[2old4toys]

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This is an unusual one piece adaptor I have on the way to me. Not expensive. Identified as “camera c/ptx adaptor”

The inside thread is exceptionally deep so I have intentions to have the front flange cut off and end up with still enough thread to make it a solid metal CS lens mount for Pentax Q’s. Forget the high priced Hawkes CS mount.

Report back later with my findings.

Anyone out there have other C mount adaptors? There seems to be a hand full of options out there.

Slim 25mm C Mount Movie CCTV Lens to Pentax Q Camera Mount Adapter Ring | eBay

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Last edited by 2old4toys; 05-16-2019 at 06:24 PM.

[Thagomizer]

Cine lenses make excellent macro lenses when mounted in reverse. I've done that with D mount lenses with great results, using a modified body cap as the camera side of the adapter.

[2old4toys]

Hi @Thagomizer, I will start a separate thread regards my recently acquired Pentax Q reverse macro ring for you soon. I do use it with my c mount lenses!


Back to the topic of dedicated C mount to Pentax Q adaptors... I have 3 types.
All are made of metal with a matte black finish.


1. “C-PQ” One piece (cheapest) may need shimming for infinity focus depending on which C mount lens you have.
2. “C-P/Q” Two piece allows for lens rotation so the markers are conveniently aligned facing upwards. Also easy to add inside shimming between the two rings for fine adjustment for infinity focus.
3. “for Camera C-PTX/Q” One piece with large diameter front flange plate arguably making it more finger friendly to mount and dismount. On the inside lip of the wide flange is a thread that is bigger than 49mm but less than 52mm. I don’t have any 50mm thread items to verify it’s actual size. Perhaps this feature may be useful to someone?
Very deep inner thread for actual mounting of C type sized lenses.

If you have other variants I am interested so please feel free to share here.

[barondla]

Neat collection of adapters 2old4toys. Wish they would build #2 and thread the two pieces, like a small helicoid. Then it would be easy to adjust lens to infinity focus and lock with set screw. All without needing shims.

Of the 3, which do you use the most? Looking forward to the reversed c mount macro thread.

Thanks,
barondla

[kayakfari]

I like the idea of using type #3 for an all metal CS adapter!

[2old4toys]

Of the 3, which do you use the most?

The #2 is the nicest design so far, having the inner ring orientation adjustment is handy. If you remember the rubber o-ring trick for easy focusing the c mount f1.8 fisheye, it’s worth a try though with a type #2 would need to grind away a fraction off one face of the inner ring.
I will certainly be getting another #2 and #3 for mods I have in mind.

No doubt #1 is not as well made as the others, some slop between the camera body and the adaptor and mine was missing the little screw but I noticed only recently (maybe that is the problem but to be honest I don’t know what the screw is for). The build tolerances are not as good as with the other 2, but then again it is the lowest priced and most commonly found adaptor out there today.

[matsQ]

Mine looks similar to the #2 posted above, except for the external grooves and branding are different. Purchased in January 2017 for $5.69 from eBay seller "rainbowimaging". They currently have a slightly different one listed for $5.99 w/ free shipping from New York (Link).

Matt

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[barondla]

Mine looks similar to the #2 posted above, except for the external grooves and branding are different. Purchased in January 2017 for $5.69 from eBay seller "rainbowimaging". They currently have a slightly different one listed for $5.99 w/ free shipping from New York (Link).

Matt

Thanks for the link matsQ and welcome to the forum.
Thanks,
barondla

[2old4toys]

Took my #3 adaptor to a metal shop that had the tools to shorten the adaptor front by 5mm. There is still plenty of thread inside to mount a CS lens. Polished the face at home with fine wet and dry to tidy up the finish.


Now have a sturdy one piece metal CS-PQ adaptor that focuses to infinity and reusable with other CS lenses.

[kayakfari]

Excellent! This is def the CS solution!!

It looks like #3 adapter is no longer available?
Can't find it on eBay nor Amaze-on anymore.

[2old4toys]

Excellent! This is def the CS solution!!

It looks like #3 adapter is no longer available?
Can't find it on eBay nor Amaze-on anymore.

I’m going to try getting another but from another seller on Toaboa
【Camera C-PTX/Q 高精度转接环 C口电影头转接宾得Q微单相机】https://m.tb.cn/h.eVhjfdz?sm=66712a 点击链接，再选择浏览器咑閞；或復·制这段描述￥6lU4YeX0gdq￥后到👉淘♂寳♀👈

Pretty hard to find!

[2old4toys]

Here is another eBay listing for what looks like the same #3 adaptor that can be shortened to make a nice CS adaptor for Q’s. Less than USD5 before shipping from China.

Slim 25mm C Mount Movie CCTV Lens to Pentax Q Camera Mount Adapter Ring | eBay

[kd1yt]

This is a great idea for a CS mount. That "#3 adapter" does seem to have gone scarce on ebay, at least from sellers willing to transact with USA, but I did find and purchase a few on AliExpress.
m1zeng C Mount 16mm cine/film cctv Movie lens adapter to Pentax Q P/Q PQ Q10 Q7camera

Depending on the width of the CS lens' flange in front of the CS lens' threads, and 'how far rearward' the focus/ aperture/ zoom collar(s) are on a particular CS lens that you want to use, you wouldn't necessarily have to shave off the whole front of the "#3 adapter"- a recessed area of sufficient diameter to "fit" the flange of the CS lens, 5mm "deep" from the original front surface of the adapter, but leaving in place the rest of the outer area, could work. That way you'd still have the outer grip area, and it would to some degree give a bit more support/ protection to the thread/flange interface. I have a metal lathe (though my skills with it are still a work in progress) and I hope to give a try at making such an approach after my adapters arrive, and when I get a chance to fire up the lathe.