Canon 35mm LTM lens made from ''trash''

[juraj_v]

Hello folks, here is another project I made during the lockdown. It's a 35mm f2.8 rangefinder coupled(!) lens for LTM mount, which I made from various old lens parts. Donor for the optics was a Canon AF35M, better known as the Autoboy. I think it's a 4 element Tessar formula with multicoating. Little soft wide open, with rather strong vignetting, but very sharp and contrasty stopped down, with typical 80's look. The body of the lens was made from various junk lens parts I found at home, the helicoid is from Industar 50-2, the mount was from Industar 26M, the front plate is from Domiplan 2.8/50, the aperture from another lens....It was a trial-error type of work, so I don't have photos from the production, but it looks and works really great on my Canon P. The aperture is set by rotating the whole front plate, it has a focusing tab, it's also rangefinder coupled, which was the hardest part of the process. I sanded it a little, then checked, sanded, checked, sanded, checked, sanded, checked, sanded, checked.......The lens sits deep because the flange distance of the donor camera was very short, but this way the body works also as a built in hood/protection so there is no need for lens caps(which I hate anyway) and it's still very compact. hope you'll like it 🙂

 

[bennyng]

Wow! That looks like a fun project! Well done! Hope to see some images from the lens in the near future.

Cheers,

 

[Phil_F_NM]

How did you calculate the rate to grind your focus cam since 50mm and 35mm focus at different rates?
Phil Forrest

 

[juraj_v]

Wow! That looks like a fun project! Well done! Hope to see some images from the lens in the near future.

Cheers,

Thanks! Of course it was great fun 🙂 I'm still waiting for the first roll, I din't expect a big surprise cause I know how this lens performs on the original camera. The only difference is that the aperture is more complex/circular so the out of focus areas may look better.

 

[juraj_v]

How did you calculate the rate to grind your focus cam since 50mm and 35mm focus at different rates?
Phil Forrest

I used a self-made device, which I use for calibrating infinity on lenses, put the camera to tripod and start with the closest point of focus. I Sanded it down in many little steps to avoid oversanding, then compare the image in the rangefinder and the calibrator and make this over and over until they were the same, then focus a little further and make the same, and repeating this until I arrived to infinity. It took a really long time 😀 Here is my self-made infinity calibrator:

 

[juraj_v]

Wow! That looks like a fun project! Well done! Hope to see some images from the lens in the near future.

Cheers,

This one was made with digital, but it's APSC (Fuji XE-1) so the image is cropped to ca 52mm focal lenght. Pretty sharp lens 🙂

 

[charjohncarter]

I have a Canon AF35m and it has a very sharp lens: one of the first AF cameras. Too bad it eats batteries like that goat.

 

[valdas]

That’s great.
And I am also impressed with that infinity calibrator. A good idea to steal (or borrow)...

 

[juraj_v]

I have a Canon AF35m and it has a very sharp lens: one of the first AF cameras. Too bad it eats batteries like that goat.

That's true 😀 But this can be solved today easily, with rechargeable ones.

 

[juraj_v]

That’s great.
And I am also impressed with that infinity calibrator. A good idea to steal (or borrow)...

Thanks! Feel free to steal 🙂 The focusing screen has a split prism and there is also a strong magnifier glass so it can be used very precisely.

 

[keytarjunkie]

Great project, the lens is very cool but I love the DIY focus calibrater most of all!

 

[David Murphy]

Super work - thanks for sharing!

 

[farlymac]

That worked out very well. Maybe this will generate a market for all those AF35M's I've got laying around. ;-)


PF

 

[charjohncarter]

That's true 😀 But this can be solved today easily, with rechargeable ones.

You missed a ? mark, but I do it all the time so my old nuns will not hit you with a ruler. I never tried that (rechargeable batteries) I would rather have a set up like yours.

 

[OlivierAOP]

Nice! Can you share more details about the cam grinding? I've been trying to put a customised 40mm lens on a Zorki-6 (panoramic conversion) but can't figure how to couple the RF to it...

 

[juraj_v]

Great project, the lens is very cool but I love the DIY focus calibrater most of all!

Thanks! Yes it's a very handy tool, also pretty easy to build.

 

[juraj_v]

That worked out very well. Maybe this will generate a market for all those AF35M's I've got laying around. ;-)


PF

I'ts easily possible 🙂 That's the only way to resurrection for these electronic point and shoots, the lenses are generally much more time proof than the bodies.

 

[Fraser]

very cool.......

 

[das]

Great work. Love the conversions folks are doing these days.

 

[juraj_v]

Nice! Can you share more details about the cam grinding? I've been trying to put a customised 40mm lens on a Zorki-6 (panoramic conversion) but can't figure how to couple the RF to it...

Thank you! Honestly, i don't recommend my method, it was very unscientific and there was a big space for errors...it was a combination of very slow, precise work and good luck that it worked well at the end.