Comparison: APS-C with Speed Booster VS Full Frame


sb test

image courtesy: eoshd

Both of these shots were taken with the same lens at 24mm. One is not a full frame camera! ” (NEX-7 top / Canon 5D Mark III bottom. Lens: Sigma 24mm F1.8)

So, eoshd started his Speed Booster testings. Almost identical field of view! “The Speed Boost effect on aperture is highly evident too. On the NEX 7 the camera reports the maximum aperture as F1.3 and it is certainly brighter.” Also the “depth of field is as shallow on the NEX 7 as the 5D Mark III despite the difference in sensor size.

Do we really need a Fuji Full Frame now? At the end of his post eoshd says: “This is a groundbreaking product for photographers and cinematographers alike.” Just click here (eoshd website) to read much more and see more comparison pics!

In another post he explained how the Speed Booster works: “If your sensor is smaller than full frame, shrink the image that the lens throws to fit over it. That is the principal behind the Metabones Speed Booster which essentially gives you the full frame look and a brighter image all at once…” He says, among the others, that with this adapter:

  • A 24mm wide angle like the Canon 24mm F1.4L becomes a 24mm wide angle on the FS100, with the same shallow DOF and field of view as on the 5D Mark III
  • A F1.2 aperture on a Canon lens becomes F0.90, a significant 1 stop brighter image in low light
  • Depth of field becomes shallower – the same as it would be on full frame

Read the whole text here.

Metabones Press Release:

Petersburg, VA, USA, January 14, 2013 – Metabones® and Caldwell Photographic jointly announce a revolutionary accessory called Speed Booster™, which mounts between a mirrorless camera and a SLR lens. It increases maximum aperture by 1 stop (hence its name), increases MTF and has a focal length multiplier of 0.71x. For example, the Canon EF 85mm f/1.2L II lens becomes a 59mm f/0.9 lens on a Sony NEX camera, with increased sharpness. The faster F-stop allows for shallow depth-of-field and a lower ISO setting for decreased noise.

Speed Booster is also particularly pertinent to ultra-wide-angle SLR lenses. The combined focal length multiplier of Speed Booster and an APS-C mirrorless camera is approximately 1.09x, making the combination almost “full-frame”. Full-frame ultra-wide-angle SLR lenses largely retain their angle-of-view on an APS-C mirrorless camera when Speed Booster is used.

The optics of Speed Booster is designed by Brian Caldwell, PhD, a veteran of highly-corrected lens designs such as the Coastal Optics 60mm f/4 UV-VIS-IR APO Macro lens with exemplary MTF performance (focusing done with visible light requires no correction whatsoever for the full spectrum from UV to IR).

Speed Booster serves double-duty as a lens mount adapter, from Canon EF lens (but not EF-S) to Sony NEX, with auto-aperture, image stablization, EXIF and (slow) autofocus support for late-model (post-2006) Canon-brand lenses. It will be available in January 2013 from Metabones’ web site and its worldwide dealer network for US$599 plus shipping and applicable taxes and duties.

Other mount combinations will follow shortly afterwards. Leica R, ALPA, Contarex, Contax C/Y and Nikon F (with aperture control for G lenses) will be supported, as will Micro 4/3 and Fuji X-mount cameras. Support for other mounts will be added in the future.

  • Thomas

    Amazing! I want one!

  • Gaffman

    Just awesome. The extra stop of light, the wider field of view… a proper adapted Tilt Shift is now possible… just for a start.

    Pwoar!!! good time to be a crop sensor shooter :)

  • Scott

    I hope the AF will work can get passed on. It would be grand If my Canon EOS 300mm f4 L IS would work with my XE1 Looking like a 300 f 2.8 ! But only if the AF works. If not may as well just shoot my Canon FD 300F4 and save the cash.

    • Bob

      I believe it would make your lens look like a 200mm f 2.8.

      • Eric Duminil

        Well, it would be like a 200mm f/2.8 on an APS-C sensor, which is like a 300mm f/4 on a Full-frame sensor :D

  • Some dude

    I’m excited as the next guy, but this will require Manual Focus I’m guessing. OK for landscapes and such but FF will be better for action.

    Great product with great potential.

  • me

    so why they don’t build this into lenses as standard?

    • Alex Watanabe

      They do, see the FT 15-35 f2 and 35-100 f2 olympus lenses.

      for most crop sensor cameras they rather make the lenses smaller/brighter for the required image circle.

  • Peter

    Am I the only one who thinks that the “native” full-frame 24mm is noticeable wider than with the Speed Booster?

    • hexx

      it depends how you define ‘noticeable’ ;) it’s a bit wider in my books of description of these two words, ‘noticeable’ and ‘a bit’.

    • Anon

      Speedbooster has a 1.09 crop effect on APS-C images so, much better than 1.5x but still you are going to lose some width.

  • hexx

    almost just bought Leica Elmarit-R 90mm f/2.8 lens. but then I was thinkinging… lens £390, adapter £350, weight 475g + 200g(?) OR Fuji XF 60mm f/2.4 for £489 and weighing 225g – well, I guess I know the answer

    • olbez

      Yep, I am in the same boat. Plus AF will still work.

  • Roger

    Any word on when the Speed Booster for Leica M lenses to Fuji x will become available. The Leica R to Fuji x is said to ship later this week. The size and range of the M lens seems to be a better match for the Fuji.

    • Anon

      Metabones has said that M and Contax G lenses will NOT be supported – not enough room behind the optics.

  • rUY

    Resolution decrease and details lost. I think the lens adapter overcharge and not as excited as expect.

    • klehmann

      Is this based on pure speculation or something You know by actually using one of the adapters? If the former, its really not adding anything meaningfull but if the later it would be very interesting if You could substantiate with ‘hard evidence’ namely images to back up Your statement…

      • GreenLens

        Common, it’s easy: gimme brick wall shots, on a tripod, and let me decide myself!

      • ruy

        When you look at both picture what did you see? they are identical? they are very different in my eyes. even the photo was so small, it still able to tell th difference. if you can’t, I have nothing to say.

    • hexx

      actually it’s the other way around, this isn’t teleconverter, with reducer you get increase in resolution and therefore better MFT (just think before you post such a drivel)

      • klehmann

        hi hexx,

        exactly my thoughts! also what the caldwell-guy+metabones mentions: the increase in mft as opposed to decrease in resolution…?

        but some people tend to get easily heated upl and so many are oh so very clever… this is directed toward the ruy-fella….”if you can’t i have nothing to say”: – thats exactly the kind of remarks that i’m referring to – amazing how people act when tugged away somewhere behind their lcd-screens – lol…oh, well….

    • klehmann

      heres a short excerpt of a walkthorough of the adapter:

      “MTF gain — the “compression” effect of the focal length reducer also tends to reduce the size of aberrations, which are a primary driver of MTF. Metabones uses a Nikkor 50mm f/1.2 as their example for plotting the lens’ normal MTF versus with use of the SpeedBooster, and there’s indeed a clear MTF boost in the central area on an m4/3 version of the adapter. The NEX version, however, shows more MTF loss as you move to the corners (the center is still higher than the original lens). The MTF gain claim is a little less reliable than the other claims: there’s going to be high variability in the size and position of the gains depending upon the lens used and the format you’re adapting to.”

      this kind of makes it a not-so-clear cut case since depending on system/lens used resolution increases on center but also decreases in the corners – again depending on your needs this can be a big no-go but could equally be something that would mean nothing to you in practical use.


      • klehmann

        whoopps: small additional info: this quote was taken from… – just to mention in all fairness.

        • Hendrick

          Regarding the MTF performance, metabones has a white paper on it. If you see the graphs, the center performance is increased (sharper) but the mid-edge and corner performance is considerably decreased. You need to read the graphs published by them. The ‘improved sharpness’ statement is only valid in the very centre.

          Using the normal lens with an adapter (non speed booster) gives you an average centre, average mid – corner sharpness. Using the speed booster, it gives you a great centre, but worse than average mid-corner performance.

          Look it up, you will see.

          • klehmann

            hi hendrick,

            i did actually read the mb whitepaper before even reading any of the comments in this section – minimum requirements i figured;o) – and i also agree to some of the other online commenters in general that sometimes new ‘magical stuff’ comes around with almost-too-good-to-be-true promises.. but lets see… perhaps in certain scenarios it will make sense to some individual..


          • Hendrick


            Apologies, it wasn’t a reply to you, but rather to the others who appear to speculate either ‘it will be better’ or ‘it will be worse’ in a rather totalitarian thought (either or, but not in between)

            I like that the centre sharpness is considerably better, but I am not sure if I can live with the considerably worse edges. I like even performance.

          • klehmann

            Hi Hendrick,

            No worries;o) And btw. I also like ‘even’ performance on my glass in most cases… I struggle plenty already using a 50mm f1.5 Sonnar via adapter already as it is on my XPro… (tried both brand and off-brand adapters but somehow corners suffer all the same).

            And we can also easily agree on this crude either/or-mentality. Strange stuff…


  • Wilson

    It sounds exciting! If everything really works as claimed that’s going to be big.

    By reading the review, it leads to think how much advantage FF sensors still has against the APS-C ones. With an FF lens and adapter on an APS-C camera, it achieves the similar FOV and DOF when an FF lens on an FF camera. Additionally with 1 stop advantage in aperture, it compensate 1 stop in high ISO. However FF sensor will still have advantages on the total number of pixels and potentially low pixel density due to the physical sensor size.

    Anyway that’s a really interesting product.

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