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02-16-2011, 01:47 PM   #1
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Lens loose with genuine M42 adapter...fix?

When the lens doesn't contact the lens mount of the camera, the lens rotates about a millimeter laterally whenever I touch it. Searched the interwebs, searched here, and couldn't find any topics that pertained to this particular issue.

Is there a remedy to this? Bending the spring on the adapter further outwards after squaring off the nearest flange on the lens mount looks to be the only way

02-16-2011, 01:54 PM   #2
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Sounds like there's something wrong with the lens thread itself!

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02-16-2011, 02:02 PM   #3
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The lens fits into the Pentax adapter snugly...in this case, I'm also using an M39 adapter. I've had this happen with a couple other M42 lenses, as well. The lens actually rests on the M42 adapter, and that moves when I focus.

When the lens doesn't contact the body, the lens moves. I have no problems with my other M42s with larger mounting flanges. I can see the M42 -> K adapter move when I twist the lens.

Maybe a video is in order? Don't really have a good apparatus for taking one...3.2MP point n shoot circa 2005 or 3.2MP BlackBerry
02-16-2011, 02:12 PM   #4
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QuoteOriginally posted by ryan s Quote
The lens fits into the Pentax adapter snugly...in this case,.... I've had this happen with a couple other M42 lenses, as well. The lens actually rests on the M42 adapter, and that moves when I focus.

When the lens doesn't contact the body, the lens moves. I have no problems with my other M42s with larger mounting flanges. I can see the M42 -> K adapter move when I twist the lens.
If only the m42 adapter is mounted on the camera can you move it sideways?

I do not understand this sentence "When the lens doesn't contact the body, the lens moves." Do you mean if the lens with adapter on it is sitting on a table, the adapter can move sideways with respect to the lens?

02-16-2011, 02:15 PM   #5
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It is the lens itself. I have one lens Rikenon EE m42 just like that... the mount surface is not flush (flat), therefore, it wobbles when you focus. I use a piece of paper as shims and it works just fine. All my other m42 lenses work fine without it. I am also using the genuine Pentax m42 adapter.
02-17-2011, 11:06 AM   #6
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QuoteOriginally posted by newarts Quote
If only the m42 adapter is mounted on the camera can you move it sideways?
Yep.
QuoteOriginally posted by newarts Quote
I do not understand this sentence "When the lens doesn't contact the body, the lens moves." Do you mean if the lens with adapter on it is sitting on a table, the adapter can move sideways with respect to the lens?
Imagine you have an f/1.4 lens...they're physically wide. The mount is still 42mm in diameter, but the total width of the lens is perhaps 60mm. That extra metal around the lens makes contact with the flange of the K mount of the camera. (You hear people say the lens needs to "short" the contacts to work [it doesn't] but that's the same principle.)

Perhaps a video is in order...let me see if I can come up with an effective way of showing it...
QuoteOriginally posted by aleonx3 Quote
It is the lens itself. I have one lens Rikenon EE m42 just like that... the mount surface is not flush (flat), therefore, it wobbles when you focus. I use a piece of paper as shims and it works just fine. All my other m42 lenses work fine without it. I am also using the genuine Pentax m42 adapter.
The adapter itself moves in the mount...even without a lens attached, though. The issue is exacerbated when the mounted lens doesn't contact the camera body.
02-17-2011, 01:32 PM   #7
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Horrible video quality, not enough light, but at least this 6-year old camera with the broken LCD can focus while taking videos...couldn't remember if it did or not Took longer to upload than it did to make...

[YT]http://www.youtube.com/watch?v=jfB-6QM79b4[/YT]

This also occurred with the Helios 44-2 in M42...the mount of the lens didn't contact the body so it wobbled. Surely I'm not the only one with this issue...

02-19-2011, 11:54 AM   #8
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Anyone?

The adapter does the same thing on the MX...can't remember if the cheap Bower version wiggled...
02-19-2011, 12:41 PM   #9
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Boy that is weird. Have not had that happen to me but the suggestion of using paper to shim might not be bad.
Perhaps a rubber ring or metal washer of sorts to shim or fill in the distance from the lens to the Pentax adapter. Don't know if that makes any sense.
02-19-2011, 01:17 PM   #10
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@Ryan S, you are right, if the lens does not have wide enough flat surface at the base to touch the camera lens mount, then it will likely wobble a bit. Most of the m42 lens I have are fine except one as I mentioned.
02-20-2011, 01:28 PM   #11
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Well, I tried shimming it with stuff I have sitting around. The Mir lens is such a small diameter at the base (3mm narrower than the M42 mount, of course) it's difficult to get anything in there. And the area where the focus scale is marked is flat--any "spacing" option will contact the focus ring.

I tried:
-Couple Cokin rings...49 and 58mm were too big
-49->58mm step ring...realllllllly close, but the lens just won't rotate far enough to lock

So close...I might have to live with it. I suppose I could file the flange on this ME Super and see what happens...maybe.
02-20-2011, 03:54 PM   #12
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Nice video, explains the problem of the mount clearly. You might want to buy a third party m42 adapter, remove the spring and really torque it on to the lens and see if that will solve the problem. 2. Buy an m42 adapter with a flange which will allow the lens lock to engage, this will most certainly fix the wobble but you will lose infinity focus. I took the springs off all of my m42 adapters (genuine or otherwise) because I'd go daft if I have to mount and dismount lenses like you do in your video.
02-20-2011, 04:56 PM   #13
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Apparently the adapter's ears are not drawing tightly to the mount's ears when there is no shoulder on the lens itself to contact the surface of the camera mount (or else it couldn't wiggle). Here are a couple ways to adjust the distance:




Put the adapter face down on a flat surface and whack the TRAILING edges of the adapter's ears (as shown) to decrease the gap between ear and flange as the adapter is rotated into the mount. Don't let whacking it freak you out too badly. It is brass. Brass responds well to whacking.

Increase whack force until you feel the adapter's ears drag when mounting it on the camera.

Dave

Last edited by newarts; 02-20-2011 at 05:11 PM.
02-20-2011, 08:27 PM   #14
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I think what newarts is suggesting has merit but I would be somewhat reluctant to do that to a $40.00+ adapter that works fine with other m42 lenses. I measured the gap between the flange and the locking tabs; on the genuine adapter it is 2.9mm and I have some defective 3rd party m42 adapter that won't mount on to the K20D, measures at 2.6mm. I have been able to mount this adapter on to the K20D by using a needle file to file down the locking tabs down. I suppose it would be hard look for some 3rd party adapters that won't mount on a camera but one such defective adapter might work for your Mir-1 lens. If you want one of mine, pm me.

Thanks,
02-21-2011, 11:49 AM   #15
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QuoteOriginally posted by excanonfd Quote
Nice video, explains the problem of the mount clearly. You might want to buy a third party m42 adapter, remove the spring and really torque it on to the lens and see if that will solve the problem. 2. Buy an m42 adapter with a flange which will allow the lens lock to engage, this will most certainly fix the wobble but you will lose infinity focus. I took the springs off all of my m42 adapters (genuine or otherwise) because I'd go daft if I have to mount and dismount lenses like you do in your video.
The first adapter I had was a cheap non-flanged one...can't remember for the life of me if it had the wobbly issue...
QuoteOriginally posted by newarts Quote
Apparently the adapter's ears are not drawing tightly to the mount's ears when there is no shoulder on the lens itself to contact the surface of the camera mount (or else it couldn't wiggle). Here are a couple ways to adjust the distance:




Put the adapter face down on a flat surface and whack the TRAILING edges of the adapter's ears (as shown) to decrease the gap between ear and flange as the adapter is rotated into the mount. Don't let whacking it freak you out too badly. It is brass. Brass responds well to whacking.

Increase whack force until you feel the adapter's ears drag when mounting it on the camera.

Dave
Very interesting...doesn't look too bad. I'll give it a shot, thanks
QuoteOriginally posted by excanonfd Quote
I think what newarts is suggesting has merit but I would be somewhat reluctant to do that to a $40.00+ adapter that works fine with other m42 lenses. I measured the gap between the flange and the locking tabs; on the genuine adapter it is 2.9mm and I have some defective 3rd party m42 adapter that won't mount on to the K20D, measures at 2.6mm. I have been able to mount this adapter on to the K20D by using a needle file to file down the locking tabs down. I suppose it would be hard look for some 3rd party adapters that won't mount on a camera but one such defective adapter might work for your Mir-1 lens. If you want one of mine, pm me.

Thanks,
The adapter only cost me like $25 And you're talking to someone who wants to find an extra silver K flange to grind the backside down to make other non-PK lenses fit without mount conversions to each
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