FAQ

Future Speed Boosters®

  • When will Fuji X-mount be supported?

    Speed Boosters for ALPA, Canon FD, Contarex, Contax/Yashica, Leica R, Minolta MD and Nikon lenses on Fuji X series of interchangeable lens mirrorless cameras are available right now. Rollei QBM and other mounts are in the works.

  • When will EOS M be supported?

    We are looking into the Canon EF-M (EOS M) mount right now but we are not ready to disclose the details of our product plan yet.

  • When will m4/3 cameras be supported?

    Speed Boosters® for m4/3 cameras are currently available for Canon FD, Contax/Yashica, Leica R, Minolta MD and Nikon G lenses. Support for Contarex, ALPA, Rollei QBM and Canon EF (but not EF-S) are planned in the future, but we do not have an estimated date yet.

    The m4/3 version also reduces focal length by a 0.71x factor. So, the combined focal length multiplier of a m4/3 camera and Speed Booster is 1.4x. (2x from camera x 0.71x from Speed Booster.) The optics are optimized for the smaller sensor size.

  • I want to use my Leica M, Contax G, Contax rangefinder and Nikon rangefinder lenses on Speed Booster®!!!

    Sorry folks, but there is not enough room for the optics. An SLR lens is required, such as Leica R or Contax C/Y. Rangefinder lenses won't work.

  • Will there be Speed Boosters® for M42 and Pentax K?

    We will be looking into M42 and Pentax K in the future. We do not have an estimated date yet. Disclaimer: this shall not be construed as a commitment to ship - we are not done prototyping any of these yet but we will conduct testing to decide if these lenses are free of interference issues with the optics of the Speed Boosters® before we will be able to turn them into actual products.

  • Will there be Speed Boosters® for DSLR camera bodies?

    No. The mirror gets in the way but there is no room for the optics.

  • Will Samsung NX cameras be supported?

    No. Unfortunately, it is not possible to fit the optics inside the Samsung NX mount owing to flange distance and physical interference issues.

Technical questions about Speed Booster®

  • Why don't we have a 0.5x MFT Speed Booster®?

    The MFT Speed Booster® reduces focal length by 0.71x times. The overriding design priority of the MFT version is optical quality, which is higher than the NEX version. With the amount of available room prescribed by the MFT mount, 0.71x is the sweet spot, the lowest we can go without compromising image quality.

  • Does Speed Booster® for Nikon G lens work with Nikon F lens?

    Yes! Nikon G supports not only Nikon G lenses, but Nikon F mount lenses, too, including non-AI, AI, AI-S, AF, AF-D, AF-I, AF-S, etc., etc.

  • Do the aperture rings on some Speed Boosters® have click stops?

    Contarex and Nikon G Speed Boosters® have integral aperture rings to adjust the aperture of the lens. The aperture ring on Contarex Speed Booster® has no click-stops.

    Since September 2013, Nikon G Speed Boosters® are shipped with no click-stops, with optional parts included to convert it clicked operation. Cinematographers who purchased the first batch of Nikon G Speed Boosters® may contact Metabones for conversion to clickless operation.

  • How does Speed Booster® affect the depth-of-field?

    The short answer is Speed Booster® 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® 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® affect bokeh?

    From practical experience, Speed Booster® has no or negligible effect effect on bokeh. In most cases the resulting bokeh is that of the lens alone. Speed Booster® does not leave its own "character" or "signature" in the pictures. It is very neutral.

  • Why is there so much confusion about all these focal length multipliers?

    "Equivalence" has always been a confusing topic. Speed Booster™ does not make it any more confusing than it already is!

    Focal length, maximum aperture and depth-of-field are physical quantities that do not care about the size of the sensor sitting behind the lens. Speed Booster™ physically reduces focal length and increases maximum aperture (smaller f-number) of the lens.

    The "35mm equivalent focal length" is not a focal length at all, but a measure of field of view (FoV). Speed Booster™ physically reduce focal length by a factor of 0.71x and the APS-C camera body reduces FoV by a "cropped factor" of approx 1.52x, so the 35mm equivalent focal length (cannot be overemphasized this ia a FoV measure) of the combined system is approximately 1.08x.

    Once we are very specific about whether we are referring to a physical quantity or a 35mm equivalent measure, it is no longer confusing!

  • Does the Speed Booster® increase only T-stop of the lens leaving F-stop unchanged?

    This is one of the common misconceptions about the Speed Booster®. However there is a contradiction right within that assertion since T-stop cannot be any faster than F-stop. It is not possible to experimentally observe a T-stop increase unless the lens has a corresponding F-stop increase.

    The logic of the allegation is that since the depth-of-field of the lens does not change, therefore neither does the F-stop of the lens (untrue). What had never been under any dispute was that the T-stop of the lens did increase, as could be seen with the increased exposure in the resulting footage or photograph.

    Before we clear up this misconception, let's find out why there is so much confusion in the first place. Focal length, maximum aperture and depth-of-field are physical quantities that are independent of sensor size. These quantities do not care whether a full frame, APS-C or m4/3 sensor sits behind the lens.

    Speed Booster® makes the focal length 0.7x shorter. F-number is simply focal length divided by entrance pupil diameter. Since the former reduces by a factor of 0.7x but the latter remains the same, F-number also becomes 0.7x smaller, or one stop faster. The F-stop increase is real.

    Note that a 35/1.0 lens (from 50/1.4 + Speed Booster®) will always have shallower depth-of-field than a straight 35/1.4 lens at any given distance.

Compatibility (Canon EF lens)

  • Is my Speed Booster® or Smart Adapter™ compatible with full-frame camera bodies?

    Smart Adapter™ I, Smart Adapter™ II and Speed Booster® are NOT compatible with NEX full-frame camera bodies. If the full-frame camera body is configured to auto-crop mode, cropping will be automatically applied and only the center of the frame will be used.

    Smart Adapter™ III/IV has a large rectangular opening and is compatible with full frame camera bodies. It will detect whether the Canon lens used is a full frame lens or a cropped lens and inform the camera body accordingly, if the camera body is configured to auto-crop mode.

  • Can I use a manual focus lens with the Smart Adapter™ or Speed Booster® for Canon EF lens?

    When a manual focus lens with no electronics whatsoever is attached to the Metabones EF Lens to E Mount Smart Adapter™/Speed Booster® , the electronics of Smart Adapter™/Speed Booster® is completely turned off, and behaves as a dumb adapter.

    However, proceed with caution when stacking another mount adapter on top of Smart Adapter™ or Speed Booster®. The following is a non-exhaustive list of common issues found in the past.

    Some Canon EF mount adapters with focus-confirmation "chips" may be incompatible with Smart Adapter™ or Speed Booster™. Remove the "chip" from the Canon EF mount adapter before using on Smart Adapter™ or Speed Booster®.

    Some improperly-made M42 screw mount lens to Canon EF mount adapters may short the electronic contacts of the Smart Adapter™ or Speed Booster™ which may cause serious damage.

    Some manual focus lenses (e.g. OM 28/2.8, OM 50/1.8 and Leica-R 15/3.5) have rear protrusions which may scratch or damage the optics or the housing of Speed Booster®. Such lenses need to be modified before they can be safely deployed.

    Remember those days when the Canon 5D first came out and there were numerous reports of manual focus lenses interfering with the mirror, causing damage? It's deja vu, this time being the manual focus lenses' rear protrusions hitting the optics of Speed Booster®.

    Check and make sure there are no rear protrusions before attaching the manual focus lens/adapter combination onto the Speed Booster®. Any damage caused by rear protrusions is NOT covered by warranty.

  • Does Canon Lens Image Stabilization (IS) work?

    Yes, IS is supported. The Canon IS lens is powered by the Sony camera body and no external power source is required.

  • Is this adapter going to be compatible with all future Sony NEX cameras and all future Canon lenses?

    We are not sure. We are not licensed, approved or endorsed by Sony or Canon. Our Smart Adapter was developed independently without any involvement by Sony or Canon. We do not have complete specifications of the respective mount communication protocols and we are unable to foresee what will happen with every future Sony camera or Canon lens. The firmware stored inside our Smart Adapter is factory-upgradable. If a compatibility issue does arise in the future we will attempt our best to come up with a resolution.

  • Does your adapter support Contax N lenses which have been modified to Canon EF mount by Conurus?

    Yes, our Smart Adapter™ and Speed Booster™ (for EF lens) support Contax N lenses which have already been converted to Canon EF mount by Conurus. However, autofocus is disabled for Contax N lenses.

  • I intend to buy a NAM 1 to use my Contax 645 lenses on a NEX body. How is your development heading in this direction?

    NAM-1 adapters modified by us to Canon mount can be stacked on top of our Smart Adapter™ and Speed Booster™ (for EF lens). By stacking these 2 adapters together you may use a Contax 645 lens on a Sony NEX.

    If you wish to change the Contax 645 lens, you may need to remove both the Contax 645 lens and the modified NAM-1 adapter, change the Contax 645 lens on the modified NAM-1 adapter first, and then mount both on the Metabones Smart Adapter™ and Speed Booster™.

  • Why is there no autofocus for my lens?

    Autofocus is not supported for

    • most third party lenses such as Sigma, Tamron, Tokina and Contax N, or
    • most older-model Canon lenses introduced before 2006, or
    • NEX-FS700 and NEX-FS100 in movie mode (AF works in photo mode only), or
    • the original Smart Adapter (Mark I), or
    • Smart Adapter II with adapter firmware version 13 or below.

Operation (Canon EF lens)

  • Why is the mount so stiff? It is hard to attach the lens!

    Your Metabones® adapter is optimized for video work, and one very important requirement is for the mount to not wobble or move while the zoom and focus rings are operated. This means lens mounting is tighter than OEM. Unfortunately this leads to a slight inconvenience when mounting and dismounting the lens. You may want to disassemble the mount ring on the adapter and weaken the 3 leaf springs underneath using a plier if your application is still photography and you prioritize ease of use over solid mounting.

  • When I open up the iris the footage becomes very bright momentarily before going back to normal. Is there a problem?

    This is as designed. To resolve this problem, use the Advanced mode instead.

    The Metabones "Green" mode emulates a LA-EA1 adapter and the Metabones "Advanced" mode emulates a native E-mount lens. Sony's own LA-EA1 exhibits the exact same "flicker" behaviour when opening up the iris. Whenever the camera opens the iris it always go all the way to wide open first, and then stop down to the selected aperture, for both Sony LA-EA1 and Metabones in Green mode.

  • Why does Auto-Magnify work with only some of my lenses?

    The Auto-Magnify MF Assist feature requires the AF/MF switch of the Canon EF mount lens to be set to the MF position and also requires a Canon EF mount lens that supports distance information. Virtually all Canon lenses introduced in the last 20 years support distance information, but a number of notable lenses, such as EF 35/2, EF 50/1.0L and EF 50/1.4, do NOT support distance information and do NOT support auto-magnify MF assist on a Sony NEX camera body. In addition, Smart Adapter II and Speed Booster need to be configured to run in Advanced Manual Focus Mode to enable the auto-magnify feature.

  • Is stepless aperture supported?

    No. Canon EF lenses are originally designed for still photography and do not support certain advanced features required for cinematographic use. The aperture diaphragm moves in 1/8 stop steps.

  • Is an external power source required?

    No. The Canon lens is powered by the camera body and no external power source is required.

  • Why does the camera body display f/1.3 when I use the EF 85/1.2L wide open?

    Different cameras may display aperture values differently.

    Sony NEX-5/3 body displays the apertures as F1, F1.1, F1.3, F1.4, F1.6, F1.7, F2 and so on, but a Canon camera body displays the exact same apertures as 1.0, 1.1, 1.2, 1.4, 1.6, 1.8, 2.0 and so on.

    They are the exact same apertures, but different companies choose to round them and display them differently. Mathematically speaking you multiply each f-number by 1.122462 to get the next f-number 1/3 stops down. The actual f-stop sequence, rounded to 2 decimal places, would then be 1.00, 1.12, 1.26, 1.41, 1.59, 1.78, 2.00.

    NEX-5N and FS100 will display 1.2, 1.3, 1.4 and other intermediate f-numbers (apertures) with a f/1.2 Canon lens.

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