Convert G lenses to Leica M-mount

If the G1/G2 lenses have a slight advantage optically over th ZM lenses, can this be actually seen from the optical designs?
 
raid said:
If the lens cost you $100, did the conversion in Japan cost you only $500?
I thought that it was $700.
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The price for a conversion of a provided lens by yourself is not shown on JapanExposures web site, where all price include a lens sourced locally.
Actually a G45 conversion is quoted ¥54,000 versus ¥68,000 for a pre-converted lens.
raid said:
If the G1/G2 lenses have a slight advantage optically over th ZM lenses, can this be actually seen from the optical designs?
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As both designs are symmetric ones (opposite to retrofocus for SLR) you cannot. At least you can think of the more lens elements, the less aberrations you will get, but it's not always true. Based on Zeiss official MTF figures, the G21 is slightly better than ZM21 (and Elmarit ASPH 21) for vignetting and distortion. But those figures don't tell anything about flare resistance, handling, mechanical quality, ... :)
 
F.Rokkor said:
As both designs are symmetric ones (opposite to retrofocus for SLR) you cannot. At least you can think of the more lens elements, the less aberrations you will get, but it's not always true. Based on Zeiss official MTF figures, the G21 is slightly better than ZM21 (and Elmarit ASPH 21) for vignetting and distortion. But those figures don't tell anything about flare resistance, handling, mechanical quality, ... :)
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Forgive me : actually ZM and G 28mm are symmetrical designs.
For 21mm, the ZM seems a retrofocus design while the G isn't.
 
Sorry for the delay. I had some trouble with the RFF console this morning and then had to go to work (imagine that). Here are a couple of quick pix of the G45 Planar. You can see the small focus "tab" on the one shot. The lens is actually a joy to use re-barreled like this. The one thing I would like is click stops for the aperture. On the other hand some of my old Zeiss Opton lenses have none and it does not bother me. In heavy sun with a UV/IR cut filter on I use a G90 hood. It is a bit large but does not vignette on either the M8 or R d1s. When I don't have that filter on I use a small vented hood.
Not sure what the consensus is but I think those damn cut filters flare too much for "Naked" use. The price was 52000Yen at the time for conversion plus another $100 for the lens and I suppose another $40 for a LTM-M adapter. I will get the G21 and G28 done this fall if it goes as planned. The 90 I'll take a pass. I just don't use anything longer than 75 on an RF.
 

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I haven't ordered any of the converted G-lenses (yet) but I just wanted to say that Dirk and Kurt are stand-up guys. Service and communications are top-notch. I've ordered some books from them as well as a Hirano leather case for my Spotmatic II (happens to be the first Spotmatic case that Hirano Kazuhiro made :) ).
 
I may get the 45mm Planar converted one day.
It is the only lens for me that I value enough to spend $500 on to have it converted.
 
I have had a nice email correspondance with Dirk also (before and after ordering the lens), and the service provided is great as well.
 
I too have just the best experience dealing with Dirk Rosler from Japanexposures. He was very helpful. I had the G Sonnar 2.8/90mm converted for M8 recently and the quality of conversion is very good and solid. The focusing is light, the whole lens rotates. The aperture has no clicks, therefore sometimes gets changed by accident when focusing. I have to learn to feel the grip of the "focusing ring" - the ring on the lens is unfortunately ribbed only from 2/4. Here are some examples of shots wide open from M8.
Andrej
 

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... more samples at 2.8:
 

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I did a simple focus test of the converted G-Sonnar lens on Leica M8. I was pleasantly surprised that I could not find any focus shift at different apertures. The focus accuracy of this lens is also incredible. Most of my Zeiss ZM lenses show more or less focus shift at low apertures (especially the 1.5/50mm ZM Sonnar).

The test photos of the G-Sonnar are here:
http://members.chello.sk/akratky/Tests/G-Sonnar_2.html
To see higher resolution files click on the thumbnail and then "Download".

The previous sample pictures at higher resolution are here:
http://members.chello.sk/akratky/Tests/G-Sonnar.html
I like the bokeh of this lens.

Andrej
 
honpan said:
I have a weird idea. Would it be possibly more economical to remount the G lens to old Contax/nikon mount, and then use it with Contax/nikon>Leica M adapter?
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No it's not, because of register distance of arround 2cm for Leica M & Contax G lenses versus arround 4cm for Contax/Yashica, Nikon F, whatever 24x36 SLR mount...
 
F.Rokkor said:
No it's not, because of register distance of arround 2cm for Leica M & Contax G lenses versus arround 4cm for Contax/Yashica, Nikon F, whatever 24x36 SLR mount...
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I think he probably means for the contax or nikon rangefinder mount, not the SLR's.

Since the contax G lenses don't have a focusing ring, I see where the OP is going with this- the nikon/contax RF mounts have a built-in focusing helical. But only for the 50mm lens I believe. So I think we'd run into issues anyway here, since we'll have to figure out some way of focusing the lenses, NONE of which are 50mm... (45mm being the closest)- might as well convert them direct to M or LTM.

-Brian
 
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