M42 -PK mount adaptors

[GWT]

I hope someone can help?

I'm just looking to pick up some sort of M42 - Pk mount adaptor and there seems to be plenty out there to choose from. Some for a few $/£'s others (being the genuine Pentax Adaptors) for a fair bit more.

The thing is which should I go for?

Is there a big different between the cheap one's and the genuine Pentax ones?

Are there any makes I should look out for?

 

[Spavinaw]

Here's what I found when searching for an M42-Canon adapter. Some adapters have the 42mm thread going all the way through the adapter like it was a nut. Others only have the thread going part way through and then there is a lip that reduces the size of the hole. Now some M42 lenses have a switch on them that puts the aperture in manual mode so you can stop the lens down by turning the aperture ring. These work fine with the first adapter. However, some lenses do not have a switch and you need the second type of adapter. The lip at the back of the hole pushes the aperture actuating pin on the back of the lens in so you can set the aperture. Without the pin pushed in there is no way to stop down this type lens from maximum aperture.
I checked out the adapters on the auction site. I only saw one type two adapter and it was $40. Maybe a cheaper one will turn up later or maybe you'll decide you won't need that type.

 

[kuuan]

first make sure that it does NOT have an outer flange that would sit around the outer surface of the K mount, as this would mean that the lens would not be able to achieve infinity focus. Or in other words, it must look similar to the original Pentax adapter which will fit flush 'inside' the K mount without introducing distance between lens and film plane.
here a sample of one with an outer flange that must be avoided: http://www.ebay.com/itm/Adapter-Rin...843?pt=LH_DefaultDomain_0&hash=item2597284993

many of the cheap ones are a pain to take off, and one must use a provided tool. Well, this is what I have read others tell, I only have used an original Pentax ( besides some with flange mentioned above that are to be avoided, I used those as replacement mounts for changing lens mounts to Pentax K, for that they work well ) and the original Pentax adapter is easy to take off just with a fingernail, no other tool required.

some ( not the original Pentax ) have an 'inner flange' which would press down a pin some lenses need to have pressed down for their aperture to work. These ( used to be, have not checked situation for a while now ) are not cheap adapters, Takumar lenses don't need that inner flange, other M42 lenses may.
for example: http://www.ebay.com/itm/FLANGED-M42...054?pt=LH_DefaultDomain_0&hash=item339f78244e
Kipon has inner flange too: http://www.ebay.com/itm/New-Kipon-A...840?pt=LH_DefaultDomain_0&hash=item1c2d979020

in short: I'd recommend to get an original Pentax adapter, if it must be a cheaper one just make sure that it does not have an outer flange, if you need it to depress a pin at the rear of the lens, look for one with an inner flange

 

[Fixcinater]

I've used some of the original Pentax and some of the flangeless copies and have had no problems using either one. They are all fiddly to release, in my mind, so one being just slightly less fiddly than the other is no great loss.

I mostly use my M42 lenses on EOS and FD bodies with cheap eBay adapters for the former and the original Canon P adapter for the latter.


As for the inner flange issue, if you are trying to use any of the later Takumars with the ES style open aperture metering lugs, beware that the lug will rub on the flange and not allow for smooth operation due to the interference. At least, as far as I can tell, that is where the interference is coming from.

 

[Ranchu]

There is some good information over here..

http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/275169-m42-pk-adapter.html

http://www.pentaxforums.com/forums/tags/pk m42 adapter/

 

[Michael Markey]

many of the cheap ones are a pain to take off, and one must use a provided tool. Well, this is what I have read others tell ....

Yes ... I had one such adapter bought from a UK company.
Very difficult to take off and therefore it was hardly used.

 

[kuuan]

some people prefer a cheap one for each lens, screw off the little spring leaf that locks the adapter into the K mount, screw it tightly on the lens, and not off again = 'convert' the M42 lens into a K mount lens by leaving the adapter permanently on the lens and take off the spring leaf to make unmounting easy. Drawback is that the lens resp. adapter doesn't lock, if not aware of that and careless the lens could fall off!

 

[GWT]

Thanks guys for all the info - looks like I've got some reading to do.

 

[ruby.monkey]

Get the Pentax adapter. It's well made, it locks securely, you can remove it without tools, and it won't shed parts into your camera body (Kood, I'm looking at you).

 

[oltimer]

Get the Pentax adapter. It's well made, it locks securely, you can remove it without tools, and it won't shed parts into your camera body (Kood, I'm looking at you).

X2 for sure. Not worth the headache of all the other cheaper stuff. Get the Pentax Adapter, and no problems

 

[GWT]

Yes, I kind of think that a genuine Pentax adaptor might be the way to go - it seems that there are horror stories of cheaper adaptors getting jammed in the camera body.

Thanks guys.

Get the Pentax adapter. It's well made, it locks securely, you can remove it without tools, and it won't shed parts into your camera body (Kood, I'm looking at you).

X2 for sure. Not worth the headache of all the other cheaper stuff. Get the Pentax Adapter, and no problems