Leica M full frame CCD sensor camera DIY prototype - with pictures!

[yongfei]

<p>Shutter in front of 35mm/1.4 lens</p><div></div>

[yongfei]

<p>Here is the result. I think my #1 Copal shutter is the main reason for causing the circled dark corners. But it is still not clear if the lens itself is also causing the vignett. Because the shutter caused vignett is obviously the dominate factor here.<br>

Conclusion: I can't do any further test with a #1 Copal shutter. A No.3 sized shutter may solve this problem and to continue the test, but unfortunately I don't have a No. 3 shutter. <br>

So please don't the 35/1.4 coverage based on this photo. I think most likely t is caused by shutter!</p><div></div>

[yongfei]

<p>So I moved on to test 50mm Summicron with the same approach:</p><div></div>

[yongfei]

<p>Same dark corners. But much better as it is a normal lens. I also tested the Industar again with the shutter in front of lens approach. It is further better than Summicron's as expected, because it is a 55mm lens.<br>

But again, this is purely because the shutter's openning circle is too small. I think 50mm Summicron will fully work. Tomorrow, I may change to shutter behind the lens configuration and do some outdoor testing under daylight condition.</p><div></div>

[yongfei]

<p>Now comes the fun part. I have a PK Sigma 24mm/2.8 lens that will have an almost correct flange distance (for Pentax) if the shutter is mounted behind. So I tried this setup for test the retrofocus wide angle coverage on Leica M: </p><div></div>

[yongfei]

<p>Surprise! This lens has the full coverage on Leica M!<br>

So it somewhat proves that if we can adapt some Nikon (Zeiss ZF) or Pentax lenses with an adaptor, we will have decent coverage on a full frame Leica M.<br>

If the new Leica wide angle lenses are refrofocus SLR type design, then Leica should be able to design a full frame Leica M. Otherwise, we can at least use some SLR type lens with a rangefinder focus coupled adaptor. But you need to manually transfer the distance value to the lens. Those adaptors were used to be available at Cameraquest.<br>

Tomorrow, I will do some outdoor testing with this Sigma 24mm and Leica 50mm Summicron. I truely appreciate your conitnued interest and support, which give me the motivation to carry on further at the risk of dropping my dimond-like lenses or scratching the jewelry-like CCD:) </p><div></div>

[samoksner]

<p>Keep it up, this is a very good idea and it has a lot of potential! The way I see this developing is by removing the rear door on an M5 (or any other M) and mounting the sensor right where the film would be. With some precise testing and adjustment I could see this working nicely and it would alow you to mount lens using the mount and even focus them regularly. The trick would be in mounting your sensor properly behind the shutter and then turning it on before the shutter opens (maybe using the flash sync?)<br>

Good Luck</p>

[yongfei]

<p>Dear Peter, thanks for your poetic and encouraging words. Actually I am just a junior software programmer who spent most of his free time on photo websites in stead of IT forums. So I am more worried about my own daily job rather than trying to immitate that great Jobs:) <br>

For all those years, I have been reading all kinds of photo newsgroups without any real contribution or purpose. There have been so many outstanding photographers, so many rich collectors etc. But tonight, I feel very happy and fullfilled, because at last I am able to contribute with an important experiment on the feasibility of full frame Leica M - one of the hottest on-going topics here.<br>

As this prototype goes, my major objective is to have some idea on the Leica lens coverage. I have a Hasselblad camera that is what this back was bought for. And I will get a Horseman Digiflex soon. Because this is a thethered back, it is not suitable for Leica M style photography. But my long term objective is to get a Hasselblad CFV back. Once I have that, I will improve this prototype with viewfinder and a fotoman style external manual rangefinder etc. That will become an Apla style high end camera. But it will be a very portable solution, with the advantage of being able to easily change the lenses on site.</p>

[yongfei]

<p>Best news ever! Mission accomplished!<br>

After writing my above reply to Peter, I turned off computer and went to bed. It's been a long night for me, and I was happy with what I have accomplished so far, and was thinking about test plans for tomorrow. Suddenly with a strike of genius, I realized that I don't even need a #3 shutter to test the 35/1.4. I can turn off the light and test it in darkness, with shutter used only to trigger the back!<br>

So I got up from bed, hooked up everything and took this picture: Leica 35mm/F1.4 Summilux ASPH at F11. I have to say, the result is astonding, much better than I have hoped for! Now this is Leica lens quality, this is the full frame 35 wide angle result you've been waiting for so many years. It's here, it's here!</p>

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[yongfei]

<p>The above picture has no color calibration whatsoever, straight from the camera. With my limited photoshop skill, I did a little adjustment and made the following 100% crop. The image is of high quality and very solid. </p><div></div>

[reinier_de_vlaam]

<p>It is a long time since I was on photonet but now I flabbergasted and need to express my respect for your little expiriment...lets just say "wow" that must be so much fun to do that I'm tempted to also buy a random digital back..</p>

[yongfei]

<p>With the above picture, I thought I have beautifully finished my Leica 35mm/1.4 testing, and detached my back. But suddenly I realized that I need to test this lens wide open at F1.4! Otherwise, you guys will bug me everyday for that photo. So here it is:)<br>

It has some purple coloration, but I think it can be easily fixed in software, or even automatically by using a 6 bit profile specific for this lens. (note: another possible reason for the purple color could be the flash light is striking directly into my lens. Notice how the wall above the cabinet is acting like a mirror in this photo. So the result at F1.4 could be better!)<br>

Now I am done with the Leica 35mm/1.4 testing. Please ask a lot of questions to validate my test procedure, but please don't ask me to test it under daylight. It is a too dangerous setup. During the above testing, I wished I had three hands to hold everything together, and a forth hand to catch something that might drop on ground. I was reallly risking with my Leica lens and digital back for nothing:)<br />Any comments? If my test is valid, we need a volunteer who has a good PR skill to talk to Leica company about those "individual" findings, and hear their comments:)</p><div></div>

[lookupinwonder]

<p>Yongfei, your are definitely on to something here.<br>

The only reason that Leica won't/can't do FF is that the traditional wide angles would suffer too much (corner vignetting) to be usable wide open. Or so it seems from your experiments. But normals work!<br>

But as you say, there would be no problem with retrofocus designs. If Leica purists would swallow that is debatable, but it COULD work.</p>

[yongfei]

<p>Ronald, if my above testing has no major flaw, it proves that this 35mm F1.4, which could be the most important lens in Leica M family, works almost perfectly. What more can the Leica purists ask for other than this lens mounted on a full frame Leica M?<br>

I have no other Leica/Zeiss ZM wide angle lenses to experiment to approve or disapprove my assumption about the image coverage of existing wide angle lenses. So Leicaphiles, now it's the time to donate your Leica/Zeiss lenses to me for some further testing:)</p>

[doug herr]

<p>"... if my above testing has no major flaw, it proves that this 35mm F1.4, which could be the most important lens in Leica M family, works almost perfectly"<br /><br>

Sorry, the above photo demonstrates quite the opposite to me.</p>

[vivek iyer]

<p>I concur with Doug.</p>

[ken_ford1]

<p>Doug, Vivek - doesn't the 35/1.4 vignette that much at f/1.4 on film?</p>

[yongfei]

<p>Ok, I might be getting a little too excited after "working" more than 12 hours on this experiment. I presented the photo as it was shot, knowing that they can be improved in the software.<br>

The F11 shot was obviously under exposed by at least 1 stop. Here is an adjusted picture with level and white balance. I have no complaints on this photo. Much beyond my expectation after the failure of the above #1 shutter before the lens test approach.</p>

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[yongfei]

<p>Now for F1.4 shot, there were three variable factors. One is my monolight flash on the left side in a 3x5 foot softbox that could overpower the shooting table. The other factor was the strong lighting was directly reflected from the wall into the lens (I didn't put on the lens shade, and had an uv filter on it), like shooting towards the sun. Also, this one was taken further away than the F11 shot, making the flash lighting to be more uneven.<br>

Now I would agree that the "raw quality" at F1.4 might not be acceptable to someone who use it all the time. But I am still not sure unless I have a safe way to shoot it under natural lighting condition which is Leica M mostly used for.<br>

Here is the white balanced F1.4 photo with the vignetting adjustment in Photoshop. Acceptability is in the eyes of beholders. But again, unless I have a chance to test under available natural light, I won't judge F1.4's performance based on this single picture.</p><div></div>

[zhengs photos]

<p>Hello Yongfei, thanks for sharing the DIY project! One quick question for the f/1.4 photo, where did you focus on?</p>

[yongfei]

<p>Hi Bruce, this is a very interesting question:)<br>

Actually this is a prototype camera built with floppy disks and duct tapes. So currently I had no control of focus at all, because the focus scale is not accurate.<br>

But I did show that my previous F11 picture was focused on the cabinet. Because I moved back a little bit, so I expect the focus would be somewhere a little bit closer. Sure enough, the focus is on the copier paper! Here is a 100% of the above F1.4 photo.</p><div></div>

[nathancraver]

<p>Wow! I am truly impressed with what you are doing. You just don't hear about people doing this kind of thing anymore. You may very well end up starting your own line of cameras. I think it is very cool and retro that you used floppy disks to make the lensboard. Keep it up, I love this sort of experimental DIY stuff. It shows that creativity (as far as electronics go) is not dead. I myself am developing a cost-effective and useful LED lamphouse for my Beseler 23C enlarger.</p>

[yongfei]

<p>As planned, today I start to test the Sigma 24/2.8 first. Again, it was a lot of work to get it into some kind of correct focus.<br>

I feel that the color presentation of this digital back is very neutral.</p><div></div>

[yongfei]

<p>100% crop of the left side tree.</p><div></div>

[yongfei]

<p>Now I need to test 50mm Summicron. Because I have a shutter after the lens, I can't get it to focus into infinite. What do I test then? Well, that famous out of focus bokeh:)<br />I think the lower dark corners are due to my lens plate openning is not big enough. So it is a little out of alignment with the back. No big deal.<br>

With these pictures, I have finished all my Leica M full frame camera prototype testing. In the past years, I've been reading many discussions about this full frame sensor topic, but have seen zero pictures. As people say, one picture is worth thousand words.<br>

Hopefully it is just a marketing decision that Leica doesn't want to pursue the full frame M. I believe the situation was similar to where Nikon was a few years ago, when Nikon executives insisted that DX format should be enough for professional use. This experiement suggests that, maybe, Leica M full frame is indeed achievable using the current CCD/CMOS technology together with some customized post processing software.</p><div></div>