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07-26-2011, 06:52 PM   #1
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Help! Blurry bears with my new DA* 60-250mm

I just purchased the DA* 60-250mm and was disappointed with the results. I'm sure it was user error, but the issue was that very few of my grizzly pictures were focused. I was using a high shutter speed of 1/1250 or 1/2500 thinking that I needed to freeze their movement. That put me at an f stop of f4 with a relatively high ISO of 800+ given it was an overcast day. I was using autofocus. Any thoughts on why I got such poor results? I called Pentax to get their opinion and they said the shallow depth of field likely meant that the bears were moving out of focus as I was shooting, but I wanted a second opinion. I've seen some nice pictures at 250mm and f4 on this forum, so I know it can be done. Thanks!

07-26-2011, 07:00 PM   #2
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You need to check whether that lens is back focusing or front focusing as that would be the most obvious candidate for OOF shots given your high shutter speed. I'll assume you are focusing using the AF point you think you are focusing with (no AF auto-11 OK?).
07-26-2011, 07:01 PM   #3
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were the bears moving? were you using af-a, af-s, or af-c mode? what focus point setting were you using?
07-26-2011, 07:07 PM   #4
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Since I'm a newbie, I'm not yet speaking your language, but let me try. I believe I was using af-s and I was trying to be thoughtful about focusing on their eyes, but in some of my pictures where they are only moving slowly nothing is in focus. When they were running toward me, they were almost entirely out of focus. And I have no idea what back focusing or front focusing means.

07-26-2011, 07:24 PM   #5
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I've read some threads about an AF adjustment needed. Perhaps that's the issue?
07-26-2011, 07:29 PM   #6
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Show us some examples with shooting data in tact (shutter speed, aperture, etc). Which camera were you using?

07-26-2011, 07:30 PM   #7
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Mount the camera/lens on a tripod, take some photos on still subjects and see if the results are good. I've tried a few copies of this lens, none of them is bad copy. I'd definitely have one if I didn't have or like the FA*80-200.
07-26-2011, 07:32 PM   #8
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Back focusing and front focusing literally means that the auto focus system incorrectly focuses behind or in front of the intended focus point. An example would be if you focus on the bear, the camera confirms focus and takes the shot, but the focus point is actually behind the bear or in front of it.

In my experience the probability of this is fairly low, but on the newer camera bodies the focus can be adjusted to correct it so it's not a big deal.
If you had the lens all the way out at 250mm and the bears were reasonably close (!), then f/4 would provide a shallow depth of field; meaning that area that objects will be in focus is small.

You might want to try a lower shutter speed like 1/500-1/800 then stop your lens down to f/8 if possible. That's assuming that you can easily see the bears again

Also, it usually helps if you post a picture as an example. Then we might be able to identify and explain the source of the blur.

07-26-2011, 07:38 PM   #9
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Hopefully this works...

This one was taken at 1/2500 f4 with a K-5. It's a good example as I focused on the back bear's nose but that's not very sharp, nor is the bear sitting right in front of him.
07-26-2011, 07:40 PM   #10
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If you have used AF-S (single shot AF), this explains why bears were out of focus when running. They moved out of focus while you were depressing the shutter button. For moving targets you should use AF-C (continuous AF).

Note also that at F4 and 250mm the depth of field (i.e. the zone where things are "in focus") is very small, so any focusing mistakes result in blurry shots... at least they do for me It takes time and practice...

As Frank said, check your focus accuracy on a static target, preferably using a tripod. If you focus on a target but still get a blurry image, try AF adjustment. If that does not help, then you may need to send your lens to Pentax for check and/or repair.
07-26-2011, 09:05 PM   #11
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QuoteOriginally posted by Traci Quote
Hopefully this works...

This one was taken at 1/2500 f4 with a K-5. It's a good example as I focused on the back bear's nose but that's not very sharp, nor is the bear sitting right in front of him
Can't see the image sorry!
07-26-2011, 11:51 PM   #12
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QuoteOriginally posted by Traci Quote
When they were running toward me, they were almost entirely out of focus.
My advice for such situations is: don't panic!
07-27-2011, 12:11 AM   #13
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You don't mention what focus points you were using. If you were using Auto 11 for example, then you have very little control over what the camera decides to focus on. And bears have little difference in contrast then a forest background. You should use only a single selected focus point.
07-27-2011, 04:01 AM   #14
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QuoteOriginally posted by Traci Quote
When they were running toward me, they were almost entirely out of focus.
QuoteOriginally posted by Laurentiu Cristofor Quote
My advice for such situations is: don't panic!
I have to disagree, LC--I think panic is an entirely appropriate response in that situation--and not simply because it's very difficult to focus on subjects moving rapidly toward or away from you.
07-27-2011, 08:33 AM   #15
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QuoteOriginally posted by Traci Quote

Hopefully this works...

This one was taken at 1/2500 f4 with a K-5. It's a good example as I focused on the back bear's nose but that's not very sharp, nor is the bear sitting right in front of him.


Change the URL tags to IMG tags.

What happens when you do Manual focus with the lens? The reason I ask is the answer may help determine if it is a Lens issue, a camera/lens issue, or a photographer issue.


Last edited by JeffJS; 07-27-2011 at 09:13 AM.
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