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Old Feb 6, 2008, 1:59 AM   #1
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I ordered a Fotodiox adapter on Ebay to see whether they will allow my K mount lenses to focus to infinity. The one I got will not.

I am going to grind away the thin part of the peripheral flange, but I can't see how that will leave the adapter where it will focus to infinity. My understanding is that the characteristic preventing infinity focus is the distance between the lens and the camera. It appears to me that merely eliminating the peripheral flange will not reduce the critical separative dimension. In that case it seems that the overall height of the adapter must be reduced a bit. An indication of this possibility is the fact that with the adapter attached tightly to the lens base, the lens will not rotate far enough to align the top-center point of the camera with the red dot marking the aperture setting. And this is true even when the removal button it depressed so the adapter passes slightly by it. It looks as if the lens lacks about ten degrees of turning far enough clockwise.

Can someone who has experimented with this please tell me how to be sure enough metal has been removed from the bottom (as opposed to the three-lug end) of the adapter.

I guess I really should have put out the bucks for an adapter known to fit right, but the challenge kind of persuaded me.

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Old Feb 6, 2008, 4:33 AM   #2
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OE,
The correct one sits right into the lens mount and becomes absolutely flush with the mounting face. Hope this helps ... Jack

This one's the no inf focus ...
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Old Feb 6, 2008, 4:34 AM   #3
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This is the one you want ...
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Old Feb 6, 2008, 4:41 AM   #4
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Here is one mounted on a body, note how it fits flush with the face of the mount.

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Old Feb 6, 2008, 9:38 AM   #5
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My adapters put the marks for the F/stop and focus at about 10:00 oclock. Still gives you infinity focus! It is the depth of the lens that makes a differance not where the legend or marks wind up after mounting! I've got a Sears lens where the marks are at 1:00 oclock and it focuses fine as well!

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Old Feb 6, 2008, 4:36 PM   #6
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bigdawg wrote:
Quote:
My adapters put the marks for the F/stop and focus at about 10:00 oclock. Still gives you infinity focus! It is the depth of the lens that makes a differance not where the legend or marks wind up after mounting! I've got a Sears lens where the marks are at 1:00 oclock and it focuses fine as well!

Dawg
me too.
even my original asahi pentax adapter puts the lens at 10 oclock.. my other original pentax was the same.. so is the kalt..

you'll know when you've taken off enough when the lens touches the cam body.. pair of channel locks and a belt sander sounds real good..

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Old Feb 7, 2008, 4:08 AM   #7
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OE,
Just be aware that if you modify the flanged model as you are suggesting that it wont lock to the body since it doesn't have the side spring that the correct one does. In that condition the lens could fall off the camera, you wouldn't want that I'm sure. ... Jack
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Old Feb 7, 2008, 9:42 AM   #8
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jachol wrote:
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OE,
Just be aware that if you modify the flanged model as you are suggesting that it wont lock to the body since it doesn't have the side spring that the correct one does. In that condition the lens could fall off the camera, you wouldn't want that I'm sure. ... Jack
You'll need a slot cut in the lens body to accomodate the spring pin and prevent the lens from unmounting itself and fall off.
[img]file:///C:/DOCUME%7E1/Owner/LOCALS%7E1/Temp/moz-screenshot.jpg[/img]
Slot for locking pin.

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Old Feb 8, 2008, 5:12 AM   #9
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Thanks about needing slot. I think my Dremel tool, with an on-end cutter about 3/32 inch diameter, I have one, should do the trick. I'll probably have to make a jig to keep the lens and tool aligned. A drill press would do it, but I have little need for one otherwise, and, since I am relatively new in Kansas City, I have no circle of putterer friends to whom I can turn.

If I find some practical way to cut the notch, I will report same here after the fact.

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Old Feb 8, 2008, 12:09 PM   #10
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i don't know what i'd do w/o my dremel. i just wish i have a different model that gives me more control over speed.

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