Nikon F-Mount to NEX Lens Turbo focal reducer adapter: impressions & samples (guest post)


Today's guest post on the Nikon F-mount to NEX Lens Turbo focal reducer adapter is by Ainga:

To begin this post, I will say that I was highly skeptical of the quality of the optics from an unknown glass company from China called Zongyi, a.k.a. Mitakon. I was intrigued with the thought of transforming my NEX to a full frame camera without waiting a year for the NEX 9, I decided to give the Lens Turbo a try.

First off, the Lens Turbo is a focal reducer. The function of this adapter is to reduce the image projected by a full frame lenses to fit within the area of an APS-C size sensor; effectively eliminating the 1.5x or 1.6x crop factor. To say the least, wide angle lenses will stay wide angle with the angle of view comparable of a full frame 35mm camera.

Secondly, the light gathering capability of the lens will be enhanced by approximately one stop. The Nikkor 35mm F2D with the Lens Turbo have the light gathering power and the DOF of a 1.4 lens. Freaking magic.

Some online commentators claimed that the Len Turbo is a copy or a knockoff of a more expensive Speedbooster. I am quite sure that this is untrue, as the reduction ratio of two FRs is different, with the Lens Turbo coming in at x0.726 versus the SpeedBooster at. x0.71. That is suggestive of a completely optical formula used in the Lens Turbo.

Full disclosure: I DO NOT have any personal or commercial relationship with the makers of the products mentioned. I am only doing an impartial report with the inclusion of my personal observations with a copy of the Lens Turbo purchased on eBay with personal funds.

The samples are shot with the Nikon 35mm F2 AF and the Nikon 105mm F2.5 AI on the Sony NEX 7 at F2 to F4 aperture. Minimal post processing WITHOUT changes in sharpness or clarity.

My Take on the Lens Turbo

The build quality is great. It feels solid and have a hefty weight to it, which to me is a good thing. The optical performance is much better than I expected, opening up numerous possibilities for the NEX line. Since the NEX 7 isn't a low-light monster and the AF not the quickest of the bunch, I have no problem going full manual with the Lens Turbo especially when I benefit from an extra stop of light! Moreover, I am a true admirer of the look and feel of chemical based film that I think modern CMOS sensors generally fail to render. Using the Lens Turbo adapter somehow brings that filmic quality back to the NEX 7 straight out of the camera.

The Good

The build. All metal construction and solidly build; confidently attaches to the camera and lens. Good weight balance on the NEX 7 body.

Image Quality. The high quality optics preserve the goodness of a lens. From what I see in the samples, the base performance of the lens is preserved in terms bokeh and sharpness. However, the opposite is also true. The "flaws" exhibited in a lens will also show up, notably chromatic aberrations when shooting wide open. Use with caution and slap the best lens you can afford for best results.

Vignetting is Well Control. Vignetting does exist but not much more than the natural vignetting from the lens.

Virtually No Distortion. Although this evaluation isn't scientifically based, I did not detect any distortion during use.

The Neutral

Improvement on the optical design. In low light scenes with areas of direct, bright light source, I did encounter the appearance of "flares". They are a slightly bluish halo-like smudge around a high contrast light source. In all fairness, I only encounter this issue in a couple out of a batch of more than a hundred shots.

Stiff Mounting Ring. It took more effort than usual to mount or dismount the lens from the F-mount side of the adapter. However, the NEX mounting ring was smooth and did not exhibit any stiffness.

All Manual Setting. For me, I don't mind shooting all manual. For others, this maybe a drawback. A useful tip for NEX users: the peaking feature is your friend!

The Bad

The packaging. I am usually not very picky when it comes to the packaging. When I first inspected the Lens Turbo minutes after the unboxing, I discovered little black flakes inside the adaptor. They resemble metal shaving which really made my heart sink for a moment. Then I realized that they were soft debris from protective black foam that the adaptor was shipped in. The debris were easily removed with a blower and a brush.

UPDATE: I received a useful tip from a DP member (emailsucks98) to ensure proper function of the aperture.

  1. The lens aperture has to be fully open when mounting
  2. Align the red dot on the lens with the red dot on the LT
  3. Rotate the lens 1/8 turn CW (photographers perspective) until the red dot on the lens aligns with the yellow dot on the LT. The lens should now sit flat on the Lens Turbo.
  4. Rotate the lens 1/4 turn CCW until lens locks into place


User experience score: 4.5 out of 5. Highly recommended. Get one if you can. The Lens Turbo literally propelled the NEX 7 to a whole new level — the photos are more film-like with shallow DOF rivaling a massive full frame DSLR camera. The freedom to choose among the 40+ years of optical masterpieces in Nikon's F-Mount lens lineup is exhilarating given the limited E-mount offerings. Shooting all manual with the tactility of adjusting the aperture and the focus ring bring back memories of the simplicity of photography with a film SLR. I simply can't wait to get my hands on excellent and interesting lenses like the Nikon 50mm F1.2 for my NEX 7!

Feel free to leave your comments or questions below. Follow me on Facebook or Twitter.

Note: realize that I gave it a 4.5 "User Experience Score" derived from combining the ENTIRE EXPERIENCE when using the Lens Turbo. Optical performance, build quality, design, tactility, and the overall enjoyment was taken into consideration when giving the score because I truly believe the usefulness of a tool should be based on more than pixel peeping test charts alone ; )

If you the type who likes test charts, I am sure that there are resources on the net to satisfy the scientific minds.

Sample images

This article was originally published here. If you have an interesting idea for a guest post, you can contact me here.

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  • Kok Yoon Lee

    Thanks for the review. I have a couple of questions.
    1. Can we use “G” lenses?
    2. Assuming I am using a “D” lens, do we have to manually open up the aperture eg to f/2 to do the focussing, and then change the aperture to say f/8 (assuming I want to shoot at this aperture) to shoot the photo?

    Thanks in advance.

    • Sahaja

      This looks all manual – so G lenses would be impractical. Metabones Speed Booster has a version for G lenses – however G lenses are not very well suited to manual focus.

      • Steve

        “G lenses are not very well suited to manual focus”

        • Sahaja

          Compared to old AIS lenses, the focus throw is too short and sloppy. No hard infinity stop either.

          • fjfjjj

            Sahaja, you’re confused about the meaning of G. Nikkor G just means no aperture ring. Yes, G lenses are also all AF, and manual focusing is poor on most AF lenses. But that has nothing to do with G.

            • Sahaja

              I know – I have some G lenses and I wouldn’t want to use them regularly for manual focus. While manual focus is poor on nearly all AF lenses – a few older AF lenses, such as the 180mm f/2.8 AF-D, are not bad.

              The focus throw on screw-drive AF / AF-D lenses seems longer than on newer AF G lenses – though still not free of play or as smooth as on manual lenses. Of course the older AF lenses also still had an aperture ring.

              Anyway I specifically mentioned G lenses because that’s what Kok Yoon Lee asked about.

    • No, you can’t. You won’t be able to open the aperture up. You have to get the Metabones version which is now available, but is a lot more expensive. (I own the Lens Turbo — luckily most of my lenses are AI-S or AF-D)

  • Ainga Frames


    G lenses can’t be used with this particular focal reducer because there isn’t a mechanical lever for adjusting aperture. The ai-s and af-d lenses have the aperture rings built on the barrel itself.

    Also, you will not have to close the aperture up when shooting. In another words, if you focus at f2, the shot can/will be captured at f2. The only thing is that you will most definitely need focus peaking to help acquire focus. It takes some practice but well worth the results.


  • Is there a m43 version?

    • Steve

      metabones makes a Nikon -> m43. It is $430, and works with G lenses. but it is all manual controls.

      I haven’t seen any cheaper “ebay” versions yet.

      • Really? Because I was obviously asking about the one that has been out for a month and has been posted to death on every photo blog ever.

        • Steve

          You are the moron who asked the question and didn’t even bother clicking twice to find out :/

          • Quick recap: I asked a valid question in good faith for which I didn’t see an answer. You then foollishly provided some obvious and irrelevant information about a product I was not asking about. I responded with sarcasm. Then you called me an idiot.

            Did I miss anything? OH, yeah, the part where you ought to feel foolish for being rude to a perfect stranger, but since this is the internet. you instead feel proud to be a useless troll. Hooray for electronic courage!

    • Martijn

      thats what i want to know too. And does the reduction increase even more with it?

  • Tony

    That sucks.. 3 out of 4 lens I own (e.g. 27-70mm 2.8) don’t have aperature rings. These guys need to build one that allow controlling aperture, even if it’s manual.

    • Sahaja

      Get the one of Metabones adapters.

    • fjfjjj

      Or you could buy the optically decent version from the people who actually came up with this idea.

      • amy

        You mean astrology & CCTV cameras, cause focal reducer available for decades 🙂

        • fjfjjj

          My astrologist disagrees.

        • AM

          Astrology cameras, LOL.

          Do they take a snapshot of your future?

        • Ainga Frames

          I agree with ya, Amy. Focal reducer is not ground breaking technology.

          Back off, patent trolls.

  • Cobus

    Really. …. who wants to shoot manual these days? For old times sake? Why don’t we just all go back to the world of crt screens and corded telephones.

    • Martijn

      hollywood still shoots manual in video… Macro is often shot manual too. Not everyone shoots action 😉

      And there’s still people using CRT’s too, because color and image quality is better (although resolution is lower ofcourse)

      • Rob

        I shoot manual for product product photography, shooting paintings, art objects, star photos and night photography, in fact any kind of photography where the object you are shooting is stationary can be a lot easier and quicker in manual focus mode.

    • Aldo

      I shoot manually most of the time… actually just settings not focusing.

    • Ainga Frames

      Sometimes AF on a camera can’t be trusted. I find shooting manual gives you more flexibility when composing a shoot, while most photographers are confined within the camera’s AF grid.

      Give it a try. Shooting manual is very enjoyable, it slows you down a bit but makes you think more. It’s almost like driving a automatic v. stick shift.

      • Not to say that there are hundreds of awesome manual focus lenses out there

      • Better yet, trying using manual lens and a film only body.

    • Noobs, noobs everywhere

    • Gil Aegerter

      I shoot almost exclusively manual. I still keep a few AF lenses around if I’m more in snapshot mode.

    • Dante R

      You’re a dumb-fack for not appreciating manual shooting, and you’re probably just a jackass who thinks your pictures are so great with your automated settings while your pictures are actually shiet that no one wants to look at.
      It’s like you’re driving an automatic and look down on all other manual drivers.
      Did you know that the manual guys will murder you inside out and up your arse with their beautiful artwork?

      • zoetmb

        I agree that there’s nothing wrong with manual shooting and for Tilt-Shift lenses, you have to focus manually, along with much macro work. But having said that, since digital body focusing screens don’t have a split-image focus spot (even though they have that little dot indicator and a beep when you achieve focus), I personally find it hard to focus manually with modern bodies and lenses.
        And I was someone who when AF lenses first came out for SLRs, wondered why anyone would ever need an AF lens. I never shot AF until I bought a Nikon N80 in early 2002.

        • hugh crawford

          and that’s why some people like live view / mirrorless cameras

    • Personally I think there is some kind of old school snobbery going on. Some people want to show they are “real photographers” by how well they can operate last decades technology. Next they’ll tell you the auto-exposure can’t be trusted and you need a light meter blah blah blah.

      I say stop talking about the tech and get out and capture some image.

  • Martijn

    Very interesting post! was looking at the metabones version, to use my Nikkor lenses on the upcoming BlackMagic Pocket Cinema Camera. Since i own enough F-mount lenses, it would be a cheap upgrade in video quality. And since the BM Pocket camera is manual focus anyway (with focus peaking) missing AF is no dealbreaker.

    i have only 2 G lenses, the 35mm but i also have a 50. And the 17-50mm tamron. But a standard zoom should be buyable online for relatively cheap.

    awesome post!

  • Samuel Morse

    Dude, I barely made it halfway through this post before I had to stop. Your grammar is atrocious, and your analysis deeply flawed. Considering heft as a positive for a mirrorless camera is lunacy. The whole point of mirrorless cameras is to be light and portable. Sony has been making waves because somehow they did this without sacrificing structural solidity. Also, saying the lens turbo didn’t copy the speed booster because the focal length reduction is a few hundredths off is like saying Windows didn’t copy the Mac OS because they put the close and minimize buttons on the other side of the window. Of course they didn’t copy it verbatim–that’s called patent infringement. That doesn’t mean they didn’t borrow heavily from the concept.

    • Aldo

      your objectivity is flawed.

    • Ainga Frames

      The Metabone and the Lens Turbo are coming from two different optical designs and focal reducers have been around since the 1970’s.

      • longzoom

        And significant loss of resolution of the combo is imminent. There is no room for miracle with such the optical system. Everything has its own price. Take a closer look at the samples. Sorry to say, great review, but all of the images are on the soft side.

    • Chris

      Perhaps he should try it in morse.

    • hugh crawford

      “The whole point of mirrorless cameras is to be light and portable”

      You seem to be forgetting that there is a long history of pretty big mirrorless film cameras. The whole point of mirrorless cameras is to get rid of the mirror box which brings with it a lot of design constraints. I’m using them because they have a shallow lens mount depth so I can use all sorts of lenses on them. Also they don’t have that mirror flopping around and are optimized for live view.

      I’d happily tale a much larger NEX camera if it had tethered operation or just a wired remote

      Also Metabones does not have a patent on focal length reduction for small format cameras. That was patented by Eastman Kodak

      The patent is now owned by Intellectual Ventures Fund 83 LLC which is in turn owned by HTC, Google, Amazon Fulfillment Services, RIM, Huawei Technologies, FUJIFILM, Shutterfly, Apple and Samsung.

      Reading the patent just now , it seems to be specific to reflex cameras which seems odd.

      • jk

        very very interesting , I have never known that, thanks.

  • vik

    “I am a true admirer of the look and feel of chemical based film that I
    think modern CMOS sensors generally fail to render. Using the Lens Turbo
    adapter somehow brings that filmic quality back to the NEX 7 straight
    out of the camera.”

    Can You explain this experience more? In what aspects the pictures get closer to film?

    • Samuel Morse

      See my post I just made. I think he’s been sniffing those chemicals too long. It’s obvious the “film look” for him is actually just nostalgia for the way his older Nikon lenses render images, nothing more.

      • Ainga Frames

        Yes, I love old/classic Nikkor lenses. I own the Nikkor 105mm F2.5 AI and it performs wonderfully with the LT. I will get the Nikkor 50mm F1.2 for some hyper bokeh action.

        • jk

          where can we get the 105mm f2.5 AIS these days?

    • Ainga Frames

      In my opinion, the attractiveness of the LT is that it renders bokeh/DOF reminiscent of a 35mm (film) camera—formerly unattainable with a DX sensor. I don’t mean to mislead you in any way, but perhaps “cinematic” is a better descriptor.

  • Rob

    When do we get the F-mount DX to F-mount FX model?

    • It’ll be available a couple months after the CX to MX mount version.

    • amy

      It will be available when nikon build DX mirrorless interchangeable lens camera, flange focal distance in DSLR will shift the focus too much make it usable for macro only and you lose infinity focus with standard and tele lens even if stop down to small aperture

      • groucher

        Nikon’s FT1 FF-CX adapter extends the focal distance but does not contain any optical elements. There’s no reason why a focal reducer (sic), consisting of a similar adapter with optics that reduce the image circle, couldn’t be made.

    • ola

      Nikon gave the “Nikon Reduction Optical System (ROS)” up in 1999, why would they want to go back? It was installed in all E-series Nikon DSLRs as far as I can remember.

      • Rob

        Thanks for those answers, hence there will be a F-mount to CX before we see F to F with a smaller sensor

    • cppguy16

      Such an adapter would be like an extension tube, so you would lose infinity focus.

    • Rob


  • Sahaja

    With things like this and theVizelex RhinoCam the NEX looks like it would be fun to paly with.

  • fjfjjj

    Unreedable grammur.

    • Ainga Frames

      My apologies.

      • fjfjjj

        Knot yore falt, edmins falt.

        • Dante R

          I am soooooo sorray!!!!!!

    • MJr

      Maby eets not hiz natif langwish ?

    • yup

      I’m so sick of you grammar nazis!!! Get a life!

      • fjfjjj

        There are certain times where you can compose an exclamatory sentence without ending with three exclamation points. For example, if you use the phrase “so sick” in an exclamatory sentence, you do not need to put an exclamation point at the end; rather, a simple period will do. The sentence is emphatic enough without it.

        • yup

          My eyes are instantly filling with tears while I read your amazing comment above. The sudden feeling I have of being in contact with such a superior creature that you believe you are is too much for my emotions. It’s almost like a 1st degree encounter. I’m in awe. Good luck for the Nobel you’re gonna get this year.

          Oh, and I’m sure that you’re very proficient in my native language as well. No question about it, for such a high intellect as yours.

          • Aldo

            I speak English, British, American and Canadian. Ha!

        • fjfjjj

          Try again.

    • fjfjjj’s vj

      You mkae me wnat to tpye lkie tihs for the rset of my etnrie lfie. Way to pormtoe gamramr.

      • Aldo

        You reminded me of something: the brain rearranges the letters as long as they are present and as long as the first and last letters of the word are correct.

        • Dyslexics already have trouble with that.

          • MJr

            Thus not even notice the difference. ^^

      • fjfjjj

        You make me want to say “pormtoe” aloud.

    • Aldo

      Good enough imo… not like this is expository prose or “literature rumors”

    • Guest

      “Unreedable” you say?

    • Marc J.

      It’s fairly obvious it’s translated/not the speaker’s native language. The point of the review was still carried across just fine.

      Your sarcastic post adds zero to the discussion.

  • HotDuckZ

    Why Nikon not get this idea to their Nikon 1? It’ll sell like a hotcake.

  • FDF

    Meh, this totally defeats the purpose of mirrorless cameras: smaller size and weight and price of lenses. And the adapter makes the camera as big as a DSLR, so what’s the advantage of using this instead of a real DSLR with proper ergonomics and a good old optical viewfinder, beside the price?

  • MB

    Here is the idea for Hasselblad!
    By a couple of those Chinese speedy thingies, stamp H on them, call them Solar, add wooden meniscus lens and start selling them for zillion or something …

  • macro

    “I was intrigued with the thought of transforming my NEX to a full frame camera without waiting a year for the NEX 9, I decided to give the Lens Turbo a try.”

    Well that would be one neat trick if you could.

  • beerknurd

    you guys are grammar nazis! its not perfect, but i mean, you gets what the dudes saying haha. good review btw, might have to invest in one soon. hope it comes out for m43 also!

  • dnguyen

    Processing is horrible.

  • nameless

    I think his English is okay. As long as I can understand it.

  • jk

    this thing is a crap , get the real SB from Germany.

  • Joshua Giggity Gilpo

    I would love to see this type of adapter for medium format to crop sensor. Ie mamiya 645 to nikon F without much/any crop. Or hasselblad to nikon F. I know the latter would pose drawbacks but I really want digital medium format and I don’t want to pay as much as a car to get it.

  • Dftg

    Without full-size pictures this review is useless.

  • pyktures

    do you have an online gallery for the set u just posted on the lens turbo?

  • saicode

    What about the dof change, does it give the same DOF as Fx cameras?

  • Pat Mann

    The difference between 0.71 and 0.726 focal reduction factor is minimal and does not imply a different optical formula – a slight difference in curvature of one internal lens surface would make this much difference. I’m not saying it’s the same optical formula, just that the slight difference in focal reduction is not evidence they are fundamentally different.

  • Pat Mann

    Thanks for posting your experience with this adapter.

    I apologize for all those here who criticize others for spelling and grammar. This is a web site with lots of international readers, and putting down those without perfect English spelling and grammar is not a way to keep up a lively conversation.

    I learned long ago that many very capable and talented people, particularly in creative endeavors, aren’t the most skilled writers and spellers. Fortunately, that hasn’t discouraged them from their efforts to achieve great things.

  • “I was intrigued with the thought of transforming my NEX to a full frame camera without waiting a year for the NEX 9, I decided to give the Lens Turbo a try.”

    You have an APS-C. That’s not a full frame sensor no matter what sort of adapters or optics you add your camera.

    Your camera is NOT a 35mm full frame camera.

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