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07-27-2011, 09:28 AM   #16
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The rear bear looks to be the where the focus is but I agree with you that the shot isn't sharp. You can see the obvious very narrow band of in focus area in the grass and it seems to be much narrower than the size of your bears. Even the in focus band looks a little soft. It appears to be between the 2 bears. Whenever I shoot critters, especially with a tele, I try to stop down to at least f/8. DOF is still pretty narrow. I prefer f/11 with 70-300 because that seems to be the sweet spot in that lens. It takes some practice with a new lens to find what does and doesn't work. An afterthought. Do you have a UV filter on this lens? They can degrade an image.

07-27-2011, 09:29 AM   #17
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I'll be interested in what the real experts say but my guess is that it's primarily a photographer issue. I'd say it was a mistake to focus on the back bear's nose: even if it was sharp as a tack, how would you know? Also, with the shallow depth of field at f4 that guaranteed that everything else would be out of focus. If I had had my wits about me (big if ;~), I think I'd have stopped down to f8 or so and focused on the front bear's cheek/neck to get a fairly broad (and noticeable) expanse that was pretty sharp.
07-27-2011, 10:02 AM   #18
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Thanks for all of the advice! I think it's a photographer issue as I didn't seem to have any issue focusing when I took some pictures on a tripod last night. I wasn't getting super sharp, but it could just be my perspective.

What's the best test? I tried simply taking pictures of book spines and comparing results of several lenses.
07-27-2011, 10:08 AM   #19
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QuoteOriginally posted by reeftool Quote
The rear bear looks to be the where the focus is but I agree with you that the shot isn't sharp. You can see the obvious very narrow band of in focus area in the grass and it seems to be much narrower than the size of your bears. Even the in focus band looks a little soft. It appears to be between the 2 bears. Whenever I shoot critters, especially with a tele, I try to stop down to at least f/8. DOF is still pretty narrow. I prefer f/11 with 70-300 because that seems to be the sweet spot in that lens. It takes some practice with a new lens to find what does and doesn't work. An afterthought. Do you have a UV filter on this lens? They can degrade an image.
More info on a UV filter, please? I've read that you always keep that on to address glare and to protect the lens, but is that bad advice?

07-27-2011, 11:20 AM   #20
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It will protect the lens, and cut some haze out on sunny days, but it won't reduce glare. You need a polarizing filter to reduce glare. If you are gonna use a UV filter, you'll have to drop $50+ to get a good, multicoated one. Don't use a cheap one on a pro quality lens, you'll just turn it into a mediocre lens.
07-27-2011, 01:51 PM   #21
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QuoteOriginally posted by JeffJS Quote
it is a Lens issue, a camera/lens issue, or a photographer issue
i can see some focus on the 2 bear
f4.0 on a long distance gives a very short focusarea

try f5.6 or even higher number if you want to have 2 large animals in focus
and 1/500 should be fast enough with 250mm
07-27-2011, 02:11 PM   #22
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QuoteOriginally posted by iFoto Quote
i can see some focus on the 2 bear
f4.0 on a long distance gives a very short focusarea
Actually, the longer the distance, the larger the DOF. It's closer that you get thinner DOF.

And for such small size image, DOF shouldn't be an issue. Here's a 200/2.8 shot:



DOF is thin, but you can't really notice it at this size.
07-27-2011, 04:18 PM   #23
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Can someone direct me to a test to see if I need to adjust/fine tune the AF?

07-27-2011, 04:54 PM   #24
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af adjustment - Tagged Discussions - PentaxForums.com

Something in here may help you. I don't see any front or back focusing in your bear image though I guess it can't hurt to try.

07-27-2011, 05:24 PM   #25
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If I may...

Dial up the contrast
Dial down the brightness
Do a High Pass Sharpen (other sharpen routines would also work)

I don't think there's anything wrong with your lens, your camera, or you.. I think you just need to make a few adjustments in your processing or change the way the camera is saving the JPGs. Unless the detail is there, this is nearly impossible and this was done with a small 100k file.

Yes, it's still a little soft and there may be a little camera shake here. If you start with a RAW file (PEF or DNG) you might be surprised at what you can pull out of your files.

.... but I don't think focus adjustment is going to change anything here. That's just my theory though, I've never even seen one of these lenses in person let alone used one.


6666
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07-27-2011, 06:21 PM   #26
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^ I don't know if it's just this mediocre monitor at work but that looks... unappealing.

Very very unappealing.
07-27-2011, 06:26 PM   #27
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I'd be testing that lens some more, maybe on a family member as they are generally less dangerous than widelife. That photo you posted looks soft everywhere, unless shot while you were moving/shaking quite a bit, I wouldn't have expected such a soft shot. It does look BF a bit which is adjustable, but I worry about how soft it is even in the DOF (behind the first bear).
07-27-2011, 07:04 PM   #28
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QuoteOriginally posted by RXrenesis8 Quote
^ I don't know if it's just this mediocre monitor at work but that looks... unappealing.

Very very unappealing.

No, It's unappealing. So why Post it? To show there are things that can be done with the image. It's over sharpened (High Pass Filter sharpen probably isn't the best to use on fuzzy animals). Give me the RAW file and I'll produce a usable Appealing photo from the file. This edit could do with some reduced saturation..

Better (over saturation pulled back)?

There is only so much I can do with a small email sized image. I still don't think it's the lens, looking at the long grass to the right of the bears.

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07-27-2011, 07:13 PM   #29
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QuoteOriginally posted by twitch Quote
I'd be testing that lens some more, maybe on a family member as they are generally less dangerous than widelife.
Feh, I'd feel safer with the bears!
07-27-2011, 07:41 PM   #30
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QuoteOriginally posted by JeffJS Quote
There is only so much I can do with a small email sized image.
I agree, and would also add that when you upload an image to pentaxforums and it is too large the forum server is configured to reduce it in a very unpleasant way. You loose a lot of sharpness. This is in stark contrast to the way other sites such as flickr handle downsizing, which involves more preservation of hard edges.

Unless his UV filter is really crap (which, it certainly could be) SOME part of that image is sharp at 1/2000 of a second.

To the OP. If and when you decide to conduct tests; please do them with the UV filter removed.
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