Nikon patents a digital back for 35mm film SLR cameras

This is probably the most interesting Nikon patent since I started my coverage in 2008: last year Nikon filed a patent (2012-242615) in Japan for a digital back that will transform a 35mm film SLR camera into a DSLR. The sensor is attached to the camera's back panel and by replacing it, you will be able to get the digital solution many have dreamed for years (digital FM2 anyone?). Since the back panel is detachable, the switch between film and digital SLR will be simple and fast. The patent application is current - it was filed on May 19, 2011 and was published a week ago (December 10, 2012). In the patent Nikon describes a mechanism for adjusting/fine-tuning the flange distance with a screw located on the digital back. Here are few paragraphs from the actual patent application I copied directly from the Japanese IPDL database (machine translated):

The camera back exchange type camera which images the object image acquired by the photographing optical system by the side of a camera body, and obtains electronic image data is known by replacing with the rear lid with which the camera body was equipped, and equipping a camera body with the camera back having an image sensor.

In the camera back of the description to this Patent document 1, when the moving mechanism to which the position of an image sensor is moved, and the position detection sensor which detects the position of an image sensor are provided and a moving mechanism moves an image sensor based on the output of a position detection sensor, The image sensor to the photographing optical system by the side of a camera body is positioned.

Figure 4

Fig.4 is a rear elevation of the film camera which illustrates the state where the rear lid 7 was opened wide. In Fig.4, the rear lid 7 is constituted centering on the hinge 17, enabling free rotation. The pressure plate 8 is provided inside the rear lid 7. The pressure plate 8 is processed so that the surface may be provided with high flatness and slidability. The rear lid key 16 is engaged where the rear lid key 13 and the rear lid 7 which were provided at the cartridge chamber 12 side of the camera body 2 are closed.

Figure 5

Fig.5 is a figure which illustrates the electronic camera back 101 by this embodiment. The rear lid 7 illustrated to Fig.2 and Fig.3 is replaced with and equipped with the electronic camera back 101.In Fig.5, the hinge 17 and the rear lid key 16 are the same as the hinge 17 and the rear lid key 16 which were provided by the rear lid 7. Unlike the pressure plate 8 in the rear lid 7, in the electronic camera back 101, the image sensor retainer board 102 holding the image sensor 103 is arranged by the camera back main part 101a. The image sensor 103 is fixed to the image sensor retainer board 102. If the camera body 2 is equipped with the electronic camera back 101 and engagement of the rear lid key 13 and the rear lid key 16 by the side of the camera body 2 is carried out, the image sensor 103 will oppose with the opening 11.

Figure 6

Fig.6 is the cross sectional view which cut the electronic camera back 101 by this embodiment with the section A-A shown in Fig.5.The image sensor chip 103a is installed in the inside of the image sensor 103. The image sensor chip 103a converts the image imaged with the taking lens 1 (Fig.2) in the imaging surface 103b to electric picture information, and the conversion is performed only in the rectangular range of a predetermined size. The glass plate 103c for protecting the image sensor chip 103a is provided by the image sensor 103.

Figure 7

Fig.7 is the cross sectional view which cut the electronic camera back 101 by this embodiment with section B-B shown in Fig.5.The left lateral of the positioning protruding part 102a functions as the X positioning part 102c as mentioned above. The X lever 117 is provided so that the end 117a may project to the camera body 2 side through the hole 102e of the image sensor retainer board 102, and it is supported pivotally with an axis parallel to Y-direction by the axis 117b pivotable to the image sensor retainer board 102. The X lever 117 stands, it has the bending part 117c, and levorotation power is given by the torsion spring 118. However, by the protruding part 117d of the X lever 117 abutting the left part of the hole 102e of the image sensor retainer board 102, the X lever 117 has the levorotation restricted and is held at the position to which the protruding part 117d abuts the left part of the hole 102e.

Figure 8

Fig.8 shows the cross sectional view cut in the state where the electronic camera back 101 was closed in this way in the same section (section A-A shown in Fig.5) as Fig.6.If the electronic camera back 101 is closed, the point of the Z-direction adjusting screw 104 will abut the inner rail 10a of the camera body 2, and the point of the Z-direction adjusting screws 105 and 106 will abut the inner rail 10b of the camera body 2, respectively. About the Z-direction adjusting screw 105, it did not illustrate in the convenience above figure 8 of a section.

Figure 9

 Fig.9 shows the cross sectional view cut in the same section (section B-B shown in Fig.5) as Fig.7 in the state where the electronic camera back 101 was closed to the camera body 2.If the electronic camera back 101 is closed, the X positioning part 102c and the end 117a of the X lever 117 will enter into the opening 11 of the camera body 2. The size of the X positioning part 102c and the X lever 117 is beforehand decided so that the X positioning part 102c and the end 117a of the X lever 117 may not bar a motion of a shutter curtain at this time.

Over 20 years ago, Kodak had a similar digital back solution with the Kodak Professional Digital Camera System (DCS 100) which was the first commercially available DSLR camera:

Here is a closer look of the Kodak DCS100 mounted on a Nikon F3 camera:

Via Egami

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  • lorenzo


    isn’t that like to put a horse in front of a Maserati, just in case one wanted a horse-cart from it?

    It is a great idea that might have been sort of O.K. last century, but today?

    I don’t get it.
    IMHO Nikon should spend more time and money investing in Quality to avoid all the defects that the recent cameras have today 🙂

    • They would still be creating cameras that are more than 2x the volume of their wonderful FE/FM series of decades ago, still with worse viewfinders, and still shipping devices that necessitate a power on in order to find f stop, ISO, shutter speed, exposure compensation, etc., and so on.

      Yesterday’s camera design is en vogue principally because it is easier to use and hold. Less weight, better eye point, bigger viewfinder, much smaller, all controls accessed by twists or swivels and easily recognisable by the naked eye.

      Nikon DO need to focus on quality – that is more obvious now than ever, but in trying to beat Canon and only Canon, they’ve left behind their stuff. Nikon of today is a big bear that imitates (and in some cases, betters) the next big bear. It no longer looks abroad to what other bears are doing.

      Nikon were at their best when they copied Contax, and when German camera makers pioneered all the best technology, Nikon had to rival or beat them. Today, they compete only with other best-for-dollar, most-features-thrown-in, auto-everthing Japanese stuff, that piles up like so many paper cups.

  • Grant


  • alam

    no lcd no sd/cf card, just wifi can be more fan…

  • I can only dream. I’ve been waiting for something like this for over a decade.

  • Julian Phillips

    I’ll take a D800 sensor for my Nikon FE anyday 🙂

  • Julian Phillips

    Here’s the thing though – it will need a power supply, some way to manage whitebalance, a memory card holder – could add quite a bit of bulk…

    • It would still be much less bulky than a current DSLR. Those things are massive in comparison. At its thinnest point, he D800’s body is thicker than the entire FE/FM2/FM3 series at their thickest points (the mount). I’m sure this device would add bulk, but if the camera could be kept reasonably small still, I’m in.

    • Richard M

      The power supply is certainly an issue but many late film SLRs had substantial batteries to drive film advance and autofocus. There were also power contacts available to the back (used for data backs). Memory might be built in (chips are really small now). Images might be RAW only so no in camera white balance management needed.

  • DigitalSprings

    If Nikon wants to replace Canon as #1 company then they will need to implement such ideas instead of just publishing it on paper. If this is implemented right then suddenly film cameras will start looking attractive as we can shoot digital and use right films for right needs as well..

    • I hope they don’t replace Canon. With greater shipment numbers comes greater foul-ups. Nikon are not ready to make great hardware whilst shipping lots of it.

      I hope they get rid of the Japanese propensity for making too many look-alike items that have no market value at all, and go back to making a few very very good cameras. Right now, Nikon are a Walmart brand and they are losing their appeal as a camera maker.

    • A film body costs just a few hundred these days and they’re fairly small and light. Camera enthusiasts buy two bodies just because they don’t want to swap lenses… and you think they will be swapping backs on field? What about the compromises in features in such a digital back compared to a proper DSLR? Don’t forget resale value too.

      This is like some pre-teen camera lover’s daydream on paper. If you like your film cameras then grow some hair and shoot film 🙂

  • António

    The best thing about film cameras is they can shoot…film.

    When digital cameras came out they were so expensive that the idea of such a “digital film” could mean the possibility to use an existing body and get a cheaper camera. Not the same today and the price of this “back” could even higher than an equivalent camera.

    Ask for camera design and functions that can get the easy of use and feeling of some film models instead.

  • moderntimes

    I would certainly buy one. Last weekend I bought 5 rolls each of Portra 160 and 400 to shoot in my FM3A over the Christmas vacations. Glad that I still have it,

  • Bratislav ILIC

    Imagine D4 with future proof interchangeable back…
    Today 16Mpix, tomorrow 36Mpix or more…
    And you will not have to replace your camera every year or so just to stay current…
    Well count me in if they ever make such a camera!

  • Marco Santa Cruz

    Actually… since it is a film back, it would be wise to make it small enough to mod it in order to fit in any number of different cameras… Focal distance is always different… but film planes don’t present the same problems… This means that any digital back manufacturer for 35mm could in theory outfit any 35mm film camera with this sensor… Who ever decides to manufacture this could in essence create and take over a ‘new’ segment.

  • EastOfGratiot

    I’ve thought about this concept many times and I hoe Nikon pursues it. I’m betting that they ARE seriously considering it as a product. If they were not they could have created a Defensive Publication instead of a patent. They also included quite a few specifics with this submission that narrows the patent down considerably. If they were only doing this to protect the space they would have done thing simpler and less expensive with a broad concept Defensive Publication. GO NIKON!
    I have quite a few canditate bodies for this idea.

  • George

    I have brought this up (not that I want to give credit to myself) with some of my trekking buddies on a Kilimanjaro trek in Feb. 2011. An older gent in that group, who had a Nikon D40, thought that I was odd (being younger than himself) to still use a Nikon FE2. I indicated the FE2 is built tough, and 99% fail-proof (the 1% is for the unlikely event of a failed shutter unit, but the camera would give you warning ahead of time…and even if the shutter unit fails it still fires with the MD12 motor-drive). I told him I still own several SLRs, including the F5, F4, FA, and FM3a, and hoped someday, someone would manufacture a digital back for these excellent and robust cameras (unlike the plastic low-end DSLR). The D40 owner laughed at my thoughts.

  • CCP

    With the wifi technology, the live view signal or review image could be sent to any mobile device at the same time. Technologically, it is possible to do so. The question is how much will it cost!

  • leica did this a few years ago, and of course at leica prices it hit the market like a lead brick. They stopped making it, but it can obviously be done………if there’s a market for it

  • Photog

    Nikon should come out with an F7. They could use the same autofocus motor that they have in the D4 and D800. This would save them a lot of money, and so it wouldn’t be as pricey to make this camera as it would be if they were starting totally from scratch. They could also use the F6 body. And, of course, they should add in the digital back as an optional item to go with it.

  • NRA Advocate

    I strongly disagree with those who say this will never happen.

    First, digital cameras are reaching a technological tipping-point. How much longer can manufacturers engage in megapixel wars before there’s no more headroom left? Maybe four or five years. The trick then will be to work on increasing dynamic range and reducing noise. That won’t take long either. Just like with PCs, a saturation point will be reached where sales take a dip.

    Another market to grow for digital, then, is to look back to all the wonderful 35mm cameras from the 1970s — who many photographers still covet — and sell digital backs that enable folks to resurrect those classic machines, many of which were superlative.

    For those who don’t care about all the bells & whistles, and don’t mind focusing manually, there is definitely an untapped market here.

    • At least we hope so. With every successive digital camera Nikon brings out, weight, size, and features increase. The market is simply this: more and more and more. There is little attention paid to design, to ergonomics, to weight, to great viewfinders and natural, manual controls that work to indicate what settings the camera is in prior to it even being on.

      The FE outclasses the D800 in every ergonomic and practical way – as it pertains to understanding the camera. The D800’s ISO, F stop, metering, shutter speed, etc. and so on, are all buried in menus or behind faceless dials.

      If a back like this becomes reality, I’ll probably upgrade my FE to an FE2, or better yet, an FM3 to get 1/4000 shutter speed. If it works well, it would be worth investing in – certainly more so than digital cameras that war only in excess and that feel worse in the hand ever generation.

      • NRA Advocate

        I have a motorized F3HP that is near mint; same with my F4s. What I wouldn’t give to trot out those fine cameras again and be able to shoot them digitally!

        Actually, I would love to be able to do the same with my mint black OM-2n with the 55mm f/1.2 “radioactive” lens and motor drive!

  • Simone

    All I have is a EM and an FG. Nikon Please Make this digital back. But I have to be a sourpuss and agree that we will probably never see this awesomeness from Nikon.

  • JJ

    It seems late indeed and somehow unlikely that this will be brought to market. But we can still hope! If it would become available, full-frame please, for a reasonable price… I’d buy one for sure! Just left to decide what body to put it on… On my Nikon F, FG-20, F-301 or F4… Choices, choices. But it would be a great way to use my old lenses (& bodies) again! I would love to have one!

  • neversink

    NEWS RELEASE – Nikon Patents Film Back for DSLR Cameras!!!!

    Imagine the incendiary comments if the above were true.

    There are digital backs for medium format cameras, but such a back for a dSLR is a little late and makes little sense. The options in current DSLRs outstrip the need for a digital back for SLRs. You can use most of your old Nikon manual lenses on current Nikon dSLRs.

    Use your old film cameras for that — film. That’s what they were built for.

    Use your dSLRs for digital. As that is all you’ll ever be able to use it for….

  • Danonino

    If the sensor is about 23×35 there could be a light sensor which register when shutter is starting to open, activate the sensor and captures the image while the shutter is open. Then stores the raw-file to the inbuild flash memory. A modern Sony sensor is iso-less, you just expose for the correct iso on iso 100, then lift the raw file in the raw-converter, thus, no need to be able to change the iso, as you get the exact same result with the underexposed iso 100-shot as for example an iso 1600 shot.
    The wheel with pigs that goes through the sprocket holes could instead be connected to something like an inbuilt dynamo that gives enough charge to take one shot and store it to the memory card. Or, the lever for reversing the film back into the cartridge be the dynamo, just twist it for a minute, and have enough charge for exposing 36 shots and storing them to the inbuild flash-memory…

    The reason this dream is still alive is because only Sony has so far given us what we want, a compact light small 35mm camera, the RX1.

  • Helge

    Having worked with the DCS100 back at college, and working with Hasselblad CF-V backs now, I think you would be surprised how awkward this solution would feel in use. For it to really be worthwhile, it would have to have a current Nikon DSLR resolution and sensitivity range – these would actually add something new. The problem is usually, that the back doesn’t automatically get told when the exposure is finished, either – cue cumbersome shutter speed selection on the digital back. And even if you got all this sorted, you would then find that your old Nikon glass doesn’t have the Nano-coating required to avoid the light bouncing back and forth between the sensor and the rear lens element.

  • Richard M

    Those who say that this is just a patent to block another manufacturer producing this product are probably right although that strategy may not be guaranteed success. A different technical solution may circumvent this patent. Do Nikon always manufacture the designs they patent? I get the impression that they may patent an invention before making the decision to produce it.

    If it did get made, I’m not clear if this is something that replaces an existing back (seems more likely and would increase bulk) or fits inside an existing back (seems unlikely). If it’s the former then each back would have to be camera model specific which would certainly push up the price. So I’m not too hopeful about being able to make my three Nikon film cameras into DSLRs which I would love to do. I have what were very expensive underwater housings for two of them. If a digital conversion still allowed the camera to fit inside the housing, I would jump at the chance to use them again.

  • Robert Mossack

    The thought of a Nikon F4s Digital really brings a smile to my face.. 🙂

  • Michel

    Great! It will be funny winding on the advance lever to take a photo, but focussing with a split image and fresnel screen again, wow….

  • Patrick Chin

    I wouldn’t say this is 10 years too late since the industry has had that many years of advance in technology and production. And the cost of FX-size sensor is starting to become within reach recently. 10 years ago such a proposition was just not feasible. So now may really be the right time to revisit this idea and inject our old FM/FE/F2/3/4/5/100…… a digital life. If they can hit the right note between a bare-bone drop-in (unlikely) and too many extra buttons(scary but likely), this would be a hit. A quick look at the drawings indicates the sensor may have to be a couple mm smaller than 24×36, but that is probably ok. I would really be interested to see this materialize.

  • Tradewind 35

    Oh yes please Mr Nikon – put me down for three. Appreciate that Nikon don’t want to loose DSLR sales but unless they come up with something like this or something to match the Fuji X Pro they are going to loose sales anyway.

  • Diego

    This rumor sets a trend of what people wants. A 90% 35mm camera plus a 10% digital technology. Everybody wants a 35mm SLR camera with a digital sensor. But not with an LCD or electronic viewfinder, not small sensors. All photographers loves the “feeling” of a film camera. Nothing more.

  • RR

    Very exiting!

  • Patrick Chin

    I took a closer look at the spec of the SiliconFilm around 2000 and really felt that snug-fit platform is the right idea ahead of its time. Now we can have a right-size detector (~10MB is enough) and a lot more powerful electronics which can fit in the silicon cartridge. Detectors at the very edge of the sensor could be used to start and end the pic recording as the shutter flies by (vertical or horizontal). Some toggle switches (like DX) can be used to pre-set the ISO on the “cartridge” matching the SLR’s setting. Or, even better, a smart phone App can change the settings and preview the pics via bluetooth. It feels very achievable with today’s parts and technology to do it on most full mechanical SLRs. F4~F6 may be more complicated because you need to bypass the motor.

  • I still miss my F3 🙂

  • This would be ahh-mazing. I love my Nikon FE, but would love to save some $$ on development. I think they should make a mode where you don’t get to see your photos for a week, that way it would still feel like your getting film developed 😀

  • vettevet2002 .

    just what control does this patent give Nikon over Canon, Olympus and Contax/Leica?

    Leica and Olympus could certainly turn profits with digital backs dedicated to their cultists;

  • James
    • I would expect that more people will support that project.

  • ronver1960

    I am going to buy huge amount of Nikon analog camera’s now …. maybe next year it pays

  • Luke

    I see it very unlikely that Nikon would NOT release this idea to market. Why? So many people want it. So how not to kill their own DSLR sales? Easy – lack of advanced DSLR functions (like AF, swivel screens etc.), restricted resolution and careful pricing can safeguard that market and make it a complement and not a substitute product. Simultaneously, the market in old MF bodies will inevitably take off again. I think they still make the FM3A…

  • Oliver Baker

    I just finished a similar project with a specific camera, the Konica Auto S3

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