 100, Ektar 100 and Velvia, perhaps. Still a lot cheaper to shoot 8x10 color with a "normal" large format lens. The 65 megapixel backs, with a sensor size of under 6x4.5, cost over $40,000.
     
  8. keithwms

    keithwms Member

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    Since most digital sensors are in the Bayer format (which have red, green, and blue photosites at different locations), chromatic aberration can become an especially big issue, and it is important for the lenses to be apo corrected or to at least have a number of ED elements. Thus the digital LF lenses.