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01-16-2010, 06:37 PM   #1
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analog to digital

We have many Asahi/Honeywell 42mm thread mount lenses. Is there any adapter for digital camera bodies to accept Spotmatic series lenses?

01-16-2010, 08:42 PM   #2
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Well, I am fairly new to photography but I believe, yes, there are several adapters available that allow M42 lenses to be used on Pentax digital cameras. Others here are much more qualified to provide more details but I would stick with the original Pentax adapter as opposed to a third party make.
01-16-2010, 10:28 PM   #3
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"Lenses compatible with this mechanism are the PENTAX K-, KA-, KAF-, KAF2- and KAF3-mount lenses; screw-mounted lenses (with an adapter); and 645- and 67-system lenses (with an adapter). Some functions may not be available with certain lenses."

01-16-2010, 10:41 PM   #4
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M42 - K-Mount adapters

QuoteOriginally posted by fixedfocus Quote
We have many Asahi/Honeywell 42mm thread mount lenses. Is there any adapter for digital camera bodies to accept Spotmatic series lenses?

There are adapters that allow you to use an M42 (screw mount) lens on a Pentax dslr. Many people swear by the genuine Pentax version:

PentaxWebstore - Search

There are other, less expensive adapters out there, as well, but some people report having difficulty removing the adapter from the camera. I have a third party adapter that I have never had any trouble with.

Here's one on ebay: Adorama Screw Mount Lens To Pentax K Body Adapter - eBay (item 220530312133 end time Jan-21-10 08:22:18 PST)

There's another type that you should avoid. Notice that the original Pentax and the better clones, all fit completely inside the mount opening on the camera. The super-cheap ones have a wide flange that sits OUTSIDE the camera, between the camera and the lens. This adds a mm or so to the distance from the lens to the sensor plane and prevents the lens from focusing to infinity. This is fine if you are only interested in closeup or macro work, but it is no good for general use.

Here's one with the flange (do not buy this one):

Screw Mount M42 to Pentax PK Mount Lens Camera Adapter - eBay (item 310194011918 end time Jan-19-10 02:43:42 PST)

Note that these adapters also allow M42 lenses to be used on k-mount film cameras, such as the K-1000 or ME Super.

01-18-2010, 03:17 PM   #5
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This gets asked (and answered) a lot here.

My latest summary [ from https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/85409-m42-k-ad...tml#post884235 ] is:

I use all three types of PK-M42 adapters:

1) official Pentax infinity-focus - it stays on the K20D or ZX-M on days when I'm mounting only M42 glass, and maybe carrying another M42 body.

2) generic non-infinity focus - they stay on old telephotos that focus past infinity, and on glass for close-up or portrait use, and on an M42 bellows.

3) generic infinity-focus - they stay on my most-used M42 glass, AFTER the (sucky) locking springs are removed. I hate those (expletive deleted) keys.
_________________________________________________________________

As mentioned above, you can mount virtually any old Pentax-compatible lens on a modern Pentax dSLR. You might not have all the operational features, but you can use it. Let's see, for my K20D I have 30 K-mount (bayonet) lenses, and 65 M42 and M39 (screwmount) lenses, and only a couple of the latter are problematic.
_________________________________________________________________

EDIT: Rereading the original question, there's nothing about putting M42 lenses only on modern Pentax cameras. Yes, adapters for other mounts are available -- just search for M42 on eBay etc. The limiting factor for adapters is what's called the Lens Register, the working distance from lens to sensor or film. Here is a table, sorted by register: [ http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html ]. A lens with a certain register can be adapted to a shorter distance, but not to a greater one. The Pentax-Practika mount (45.46mm) can be adapted to Exakta, Minolta-Sony, Canon, Konica, Leica, Olympus 4/3, etc -- but NOT to Petri, Ricoh, Olympus OM, Nikon, etc, at least not without losing infinity focus.

Last edited by RioRico; 01-18-2010 at 06:07 PM. Reason: addendum
01-18-2010, 03:49 PM   #6
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QuoteOriginally posted by fixedfocus Quote
We have many Asahi/Honeywell 42mm thread mount lenses. Is there any adapter for digital camera bodies to accept Spotmatic series lenses?
Seems you question is a bit open.. Olympus 4/3rd's cameras have adapters and I believe Canon as well:
Towards the bottom of this page there are a bunch of screw mount adapters. Which ones function correctly is unknown but I'm pretty sure the m42 to K mount WILL NOT function correctly. Why they continue to sell this piece of junk is a mystery to me though I suppose many don't bother to return it as they should...
Pentax M42 screw mount, Canon EOS/FD, Nikon, Minolta AF/MD, Contax/Yashika, Kiev lenses
01-18-2010, 04:29 PM   #7
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Most of the prices at this website are absurd, 200%-500% higher than elsewhere. That said, cruddy adapters are still sold because people buy them. And even the cheap cruddy ones have their place in the bag-of-tricks, as I mentioned above. I've had generic-Bowers infinity-focus adapters on some of my M42 and M39 lenses for so long that I've almost forgotten they aren't PK native.

Your website link has, at the top of the page, a Rubinar 1000/10 mirror lens. (Their price: over US$900. I got mine on eBay for US$220.) It will not mount directly on my K20D because of the protruding onboard flash thingy. So I use a cheap non-infinity-focus (flanged) adapter, and enough extension tubes for adequate clearance, a bit under 20mm -- and those stay on the lens, making it effectively 1200/12. Why waste a pricey Pentax-made adapter there?
01-19-2010, 06:25 AM   #8
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QuoteOriginally posted by jeffkrol Quote
Seems you question is a bit open.. Olympus 4/3rd's cameras have adapters and I believe Canon as well:
Towards the bottom of this page there are a bunch of screw mount adapters. Which ones function correctly is unknown but I'm pretty sure the m42 to K mount WILL NOT function correctly. Why they continue to sell this piece of junk is a mystery to me though I suppose many don't bother to return it as they should...
Pentax M42 screw mount, Canon EOS/FD, Nikon, Minolta AF/MD, Contax/Yashika, Kiev lenses
No, I don't think the question remains open. M42 lenses can easily be used on all Pentax DSLRs with the help of a small adapter, which fits entirely inside the camera mount.

Ofcourse there is no AF, no matrix-metering and P-TTL control and all focusing and metering must be done with the lens stepped down to the desired aperture (unless you want to focus fully open and then step down for metering and taling the image).

Ben

01-19-2010, 06:52 AM   #9
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QuoteOriginally posted by RioRico Quote
Most of the prices at this website are absurd, 200%-500% higher than elsewhere. That said, cruddy adapters are still sold because people buy them. And even the cheap cruddy ones have their place in the bag-of-tricks, as I mentioned above. I've had generic-Bowers infinity-focus adapters on some of my M42 and M39 lenses for so long that I've almost forgotten they aren't PK native.

Your website link has, at the top of the page, a Rubinar 1000/10 mirror lens. (Their price: over US$900. I got mine on eBay for US$220.) It will not mount directly on my K20D because of the protruding onboard flash thingy. So I use a cheap non-infinity-focus (flanged) adapter, and enough extension tubes for adequate clearance, a bit under 20mm -- and those stay on the lens, making it effectively 1200/12. Why waste a pricey Pentax-made adapter there?
bowers are fine, adapters that don't allow infinity focus are a scam. Especially since they rarely spell out the limitations..
Apologies for not "price checking". It was a handy list of adapters for screw mount lenses only...

QuoteOriginally posted by Ben_Edict Quote
No, I don't think the question remains open. M42 lenses can easily be used on all Pentax DSLRs with the help of a small adapter, which fits entirely inside the camera mount.

Of course there is no AF, no matrix-metering and P-TTL control and all focusing and metering must be done with the lens stepped down to the desired aperture (unless you want to focus fully open and then step down for metering and taling the image).

Ben
OP's question re: lens compatibility did not seem to include JUST Pentax bodies....
Is there any adapter for digital camera bodies to accept Spotmatic series lenses?

though that is a matter of interpretation. To be on the safe side (and answer a possibly implied question) I included other then Pentax adapters in my answer. Unfortunately I picked the expensive ones
01-19-2010, 01:26 PM   #10
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QuoteOriginally posted by jeffkrol Quote
bowers are fine, adapters that don't allow infinity focus are a scam. Especially since they rarely spell out the limitations..
It's caveat f***ing emptor, eh? A novice, buying a non-infinity-focus (flanged) adapter, quickly learns its limitations, hopefully at not too great a cost. Knowing its limitations, it does have its uses, as I mentioned above. One could even include such into a project or challenge -- mount a good fast lens on a flanged adapter and shoot ONLY what's within its focusing range. That's one way to guarantee blurry bokeh-rich backgrounds, eh?
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