Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax Lenses

Reply
 
Thread Tools Search this Thread
Old Jun 21, 2007, 8:38 PM   #31
Senior Member
 
Join Date: Jun 2006
Posts: 400
Default

Quote:
Does NOT is ANY way come off if you don't hit the release button (or just didn't full lock it on).
One should take this statement with a rather large pinch of salt.

A Pentax adapter, and I assume any others of the fully flush design, are not held in any way by the release button. These fully flush adapters are the ones that allow infinity focus on all lenses.

The release button requires a notch of some kind in whatever is attached to the camera. Now this could be a notch in a non-flush type adapter, it could be a notch in the back of a regular 'K' type lens or it could be a notch added as a modification to a screw mount lens fitted to a flush adapter.

Non flush adapters have a ring that may include a notch for the camera locking pin.

IMHO, for lens security you must either have the spring clip or something for the camera locking pin to engage. If a flush type mount is fixed to a screw lens and the spring clip not removed it will be very difficult to get the lens off the camera.

One might be wondering how the lens could be accidently twisted off the camera, this is how it happened to me. We were at a crowded farmers market andI was holding the camera with the lens downwards and close to my body. Someone (with an ample butt) wobbled pastand as they leaned towards me the lens was twisted off neat as a whistle to land in a carton of cabbages.

I put notches in the back of M42 lenses that I have fixed Pentax adapters to.



John Hill is offline   Reply With Quote
Old Jun 21, 2007, 10:33 PM   #32
Senior Member
 
robar's Avatar
 
Join Date: Mar 2005
Location: D/FW area Texas
Posts: 7,590
Default

as i stated. it's only about an 1/8 of a revolution

roy
robar is offline   Reply With Quote
Old Jun 21, 2007, 10:44 PM   #33
Junior Member
 
umenon's Avatar
 
Join Date: Dec 2003
Posts: 22
Default

Ok .. got my Kalt Adapter (read my post on the other thread) from B&H today.

Even before trying it on, I used a small screwdrive to remove the springy stopper (an appropriate functional title for this tiny piece of metal).

Threaded it to my favorite m42 lens. Mounted the combo onto the K10D. Traced the spot on the lens thats on top of the release pin on the camera body (this pin is located at the 8'oclock position on the camera when viewed from the front).

Unmounted the lens; took out my dremel tool ... selected a small cylindrical tip with rough texture and created a notch on the lens body which happens to be metal. The notch is not very deep but deep enough to catch the pin. I don't hear the distinct click (as heard when you lock the kit lens into place) ... but thats because the notch has smooth sides.

Also, I would advise everyone to make a notch for that pin to settle in ... else keeping the pin pushed in for a long time (i.e keeping a m42 lens mounted on the body for an extended time) ... could make the release pin lose its elasticity ... making it ineffective for locking in any lens (K-mount or otherwise) to the camera body.



/\/\ax

umenon is offline   Reply With Quote
Old Jun 21, 2007, 11:06 PM   #34
Senior Member
 
Join Date: Jun 2006
Posts: 400
Default

I am sure you will not be disappointed Max...

Now for another tip on this subject, instead of using glue or whatever I just screw the adapter onto the lens rather tightly and for that purpose I use an old teleconverter as a sort of 'wrench'.
John Hill is offline   Reply With Quote
Old Jun 21, 2007, 11:30 PM   #35
Junior Member
 
umenon's Avatar
 
Join Date: Dec 2003
Posts: 22
Default

This adapter from B&H is impossible to remove from the lens with bare hands. I have to use that silly adapter key to remove it. No need for glue.
umenon is offline   Reply With Quote
Old Jun 22, 2007, 12:39 AM   #36
Senior Member
 
Fred2726's Avatar
 
Join Date: Oct 2006
Posts: 305
Default

umenon wrote:
Quote:
This adapter from B&H is impossible to remove from the lens with bare hands. I have to use that silly adapter key to remove it. No need for glue.
I second that as I sliced my thumb open trying to remove it once...

Fred
Fred2726 is offline   Reply With Quote
Old Jun 22, 2007, 2:26 AM   #37
Senior Member
 
Hayward's Avatar
 
Join Date: Jan 2007
Posts: 1,318
Default

John Hill wrote:
Quote:
Quote:
Does NOT is ANY way come off if you don't hit the release button (or just didn't full lock it on).
One should take this statement with a rather large pinch of salt.

A Pentax adapter, and I assume any others of the fully flush design, are not held in any way by the release button. These fully flush adapters are the ones that allow infinity focus on all lenses.
Indeed there is a notch for the pin.... but the adapter is totally flush to the mount. And comes off easily with no tools just wedging fingers into the thread opening, pushing the button and twisting

Maybe a picture of what you mean by fully flush fitting is in order? (Mounted on body) To avoid any confusion that may be going on for any reading the thread.


Hayward is offline   Reply With Quote
Old Jun 22, 2007, 3:58 AM   #38
Senior Member
 
Join Date: Jun 2006
Posts: 400
Default

Hayward, by fully flush I mean that the lens mounts right up to the camera and that the adapter does not change distance between the lens and the camera.



I see some adapters have a flat flange between the camera and the lens which changes the register distance and (so I have heard) causes loss of infinity focus on some lens. All my adapters are Pentax type and dont have that flange so I dont really know about the infinity focus issue though I do note that all the M42 lenses I have tried still focus to infinity even when screwed out a little.



Pentax adapter, what I call fully flush...



A non Pentax adapter, notice the greater diameter.



The Pentax one allows the lens to screw right up to touch the camera body (thats what I call flush), the other adapter introduces the thickness of the flat flange between the lens and the camera, what I call not flush.

If the infinity focus issue is not a problem than I suggest the non-Pentax adapter is actually better if you want to permanently mount the adapter on your favourite M42 lens. Just screw that baby on tight, or lock with glue, and you have all the convenience of a manual K mount and it will be secure because the camera lock pin engages the notch we see on the left of the second picture.

Me, all my adapters are Pentax type so I have to cut a notch in my lens to make it secure on the camera lock pin otherwise it can easily fall out. But I would be more than happy with the second type of adapter provided I could focus to infinity.

My advice to anyone contemplating screw mount lenses would be to get the non-flush adapter, (i.e. the one in the second picture) and only go to the Pentax (flush type) if you have infinity focus issues.






John Hill is offline   Reply With Quote
Old Jun 22, 2007, 4:44 AM   #39
TDN
Senior Member
 
TDN's Avatar
 
Join Date: Jun 2006
Posts: 1,288
Default

I've read on a different forum about someone that had focus issues with an adapter to Canon EOS mount.

What he did was grind the adapter until it was thin enough not to make much difference...I guess you could try that with these too...although if it fails, you'll have literally grinded your money away...

Tom
TDN is offline   Reply With Quote
Old Jun 22, 2007, 5:21 AM   #40
Senior Member
 
Join Date: Jun 2006
Posts: 400
Default

TDN wrote:
Quote:

What he did was grind the adapter until it was thin enough not to make much difference...I guess you could try that with these too...although if it fails, you'll have literally grinded your money away...

Tom
Well not exactly, if you did that you would have something akin to the Pentax adapter with the springy bit removed! You could still permanently mount that on your lens and put a notch in the lens body like I have done.
John Hill is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 4:45 PM.