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01-22-2018, 02:24 PM   #16

Join Date: Feb 2009
Location: Arizona
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QuoteOriginally posted by optikus Quote
last week I got a non-EDIF 300mm f4 in near mint condition for a minimal invest,
There is a reason why the old 300 is cheap--- No tripod mount, some tertiary spectrum seen wide open, contrast is only fair, very susceptible to shutter vib when used on the 67.

01-23-2018, 12:16 AM   #17
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Join Date: Dec 2017
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Original Poster
Hello Desertscape,

the mess with the missing tripod mount is the dominating problem I think, also as it intensifies the vibrations if you have the lens attached to the 67 without a point to stabilize the setup nearer to the front... - as I wrote I use it with a EOS 1Ds MkII - how the hell use the tripod mount of the adapter???

With a better hood contrast now is ok as I found, I'll try it with a polarizer the next days if the weather will be better as should be as the told in the tv. A rear filter would have been nice also with such a voluminous lens, but we have none.

The lens itself mechanically as Pentax produced it is very fine, the parallel developments of Pentacon and Zeiss Jena for the SIX are archaic in comparison with it. And even heavier, but with tripod mounts. The problems with contrast when the szene is not lighted exaktly from behind with the delivered hoods of the Pentacon 4.0/300 and the Sonnar 4.0/300 are the same, therefore I had the Heliopan-hood which is showed on the foto.

Concerning fringing - will test it stoppend down 1 or 1.5 stops next days at the night sky ...

Kind regards
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Last edited by optikus; 01-23-2018 at 07:53 AM.
01-28-2020, 02:45 PM   #18
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Good evening,

more than one year passed by until I found what I looked for - a solution fr a rigid mounting of the lens. Have a look to the fount solution using a ASI astronomy camera mounting ring. It works properly with an arca adapter on the tripods ball head. The Ring uses the P67-EOS-adapter on a diameter of 86mm. The ring bought at teleskop express webshop was manually manipulated to handle the release-knob of the P67 mount and the foam insinde was removed. The shade was a smaller one from Heliopan, inside covered with ultra black color by airbrush. Stray light sensitivity is reduced as I expected and the mech. dimensions are better to handle. The lens is large enough. Works with GFX50R via adapter as well. The camera attached here is "M" from Canon. All Adapters from K&F Concept or similar work as well, K-Mount, 645, GFX, EOS...

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Last edited by optikus; 01-28-2020 at 02:52 PM.
01-29-2020, 03:31 PM   #19
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I think you will find that the conventional glass lenses to be murder on digital sensors, especially the 300mm. I've used the 300 Takumar for 6x7 astrophotography with good results at f/5.6

The 400 Takumar actually performs better than the 300, which is a bit odd considering that they share the same glass technology. All things being equal, larger lenses have more spectrum aberrations.

With 6x7, the 300 is adequately sharp, but just barely so. I've pulled off some good work with it.


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