[gtxSeries]

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Greetings!

I've been having my eye on M42 lenses for a while and I would like to get myself a cheap Helios for the swirly BOKEH. Now there's many-many types adapters floating around. I don't want a genuine pentax, if possible, simply because it's not cheap. I'm looking to get a good third party one.

I have my eyes on this: Pentax M42 42mm to PK K Mount Adapter Infinity focus | eBay

Is this a type that works well, or there are other things I should look out for?

As far as I know, I need M42 lenses with a manual diaphragm and I can use both M mode with stop down metering, or plain Av mode if I set the aperture beforehand. I have a split screen in my K10D to help focusing.
However I have no idea how these M42 babies work with my Pentax MX.

Any tips for a beginner?

Help is much appreciated!

[ZombieArmy]

Anything with infinity focus will work. I use a random cheap Chinese adapter that I took the spring off of and just screw it onto the lens to make it a pseudo k mount lens

Also "auto" m42 lenses will work, my sears zoom has the auto aperture pin without the notch and all you have to do is stick it down with something like a bit of pen ink tube or get it stuck in the lens so it acts like a fully manual lens.

[marcusBMG]

Anything with infinity focus will work. I use a random cheap Chinese adapter that I took the spring off of and just screw it onto the lens to make it a pseudo k mount lens

+1 but watch out for the lens coming off - the locking pin on the camera doesn't have a slot to enagage in (unless you diy one). I fine tune the fit with little bits of eg insulting tape under the M42 adapter so that the lens is a good firm fit on the camera - not too tight (too loose is not so easy to fix*, but it's normally too tight). I also use little bits of tape as "thread locker" to stop the adapter unscrewing as you try to take the lens off.
* this case is typically with a M42 lens with a narrow base - see link below, and consider the virtues of a flanged adapter for photography where the loss of infinity focus isn't an issue ie close focus. IMO if you're using M42's you should have a flanged adapter in your kit.

FYI:
An Adaptall to M42 adapter modification - PentaxForums.com

M42 Lens Aperture Control on Modern DSLRs

Preventing M42 adapter light leaks and dust ingress - an easy solution! - PentaxForums.com

[Just1MoreDave]

If you have a manual for the MX, it should have a paragraph or two on using M42 lenses with the adapter. The MX mount has an arm at about 2 o'clock that fits into a slot on a K-mount. That slot has a tab that moves with the lens's aperture ring. That's how the camera meter knows where the aperture ring is, so the meter gives the correct reading. The adapter is supposed to shove this arm over to about 4 o'clock when it's installed, so the meter is fooled into working correctly. So when you get the adapter, make sure it the right side notch in the adapter (opposite the flat spring) fits over that arm and moves it when the adapter rotates. I am not sure how well the MX meter functions with an M42 lens.

[stevebrot]

I don't want a genuine pentax, if possible, simply because it's not cheap. I'm looking to get a good third party one.

I feel your pain. Unfortunately, there is no easy way to determine a quality 3rd-party adapter. The best advice I can give is to be wary of shoddy machining and to remove the retention spring. Most 3rd-party adapters do not properly engage the retention mechanism on the camera and may become stuck in the mount. Removing the spring solves this, but leaves the lens "unlocked" on the mount. Depending on the lens, you may be able to notch or drill the base to engage the camera's K-mount lock pin.

As far as I know, I need M42 lenses with a manual diaphragm

Yes, the diaphragm must be fully in a fully manual mode. For Helios 44, that means a version with pre-set diaphragm (44, 44-2, 44-3), one with the A/M switch (44M), or one that has been modified so the diaphragm is always manual.

However I have no idea how these M42 babies work with my Pentax MX.

As noted above, there are instructions in the MX manual. The short version is to simply put the lens in manual diaphragm mode and meter the shot as normal (stop-down metering). The basic flow goes like this:

1. Focus with lens wide open
2. Stop lens down
3. Adjust aperture and shutter speed for appropriate exposure with the built-in meter
4. Take the shot

As you can see, this is cumbersome when doing multiple shots. It is easier with an A/M switch or a preset lens.

Steve

[stevebrot]

IMO if you're using M42's you should have a flanged adapter in your kit.

Yes, they do come in handy for some purposes!


Steve

[djam]

Greetings!

I've been having my eye on M42 lenses for a while and I would like to get myself a cheap Helios for the swirly BOKEH. Now there's many-many types adapters floating around. I don't want a genuine pentax, if possible, simply because it's not cheap. I'm looking to get a good third party one.

I have my eyes on this: Pentax M42 42mm to PK K Mount Adapter Infinity focus | eBay

Is this a type that works well, or there are other things I should look out for?

As far as I know, I need M42 lenses with a manual diaphragm and I can use both M mode with stop down metering, or plain Av mode if I set the aperture beforehand. I have a split screen in my K10D to help focusing.
However I have no idea how these M42 babies work with my Pentax MX.

Any tips for a beginner?

Help is much appreciated!

I made this video after getting my M42 adapter stuck on my camera. Watching it may help you see how the little spring works and why it gets stuck.

You Tube

You Tube

[gtxSeries]

Thank you very much! This video is very-very useful! I can't thank you enough!

[ripper2860]

IMO if you're using M42's you should have a flanged adapter in your kit.

Yes, they do come in handy for some purposes!


Steve

OK. My curiosity has peaked. Please elaborate.

[Skodadriver]

OK. My curiosity has peaked. Please elaborate.

Some M42 lenses have a narrow mount that leaves the camera contacts exposed. The flanged adapter covers these.
This adapter will make you lose infinity on most if not all lenses so when using extension tubes or bellows (no infinity focus required), this adapter will provide what I find to be a slightly stronger mount.

[Jonathan Mac]

Get a genuine one, don't even consider a third-party one. They are of variable quality and can get stuck on the camera.

I've paid an average of €35 for each of mine, I don't think they're that expensive. It's certainly not worth trying to save money and ruining your camera.

[niceshot]

Get a genuine one, don't even consider a third-party one. They are of variable quality and can get stuck on the camera.

I've paid an average of €35 for each of mine, I don't think they're that expensive. It's certainly not worth trying to save money and ruining your camera.

Yes if you have the money it is thew way to go. Having said that, the main problem with third party lens adapters is the metal filings they release into the camera. To avoid this dilemma when I purchase a new third party adapter, I take a junk lens and the adapter and use a little Zippo lighter fluid on the threads and work it for about ten minutes. Then clean it all up, and now it is safe to use.

---------- Post added 04-04-17 at 05:53 AM ----------

I made this video after getting my M42 adapter stuck on my camera. Watching it may help you see how the little spring works and why it gets stuck.video

Nice video, well presented. read my below thread.

[stevebrot]

Some M42 lenses have a narrow mount that leaves the camera contacts exposed. The flanged adapter covers these.

...or more importantly, the lens flange may not engage the body flange. A non-flanged adapter is intended to "snug up" in the mount as the lens tightens on such that the registration distance is correct and to permit the lens from rocking. That brings up another point. The genuine Pentax adapter is designed to fit loose in the mount with no tension on the spring-loaded tangs. Third-party non-flanged adapters are typically machined for a tighter fit and defeat the "snug up" feature.

Despite the generalizations regarding most 3rd-party adapters (get stuck, poor machining, etc), there is one potential vendor that might be worth considering. SRB ~ Griturn Ltd in Britain is a manufacturer of various photo products and machine their own line of adapters. On examination of their product photo, it appears to be a close copy of the genuine* at £18.95. I have not personally used their product, but at that price point they may be worth looking into.


Steve

* Most 3rd-party adapters are chamfered (scalloped?) on both ends of all three tangs. Genuine Pentax and accurate copies are straight cut on the ends either side of the retention spring. It is that small difference that is linked to adapters becoming stuck.

[Erictator]

Get a genuine one, don't even consider a third-party one. They are of variable quality and can get stuck on the camera.

I've paid an average of €35 for each of mine, I don't think they're that expensive. It's certainly not worth trying to save money and ruining your camera.

+1

I've bought several different chi-com cheapies, and some were "ok" and others were downright BAD. The worst offenders had poor chroming, and the chrome started powdering off like sparkly glitter into the mirror box.
Cleaning metal shavings off your sensor and scratching it or getting into your inner workings to short your electronics is NOT something you want to experience, trust me!!!

When you look at it like that, the genuine adapter starts to look like a darn good deal. I leave one on my old *ist D body and fondly refer to it as my Spotmatic D

Eric

[Topsy]

SRB ~ Griturn Ltd in Britain is a manufacturer of various photo products and machine their own line of adapters. On examination of their product photo, it appears to be a close copy of the genuine* at £18.95.

Just fyi, they most likely are getting theirs from asia too.
I once messaged them asking if they could make me a one off with out the 'slits' to loosen it off the camera, and thus sealing it better for lenses that have a narrow mount. (I intended on drilling a small hole in the thread as a spot for emergency removal with a lens spanner)
I've got a plastic 3d printed proof of concept but came to the conclusion that it's not worth the cost when you can cover the holes with blutac..

Their reply:

"We do not make the PK/M42 adaptors. But obtain them as a standard item from another source.While we could make one for you, the amount of machine set up time would make it uneconomic."

I've since also bought a couple from K&F concept and they seem to be decent too (again, remove spring)