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Old Mar 6, 2009, 10:24 AM   #11
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I just put the one FA lens that I own on the K20, took it off of "A", put the camera in M mode to see if the AF still works. It does.

So your focus problem isn't connected to whatever mode you are using necessarily. There could be several things that are happening - the most obvious is whether the camera's button is set to M, AF-C or AF-S (suggested because I've forgotten to change the switch way too often!). It could be because you are too close, but is the camera indicating focus lock? Can you see where its focusing in the viewfinder (I can mostly, but with tiny DOF it can be easy to miss it slightly)? My M 50mmlensesminimum focus is actually pretty close for a non-macro lens. The final thing is whether the camera has a back-focus or front-focus problem with that particular lens. So shoot some charts using various apertures. If you were using any mode other than M, you were shooting wide open and f1.4 is really small for DOF - your lens might be front or back focusing just a bit.

So what did you conclude?
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Old Mar 8, 2009, 10:41 AM   #12
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I'm sorry it's taken so long to get back to this. It's been a long week dealing with issues with my mom and I've been exhausted. Things have finally slowed down a bit.

I'm attaching one of the images so you can see what I was looking at. No PP done except to resize to display here. I need to read through everyone's posts here and research it. But, I think what's happening is I just have a really shallow DOF and nothing is in focus. I was in AV mode and maybe I can't use that mode when the lens is not in A. I thought I had done what the manual said for setting to use in non-A mode, but maybe there was more too it than I read into it.

I'll read through everyone's ideas and post back what I find.

Patty


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Old Mar 8, 2009, 12:02 PM   #13
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I sometimes think that the English language isn't set up well for explaining some concepts, and this is one of those times, I think.

I'll try to explain it like this, I know this isn't anything new but it's the difference between a concept and a method, I guess.

Aperture priority as a concept is simple - you set the aperture and the camera sets the shutter speed. You can ask the camera to change the aperture or you can change the aperture on the lens, it doesn't matter because you are adjusting the aperture.

That's what happens when you have a LENS set to "A" and the CAMERA set to Av - you change the aperture ON THE CAMERA and it changes the aperture on the lens. The camera knows what the aperture is because you've told it, and it sets the shutter speed based on that.

Now you take the lens off of it's "A" setting. The camera no longer knows what the aperture is set for, so the Av mode no longer works right - the camera can't go to its software and say "I'm setting the lens to f5.6 so the shutter speed should be 1/125." It doesn't know what the aperture is, and can't change the aperture so it only meters with the lens wide open.

But you want to use f5.6, you have the lens set that way. Pentax got around that by offering the "M" mode on the camera and the green button. When the camera is set to "M". You set the aperture on the lens and press the green button to temporarily stop down the lens and allow the camera to meter. It's still "aperture priority" because you've set the aperture and the camera sets the shutter speed based on what you set. But you can't get it when using the Av mode on the camera, only using the M mode.

Does that make sense? I understand it but not sure I can explain it any better than those who are trying to write the manual.

As far as the focus, f1.4 is really tiny for DOF, and my M 50mm 1.4 is pretty soft wide open (much softer than your picture is, by the way). That's probably what you are seeing.
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Old Mar 10, 2009, 10:34 PM   #14
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Harriet,

Okay, I think I get what you are saying. Don't hold me to that, though. :G I keep trying to learn too many things on the camera at once. I need to just pick one thing until I master it, then move on. I did just discover the green button on the camera and wondered what it would be used for. I'm still working my way through the manual.

I'm not sure I understand what you mean about the soft focus. Do you mean you think mine should be softer focus all over? I canget the EXIF data of my image if that helps.

Thanks everyone for the help. This camera is so much more advanced than the K100. And, I don't think I ever actually learned everything on it.

Patty


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Old Mar 10, 2009, 11:05 PM   #15
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When you take an "A" mode lens off the "A" setting, it doesn't actually change the aperture. It simply tells the camera you are using the lens in manual mode, and will not stop down the lens unless you set the camera to manual also. The Exif of your picture correctly reports f/1.4, which is the wide open setting of the lens.

A lot of lenses seem to have a soft focus effect when wide open - the larger the aperture, the more pronounced it can be.

To take that picture at f/16 with non-"A" lens, you would need to use manual mode and meter using the green button. ( believe this is correct, as I am guessing the K20D works very much like my *istD)

brian
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Old Mar 10, 2009, 11:21 PM   #16
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Yes - what Brian said (it works the same on the K10 and K20).

Well done - you said in three sentences what I tried to explain in 5 paragraphs and 3 posts. How I wish I could be so succinct!
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Old Mar 11, 2009, 10:05 PM   #17
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Just simple answers 'cause I'm simple minded:-).

brian
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