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04-18-2011, 07:30 PM   #16
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QuoteOriginally posted by JohnBee Quote
I second that.
AF confirm is useless with MF lenses(far to much play) and accuracy degrades as total aperture size increases(f/2 or less).

Best thing to do is use LV and magnify to focus.
Or... if you prefer VF, incest in a split prism focusing screen.
Thanks for the tip. I never thought of using the magnify to focus. Sorry if someone said that I didn't see it. Better buy the rechargeable batteries...

04-18-2011, 07:37 PM   #17
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QuoteOriginally posted by JohnBee Quote
Best thing to do is use LV and magnify to focus.
Or... if you prefer VF, incest in a split prism focusing screen.
You mean "invest" right?



Split prism focusing screens are a great tool too. Sometimes they take some calibration (using different shims to make sure they're seated properly) and some getting used to, but much more reliable than a beep.

But live view--well, that's infallible.
04-18-2011, 07:39 PM   #18
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I have dumb question. If I use LiveView and magnify aren't I magnifying the image that is capture and doing so digitally instead of optically. And, sorry, isn't that degrading the IQ?
04-18-2011, 07:40 PM   #19
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I would second using live view with magnification if necessary to really nail focus (for those applications where time is not of the essence and you want the sharpest focus you can get).

If you are considering staying with MF lenses for a while, you could be well served purchasing a split prism focus screen. I have a Katzeye and it's very useful -- although I find the microprism collar a better tool than the split prism portion itself.

Manual focusing is a great skill to learn -- I actually generally don't trust my camera's AF mechanisms for sensitive applications and will take over manually even with my AF lenses, because my eye has become so much more reliable than the whims of my camera.

04-18-2011, 07:41 PM   #20
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QuoteOriginally posted by justtakingpics Quote
I have dumb question. If I use LiveView and magnify aren't I magnifying the image that is capture and doing so digitally instead of optically. And, sorry, isn't that degrading the IQ?
The magnifying is just for your viewing pleasure (so you're only looking at a part of the image when you do it)--it doesn't affect the image.

Try it, you'll get it pretty quickly.
04-18-2011, 07:42 PM   #21
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QuoteOriginally posted by justtakingpics Quote
I have dumb question. If I use LiveView and magnify aren't I magnifying the image that is capture and doing so digitally instead of optically. And, sorry, isn't that degrading the IQ?
Live view shows you a digital preview of a shot you can take, but the shot has not yet been taken. It is being fed in at very low quality, and I assume some grotesquely high ISO to provide a real time stream of information. You are still focusing manually in real time when you turn the focus ring of your lens, but the feedback you are judging your focus accuracy off of is a digital preview instead of the photons themselves coming right to your eyeballs.
04-18-2011, 07:43 PM   #22
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QuoteOriginally posted by farfisa Quote
The magnifying is just for your viewing pleasure (so you're only looking at a part of the image when you do it)--it doesn't affect the image.

Try it, you'll get it pretty quickly.
Ah, this is what he meant. Yeah, the magnification is just zooming in on a part of a larger image: it is not altering what the actual image will look like. The only issue is that unless you return to normal 1X magnification once you've got your focus locked, your composition may have drifted rather substantially.
04-18-2011, 07:50 PM   #23
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One other thing to point out that is specially critical when using MF lenses - make sure your diopter correction is set correctly - slide it back and forth until the bottom line in the viewfinder is in sharp focus.

I mess this up all the time because sometimes I have my glasses on and sometimes not - if I forget to reset the diopter correction my MF shots are all out of focus.

04-18-2011, 07:55 PM   #24
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If I put a split prism focusing screen on, will it affect af in any way? I didn't know what it was until I looked it up. I remember if from a while back with a Minolta. It didn't look too hard to use but I am concerned that someone else using the camera might get confused if that AF is affected in some way.
04-18-2011, 08:25 PM   #25
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QuoteOriginally posted by justtakingpics Quote
If I put a split prism focusing screen on, will it affect af in any way? I didn't know what it was until I looked it up. I remember if from a while back with a Minolta. It didn't look too hard to use but I am concerned that someone else using the camera might get confused if that AF is affected in some way.
For the most part split prisms are a joy to use(not to mention how awesome they look). However, I've never had any side effects other than with spot metering which would over expose by about 1/2 a stop. - Or perhaps it was under expose( I can't remember). Either way, I use center weighted metering and the eV adjust is so easy to use that it's never really come-up as an issue.
04-18-2011, 08:27 PM   #26
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QuoteOriginally posted by JohnBee Quote
For the most part split prisms are a joy to use(not to mention how awesome they look). However, I've never had any side effects other than with spot metering which would over expose by about 1/2 a stop. - Or perhaps it was under expose( I can't remember). Either way, I use center weighted metering and the eV adjust is so easy to use that it's never really come-up as an issue.
Are they pretty easy to put on? You're just putting them on the mirror right?
04-18-2011, 08:28 PM   #27
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QuoteOriginally posted by v5planet Quote
I have a Katzeye and it's very useful -- although I find the microprism collar a better tool than the split prism portion itself.
I too find the collar to be somewhat easier to use. And I think I once asked the Katzeye CO if there was such a thing, but if memory serves me right, I don't think it was possible to get one. - Can't remember why though.
04-18-2011, 08:38 PM   #28
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QuoteOriginally posted by JohnBee Quote
I too find the collar to be somewhat easier to use. And I think I once asked the Katzeye CO if there was such a thing, but if memory serves me right, I don't think it was possible to get one. - Can't remember why though.
Yeah I find the split prism is best for those rare situations when you are photographing something with clear straight lines that are perpendicular to the split in the prism. Otherwise I always "double check" with the microprism collar.
04-18-2011, 08:39 PM   #29
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QuoteOriginally posted by justtakingpics Quote
Are they pretty easy to put on? You're just putting them on the mirror right?
Eh, installation can be tricky for a first timer.
But it can and has been done but many many people. So it definitely isn't rocket science./
The only thing I'd recommend is to take the proper precautions and preparations when installing one.

ie. invest in a few pairs of sealed surgical gloves(to avoid contamination). You'll also want to order some of the original shims(spacers) from Pentax to adjust the screen(and get that perfect focus).

Other than that... my only advice would be to work in a damp environment(keep the dust down) and everything will be A-OK. Most mishaps with first timers come in form of dust or skin contact contamination. But other than that, focusing screens are very easy to install. - I once installed one sitting in my car while waiting for my wife to finish the groceries. The entire operation took 30 seconds and I was enjoying the new screen.

PS. sometimes its best to start off with one of the affordable screens
04-18-2011, 09:12 PM   #30
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QuoteOriginally posted by justtakingpics Quote
Then I don't understand what the problem is if AF points won't help.
You need to understand what an AF point is. First all cameras have them. Most cameras have more than one. I don't know how many your camera has, but chances are, it has no fewer than any other camera in its price range or age. The only difference is that some camera *show* you the different focus points in the viewfinder and others don't.

But seeing the focus points in the viewfinder wouldn't help one bit here, for several reasons.

For one thing, no matter how many focus points your camera has, when using an MF lens, the center focus point is the only one the camera uses. So you don't need a light in the viewfinder to tell you the camera is using the center point - you know that the moment you mount the lens.

Second, the hexagon is already telling you when the center point thinks it is in focus. Seeing a light in the middle of the viewfinder adds no new information.

Third, the light that appears in some cameras to show you which focus point is active doesn't tell you *exactly* where focus was achieved. You'd get a light in the middle saying, "focus is somewhere around here". But if you're taking a full body shot picture of a person, then "somewhere around here" could just as easily be the face as the shirt, or a tree right behind the person. The focus "point" doesn't know what object near the center you care about, so it happily report success (green hexagon) if *any* of those things are in focus.

AF can fail too for the same reason. But I'm guessing none of your AF lenses have as shallow a DOF as your M42 lenses can, so slightly discrepancies are more likely to go unnoticed.
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