Converting a Nikon Nikkormat EL to digital with a Sony Nex-5N

 

The Concept:

Take a vintage film camera that no longer works and convert it to digital.

Many of us love vintage cameras and we don’t find exactly what we are looking for in today’s modern (even retro inspired) SLRs or mirrorless cameras. Today’s digital cameras are amazing, but lets face it, things just used to look better. I started collecting a few vintage cameras and went as far as developing film in my own bathroom. But the advantages of digital photography are numerous and as an infrared enthusiast those advantages multiply quickly (such as actually being able to see what you’re focusing on!). So I set about trying to turn a vintage camera into a modern mirrorless ILC.

 

Ideas and considerations:

There are 2 ways of going about this that I can think of.

1. Design a digital back for a specific camera so that the digital sensor is placed at the same flange focal distance as the film would be and leave the original film camera intact. This has two major drawbacks. Firstly, the electronics that are necessary for digital photography take up considerable space and that means that the digital back will protrude much further out from the back of the camera than the original film back. Secondly, the firmware for the digital sensor and image processor has to be custom designed to take cues from the existing mechanical film controls. The sensor has to know when to be ready for a picture and when the exposure has finished so that it can process and store the image, and then get ready for the next picture. This is not a simple task.

2. Replace the innards with an existing fully functional digital mirrorless camera, essentially housing the camera in a new enclosure. The main drawback of this is that it is destructive to both the original film camera and the digital camera, as they have to be irreversibly modified. Also, the flange focal distance will be reduced in order to fit the digital camera inside the film camera without protruding as with a digital back. This means an extension tube is required to maintain the correct flange distance for the lens. The effect of not doing this will be to greatly increase the minimum focusing distance of the lens (you would still be able to focus at infinity without the extension tube). This is the method I chose to try.

As a Leica and Nikon S appreciator, I first thought of buying an M3 that was for parts, but even a broken M3 is costly and is still very collectible. So it would be a shame to totally ruin one without even knowing if it is possible to do. I do have a broken Nikon S that may turn in to project no.2.

Instead I had a Nikkormat EL lying around that would be perfect for a first attempt. Its cheap, common and easy to work with. If you decide to attempt a similar project I recommend trying it out on something similar first.

The next important consideration is which digital camera to use. There are 2 main considerations;

1. Dimension of the camera, screen and electronics – will it be able to fit with minimum modification?

2. Layout of the controls – how easy will it be to map the physical controls of the digital camera to the mechanical controls of the film camera?

After careful consideration, the Sony Nex-5N provided a relatively affordable camera that fit the criteria. But it also has a very useful feature for this project – focus peaking. This is when the liveview screen or EVF will highlight exactly what is in focus. This provides a very effective way of being able to focus manually, as the finished camera will not be able to autofocus. The fact that the 5N did not have a built in EVF was a bonus because the EVF in an SLR would be directly above the center of the sensor, rather than to the left like in a rangefinder. I was able to get the sony add-on EVF for the 5N and that will fit very nicely in place of the original prism viewfinder.

As I mentioned before, I’m an IR photography enthusiast and so I will be removing the hot mirror filter, allowing me to use infrared filters on the lens. I have had a couple different infrared converted SLRs, but this was an opportunity to have a full spectrum camera that can use any filter. The problem with this approach is that filters are expensive and sizes vary from lens to lens. This got me thinking, since I have to custom design an extension tube to maintain the flange focal distance, maybe I could design this extension tube to take changeable filters, allowing me to use one set of filters for all lenses. This is still just conceptual as I haven’t got to the stage of designing the extension tube yet. The extension tube will be custom milled, probably from aluminum.

Once the camera has been built I will do my best to restore it with some good looks. The leatherette will be replaced and the black paint repainted. I will try to seal the camera as well as possible from dust and light with some rubber seals and light proofing materials too.

 

The Build:

Part 1: Stripping the Nikkormat EL

It’s quite amazing how many moving parts there are in an old SLR camera. There are hundreds of tiny mechanical pieces and screws. I had no prior experience tearing down an SLR so I did it like anybody else would. Just started taking it to pieces and see what I found.

Tools required: Small philips and flathead screwdrivers, spanner wrench, tweezers, cutters

I have this kit from iFixit that has most of what you would need. Micro-tools.com can provide spanner wrenches

Nikkormat vs Nex-5N Size comparison

As I started taking the Nikkormat apart I thought about how the Nex 5N would fit. You can already see the first problem. The battery housing in the grip of the 5N is wider than the Nikkormat. In order to fit the battery inside the Nikkormat it would have to be turned sideways, and this means modifying the electronics of the 5N…

 

I’m not going to give you a detailed step-by-step of taking apart the Nikkormat, because it would be endless. The basic method is, if you see a screw unscrew it! Be very careful to save all the screws in a way that you can identify where they came from. Getting the top plate off is a little bit tricky. There are 3 small screws visible around the sides of the plate. There are 2 screws holding the Nikkormat name plate to the prism housing that have to be removed. Then the ring surrounding the battery charge indicator button to the left of the viewfinder has to be unscrewed. Next the winder and ISO dial on the left need to be taken apart and removed. The ring around the base of the exposure speed dial has to be unscrewed (there are no holes for a spanner wrench). Finally the winding lever has to be removed. Now you can take off the top plate.

Top Plate Removed

The purpose of stripping down the Nikkormat was to clearly see how the Nex 5N will fit and to prepare it for modification by Dremel. So I took almost everything out. You don’t have to take apart many of the individual mechanisms in order to remove them, so try to identify which screws are holding them in. Since there was no turning back on this project I just cut all the wires and removed them as much as possible.

Nikkormat Faceplate Removed In order to remove the face plate and expose the shutter mechanism, you have to strip the leatherette off to expose 5 screws on the front. 2 more screws on the top where the prism should be also hold it. The shutter mechanism is easy to remove unharmed and can probably be sold as parts. The faceplate with the lens mount has a deep light proof box on it. This would have to be cut off as well as much of the film plate behind the shutter. There would then be enough space to comfortably fit the Nex 5N sensor and electronics.

 

Part 2: Stripping down the Sony Nex-5N

Instead of removing the sensor and electronics from the Nex, it makes more sense to leave them attached to the Nex enclosure so that they are held firmly in place and then cut down the Nex enclosure to fit snuggly in the Nikkormat. This way you avoid any risk of the sensor and mainboard moving around.

Open Nex 5N

There are already some videos of people tearing down a Nex 5 on youtube so you can follow those if you want a step-by-step. The Nex is very simple and consists of the sensor, shutter mechanism, mainboard, sd card slot, battery compartment and controls. Be careful when pulling out the ribbon cables, they are delicate and some clip in, others dont.

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I was concerned that I would have to extend some of the ribbon cables in order to move some components around, but as it turns out none of them will have to be extended. Only a couple of the buttons will have new switches soldered on the board by thin wires in order to move them onto the Nikkormat top plate (the playback and record buttons).

 

Part 3: Combining the cameras

dremel cutter

 

 

Using a dremel cutter I cut out the center part of the film plate and the box that is attached to the lens mount, to make enough space to fit the sensor and mainboard.

 

 

 

 

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It takes quite a long time to cut and grind so much of the metal but the metal is quite soft and one cutting wheel was enough to do the whole body

 

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Getting the size right was just a matter of cutting a little bit at a time and constantly comparing the space to the digital parts that I would put inside. You don’t want to cut too much because it’s easy to weaken the structure beyond repair, so cutting small and then enlarging it bit by bit is the way to go.

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The casing of the Nex 5N also had to be cut down substantially. I cut it as close as possible to electronics without losing any of the screw holes with which they are secured to the casing. The Nex casing is made of aluminum and is very easy to cut with a dremel. I then was able to place all of the nex 5 parts inside and make some small adjustments to the cuts with a tungsten carbide cutting bit.

WP_20130123_008 The EVF proved to work out extremely well and fit perfectly in the old viewfinder spot, as the accessory connector is dead center of the sensor, just like a hotshoe on an SLR. I did have to remove some the plastic casing of the EVF to make it sit further back but the EVF is still intact. The battery had to be turned sideways as I mentioned before, and it fits very snuggly with some extra grinding, with just enough room for the SD card reader to sit infront

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In order to sit the battery in this position, the battery connector has to be removed from the original power ribbon cable (by desoldering) and reattached by wires allowing it to be further away from the mainboard than the ribbon cable will allow.

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With everything in place I cut the back door to make way for the screen and the scroll wheel controls

 

 

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The sensor needs to be as parallel as possible to the focal plane which means some fine tweaking will be necessary. In order to fix the components in their final position I will design and 3D print some small brackets to screw the Nex casing to the Nikkormat structure. Unfortunately it takes about a month to receive a 3D print order and I want to print one piece at a time minimize errors in measurements, so I will print one piece and attach it, then measure for the next.

Camera top dimensions

 

 

The first bracket I have ordered is for the top.

Camera top plate

 

 

This piece was ordered from iMaterialize who are a 3D printer based in Belgium. They provide a good choice of materials and the most suitable for these small parts is brass which unfortunately is relatively expensive. I also ordered a bracket to hold the EVF in place at the same time. These should arrive around the end of Feb 2013.

In the mean time i have some soldering to do and I need to design the pieces that will extend the controls from the Nikkormat to the Nex, such as the winding lever. This will act as the on off switch. When the lever is pulled out slightly to reveal the red dot, the camera should be on. Luckily the on/off switch on the Nex 5N is very similar, so it shouldn’t be too difficult to do. The shutter release is also almost directly on top of the Nex shutter release making it relatively easy to extend down too.

 

In the mean time please ask questions and leave comments below. Here are some pics of the camera partially assembled

Front assembledRear assembledSide assembledrear screen raised

 

Update 02/09/13: Whilst waiting for pieces to arrive I’ve designed the F Mount attachments ready for my custom extension tube

F Mount Male F Mount female no springs

NikkorNex Extension Tube Assembly

Finally my 3D printed brass mounting brackets have arrived after more than a month of waiting! The project goes on…One secures the digital components to the Nikkormat body and the other secures the EVF in place. I had these made at i.materialise in Belgium out of brass. They get gold plated by default so I feel like my ghetto camera hack has some gold teeth to match now.

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The camera takes its first breaths. Proof that it lives! I know it still looks like crap but the looks will be the final stage. Unfortunately I somehow damaged the accessory port and the camera doesnt recognise the EVF :(  I have a backup 5N that was broken on ebay for parts, but the lcd output on the mainboard on that one doesnt work and the EVF does… cant believe it. Which means I have to find another 5N mainboard from a broken camera that works. Next stage is the transferring camera controls to the Nikkormat buttons.

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19 Comments

  1. awesome! more power to your endeavors!

  2. You are an evil genius!

  3. I am not sure where you’re getting your information, but good topic. I needs to spend some time learning more or understanding more. Thanks for magnificent info I was looking for this information for my mission.

  4. stunning work, looking forward to see it complete!

  5. You need to clean your mac keyboard! On the topic though, why didn’t you go with rangefinder? And, why did you decide to keep the screen articulated and not removing all the extra stuff to make it protrude less outside the camera body?

    • Hah. Yes, my keyboard really does need a good clean. I didnt go with a rangefinder because this is a first attempt or “trial” conversion, and rangefinders are more collectible = more expensive. Camera number 2 will be a Nikon S. I didnt remove the hinge on the screen partly because I like having an articulating screen, but mainly because it is more convenient with respect to placing the other components in the camera. It’s not possible to move the top controls any further forward without detaching them from the mainboard/sensor unit all together and that involves a lot more work (ie custom ordered flex cable and more custom designed mounting brackets), and hence there is no room to move the screen entirely inside the body.

  6. You said “the finished camera will not be able to autofocus”. Did you have to remove autofocus parts to get the 5n to fit?

    Dan

    • Brendan Taylor

      The camera will use nikon lenses (or leica R lenses) and not sony E lenses. Although it may be possible to create an electronic adapter to transmit lens data/controls there are currently none on the market, which means its probably not straightforward (at least for the autofocus) and not a task I want to take on right now. To be honest, it’s not a feature I care about greatly for this camera as most of my lenses are manual focus, and even if autofocus was achievable it would be very slow.

      • I was thinking of leaving the 5n in manual focus and let the Nikon do it’s normal film focus with Nikon lens.

      • Forget my earlier message. I saw my Minolta SR-3 in the closet which reminded me the old cameras do not have autofocus! I am thinking of converting a EOS 3 to digital and got carried away.

        Dan

  7. This is a very beautiful piece of work! Don´t you have a problem with the backfocus because the tolerance is 2/100 mm. If the tolerance is bigger there won´t be a sharp image.

    • Brendan Taylor

      Thanks. Not on a mirrorless camera, its not so problematic as the focus is done on sensor, and the NEX’s allow for focus microadjustment. As long as the sensor is even a fraction of a mm closer to the lens than the standard flange focal distance, then I will have no problem focusing at infinity too.

  8. Hey, awesome work so far, keep it up!

    I’ve been planning a similar project for a while now, but i plan to use an F3 as the donor camera, putting the internals into a Canon AE-1 Program.

    The lovely thing about the NEX cameras is that their internals are linked via ribbons instead of having the different components and mini boards hard soldered to the main board. This allows many elements to be relocated without too much hassle.

    My only set back so far has been budget, as im pretty limited with funds right now.

    I plan to start with the EVF and make sure it can be fitted into the Canon, then move onto the body. I am going to keep the E mount as it allows me to use a wider range if lenses using adapters, in particular the metabones speedbooster, which maintains focal length and actually boosts speed by up to a stop. This would come very close to a digital 35mm conversion in a very beautiful body.

    Space permitting, ill try to retain the power and shutter of the AE-1, and if possible, it would be nice to relocate the command dial to either the shutter dial or ISO dial / film winder.

    Im a little worried about the location of the SD card though, as it would put it in line with the tripod mount. If it can be relocated easily, i may have to sacrifice the tripod mount.

    Im going to try and keep the F3 body as intact as possible, only breaking it down when absolutely necessary.

    I think one of the main reasons we have not yet seen a viable digital back solution for 35mm cameras, is the reason you mentioned in your brief. There is not an easy solution to communicate with the digital back. Some kind of pc port or flash hot shoe link might work, but with so many different 35mm bodies, a versatile solution will be difficult.

    I think manufacturers need to keep things simple and focus on handling rather than features. As an Epson R-D1s user, and having owned a lot of different cameras over the years, i am yet to see a digital SLR camera that im willing to spend serious money on. I think Sony and their transparent mirror tech will help lead the way with a truly great full frame SLR system. When that is though, who knows.

    Anyway, awesome job so far, keep it up, ill be watching closely.

    P.S Any chance you could post or email me some photos of the EVF internals? I have not got an EVF of my own yet.

    Cheers.

    • Brendan Taylor

      I’d be interested to see your progress. I’ve had this project on hold for a few weeks now as I have some other immediate priorities I need to attend to in life, but hope to finish it up soon. I have some good plans for digital backs on the leica M cameras, as I figured out a good way of communicating the shutter release to the back, but the market is very finite and diminishing everyday. It would take a fair amount of cash to bring it to market, although 100% doable. Problem is a full frame sensor would need a custom designed bezel/mount in order to place the sensor die right up against the film plane otherwise it would be a few fractions of a mm behind it causing infinity focus issues. Also the microlenses would need to be custom offset for M lenses. And custom means $$$. If you could produce one for $2,000 a piece I bet it would be popular. An M3 + digital back would still be less than half the price of an M 240. A dream sensor would be a full frame foveon. I would leave out all the bells and whistles. No screen. RAW output only, so no serious image processing required. Just controls on the back for ISO and power, with dials for battery life and shots remaining. I love the idea of the R-D1. If there was an R-D2 with modern fullframe sensor I’d be all over it. The analog dials are beautiful.

      I’ll try to post some pictures of the EVF internals soon

      • Thanks mate, that would be awesome.

        A FF Foveon (FFF?) would be amazing. I had one of the original DP1s and i still regard the image quality as some of the best ive encountered, considering the significantly less MP.

        Speed is a big concern with the foveon sensor, but if they can overcome that, they will be unmatched. I would love an SD1, but sadly i just cant afford one yet.

        Its a real shame Epson aren’t making more cameras, as the R-D1 is a truly one of a kind machine. The dials are gorgeous and anyone i show it to is immediately blown away by it. Cocking the shutter is a great touch, as its not only a natural feeling action, it also helps hide the cameras low memory buffer.

        I’d love to see a new one with an optional motor drive. That would be very cool and keep up the classic handling :-)

          • Thanks heaps for that!

            Im now leaning towards a 5n instead of an F3, as the F3 body is a bit taller, which must be due to the flash. It may not be much taller internally, only where the flash is, but the flash would no doubt create a bit more work. Going off rough measurements against the AE-1, it will be cutting it very close as it is.

            Just out of curiosity, does the NEX still function when the LCD is disconnected, but the EVF is connected? Im quite happy to go without the LCD all together if the NEX can function without it. It will be a tight squeeze anyway, and i think it will make for a more classic feel to the handling.

          • Brendan Taylor

            No prob. Yes the camera should work with the evf even if the LCD is disconnected. And I agree if I did it over again I would ditch the LCD and just go with the EVF. If you do open up an F3 be very careful around the flash and its capacitor. It will give you a hell of a shock.

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