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10-29-2012, 08:46 AM   #16
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Using a K-r like a K-1000 match needle

This all assumes you are using some kind of A-series lens, all the way from the manual focus K-A to current K-DA....

Optional: From the back of the camera - set your AF/MF selector on the left side of the mirror box to MF for the most K-1000 like use.
  1. Turn your selector knob on top to 'M' (manual).
  2. Turn your camera on.

From the Viewfinder:
  1. Focus the lens (manually, or use the camera's AF) - if manual , you can use a combination of your judgement, or the green octagon that appears in the viewfinder
  2. Press the +/- button on the top of the camera to toggle between shutter speed and aperture. Item selected is underlined.
  3. When shutter speed is underlined - turn e-wheel to desired speed (note +/- change in EV to the right)
  4. When aperture is underlined - turn e-wheel to desired speed (note +/- change in EV to the right)
  5. Aim for 0.0 EV and you have done the same as centering the match needle on a K-1000.
From the status screen:
It all works the same except for focus. Do step #1 above for focus.

10-29-2012, 02:32 PM   #17
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Thanks, although I have never touched a K-1000. It's the Spotmatic I was reminiscing about, but presumably the match-needle centering was similar. It's a matter of retraining myself, your notes are a very good start, much appreciated!

Yes, for the moment all of the lenses in use are A lenses. I have some M42 manuals but at present no adapter for them so they remain in the bag against the arrival of the M42 adapter.
10-29-2012, 04:43 PM   #18
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QuoteOriginally posted by OrchidJulie Quote
Thanks, although I have never touched a K-1000. It's the Spotmatic.
Oops. Yep. I got carried away. The K-1000 is also strictly a match needle camera.

Although to drag this thread back to the original topic... Auto-focus and exposure method are two completely separate topics. You can play 'match needle' to your heart's content and still let your K-r handle the focusing.
11-02-2012, 05:27 PM   #19
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You're right. It drifted (as threads do!), partly my fault, because I was cogitating on all the ways the perceived focus problem could have been the result of other issues.

Everyone's expertise is much appreciated, thanks!

11-03-2012, 01:07 AM   #20
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OrchidJulie, one test that i did not see [unless i missed it] is to set the camera up on tripod and live focus on the afore mentioned cereal box or newspaper.

then switch off live view and watch the focus ring and press the shutter button or focus button and see if the ring moves ,even a fraction movement indicates a front/back problem.

however as has been said already on your Kr you can only store a global setting which affects everything, my understanding is it is a adjustment is for the body not just that lens when fitted and will therefore affect every lens. and it is no good for zoom lenses

On the likes of the k5 with multiple individual settings they are,[providing the camera can "read" that lens data,] applied to each lens as adjusted when that lens is fitted.
11-03-2012, 04:53 AM   #21
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Thanks, adwb. That's easy enough to try. As previously noted, at present I only have one "prime" -- a macro -- plus four zooms (kit lenses from several bodies), so if I were to use the AF adjustment it would only be for that macro. And of course the K-r only stores one adjustment. Recent shots (I wouldn't call them tests) suggest that the AF may be working correctly and what I thought was a front or back focus problem may be the result of some other issue (meaning shutter speed or some other factor in the calculus...). I do need to set up the tripod and do some concerted test shots... there just hasn't been a good opportunity recently to devote the necessary time and attention.
11-03-2012, 10:33 AM   #22
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QuoteOriginally posted by jlaubza Quote
......
But with zoom lenses, which part of the zoom range do you adjust? Here's my dllemma - I use a Tamron 18 - 250mm zoom lens. At wide angle, the lens 'focuses' at a range that clearly exceeds the actual distance for medium close up objects - one can read the distance indicator off the lens barrel. By zooming in, I can refocus, accurately, and then I need to lock that focus and zoom out again.
....
.
WIth Tamron zooms I don't think you can rely on the distance scale at all. If you are judging the accuracy of the autofocus by reading off the distance scale you will probably be misled. I have two tamron zooms, 18-250 and 10-24.

If your 18-250 is anything like mine then that technique of zoom-in, focus, lock focus and zoom out will guarantee out of focus photos.

I'm assuming the 18-250 I have is the same one you have. At 250mm the distance scale on mine is rather accurate but as you reduce focal length the focus scale goes all wrong. For instance at the widest 18mm the focus ring reads 7 metres when focusing at infinity and 1 metre when focusing at 2 metres. (The 10-24 is even worse).. However I don't think this is really a problem but just something that is 'not nice'. You just have to learn to ignore the scale.

Many Pentax zooms 'solve' this problem by simply not printing a distance scale at all, but you can see they behave the same from the need to refocus when you zoom in/out.

Despite this apparent 'problem' the lens in reality focuses perfectly throughout the zoom range. On the K-r I set the fine autofocus permanently to -10 which also works fine with all but one of the other lenses that I have. On the K-30 it works fine with no fine adjustment.

The one lens I have that requires me to adjust the fine AF adjustment is the Tamron 10-24. On the K-r I have to set it between -8 and 11 depending on the focal length (but unfortunately 11 doesn't exist). I haven't used it much yet on the K-30 so I don;t know if this is camera or lens specific.

I think you should entirely ignore the distance scale and only use the actual photos and to figure out how well the autofocus works.

11-03-2012, 01:02 PM   #23
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one can read the distance indicator off the lens barrel. By zooming in, I can refocus, accurately, and then I need to lock that focus and zoom out again.

Nope. Not all zooms have constant focus - in fact I think few do - meaning focus will shift slightly as you zoom in and out. You have to focus at the focal length that you intend to use to shoot the picture.

Liveview zooms in to focus, but it uses digital zoom, not optical zoom. Or you can purchase one of the magnifiers for the view finder. But using the lens itself to zoom in for focus will only get you several out of focus shots, unless you also use a small enough aperture to offset any focus shift.
11-05-2012, 03:47 PM   #24
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I've had decent luck with doing an adjustment on my Tamron 17-50. It pretty much just needed a -5 adjustment throughout the zoom range. Zoom lenses do experience some focus shift as you zoom but that doesn't necessarily make them impossible to dial in.
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