Lens Turbo?

Discussion in 'Adapted Lenses' started by crashwins, Jul 29, 2015.

  1. crashwins

    crashwins TalkEmount Regular

    91
    Jul 17, 2014
    Just ordered a LT version 2. Anyone have good experience with them? I saw many great pics on Flickr, which inspired me to try it out. I'm getting the FD->E-mount one. I have an FDn 50 1.4..Any other lenses I should be considering? Thanks
     
  2. shaolin95

    shaolin95 TalkEmount Top Veteran

    942
    Jul 3, 2013
    • Like Like x 3
  3. addieleman

    addieleman Passionate amateur

    Nov 13, 2012
    Netherlands
    Ad Dieleman
    Irrespective of technique, that's a great shot!
     
    • Like Like x 1
    • Agree Agree x 1
  4. crashwins

    crashwins TalkEmount Regular

    91
    Jul 17, 2014
    Indeed! Looks like I made a good choice with the purchase.
     
  5. shaolin95

    shaolin95 TalkEmount Top Veteran

    942
    Jul 3, 2013
    Thanks guys!
    And yes, I think you will be very happy with it. :)
     
  6. tillman

    tillman TalkEmount Regular

    91
    May 28, 2014
    Keizer, Oregon
    Tillman
    I've wondered but I haven't been able to find any solid answers, does the look of the bokeh change at all when using the Lens Turbo? Or would using an f2.8 lens for eample give the bokeh on a APS sensor as it does on a full frame?
     
  7. BrorSvensson

    BrorSvensson TalkEmount Regular

    106
    Feb 6, 2015
    It gives the full frame fov and dof of the lens
     
  8. tillman

    tillman TalkEmount Regular

    91
    May 28, 2014
    Keizer, Oregon
    Tillman
    So if I'm understanding properly, with the lens turbo you achieve a shallower depth of field than when using the same lens with a standard adapter on an APS sensor.
     
  9. BrorSvensson

    BrorSvensson TalkEmount Regular

    106
    Feb 6, 2015
    yes alot shallower
     
  10. Kirkp

    Kirkp TalkEmount Regular

    151
    Nov 2, 2014
    From the Metabones FAQ (a similar more expensive focal reducer):

    How does Speed Booster[emoji768] affect the depth-of-field?
    The short answer is Speed Booster[emoji768] on an APS-C sensor gives essentially the same depth-of-field effect as if a full-frame camera body were used.

    The long answer is complicated. If we are referring to depth-of-field in the mathematical sense, that depends on the aperture, magnification and circle of confusion (CoC). Magnification in turn depends on distance and focal length. The 50mm lens now becomes a 35mm lens which behaves very differently in terms of perspective. The question is, do we still keep the distance the same? Should the CoC be kept the same? There are many missing variables we need to choose and fill-in before we could get a meaningful answer. When people claim Speed Booster[emoji768] does not change the depth-of-field, they usually neglect to state the implicit assumption that the distance is kept the same (thereby changing the object size) and the CoC is kept the same. The same logic would lead to the conclusion that an APS-C camera has the same depth-of-field as a full-frame camera, too, which under the same implicit assumptions is mathematically true (the depth-of-field formula is format-size-agnostic, after all), but with which many people would disagree from practical experience.

    However, when most people ask about depth-of-field, they are not interested in mathematics, but rather, they are after a certain kind of shallow depth-of-field "look". If this is the case, the short answer above applies.

    How does Speed Booster[emoji768] affect bokeh?
    From practical experience, Speed Booster[emoji768] has negligible effect effect on bokeh. In most cases the resulting bokeh is that of the lens alone. Speed Booster[emoji768] does not leave its own "character" or "signature" in the pictures. It is very neutral.

    (http://www.metabones.com/article/of/faq)
     
    • Informative Informative x 2
  11. Kirkp

    Kirkp TalkEmount Regular

    151
    Nov 2, 2014
    Thinking about this more carefully...

    The Metabones FAQ is comparing a lens mounted on an APS-C camera with a focal reducer to the same lens mounted on a full frame camera. They claim DOF is about the same. I have no reason to doubt them.

    But the OP wants to compare to the same lens mounted on an APS-C camera, with and without the focal reducer. The Metabones FAQ suggests the answer depends on what parameters you are holding constant. I'll assume that you're focused on a fairly close subject and that you want to keep the size of the image constant, not the the distance from camera to subject. In other words, magnification is held constant. I'll also assume the lens aperture is kept wide open. Under those conditions the DOF will be much smaller with the focal reducer -- much as if you had opened the aperture by one stop.
     
    Last edited: Aug 11, 2015
  12. jai

    jai TalkEmount Top Veteran

    589
    Feb 4, 2013
    Yep that is correct.

    Put a fast legacy prime on there and you'll have more blur than you know what to do with.

    When you get bored of that, use it to get same blur as before but with the lens stopped down a stop for increased contrast and sharpness.
     
    • Like Like x 1
  13. tillman

    tillman TalkEmount Regular

    91
    May 28, 2014
    Keizer, Oregon
    Tillman
    That's what I'm interested in, f1.8 on APS looks good to me when I'm trying to isolate my subject, but being able to achieve that same look while getting more performance out of my lens is really interesting.
     
  14. jai

    jai TalkEmount Top Veteran

    589
    Feb 4, 2013
    There is an even more subtle effect, hard to pin down at first. Things look a bit bigger.

    And I mean even while taking up the same amount of space in the frame, they look bigger. It is what people mean when they say full frame "look".

    If you have a 24mm with a standard adapter vs a 35mm with a speed booster, same distance, your subject is roughly the same size. But on the 35mm the subject feels bigger but further away. On the 24mm lens the subject feels smaller but closer.
     
    Last edited: Aug 12, 2015
  15. tillman

    tillman TalkEmount Regular

    91
    May 28, 2014
    Keizer, Oregon
    Tillman
    I'm considering buying a Lens Turbo, I'm a bit undecided on which mount to get. The legacy lenses I have are M42 so I can adapt those to practically any mount, but I think I might like to try some Minolta MD and Canon FD lenses. EF seems pretty adaptable but I don't think there is a glassless adapter offered to fit these two mounts to it, so it seems like I need to pick one or the other?
     
  16. jai

    jai TalkEmount Top Veteran

    589
    Feb 4, 2013
    I have the Minolta MD version, which I also use with M42 mount lenses. The MD to M42 adapters are good because they screw in nice and firm, no play. Super cheap too.

    I would think either Minolta MD (SR) or Canon FD are your best choices
     
  17. Kirkp

    Kirkp TalkEmount Regular

    151
    Nov 2, 2014
    I have the Minolta version, but was disappointed that some of mid and shorter focal length Rokkors won't work with it because the back of the lens hits the Lens Turbo glass when focused to infinity. Others need a bit of the aperture preset pin filed off. For example, my 50mm f/1.4 and 28mm f/3.5 have problems with it. All of my longer focal lengths work great with it. One of these days I'll make a list of the lenses I have that do and don't work with it.
     
  18. tillman

    tillman TalkEmount Regular

    91
    May 28, 2014
    Keizer, Oregon
    Tillman
    Anyone have any input on the FD mount version using FD lenses as well as with a M42 adapter?
     
  19. Sympa

    Sympa TalkEmount Rookie

    15
    Sep 19, 2015
    I just got my Lens Turbo II in EF mount. For EF, it is easy to find adapters, but Minolta and FD cannot be fitted. I must say it works very nicely. But my 300mm and 500mm lenses show quite hard vignetting in the corners. I suppose that is because the rays enter the LT from a point very far in front of the camera. My Pentax K to EF adapter fits very snugly, but my M42 to EF is way too loose: it rattles.