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07-24-2012, 08:16 PM   #1
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K-5 AF, the lens or me?

I recently rented a Sigma 150-500mm f/5-6.3 DG OS HSM APO lens from Camera Rentals and some of my shots with it @500mm are not sharp at all. I used a tripod with the sample pics but I don't remember if I used the 2 sec timer for the hawk photo. I remember using the 2 sec timer for some photos of the hawk but the kid shot was handheld with my elbows rested my knees making sure to carefully pressing the shutter release.

EXIF is AP mode, 1/1000 sec, f/10, iso 400, -.7 ev





EXIF is AP mode, 1/1000 sec, f/13, iso 800, -1 ev




Both were AF.S Center, auto WB and the metering mode was center weighted. About half or most of the long range photos at 500mm were the same as the above photos while most the close range shots were pretty good.
My longest lens prior to this rental is the DA 55-300 and I do occasionally get a fuzzy photo with it when I'm not careful but not as much as I got with this sigma.
Am I doing something wrong or is it the lens or is my K-5s AF acting up?

07-24-2012, 08:19 PM   #2
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At that shutter speed and aperture, provided you did get the focus confirmation, it should be tack sharp.

I've had similar issues with the 50-135. It could be the K5. Hopefully others can help!
07-24-2012, 08:20 PM   #3
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It could be a bf/ff issue, I am guessing it's backfocusing, try adjusting your camera by zooming up 8x (which is %100) every time you take a photo and adjust in your K-5's lens fine tuning settings.

EDIT: Nvm, looking at the f-stop it shouldn't look like bf/ff from the point you are focusing at, I would suggest what FrancisK7 says and upp your shutterspeed by bumping ISO.
07-24-2012, 08:24 PM   #4
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Have you got both the K-5 SR and the lens IS turned on at the same time?

07-24-2012, 08:31 PM   #5
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Looks like motion blur to me in that shot with the kids.

Chaos has a good point. I think if I was wielding a 500mm lens, I'd go for 1/1500s or 1/2000s just to be safe. It's not just the focal length, but also the weight distribution of of that lens as it is extended. And are these 100% crops?
07-24-2012, 08:34 PM   #6
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I think your settings are fine. If you still have the lens I'd check the stabilization settings, although from the viewfinder it should be easy to tell the difference.
07-24-2012, 08:49 PM   #7
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My experience has been that some of these 500mm zooms do better backed up a bit from 500, better around 400-450.

Definitely a faster shutter at least twice the focal length will help, and choose either SR or lens OS unless you are on tripod then turn it off.

But don't expect perfect IQ if the subject is far away and you are at max focal length.

Best to get as close as feasible.

A sample shot of some far away subjects with a borrowed 150-500 at 500mm, 320ISO, F8, 1/1600. It was a hot day as you can see by the heat waves on the houses, so atmospheric conditions may play a part. I used a monopod, with SR on.


07-24-2012, 08:51 PM   #8
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Not perfect by any means, but this is the 150-500 at 1500 mm (cropped away ~90%)



07-24-2012, 09:07 PM   #9
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ElJamoquio, that looks very good, seems better than the copies I have tried for sure. That lens is a keeper.
07-24-2012, 10:34 PM   #10
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QuoteOriginally posted by crewl1 Quote
ElJamoquio, that looks very good, seems better than the copies I have tried for sure. That lens is a keeper.
Well, the 150-500 seems to be better at the long end according to everyone I've seen talk about it.(Just doesn't offer than insane 10x zoom range)
07-25-2012, 12:05 AM   #11
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Original Poster
Thanks everyone for your input.

QuoteOriginally posted by LeDave Quote
It could be a bf/ff issue, I am guessing it's backfocusing, try adjusting your camera by zooming up 8x (which is %100) every time you take a photo and adjust in your K-5's lens fine tuning settings.

EDIT: Nvm, looking at the f-stop it shouldn't look like bf/ff from the point you are focusing at, I would suggest what FrancisK7 says and upp your shutterspeed by bumping ISO.
I'll try that the next time I have better light. Right now it's overcast skies and the test shots with/without SR on and on a tripod didn't come out sharp. 1/2000 sec shots were at iso 5000 though.

QuoteOriginally posted by Chaos_Realm Quote
Have you got both the K-5 SR and the lens IS turned on at the same time?
No, they were both off but, I do remember toggling the SR on and off on the kids shot, I even tried taking some with the camera on the tripod when I noticed in them in the lcd screen that they weren't sharp. I tried focussing in different areas in the frame with the focus indicator lighting up every time and I even pressed the AF button a few more times.

QuoteOriginally posted by JinDesu Quote
Looks like motion blur to me in that shot with the kids.

Chaos has a good point. I think if I was wielding a 500mm lens, I'd go for 1/1500s or 1/2000s just to be safe. It's not just the focal length, but also the weight distribution of of that lens as it is extended. And are these 100% crops?
The first versions are uncropped while the second ones are but I don't know if they are 100% crops.

Here's a couple that I took handheld that aren't tack sharp but, they are a whole lot better than the ones above, that I took at 500mm at close to minimum focus distances with the SR on. They are both cropped but not very much.

AP mode, ISO 800, 1/640 sec, f/13


AP mode, ISO 640, 1/640 sec, f/10
07-25-2012, 08:14 AM   #12
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The lenses do well at closer distances. You seem to have a steady hand as the pics above show.

This one at closer range with the lens, but I kept the speed up and was on a monopod.

f6.3, 1/2000 ISO640 500mm

07-25-2012, 09:58 AM - 1 Like   #13
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from my experience, and looking at the hawk, I am not sure you will ever get an image at what I perceive to be the shooting distance, that will satisfy you.

Assuming this is a full frame in the first image, re-sized for posting to about 30% resolution, by scaling the size of the image, and percentage of the frame used, with the size of the sensor, and focal length of the lens, my best estimate is you were 130 meters (500 feet) away. getting a razor sharp shot at that distance is tough. Period.

When I shoot birds, I call shots like this a record shot, it has enough detail to prove what you saw, but not enough to really print. This is especially true when you consider the talons, which are probably close to 5-7 mm thick in real life are reduced to 1-2 pixels.

however, having said that, one thing i find especially with shooting subjects like this is that AF-C can hunt around but never lock, you are better with a stationary subject using AF-S
07-25-2012, 10:16 AM   #14
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Did you have the shake reduction turned on while you were using the tripod?
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