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05-09-2008, 05:36 AM   #16
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Scott:
Yes that is the step I was referring to. Have found that the width of this step varies depending on the manufacturer. I have no solid explanation of why they did it that way.

Regards

Jan

05-09-2008, 06:11 AM   #17
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QuoteOriginally posted by sabarrett Quote
I guess here is another question: What actuates the auto pin? I don't see a lever or something in the body that would stop down the lens when the switch is set to auto.
Nothing. You need to run the lens on the 'M' setting when taking the picture. The 'A' setting IS useful, in the following regard:

1. Set lens to 'A'; focus. Pentax used to call it "bright field focusing' back in the M42 days;
2. Set your aperture to the desired value;
3. Set the lens to 'M';
4. "Stop down" using green button
5. Fire away.

Now, if you need to refocus but the exposure conditions do not change, you can quickly flip to "A", refocus, and flip back to "M' to take the picture.

If you work through this you can mix and match the order of things to fit the way you want to work. You can set the aperture, switch to "A" focus, stop down, fire, etc... however, it all comes down to changing BACK to "M" mode to take the picture.

Indeed, you can leave it in "M" mode and open the aperture all the way up to focus and then shut it back down, much like what you would do with a preset. I do work this way often. This works well if you have a good handle on Sunny 16, etc.

That's it for the "Auto" mode on a M42. It is about a half-step better than a preset lens, and is used in essentially the same way.

woof!
05-09-2008, 06:18 AM   #18
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QuoteOriginally posted by hinman Quote
I wrote up a blog post talking about the Genuine Pentax adapter

As far as I remember, I don't recall any wiggling that I have observed from both the genuine and 3rd party adapters
My genuine doesnt look like that. Well the adapter looks the same on a quick glance, but my text is not black, just etched in.
05-12-2008, 04:52 PM   #19
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Makes sense. I'll keep playing again. I am sure my manual instincts will come back to me after many years of being spoiled....

I just gotta decide if that step is interfering with anything or not. Not sure if it is easier to remove the step on the lens or to make the chamfer on the inside of the adapter a little larger. Not sure which would have better effect. Probably modding the lens, as the adapter is quite thin, as I think about it.

Scott

05-29-2008, 02:07 PM   #20
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Well, I got that step machined off. I have had to add a 0.013 shim on the mount surface to get the lens to line up so the aperture markings are at the top. When the step got machined, the mount surface got a little dusting off in the process. However, now it seems to work nice. The first shots are a little purple fringed, however not too bad. I will shoot more this weekend probably.

Anyway, I wanted to re-install the auto/man mechanisms back in the mount. However they do not work properly when they are remounted. I imagine different manufacturers lenses have different mechanics inside, but does anyone know if there is a website that shows pictures of the inside or a description on how that might work so I can try to get it back together? I think the a/m switch would be nice to have as others have posted - to make it easier/quicker to check focus.

Scott
05-29-2008, 03:01 PM   #21
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QuoteOriginally posted by sabarrett Quote
Well, I got that step machined off. I have had to add a 0.013 shim on the mount surface to get the lens to line up so the aperture markings are at the top. When the step got machined, the mount surface got a little dusting off in the process. However, now it seems to work nice. The first shots are a little purple fringed, however not too bad. I will shoot more this weekend probably.

Anyway, I wanted to re-install the auto/man mechanisms back in the mount. However they do not work properly when they are remounted. I imagine different manufacturers lenses have different mechanics inside, but does anyone know if there is a website that shows pictures of the inside or a description on how that might work so I can try to get it back together? I think the a/m switch would be nice to have as others have posted - to make it easier/quicker to check focus.

Scott

Try forum.mflenses.com
There are some real fountains of knowledge there.
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