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Zoomar 75mm/1.3 – first impression on the G1

petermcwerner

petermcwerner

Member
View attachment 11626


In my collection I had a 75mm/1.3 Kilfitt Zoomar, http://www.kilfitt.org/Lenses/Zoomar_75.htm that I had never been able to use before. It is an odd lens that has both a C-mount and a Leica screw mount attachment. As I have not yet received the ordered C adapter, I tried attaching it to the G1 via the LSM. It turned out that I could not focus on anything, it needed a spacer. I am not very good with my hands, so I looked for the thinnest LSM extension ring I could find, a 17675 X that adds approx.10mm. It proved too long and set at Infinity the lens would focus at about 30cm.

I was impatient to get some results. Although this is not a macro lens, I decided to take an orchid at approx. 30cm . On the first image, I drew a black circle on the point I focused on.

The good surprise: it covers the whole sensor without any vignetting. Fully open, as is to be expected the DOF is minimal,

View attachment 11627

Zoomar 75mm on the G1 at f/1.3 - a bit on the soft side


View attachment 11628

Zoomar 75mm on the G1 at f/2.8 - already quite sharp



View attachment 11629

Zoomar 75mm on the G1 at f/5.6 - sharpness is excellent


I am looking forward to the C adapter, hoping that it will allow to focus correctly. On the other hand, I also wonder whether a C-mount adapter on the G1 will bear the weight of the lens, approx. 500g on my kitchen scale Otherwise I would need a thinner extension ring to continue using the LSM

I shall be glad for any tips.
Peter
 
M

monza

Active member
Impressive glass. :) My concern is the diameter of the rear of the lens, it may not fit as the c-mount is recessed into the G1. I would venture that the G1 is supported by the lens, not the other way around. :) So things should be ok in that regard.
 
m3photo

m3photo

New member
Re: Weight Distribution

monza said:
I would venture that the G1 is supported by the lens, not the other way around. :) So things should be ok in that regard.
Click to expand...
IMO quite the contrary considering the aspect of manual focus. I'd say such added weight would put quite a strain on the lens mount; if you're holding the combination in your right hand by the camera's grip and fine focusing with the left very little support must be coming from this hand. ?????
 
M

monza

Active member
If it were me, I wouldn't hold it that way. On a tripod, though, would have to be careful.
 
V

Vivek

Guest
petermcwerner said:
View attachment 11626


I am looking forward to the C adapter, hoping that it will allow to focus correctly. On the other hand, I also wonder whether a C-mount adapter on the G1 will bear the weight of the lens, approx. 500g on my kitchen scale Otherwise I would need a thinner extension ring to continue using the LSM

I shall be glad for any tips.
Peter
Click to expand...
Peter the c-mount adapter from Rabe weighs ~10-15gms. A nice and tight fit on the G1. If you hang this lens on the G1 using that adapter, it will rip the mount right off.

Make some approximate measurements about the length of the LTM adapter tube you need and let me know. I only have one or two thin LTM extension tubes (i think 5 or 6mm long).
 
petermcwerner

petermcwerner

Member
Vivek said:
Make some approximate measurements about the length of the LTM adapter tube you need and let me know. I only have one or two thin LTM extension tubes (i think 5 or 6mm long).
Click to expand...
Vivek, thank you for your offer. I had ordered an OUFRO from Austria, it should arrive any day now, I shall try that one and if does not do the job I shall come back to you.
 
petermcwerner

petermcwerner

Member
3 items arrived today in the mail: the OUFRO, the Chinese M->MFT adapter and the Rabe C-Mount->MFT adapter. The C-Mount does not fit the lens. I did not notice in time that the second thread on the back of the lens looks similar to c-mount but must be something proprietary, so the only one I can use is the LSM

Vivek said:
Make some approximate measurements about the length of the LTM adapter tube you need and let me know. I only have one or two thin LTM extension tubes (i think 5 or 6mm long).
Click to expand...
- The OUFRO is of no use

- W/o adapter tube (directly on the LSM->MFT adapter) I can focus on infinity when the distance scale shows 5 meters but I cannot focus any nearer than approx. 4 meters (2.5m on the distance scale)

- With a 7.5mm adapter (the shortest I have now found) I can focus between approx. 1.5m and 5m

- With a 10mm adapter I am limited to approx. 30cm +/- 5cm

When focusing the lens, the back of the lens does not move; the front of the lens extends some 7 cm between infinity and minimum distance (2.5m on the scale), there must be some internal focusing also taking place.

With this, for me it seems quite difficult to determine the correct extension needed, as I have no optical bench or other measuring possibility, It must be somewhere between 0 and 7.5mm

Thanks for any suggestions.
 
V

Vivek

Guest
It looks like you need to get someone to fit an adapter/extension for you.
 
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