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Pentacon Pancake on a Pentax!
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PostPosted: Thu Nov 09, 2017 4:00 pm    Post subject: Pentacon Pancake on a Pentax! Reply with quote

This conversion was a lot easier than I though it was going to be!

1. Unclip the plastic "shroud" on the rear of the lens mount (this may already be missing).
2. Remove the metal Praktica bayonet mount (4 screws)
3. Remove the plastic piece with the orange "dot", containing the three electrical contacts (3 screws), including the aperture actuating lever. Be careful to not allow the aperture mechanism to come loose, it'll just sit there if you leave it alone!
4. Affix "non-infinity-focus" M42/PK flange to the metal lugs exposed in the previous step ... I used super-glue but you could drill and screw if you've got the facility.

Job done! The lens will operate with a full range of apertures in "manual stop-down" mode.

The lens I used is an early model, with the orange "dot". The later model (no "dot", plastic body) may be different.

The final result does focus slightly "beyond infinity" at one end of the scale and to around 2ft., similar to the original minimum focus, at the other end of the scale. The super-critical may want to fiddle with shims to align the focussing scale more accurately.


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Last edited by kypfer on Thu Nov 09, 2017 6:44 pm; edited 1 time in total


PostPosted: Thu Nov 09, 2017 4:45 pm    Post subject: Reply with quote

Good adaptation.
The flanged M42-PK (or EOS) adapters are very useful for this, I always have a few around just in case some easily adaptef lens like this turns up.


PostPosted: Fri Nov 10, 2017 8:48 am    Post subject: Reply with quote

Now that it fits: samples please! Wink


PostPosted: Fri Nov 10, 2017 11:57 am    Post subject: Reply with quote

Well done.
I notice that you are shooting film - it will be interesting to see what you think of the results.
Thanks for sharing this fix
Tom


PostPosted: Fri Nov 10, 2017 12:59 pm    Post subject: Reply with quote

I have a Pentax brand M42-to-K adapter and it fits the camera like an insert, converting the camera to an M42 mount for all practical intents and purposes. It's a bit of a delicate operation getting the adapter off the camera.


PostPosted: Fri Nov 10, 2017 4:57 pm    Post subject: Reply with quote

Oldhand wrote:
Well done.
I notice that you are shooting film - it will be interesting to see what you think of the results.
Thanks for sharing this fix
Tom


Sorry, I'm not using film any more. I just use the old chassis for testing stuff, just in case the mirror gets jammed or something. I'll be using the lens on my Pentax digital SLR's ... examples to follow.


PostPosted: Fri Nov 10, 2017 5:06 pm    Post subject: Reply with quote

cooltouch wrote:
I have a Pentax brand M42-to-K adapter and it fits the camera like an insert, converting the camera to an M42 mount for all practical intents and purposes. It's a bit of a delicate operation getting the adapter off the camera.


I use that type of adaptor as well. My original "Mount Adaptor K", as made and badged by Pentax, is a precision item and fits and unclips very easily. They are also horrendously expensive these days. I managed to get mine before using the old manual-focus lenses became popular and the prices went up! The similar after-market adaptors that I've tried can be a real PITA, needing the supplied tool to unclip them!

Fortunately, for this type of conversion, the flanged adaptor is more suitable (and significantly cheaper!)


PostPosted: Fri Nov 10, 2017 5:12 pm    Post subject: Reply with quote

TrueLoveOne wrote:
Now that it fits: samples please! Wink


Blowing a bit of a gale this afternoon, with the sun going in and out and the foliage blowing all over the place. This one shot, taken "wide open" with my Pentax K5, gives an idea of the resolution and bokeh. Hopefully, I'll get a wider range of results in the future Smile



PostPosted: Mon Nov 13, 2017 3:18 pm    Post subject: Reply with quote

A couple more examples taken this morning at 100ASA sensitivity in my Pentax K-5:


Up close and personal, minimum focus and 1/2000sec @ maximum aperture.


1/1000sec @ f/8 with a lens hood. The full sun is just out of shot, upper right.


PostPosted: Mon Nov 13, 2017 4:06 pm    Post subject: Reply with quote

"How to convert Practika mount to Pentax PK"


PostPosted: Mon Nov 13, 2017 8:35 pm    Post subject: Reply with quote

kypfer wrote:
Oldhand wrote:
Well done.
I notice that you are shooting film - it will be interesting to see what you think of the results.
Thanks for sharing this fix
Tom


Sorry, I'm not using film any more. I just use the old chassis for testing stuff, just in case the mirror gets jammed or something. I'll be using the lens on my Pentax digital SLR's ... examples to follow.


You should be pleased with your results - the lens performs very well indeed
Tom
Like 1


PostPosted: Mon Nov 13, 2017 9:13 pm    Post subject: Reply with quote

The last picture is superb!

I have the same lens, but in Robot screw-mount (and bought it out of curiosity.) Now getting curious to actually test it Idea