My article on the C-Sonnar 50/1.5 and Focus Shift on "Theme"

Discussion in 'Leica News and Rumors' started by Brian, Jun 26, 2013.

  1. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    I've put together an article on the C-Sonnar 50/1.5 and an attempt of an explanation for focus shift, and it has been published on "Theme".

    Lesson in History: The Magic of the “Value for Moneyâ€￾ Zeiss C-Sonnar 50mm F1.5 | THEME


    Theme is an online "Photography Daily", and is a nice complement to discussion forums. Interesting articles and photographic news of the day. this is the second article of mine that has been published. The editor has also placed a link back to Leicaplace at the end of the article.
     
  2. CaptZoom

    CaptZoom Leica Place Regular

    56
    Apr 11, 2013
    Thanks for sharing and explaining the Sonnar.
     
  3. Amin

    Amin Administrator

    399
    Mar 28, 2013
    Excellent article, Brian. I've always liked the character of that lens. Is it true that given focus shift, Zeiss optimizes the lens for perfect focus at f/2.8?
     
  4. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    Zeiss optimizes the newer lenses for F1.5, I think the switch-over was 2007. The issue on recent lenses is Film vs digital. Film does not lay flat, so the lens maker has to make assumptions for film curvature, and Zeiss used the measurement for their cameras. It will most likely front-focus slightly on an M9, mine did. On the M Monochrom, with a yellow or orange filter: perfect at F1.5.
     
  5. CaptZoom

    CaptZoom Leica Place Regular

    56
    Apr 11, 2013
    Huff reviewed the lens a couple of months ago. His copy was not optimized for f/1.5.

    Ziess will optimize the lens for f/1.5 or f/2.8 (or whatever aperture you choose). You just have to send the lens in and pay a nominal fee.
     
  6. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
  7. CaptZoom

    CaptZoom Leica Place Regular

    56
    Apr 11, 2013
    That's a reasonable explanation, though I don't think it's a complete explanation. Regardless, it's noted in the PopFlash link that Ziess can calibrate the lens to the specs desired by the customer.
     
  8. trisberg

    trisberg Leica Place Rookie

    17
    Mar 30, 2013
    Mine is optimized at 2.8 and I'm debating whether to send it together with my M9 to DAG and have it calibrated for optimal focus at 1.5. Would be nice to be able to shoot wide open without worrying about focus shift.

    -Thomas
     
  9. CaptZoom

    CaptZoom Leica Place Regular

    56
    Apr 11, 2013
    It will become a f/1.5 lens, as the shift will still occur (just further down the aperture scale). I trust you have other 50s that you like for narrow aperture work.
     
  10. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    I have a lot of Sonnars...and calibrated most of the vintage ones myself, most are set at F1.5. When using stopped down, either focus and then move the focus ring towards infinity "just enough" to get a "sliver" of a split in the RF image. Practice on something like a fence post.
     
  11. trisberg

    trisberg Leica Place Rookie

    17
    Mar 30, 2013
    I've been using the "focus and then lean forward a few inches" technique when shooting my 2.8 optimized lens at 1.5. While it sort of works, it would be nice to feel confident that I nailed focus when shooting wide open. If I have the lens re-calibrated for 1.5 I'll probably end up using it wide open or stopped down to 5.6 or 8 most of the time. Hopefully the depth of field will cover the focus errors at f8.

    -Thomas
     
  12. asiafish

    asiafish Leica Place All-Pro

    Aug 9, 2013
    Bakersfield, CA
    Andrew
    Mine (Jupiter 3) is optimized for f/1.5 and that is where I shoot it 90% of the time. I'll go so far as to put an ND filter on top of the yellow or orange to keep it wide-open, not for focus, but because I am a bokeh fanatic and NOTHING can match that Sonnar bokeh.

    When I do stop down (not every shot is ideal for narrow depth of field) I tend to skip right to f/4 where focus shift just isn't a problem on my lens. f/2 to f/2.8 is where I need to use Brian's technique and nudge the focus a bit.
     
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  13. asiafish

    asiafish Leica Place All-Pro

    Aug 9, 2013
    Bakersfield, CA
    Andrew
    Just paid for my C Sonnar today, yippie for me! This will bring my M mount lens arsenal to seven, three of which are 50mm and two of those being Sonnars.

    Hopefully, this will end my GAS for a long while, at least until I get my end-of-year bonus and start looking for another M8.2 or one of the new full-frame Sony A7 twins.
     
  14. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    50'S ARE ADDICTIVE...

    I have Twelve 50mm F1.5 Sonnar formula lenses in LTM mount alone...from 1934 through to the C-Sonnar...
     
  15. asiafish

    asiafish Leica Place All-Pro

    Aug 9, 2013
    Bakersfield, CA
    Andrew
    Actually I've been thinking about your suggestion of a 10.5 cm Nikkor tuned for my Monochrom. Won't have any money for another month though. That, or a vintage 3.5 cm. Would be nice to have a whole set of vintage glass.
     
  16. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    The Vintage Wide-Angle lenses are out-classed by the 35/1.7 Ultron and about the same price: wide-angle lenses are more complex than Telephoto lenses.

    Go for the 10.5cm F2.5- Sharp enough to push the limits of the M Monochrom, and beautiful rendering that would run much more in a modern lens.
     
  17. asiafish

    asiafish Leica Place All-Pro

    Aug 9, 2013
    Bakersfield, CA
    Andrew
    Is any "tuning" required, or do they just work? Wjere should I look to get one?

    UPS says my C Sonnar arrives today, hopefully I'll get a chance to play with it a bit this weekend.
     
  18. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    On the 10.5cm F2.5 Nikkor: mine is perfect on the M Monochrom; manufacturers all make assumptions about how film sat in the chamber- Nikon must have assumed that is was flat.

    The lens can be shimmed, or a slight back-focus can be corrected with a layer of copper tape on the RF cam. Mine- no adjustment necessary.