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07-27-2009, 07:39 PM   #46
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I think she just needs some AF adjustment. It can really throw you off if your diopter is adjusted to when the camera thinks it's in focus. Another brand lens may help... I had a Tamron that was light years off in focus compared to Pentax lenses (something like +220um). Also, does Pentax calibrate when you send in 3rd party lenses? I thought I've read over the past that they would only do Pentax body with Pentax lenses only.

07-27-2009, 08:22 PM   #47
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Ooh! Tuna Helper's on sale!!
07-28-2009, 04:43 AM   #48
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THANK YOU to everyone

Wow, this thread is a clear reason why Pentax Forums are the best! Everyone who responded put a lot of thought into helping and I appreciate it.

OK, now that I've buttered you up, I hope you will not laugh too loudly when I tell you what the problem was ....

<AHEM> I've been using my camera for almost 2 years now. I've been using these lenses for about 5 months. The 28-75mm is clearly slower to focus. Wellllll ... turns out, I always thought/ASS-U-MED that the red AF-point light in the VF was letting me know my subject was in focus!!

With a faster lens, not so much of an issue. With a slower lens .. clearly an issue, and I was pressing the shutter way too soon. After reading the manual AGAIN .. I realized that the green indicator at the bottom of my VF was actually my AF indicator.



That being said - here are three quick unedited shots from my AH-HA day in NYC this weekend! That last one is me, reading my camera's manual. J/K!
(it is me, though)
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07-28-2009, 05:14 AM   #49
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Late getting to this, but tyour examples are the same as what i was getting with the copy of the Tamron lens i bought.
Usless from 2.8 to f4.
I returned it and bought the D FA 50

Dave

07-28-2009, 05:22 AM   #50
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Thank YOU deludel!

Thank you so much for reporting the resolution of your problem. It may well help many people & it is a good reminder for all.

I think one of the greatest faults with these forums is that people don't do a good job of reporting solutions to problems they've posed.

With no such feedback, all those who tried to help are left floating; assuming either that their suggestion was right or not - how much better to actually know & learn!

I imagine many fine lenses have been abandoned (or at least, shots missed) by users because of red/green light confusion! I'm sure I've done the same.

Dave in Iowa
07-28-2009, 07:03 AM   #51
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QuoteOriginally posted by deludel Quote
With a slower lens .. clearly an issue, and I was pressing the shutter way too soon.
Hmm, since you said you used AF-S, you should not be able to release the shutter unless something is in focus. You also mentioned you focus first with the centre AF point then recompose. This suggests that you need to wait longer before you recompose (as opposed to waiting longer before you press the shutter button).

Try to use some of the other AF points too. It is worth it, AFAIC, in particular if you are trying to use a thin DOF and the recomposition can throw the subject out of the focus plane.
07-28-2009, 09:21 AM   #52
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QuoteOriginally posted by Class A Quote
Hmm, since you said you used AF-S, you should not be able to release the shutter unless something is in focus. You also mentioned you focus first with the centre AF point then recompose. This suggests that you need to wait longer before you recompose (as opposed to waiting longer before you press the shutter button).
Yeah, sounds like she was picking her spot to focus on, half pressed, then recomposed while it was still attempting to focus, and by the time she took the shot it was done focusing on the wrong area.

Thanks for posting the resolution, OP! Glad it was just a simple thing and nothing seriously wrong with your gear.
07-28-2009, 11:32 AM   #53
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Thanks for coming back and "admitting" the problem. Glad to see that the new shots look great. Now how hard do you think it will be to get the original subject to pose again?

Oh and you taught me something...I didn't even realize that the red lights can be out of sync with the AF. I don't pay attention to it. I think I subconsciously listen for the "beep" for AF. In fact, after reading your post, I have shut off the red light. I never use anything but center focus (why would I want to let the camera decide what to focus on?) and since it doesn't confirm focus, why should I leave it on?


Last edited by PentaxPoke; 07-28-2009 at 12:13 PM.
07-28-2009, 11:47 AM   #54
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QuoteOriginally posted by deludel Quote
I hope you will not laugh too loudly when I tell you what the problem was ....
Anyone who would laugh must suffer from very selective memory loss - everybody makes mistakes once in a while! Great sleuth-work figuring it out. That's a nice shot of the guy playing fiddle, by the way. So glad it wasn't an equipment problem.

Julie
07-28-2009, 01:18 PM   #55
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Hm, I still think some of your issues might be from the UV filter, but what the heck, if this fixes everything for you then good enough!
07-28-2009, 03:08 PM   #56
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QuoteOriginally posted by PentaxPoke Quote
I never use anything but center focus (why would I want to let the camera decide what to focus on?)...
Using an AF point other then the centre one, does not mean you have to leave control to the camera. There is an "AF select" mode where you manually select one of the AF points the camera should use.

This is very helpful when you shoot action (no time to recompose) and don't want the subject to be in the centre, and to avoid focusing errors when using thin DOF.
07-28-2009, 03:30 PM   #57
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QuoteOriginally posted by Class A Quote
Using an AF point other then the centre one, does not mean you have to leave control to the camera. There is an "AF select" mode where you manually select one of the AF points the camera should use.

This is very helpful when you shoot action (no time to recompose) and don't want the subject to be in the centre, and to avoid focusing errors when using thin DOF.
I have used the selective autofocus points to my advantage. However, I am using manual focus more often when I am shooting a fixed object, like a portrait.
07-28-2009, 04:55 PM   #58
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This is perhaps my favorite PF thread, ever!

QuoteOriginally posted by newarts Quote
I imagine many fine lenses have been abandoned (or at least, shots missed) by users because of red/green light confusion! I'm sure I've done the same. Dave in Iowa
No disrespect to anyone who tried to give advice within this thread, but some would have had me do that very thing!

QuoteOriginally posted by pingflood Quote
Yeah, sounds like she was picking her spot to focus on, half pressed, then recomposed while it was still attempting to focus, and by the time she took the shot it was done focusing on the wrong area.

Thanks for posting the resolution, OP! Glad it was just a simple thing and nothing seriously wrong with your gear.
That's pretty much what was happening. And you're welcome (to all who said so) for posting the results. Silly question, what does "OP" stand for?

QuoteOriginally posted by PentaxPoke Quote
Thanks for coming back and "admitting" the problem. Glad to see that the new shots look great. Now how hard do you think it will be to get the original subject to pose again?
Actually, I did have SOME shots that were keepers from that day! I tried to make the best out of them .. see attached. The effect was a Lightroom effect that they liked, so I went with it.

QuoteOriginally posted by tscip22 Quote
I have used the selective autofocus points to my advantage. However, I am using manual focus more often when I am shooting a fixed object, like a portrait.
A few of you mentioned these selective autofocus points. I guess I don't get the concept ... my Lori-Logic (which has led me astray many times!! ) says that with center-point, I have more control, 'cause it's the one point I can point my camera to and recompose. With selective focus ... it seems that your focal point can change with every single shot, so theoretically you are changing the point within the camera on every shot? Unless you are a landscape/portrait photographer, it seems like that's too much work. What am I missing?
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07-28-2009, 05:35 PM   #59
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QuoteOriginally posted by deludel Quote
That's pretty much what was happening. And you're welcome (to all who said so) for posting the results. Silly question, what does "OP" stand for?
OP = original poster, the person who started the thread.

Glad things worked out for you! I never do people picture work because there's just too much stress involved (have done a couple wedding things for free for friends but nothing tor money). Animals are much better to deal with and they don't sue you if you screw up.
07-28-2009, 06:19 PM   #60
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QuoteOriginally posted by deludel Quote
No disrespect to anyone who tried to give advice within this thread, but some would have had me do that very thing!
It's tough enough to diagnose problems when you've got the gear right in front of you; it's much tougher still to diagnose problems from afar. So no real surprise answers were all over the map - but I agree that it's a mistake for people to assume its defective equipment before ruling out the possibility of photographer error.

QuoteQuote:
A few of you mentioned these selective autofocus points. I guess I don't get the concept ... my Lori-Logic (which has led me astray many times!! ) says that with center-point, I have more control, 'cause it's the one point I can point my camera to and recompose. With selective focus ... it seems that your focal point can change with every single shot, so theoretically you are changing the point within the camera on every shot? Unless you are a landscape/portrait photographer, it seems like that's too much work. What am I missing?
You are assuming, as I do too, that "recomposing" for every shot is less work than selecting a different focus point for every shot. That's largely because you and I are used to recomposing. People who are accustomed to selecting focus points on every shot often think of that as less work. There is also a slight possibility of focus error from focus-recompose caused by shallow DOF - something in focus when the camera is centered on it might not still be in focus after recomposing. I believe that was the topic of the link embedded in one of the previous posts. In my experience, while I totally understand the science behind why it might be so, my own tests show it isn't that big of an issue, and in the cases where it is, I'm likely to be focusing manually.

Last edited by Marc Sabatella; 07-29-2009 at 09:43 AM.
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