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06-02-2008, 07:18 PM   #16
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QuoteOriginally posted by NicholasN Quote
So basically the reason for the camera not taking a clear image at ISO100 is because there is not enough light coming through the lens for it to focus correctly?
It would really help us if you posted a link to a picture. That way it would be much easier to diagnose. We will need to know for the picture your f#, shutter speed, and ISO. Is your blurred image due to focus, or is it due to shake, or is it due to motion? I was taking pictures of aiplanes flying overhead once, and I was at 250mm focal length, 100 ISO, and 1/500 sec. I noticed my pictures were a bit blurred. I determined that in the position I was in and the planes flying over head, I was shaking alot when holding the camera and tracking the planes, beyond the capabilities of the SR. I bumped the shutter speed to 1/750, and the blurring was gone.

ISO does not affect the amount of light coming into the camera. Only the sensitivity of the sensor. If you are shooting in daylight, I am sure you have plenty of light to focus properly.

Edit: OK Nick are you just messing with us? I went to your site, and looked at some of your plane pics. This one for example:
http://www.aroundsydneyphotography.com.au/imgp3205website.jpg
Is at 300mm, 1/1000s, ISO200, and f8.0. That is f8.0, so you are not running into aperture limits on your lens.

What gives?


Last edited by PentaxPoke; 06-02-2008 at 07:24 PM.
06-02-2008, 07:53 PM   #17
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QuoteOriginally posted by NicholasN Quote
I love aviation photography however since purchasing the k20D with the Tamron 28-300mm f/3.5-6.3 I have found the lens too slow at anything over 150mm for action shots resulting in blurred images.

Anybody here use a K20D for action photography who could recommend a faster lens that won't ruin my savings account balance?

I miss my love of planes and desperately want to get back into it.

Regards

Nick
That's really surprising. I used the 28-300 on my K100D and got some great air show shots. Usually it's pretty bright, so I'm shooting at f/8 and 1/500 or 1/1000. I can't see how you'd need a fast lens for shooting air shows. Heck, the last one I shot was on an overcast day with the Bigma (an even slower lens).

QuoteOriginally posted by NicholasN Quote
The camera store guy tells me that the aperture is too slow and that the 15MP camera has alot more noise (due to more MP?) than my K100D.

My technique (panning etc) is well perfected, visit my site to see some of the great aviation shots I have on file:

Swirl Page 1 of 15

I suppose I just have been given some really bad info from the camera store guys.

I really appreciate you guys helping me it gives me more confidence in my new camera.

I'd change camera stores. The sales person is full of it.

Resolution has nothing to do with aperture, and your Tamron is plenty fast enough to take all kinds of aviation shots. He just wants to sell you a new lens.
06-02-2008, 08:47 PM   #18
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The photos on my website were all from the old K100D Super + Sigma 70-300mm. I have not used any of the K20D shots for the website yet.

I will post some shots of what I mean when I get home (at work now) and show you what I mean.

Basically, the K100D would give me great crisp shots at 1/400 and over, yet the K20D gives me blurry shots at 1/750. Admittedly the K100D was 200ISO and the K20D is at 100ISO but with a shutter speed of 1/750 even the most shaky of hands should still produce a decent picture on the K20D. I have done heaps of 300mm shooting before and I am a little perplexed.
06-02-2008, 09:21 PM   #19
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hmm, interesting. possible back/front-focus problem? At ISO 100 most cameras made in the last few years are *incredibly* similar in noise (or the lack thereof), so I wonder if it's something to do with the lens...

Now that I think about it, the weakest spot on the super-zooms is the long end, so it could just be you got a lens that doesn't perform well at 300mm... Did you sell the sigma 70-300? If not, try shooting some shots with that lens and your k20. If they come out remarkably better, you should probably not use the 28-300 at the long end.

06-02-2008, 09:44 PM   #20
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I sold the 70-300 with the K100D unfortunately.

I am not that cluey about lenses as you can tell, what is a back/front focus problem? I know the K20D you can adjust the focus point would that help? How do you diagnose a back/front focus problem?
06-04-2008, 12:41 AM   #21
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Sorry for the delay, here are the sample pics.

Now before we go anywhere, my panning technique and knowledge of aviation photography is well founded and tried and tested. This has to be a lens issue of some sort.





If anyone can please provide feedback it would be great.

Regards

Nick
06-04-2008, 01:29 AM   #22
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The second two actually look pretty good (except for the dust spec on your sensor) but the first one is obviously not sharp. I cant tell if its focus or motion, but your shutter speed was pretty fast and I'm sure your SR was on right? The odd thing is that while the first one is soft all over, the right side is worse than the left.
06-04-2008, 02:05 AM   #23
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Funny you should mention the right being softer than the left, a huge majority of my pictures taken on moving objects feature the same problem - right side soft and blurry - left side sharp.

What the hell would be causing that?

Any none of the shots are anywhere near good enough, all are poorly focused and nowhere near sharp. I have no idea what to do.

I hope someone has some possible ideas.

06-04-2008, 03:15 AM   #24
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Is this the same lens that took the nice aviation pictures on your web site, it is just on a k20d now? If it is, then maybe there is an issue between the k20d and that lens, such as the focus setting needs to be adjusted. Out of curiosity, does it get better/worse when SR is turned off?
06-04-2008, 01:41 PM   #25
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Check your EXIF data and see if the SR was in fact activated (not just ON, but active). It takes a moment for SR to activate and there have been reports where people are taking quick shots and then finding that the SR wasn't fully activated.

Also, if all your shots are blurry on one side, it might be a lens issue (lenses out of alignment?).

The second and third shots look fine to me. The first one is obviously blurry.

Bottom line, there may be an issue with your lens, but it's not the aperture or camera resolution that's causing it.
06-04-2008, 02:45 PM   #26
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PentaxPoke,

The shots from my website are all from the K100D Supper + Sigma 70-300.

I am ashamed to say the K20D + Tamron 28-300 Cannot give me a shot of enough quality for me to consider adding it to the site. As for the SR, it honestly makes little or no difference.

All the existing shots on my site were all taken with no SR, I have never used SR before until the K20D and this issue came along.

Nick
06-04-2008, 03:49 PM   #27
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On your pictures. I think the problem might be caused by chromatic aberrations, and they seem worst on the right side, too. It would be nice (wishful thinking) if you could try another lens of the same type and then another lens of different design (like a Sigma or Tamron 70-300) to see if the problem could be caused by the camera or the lens. By the way, I own a Sigma 70-300 Apo, and the edges at the long end seem softer on my K20d than they seem on my K10D (purely subjective, since I haven't been able to exactly replicate the same thing with both cameras), but, on the other hand, some of my lens seem a lot sharper on the K20D.
06-04-2008, 08:26 PM   #28
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QuoteOriginally posted by NicholasN Quote
PentaxPoke,

The shots from my website are all from the K100D Supper + Sigma 70-300.

I am ashamed to say the K20D + Tamron 28-300 Cannot give me a shot of enough quality for me to consider adding it to the site. As for the SR, it honestly makes little or no difference.

All the existing shots on my site were all taken with no SR, I have never used SR before until the K20D and this issue came along.

Nick
Well, I'm thinking your particular lens is faulty, then. There's no good reason I can think of that would prevent the K20D and 28-300 combo from taking as good shots as you previously had with the K100D and 70-300. How do other shots (non-aviation, non-action shots) look with the 28-300?
06-04-2008, 09:00 PM   #29
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The other shots (non-aviation) are hit and miss sometimes also. They are not as sharp as I would have expected.

Can someone explain to me what chromatic aberration is exactly and how I will know if it is lens or camera body based?
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