Zeiss (Germany) offers new service

[Grober]

I quite like my Biogon 25mm ZM lens. I use it for both film and, when I get my M8 back from Leica Germany, intend to use it on the digital camera as well. However, the lens would work better on the M8 if it's lens mount invoked the more proper 24mm frame in the camera instead of its current selection of the 28mm frame.

I am aware that it is possible to file down one of the lugs of the Biogon's rear lens mount to then make the camera think a 24mm (or 35mm) lens has been mounted. But given my high school metal shop skills, I would surely butcher the job horribly. Two months ago I launched a query on the Zeiss website to inquire about the cost of having Zeiss change the mount. The quickly replied that they were studying the question.

This morning I received an e-mail from the same gentleman indicating they would change the Biogon's lens mount for a fee of 40 Euros + shipping costs. I believe that's a fair cost to have the mount properly changed by the manufacturer of the lens. I'll now investigate the roundtrip shipping costs that I'll need to bear.

I'm still looking for a service source for professional 6-bit coding of non-Leica lenses.

-g

 

[Huck Finn]

I quite like my Biogon 25mm ZM lens. I use it for both film and, when I get my M8 back from Leica Germany, intend to use it on the digital camera as well. However, the lens would work better on the M8 if it's lens mount invoked the more proper 24mm frame in the camera instead of its current selection of the 28mm frame.

I am aware that it is possible to file down one of the lugs of the Biogon's rear lens mount to then make the camera think a 24mm (or 35mm) lens has been mounted. But given my high school metal shop skills, I would surely butcher the job horribly. Two months ago I launched a query on the Zeiss website to inquire about the cost of having Zeiss change the mount. The quickly replied that they were studying the question.

This morning I received an e-mail from the same gentleman indicating they would change the Biogon's lens mount for a fee of 40 Euros + shipping costs. I believe that's a fair cost to have the mount properly changed by the manufacturer of the lens. I'll now investigate the roundtrip shipping costs that I'll need to bear.

I'm still looking for a service source for professional 6-bit coding of non-Leica lenses.

-g

Once modified, I guess you'll have the problem that it will bring up the wrong frame lines with your film body, i.e. 35/135 with a Leica M body & just 35 with a Zeiss Ikon. I guess that 28 made sense when the lens was designed, given that there was no M8 on the market & no camera with 24/25 frame lines. It sure would be nice to have a manual override for these auto fram selection cameras so that we could choose which frame lines we want for our 40's, 28's, 25's, etc.

 

[Grober]

Right. But with any film body (other than a Leica .58) I always use the Zeiss 25mm aux. viewfinder so I really don't care what the modified lens mount on my Biogon is invoking inside the camera. Bringing up the 24mm frame in the M8 with the 25mm Biogon lens is a big step forward.

I just wish Zeiss (or SOMEONE!!!) would offer a professional 6-bit encoding service too.

-g

 

[Huck Finn]

Some people have been using the 25 without an auxiliary finder & with 28 frame lines as a guide plus the full limits of the vewfinder as their extreme; they might mind if the lens brought up 35 mm frame lines. But otherwise your point is well taken.

I agree that Zeiss would be wise to offer the 6-bit encoding as an option.

 

[Kyle]

When I had my ZI and 25 ZM combo I actually wished that it would bring up the 50 frames or something. It would have made it easier for me to frame using the entire finder and I could simply ignore the framelines all together. Although I used it all the time, the 28mm framelines got in the way at times.

 

[Mazurka]

Leica's 6-bit encoding apparently doesn't transmit shooting aperture information and therefore doesn't correct light fall-off.

Does anyone know its actual function besides the transmission of focal length/max aperture to the EXIF? 😕

 

[rxmd]

What's the point of 6-bit encoding a non-Leica lens? All you get is extra EXIF data with wrong information in it.

If the camera applies any image correction based on lens coding at all, it will apply correction for a different lens. If you fool your M8 into thinking that your Biogon 25 is actually a Leica 24mm lens, it will apply correction for the Leica lens, and you're taking a gamble that this correction might actually produce positive results for the Zeiss as well. This will probably be counterproductive, since two lenses with similar focal lengths can be quite different construction-wise.

Philipp

 

[Nachkebia]

There was a post on leica forum (also a dedicated web-site) about self coding lenses with home gadgets for $5 😀

 

[Grober]

What's the point of 6-bit encoding a non-Leica lens? All you get is extra EXIF data with wrong information in it.

If the camera applies any image correction based on lens coding at all, it will apply correction for a different lens. If you fool your M8 into thinking that your Biogon 25 is actually a Leica 24mm lens, it will apply correction for the Leica lens, and you're taking a gamble that this correction might actually produce positive results for the Zeiss as well. This will probably be counterproductive, since two lenses with similar focal lengths can be quite different construction-wise.

Philipp

Thanks, Philipp for making some good sense with your comment.

I'm thinking I'll probably sell this lovely lens and buy the Leica 28mm Elmarit-M as a replacement. I save myself the angst of having to get the Biogon coded and a new rear lens mount installed.

-g