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Old Dec 9, 2006, 2:49 AM   #1
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Can someone please remind me how to set the camera so that with the shutter button pressed and manually focussing the shutter automatically releases when the subject comes into focus?

Thanks

(I did try the "search" function but either I dont know how to use it or it not working, the "help" is not very illuminationg on this topic. :sad


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Old Dec 9, 2006, 5:08 AM   #2
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''search'' is pretty much worthless here

when using a manual lens , use spot focusing, set the cam to auto focus, depress shutter button, focus on subject, adj focus, shutter will not fire until subject is in focus.

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Old Dec 9, 2006, 5:11 AM   #3
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John Hill wrote:
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Can someone please remind me how to set the camera so that with the shutter button pressed and manually focussing the shutter automatically releases when the subject comes into focus?

Thanks

(I did try the "search" function but either I dont know how to use it or it not working, the "help" is not very illuminationg on this topic. :sad

How to focus trap with auto focus lenses:
http://forums.dpreview.com/forums/re...ssage=15117360

How to focus trap with screwmount (M42) lenses:
http://forums.dpreview.com/forums/re...ssage=17840042

How to focus trap with K, M, and A lenses:
http://forums.dpreview.com/forums/re...ssage=14464406

The above is to quote Ron of dpreview forum

Have fun

Daniel
Toronto

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Old Dec 9, 2006, 1:45 PM   #4
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Thanks very much!
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Old Dec 10, 2006, 1:00 AM   #5
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Just a quick recap, I have a *ist DS and a number of old lenses of various dimensions. Inspired by recent discussion of the SMC Pentax F- 1.7x AF Adapter
which is claimed to give auto focus functionality to manual lenses, but disenchanted by the price, I decided to see what I could do with what I have.

My best long lenses at 450, 500 and 600mm, none of which are overly fast, are really too long for convenient use with a teleconverter but I do have a Takumar 200mm f1:3.5 with M42 mount which I think is a more practical.

The TC I have is a Vivitar 2X macro focussing marked P/K-A R-P/K. I assume the 'R' stands for Ricoh? So the first thing I did was to take the mount flange off the TC and remove the pin of the extra contact which could foul the auto focus drive on the DS.

Then, armed with the information so kindly linked to I set out to investigate focus capture. Unfortunately one of the sitesdoes not appear to be available any more. Most of a fine Sunday afternoon has been expended in getting thus far. I knew from the links that it was necessary to short a particular pin to the lens body but finding exactly which one was quite a task! The DS has 7 contacts and the TC has 6 pins (not counting the one that would have fouled the auto focus drive). Pin number 1 in the TC does not coincide with pin 1 on the camera! It was very confusing with the scattered scraps of information to determine just which contact had to be connected to ground and connecting them all made the camera flash its LCD in irate disgust! After trying several combinations I eventully engaged my gray matter and took a close look at the camera pins, then I did a simple check.

With the lens off and the camera lying on its back I turned it on and pressed the shutter which immediately fired, then I shorted each pin in turn to the camera body and when I got to the 5th pin the shutter did not fire.

I took the flange off the TC and removed all pins except the one that lined up with the 5th pin on the camera which I connected to the TC body. Now I have focus capture with M42 and presumably later lenses.



Focus capture is not the same as auto focus but it is a step along the way, IMHO.

Precis: for focus capture short Camera's 5th pin to frame, note that this is the pin that is normally below the surface of the flange and which at first glance appears to be stuck down.














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Old Dec 15, 2006, 1:16 PM   #6
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I was a little premature on this one, grounding the 'A' pin does indeed allow focus capture on my *ist DS and screw mount lenses but only as far as shutter releasing.

Presumably the camera tries to stop down what it thinks is an 'A' lens which of course it cannot the end result being that several, themajority really, of shots areoverexposured.

The focus capture shutter release does not work in the Av mode so it is back to the drawing board for me.




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