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Forum: Pentax K-30 & K-50
03-04-2018, 04:30 PM
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btw. it seems there are not many modded Pentax firmwares around...
and it made me switch in an unexpected way from K-30 to K-5 :)
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Forum: Pentax DSLR Discussion
03-02-2018, 01:30 PM
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I am thinking I will just give more time to the K30. I have been taking shots with a couple Takumar and Mir lenses, and me too, I had much better luck with green button and liveview.. Works very nicely.
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Forum: Pentax SLR Lens Discussion
02-11-2018, 09:34 PM
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This post is about the adaptation of the Industar-50 on a PK body. The classic alternatives are well known and discussed for instance here:
Converting M42 mount to K-mount - PentaxForums.com
but I can't find online the way I have done it.
the Industar-50 in M39 can be mounted:
- with a M39-PK adapter, I know only one kind, flanged:
it has the notch for the pin lock, so easy to put in and out, and it covers the pk bayonet external connectors on the camera body:
but the flange puts the lens ahead and infinity focus is lost
- with a M42 recessed adapter on a M39-M42 ring. Which is also the way to mount the M42 version of the Industar-50:
the M42-PK Pentax or replica:
inconvenient: the lens must be unscrewed and the wrench used to extract the M42-PK adapter every time.
And the connectors ring of the body is not covered:
So I wanted to cut the M39-PK adapter, to keep just the external lip with the locking notch, and set it around the base edge of the Industar-50, in order to get a locking, infinity compatible, and large enough to cover body connectors, mount.
the base of the Industar-50 is 50mm.
The idea was to use:
- hole cutting saw blade of 51mm, in order to leave ~1mm between the hole cut in the M30-PK adapter and the lens base
- epoxy putty, to fill in the gap around the lens base and the cut ring.
- sand, brush/polish and paint black
- set the M39-M42-PK adapters together on the lens with blue threadlocker (removable)
the retainer clip on the M42-PK adapter is of course removed (otherwise impossible to unmount the lens)
Industar-50 are very cheap so no need to be afraid.
I have done this relatively fast, without perfect sanding job. It's good, but not pretty.
the M39-PK adapter to be cut, and the hole saw blade:
the M39-PK must be immobilized somewhere somehow. I just screw it on a piece of plank clamped to a table:
it wasn't secured enough with just screws holding it by the edges and it started rotating with the hole saw, I had to bore three small holes in order to immobilize well the M39-PK. A bit messy but working solution:
ok, so M39-PK adapter lips cut off:
some fine sanding of the edges:
now, protect the lens with blue painter masquerading tape (put some piece of paper pulp like toilet paper between the tape and the glas front and back).
Only the base edge of the lens is uncovered, that's were the epoxy putty will "weld" the M39-PK ring:
cut a bit of epoxy stick, mix and knead it, position the ring around the lens base and fill the gap with the epoxy putty. From now on I will pay attention to keep the red point and the locking notch.
then sanding, brushing, polishing. I applied putty twice in order to have a full filling, and sanding before the second coat. This can be done much better, I just did it good enough, not until pretty. On the first picture (back of the lens) the dried epoxy putty is seen in grey, between the base of the lens and the mounting ring:
carefully wax any dust, and clean with denatured alcohol, remote the masquerading tape, fix edges of the epoxy area, clean again:
Masquerading tape again, and ready for paint job. I used a spray of regular metal primer and a spray of black paint. Next time I will use a flat black, the one here is glossy.
So, result of the paint job:
i was careful to masquerade the red point and the notch, on the back:
Next, blue threadlock on the M39-M42-PK adapters, and blue threadlock on the lens thread:
here we can see there ~1,5mm thickness difference between the M39-M42 brass ring and the M42-PK adapter (so will it affect infinity focus?):
End result:
Mounted on a camera:
also, I have metal hood for this lens, it clicks on the aperture ring, so the hood is in fact convenient for setting aperture (It's possible to very carefully epoxy glue the hood on the lens)
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Forum: Welcomes and Introductions
11-05-2017, 04:12 PM
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Hi all,
I bought a K-30 the other day, and now I am reading anything Pentax related.
Looking around for technical informations, this site is a great resource.
Thanks!
:)
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