1. Reminder: Please use our affiliate links for holiday shopping!

Fun Fact: Speedbooster with Four Thirds Glass

Discussion in 'Adapted Lenses' started by MAubrey, Jul 29, 2013.

  1. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    Out of curiosity, I did a bit of free lensing using the Nikon G - μ43 Speedbooster with lenses that have a shorter register distance than Nikon just to see what works.

    Here's a fun fact: High Grade Olympus Four Thirds lenses have a large enough image circle to be used with the speedbooster without vignetting. Or, at least one does: the 50-200mm SWD.

    At 50mm f/2.8 (SB = 35mm f/2):
    _7280082.

    With the short register distance, this is the farthest away I could focus at 50mm, but as you can see, vignetting isn't a problem at all.

    At 200mm f/3.5 (SB = 142mm f/2.5):
    _7250021.

    Again, no vignetting problems here either. At this focal length, I could focus several meters. Both images are very sharp, too.

    So now I'm wondering...would a 25-70mm f/1.4 (35-100 f/2) be possible?
     
  2. nstelemark

    nstelemark Mu-43 Hall of Famer

    May 28, 2013
    Halifax, Nova Scotia Canada
    Larry
    Wow - cool.
     
  3. flash

    flash Mu-43 Hall of Famer

    Apr 29, 2010
    1 hour from Sydney Australia.
    Gordon
    the optical design of the 35-100 f2 already includes a speedbooster like group. it might works. but it would be like stacking speedboosters.......

    Gordon
     
  4. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    This is true. But all that really matters is whether there's enough image circle left over--especially considering how incredibly well corrected the group that exists in the 35-100mm is. Considering the general lack of vignetting on the 35-100mm, I'd bet that there is.

    I could also imagine a 60-180mm f/2 zoom (90-250mm)...
     
  5. pen2omd

    pen2omd Mu-43 Regular

    46
    Jul 29, 2013
    California
    Out of curiosity, how do you attach the FT lenses to the Nikon G speedbooster?
    I know adapter Nikon to FT but not FT to Nikon.
     
  6. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    "Free lensing" involving holding a lens with your head unattached in front of the sensor. Some photographers use the technique to achieve tilt/shift effects. So the answer is that I didn't attach it, I just held it in front of the adapter.
     
  7. pen2omd

    pen2omd Mu-43 Regular

    46
    Jul 29, 2013
    California
    That what I thought initially, but as all my FT lenses are MF by wire, without any contact I cannot focus the lenses.
    So you focus by moving the lenses away or closer to the camera+speedbooster?

    I would have to give a try. I initially got the speedbooster for a Nikkor AIS 105mm and AI 180mm
     
  8. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    Ah, I see what you're saying. Lenses with SWD motors have mechanical focus rings, which allowed me to do this. It also means that for the vast majority of other lenses, speedbooster remains a hypothetical...unless some enterprising person decided to risk blowing $600 on merging a speedbooster with an electronic four thirds adapter...
     
    • Like Like x 1
  9. RobWatson

    RobWatson Mu-43 Hall of Famer

    Me chuckle lots ...
     
  10. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    I'm here all week.
     
    • Like Like x 1
  11. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    Thanks for doing this. I'm not too surprised - I recall somebody on DPR tried several 4/3 lenses on Canon FF bodies and found only minimal vignetting, so a 0.71x WA converter doesn't seem like a huge stretch.

    The video folks are the ones who are still crazy for fast 4/3 lenses (or at least they used to be), so I suspect that if the optics do indeed work out, somebody will try it eventually...
     
  12. pen2omd

    pen2omd Mu-43 Regular

    46
    Jul 29, 2013
    California
    Zuiko FT 150mm on the Sony A7r

    I did a little experiment this morning. I put a Zuiko FT 150mm on a E-mount A7r (Kipon adapter).
    Being a mechanical adapter I could neither focus nor change the aperture.
    I set up the lens to its minimal focusing distance with a m43 body and shoot wide open on the sony full frame:

    Straight out of the camera no cropping...

    <a href="http://www.flickr.com/photos/82954450@N05/11421849856/" title="Fall Color by cdg2lax, on Flickr">"1024" height="683" alt="Fall Color"></a>

    Surprise the 150mm is full frame capable!
    Now I have to compare that with the E-M1 75mm combo at f/2.0...
     
  13. While the 150/2 (above) apparently works on a larger sensor, I would be careful in assuming from free-lensing that other lenses will to. The inability to focus to infinity means that the lens is being held beyond it's normal register distance. Unless the lens is totally telecentric, this means that it will create a larger than normal image circle at the sensor plane. This is how macro lenses usually work at their closest focusing distances, and also why their light transmission reduces as you focus closer.
     
  14. pen2omd

    pen2omd Mu-43 Regular

    46
    Jul 29, 2013
    California
    Indeed I tested the 14-35mm -> APSC same for the 35-100mm.
    The 14-35mm with 1.4x converter vignette less than the 14-35 alone.
    With the ability to mechanicaly focus the 14-35 is useable (Albeit always wide open) on the A7r in APSC mode.
    The 7-14mm f/4.0 just cover a FT sensor at 7mm and cover a FF sensor at 14mm...