[Leica] OT: Advice needed: Franken-lens choice for XPan

[henningw at archiphoto.com (Henning Wulff)]

>OK, if we have a lugger who uses electron microscope to check out 
>lens coating, I am sure your collective wisdom will give me much 
>insight on the following subject. Bear with me please, or delete if 
>not interested.
>
>As you may know, XPan has a ultra wide 30mm lens in this lineup. Its 
>performance is top notch. Unfortunately, it's F5.6 and since it 
>vignettes like crazy, it requires a 1.5 stop center filter, so it's 
>really a F8 lens, at best. So my thinking is that, I will have a 
>faster lens of similar focal length converted to work with the XPan. 
>I have found a mechanic who is willing to RF couple lens of my 
>choice. Their work on my converted Summicron 50R is excellent so I 
>have no doubt that they can do the job. I do have a XPan 30mm lens 
>already.
>
>So my choices are:
>- Give up and continue to use my 30mm lens
>CON - slow speed...
>
>- convert a 645 35mm/4 lens.
>PRO - relatively cheap, and certain lens reputedly are stellar 
>performers (at least for a medium format lens)


Compared with the 30 Xpan lens, the 35 Mamiya is a dog. Don't bother. 
I have both lenses, and even though I've used the 35 Mamiya quite a 
bit, I got a Hasselblad SWC as a complement to my 645 outfit because 
of the 35's poor performance. It's useable, to the same degree that 
the old 40/4 Distagon is useable, ie, rather minimally.




>CON - the XPan flange to film distance is short by about an inch so 
>a long "tube" is needed. I worry that this may cause the lens to 
>cast a shadow on the XPan's panoramic format
>CON - 35mm focal length is not quite 30mm
>
>- convert a PC Distagon 35/2.8
>PRO - supposedly a stellar lens
>CON - more expensive than the Nikkor, but cheaper than the Schneider.
>CON - 35mm focal length is not quite 30mm
>
>- convert a shift 28/3.5 Nikkor
>PRO - relatively cheap.
>CON - the performance is good, but is it "good enough?" Vignette at 
>the corners and does not cover the full XPan format, may be 24x62 
>rather than the 24x65.
>
>- convert a shift 28/2.8 Schneider (aka Leica R PC Angulon)
>PRO - um, possibly better than the 28/2.8 Nikkor
>CON - expen$ive. Reputedly not a stellar lens, whatever that means.
>
>Thoughts? Suggestions?


The 28's are fairly decent lenses, but certainly not up to the 
performance of the 30 Xpan. Also all these solutions vignette 
slightly not due to the optics of the lens, but the Xpan lens mount 
flange.

I think that in terms of performance, your best be is the 35/2.8 
Canon T&S lens in FD mount. That lens has significantly higher 
performance than the 28's mentioned, and the image circle is also 
larger. The best shift lens I've tried for 35mm. The aforementioned 
physical vignetting will still be an issue though. The PC Distagon is 
I believe the only lens I have not tried.

But again, if you have the 30 you'll be quite unhappy with anything else.



>At the moment, I am leaning toward the Nikkor as it is relatively 
>cheap solution. If I have it converted, even if the performance is 
>not stellar, I am almost certain that I can sell it, as the 30mm is 
>quite expen$ive so a cheaper alternative should find a buyer.
>
>// richard (This email is for mailing lists. To reach me directly, 
>please use richard at imagecraft.com)
>
>_______________________________________________
>Leica Users Group.
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-- 
    *            Henning J. Wulff
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