Author Topic: Adapter thread. The new Lords of the Rings.  (Read 3951 times)

Akira

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Re: Adapter thread. The new Lords of the Rings.
« Reply #120 on: May 22, 2020, 13:50:04 »
I also use the ZM39 Helios-44 with M42 to Z adapter as first image shows. Then I first mount a M39 to M42 ring that keeps the same flange distance.
But infinity focus is just not there. It is close. I am sure it is the missing 0.26 mm. If I stop down I can "hide" the error. It is the same with both Helios 40 and 44. Lenses can probably be "re-adjusted" to be "real" M42 lenses like Pentax M42.

2nd image is with Helios-44 and is about as far I can focus. It was stopped down to f8. I could focus on wall but not at roof.
3rd image is as close as I can focus at full aperture just to test the lens. It is quite sharp even wide open. I need other kind of images to evaluate the bokeh. 

I took it granted that M42 and Zenit M39 mounts share the same flange back.  Industar 50 is the only Zenit mount lens I've ever had and had no problem with the M42 adapter.  It is a 50mm f3.5 lens and show quite strong field curvature.  So, its relatively large DOF and pronounced field curvature made the infinity focus error unnoticeable. 
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"Limitation is inspiration." - Akira

Alaun

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Re: Adapter thread. The new Lords of the Rings.
« Reply #121 on: May 22, 2020, 14:15:06 »
The Noflexar have a 50mm opening on the backside, ending with a rim and the inner surface is riffled. That is perfect to put a filter glass in from a 52mm filter and thanks to the riffles, you can make a little spring to fix the filter. Seems to work perfectly for UV  :)



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      ner         ste

Frank Fremerey

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Re: Adapter thread. The new Lords of the Rings.
« Reply #122 on: May 22, 2020, 15:56:39 »
The Gem arrived! OM Zuiko 1.2/55mm (1982): http://www.mir.com.my/rb/photography/hardwares/classics/olympusom1n2/shared/zuiko/htmls/50mm.htm

Wonderful dreamy rendering at f/1.2
You are out there. You and your camera. You can shoot or not shoot as you please. Discover the world, Your world. Show it to us. Or we might never see it.

Me: https://youpic.com/photographer/frankfremerey/

MEPER

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Re: Adapter thread. The new Lords of the Rings.
« Reply #123 on: May 22, 2020, 16:32:32 »
I took it granted that M42 and Zenit M39 mounts share the same flange back.  Industar 50 is the only Zenit mount lens I've ever had and had no problem with the M42 adapter.  It is a 50mm f3.5 lens and show quite strong field curvature.  So, its relatively large DOF and pronounced field curvature made the infinity focus error unnoticeable.

There is a little bit of a difference. The "lens man" from Ukraine also suggest that the adaption was made on M42 adapter. Then I took a close look at the adapter and found out it is a 3 piece construction. The 42mm thread, a spacer and the Z-mount extender. The spacer is 1.5mm thick and if I just remove that then Helios-44 can infinity focus and a good way past infinity. The Helios 40 also works. It just sit a little bit deeper in the mount but not as deep as the Helios 44.
If I can find a spacer at about 1.2 mm it would be perfect. Spacer is 50mm in outer diameter and 36-37 inner diameter. So that was quite a "quick fix". I was not aware the M42 adapter had that construction.

Akira

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Re: Adapter thread. The new Lords of the Rings.
« Reply #124 on: May 22, 2020, 19:00:14 »
There is a little bit of a difference. The "lens man" from Ukraine also suggest that the adaption was made on M42 adapter. Then I took a close look at the adapter and found out it is a 3 piece construction. The 42mm thread, a spacer and the Z-mount extender. The spacer is 1.5mm thick and if I just remove that then Helios-44 can infinity focus and a good way past infinity. The Helios 40 also works. It just sit a little bit deeper in the mount but not as deep as the Helios 44.
If I can find a spacer at about 1.2 mm it would be perfect. Spacer is 50mm in outer diameter and 36-37 inner diameter. So that was quite a "quick fix". I was not aware the M42 adapter had that construction.

Lucky you!  That could be the solution good enough to use these lenses, unless maybe you zone-focus with the wideangles.
"The eye is blind if the mind is absent." - Confucius

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MEPER

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Re: Adapter thread. The new Lords of the Rings.
« Reply #125 on: May 22, 2020, 19:30:08 »
Lucky you!  That could be the solution good enough to use these lenses, unless maybe you zone-focus with the wideangles.

Yes, I think it will be fine. I can look for a thinner spacer ring but probably not easy to find one that just fits. What I observed was that the 42mm thread ring has conical surface where the 3 set screws locks the ring. And according to my knowledge the ring was inserted reversed. I inserted it so set screws will press on the conical surface so ring can not easily fall out if set screws go loose. Maybe other with Pixco M42 adapters can check that. Set screws was on the "loose side" when I unscrewed them.

MEPER

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Re: Adapter thread. The new Lords of the Rings.
« Reply #126 on: May 25, 2020, 21:59:27 »
Just a small update on my use of Zenit M39 SLR lens using M42 adapter adjusted so infinity focus is possible.
I tried Helios-40 which is a large lens for the Z50 2nd image is just a test for infinity sharpness stopped down. It was overcast but I was surprised that stopped down this lens is sharp and I did not see any CA. 3rd image is a 100% crop. 4th image is at full aperture (f = 1.5) just to get a feeling for bokeh. I did not find anything real exciting on the short walk I had. But lens may be fun to use for some special "bokeh" images as lens seems sharp enough wide open if focus is "nailed spot on".