Pentax K-r adapter ring


voneout

Link Posted 12/06/2012 - 19:06
I bought a Sirius 28mm F:2.8 macro lens. I need an adapter ring for it. Is it (M42 adapter ring) good choice for me? Thanks
Pentax K-r, Pentax SMC DA AF 18-55mm F3.5-5.6 AL, Tokina SD 28-70mm 1:3.5-4.5 MF Japan, HELIOS-44M-4 58mm F2 M42, Velbon CX 440
PENTAX DA-L DAL 55-300mm F/4-5.8, YONGNUO YN-560 II Flashgun

voneout

Link Posted 12/06/2012 - 20:32
Here we are with some pitures about it:







Pentax K-r, Pentax SMC DA AF 18-55mm F3.5-5.6 AL, Tokina SD 28-70mm 1:3.5-4.5 MF Japan, HELIOS-44M-4 58mm F2 M42, Velbon CX 440
PENTAX DA-L DAL 55-300mm F/4-5.8, YONGNUO YN-560 II Flashgun

PeterKR

Link Posted 12/06/2012 - 21:24
Dear Balazs

Your photos show a Helios 58mm f2 lens and from the side view it would seem to be a later version than my old one from my Zenit E 35mm camera.

However, it is more than likely an M42 thread and there are adapters widely available on Ebay, I got some for around 2 to 4.

I posted a similar question recently - see the thread on this forum entitled.....'Using Helios 58mm on K-r'

BEWARE - take note of the advice in that thread concerning adapters which fit INSIDE the K-r ! If you get one with a small spring on the side REMOVE it FIRST or it is likely to jam in the camera !!!

A safer bet are adapters with a flange which sits OUTSIDE the K-r. The only disapdvantage with these is the small distance it places the lens away from the sensor resulting in lack of focus at infinity (at f2 !)

Also, here is a quote from the USA Pentax Forum ...
http://www.pentaxforums.com/forums/pentax-slr-lens-discussion/187767-old-lenses-...

"It's common for folks with just a few M42 screwmount lenses to buy just one Official Pentax adapter, a narrow-flange guy that's safe and somewhat tedious and not super-cheap. The narrow flange allows lenses to reach infinity focus. Mount the adapter in the camera and it becomes an M42 camera with no aperture automation.

Those of us with many M42s tend to buy batches of cheap clones of the Official Pentax. These may be marked as Bower or FotoDiox or other brands. These are usually fine, but remove the screw and clip or YOU WILL GO APESH!T as the adapter jams on the camera. We mount these on the lens, not the camera. Use a PK rear lens cap as a wrench to tighten the adapter. I've had adapters on some lenses for so long that I've almost forgotten they aren't native PK.

A third type of adapter has a wide flange that does not allow infinity focus. These are cheap and safe, no possibility of jamming on the camera. I use these with old teles that normally focus past infinity, and for macro and closeup and portrait and other work where infinity doesn't matter. On something like the Takumar 200/4, it pulls the focus range in to about 1.5m-150m."

As I said before TAKE NOTE of the warnings !

I hope this helps ?

Peter

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johnha

Link Posted 13/06/2012 - 01:58
PeterKR wrote:
BEWARE - take note of the advice in that thread concerning adapters which fit INSIDE the K-r ! If you get one with a small spring on the side REMOVE it FIRST or it is likely to jam in the camera !!!

Hi Peter,

If using the genuine Pentax adapter, which contains a spring, there is no problem removing it from the camera. A pencil, small screwdriver or even a finger nail easily depress the spring and allows the lens to be unmounted. Unfortunately the Pentax adapters aren't cheap at the moment, but they are the only ones I would use.

Many people try to minimise the time the camera is open to the elements and try to permanently mount the adapter to their lenses. As there's nothing to lock the lens/adapter unit on the body if you remove the spring in order to do this, I wouldn't try this either.

John.
PPG Flickr

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DoctorJeff

Link Posted 13/06/2012 - 10:15
I found a small pair of engineer's tweezers to be just right for squeezing the spring out of the retention position and then unscrewing the adapter.
Do a quick google on "Helios 44M" lenses and you can find out about all the variations. But, they are all quite good - or better - and well worth playing with.
I will go along with PeterKR about removing the spring and fitting the adapter permanently to the lens. I have a Hoya f2.8 f135mm in my collection that is permanently adapted. It is short, fast, balances well on the K20, and is about as much as I can hand-hold on a good day (MS is not kind to photographers, but in-body image stabilisation is).
Geoff
Water can wear away a stone - but it can't cook lunch
X-5
istDS
K2000
P50.
Lenses Digital: 50-200, 18-55 KAF: 28-80.
Lenses KA & K: SMC-KA f2.0, SMC-K f1.4, SMC-K f1.7 Tokina KA 28-70 , SMC Pentax 70-210 F4, Sigma KA 75-300 , Hanimex 500mm Mirror, and the Tamron Adaptall-2 stuff.
and then there's all the M42 kit, and the accessories ...

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johnriley

Link Posted 13/06/2012 - 10:49
The point of the Pentax Adapter K http://www.srsmicrosystems.co.uk/156/Pentax-Mount-Adapter-K.html
is not to convert a lens to K mount. It is to convert a K mount body into a screw thread body so that screw mount lenses can be used on it.

This was to allow those who needed to upgrade/replace their Spotmatics with something newer to continue to use their old lenses. (Prior to this there was a similar adapter to allow the new screw thread lenses to be used on the older Asahiflex bodies.)

The technique is to fit the adapter to a lens and mount it onto the camera. The adapter clicks into place and the lens can be removed and replaced with another as and when required. The Pentax Adapter K may seem expensive, but is beautifully engineered and will not jam into the bayonet.

When you want to remove the adapter, release the catch as descibed by others and, holding the camera pointing down just rotate it until it drops out into your hand.

The catch is needed to ensure the lens does not become detached in use.
Best regards, John

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voneout

Link Posted 13/06/2012 - 12:07
Thanks guys! Cheers!
Pentax K-r, Pentax SMC DA AF 18-55mm F3.5-5.6 AL, Tokina SD 28-70mm 1:3.5-4.5 MF Japan, HELIOS-44M-4 58mm F2 M42, Velbon CX 440
PENTAX DA-L DAL 55-300mm F/4-5.8, YONGNUO YN-560 II Flashgun
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