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01-20-2009, 08:05 PM   #16
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Like a few others suggested, this is nothing more than CA (at nearly its worst).

This lens will do okay, so long as you stay away from scenes like this.

01-20-2009, 08:53 PM   #17
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QuoteQuote:
Like a few others suggested, this is nothing more than CA (at nearly its worst).
If the lens is that bad it is a bad copy and needs to be replaced. He shouldn't have to "put up with it".
01-21-2009, 05:58 PM   #18
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QuoteOriginally posted by NicholasN Quote
This lens is renowned throughout the land as being either REALLY good or REALLY bad. You may just have a bad copy.
Not shooting this down, but have thought about this alot... thanks for your reply...

I would expect "bad" or perhaps I should say THAT bad to effect IQ. Here are some recent samples using my other body. Frankly on the second one, I'd have expected to see some CA, though I was significantly more stopped down there...

... so again, if "bad" would tend to show itself in IQ, I am not sure I have a bad one... especially since it made a trip to Japan for calibration/correction about mid-summer.

That said, the last photo while not as brightly backlit as the scene I was shooting with the new camera, ** was ** backlit to some degree and I was shooting at f/5 (1/13th). No hint of CAs in the color version... not even close. Again, the older body.

The only ** REAL ** proof I can properly submit will have to wait, but the evidence seems to point to the following:

If it IS the lens, then the defect that makes it a really bad copy does not effect IQ much and I simply have not shot anything like the offending photo before. I shoot a LOT of brackets.

I noticed a subtle green wash color shift the very first time I took this camera out. I'll post that photo if I can find it shortly. Thanks again to all for opinions. It all helps very much, and frankly, if it is the lens I won't put up with it... I just need to prove that is the case. Unfortunately for me, I go to work when it is dark and return when it is dark... further proofs will happen Saturday. Sadly that is also the day I need my camera for a local newspaper assignment...





01-24-2009, 12:51 PM   #19
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I appreciate your looking...

This morning I did some work to reproduce this issue. I did not have as strong a backlight, and it was getting weaker as I went, but the following 4 photos are

1. the Tamron 28-75,
2. a Pentax FA 55-300,
3. a Pentax F 50mm 1.7,
4. a Sigma 105mm EX DG Macro.

I don't even have to label them. They all have the issue equally all other things being equal. Actually I think the 50mm has a lot of green shift too. Do I really need to label them? I will if anyone wants to see it, but I doubt very, very much that all of these lenses would be this "bad." Honestly, would you expect or accept this in your equipment?

The last picture was a bonus example that I got trying to take a bracket of a truck for a newspaper assignment. Quite frustrating. That's not CA. Too pink, too all pervasive, and it's not lateral. It's all consuming.

Look at the supposed "CA" All of it in all of the pictures. CA is normally a fringe along the border of the thing to which it is associated. See the other pictures posted by people in this thread who really are showing extreme CA.

CA may be thick but it glows OFF the thing, not into them so much. It tends to remain relatively smooth. This is not a fringe. It is ragged and intrudes into the thing that it is coloring. In the last case it completely takes over shape. This has got to be sensor based. I'd really like to hear opinions.










Bonus!



Thanks...

Seaain

01-24-2009, 01:28 PM   #20
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This is a sensor issue I'm sure. I have owned and used the 50mm, Sigma 105mm and the Tamron. none of these lenses have ever produced images anything like this even in tough conditions. The camera needs to go back or into service.
01-24-2009, 01:44 PM   #21
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Yeah, that looks like a sensor issue to me - I don't normally see anything that bad, either.

However, I feel compelled to post the following. It's *really* unfair, I admit. It was taken wide open with the M135/3.5, which *is* known for CA issues, but I've shot musicians in concert with it on dozens of occasions with no unusual problems. Last week, though, I was shooting in a venue where the stage lights were on a rotating cycle through the various colors. And when the purple light was shining on the piano, I got this:



Much as I admire good B&W photography, and of course there is a great history of in jazz, I don't usually go there myself. But in this particular case, I had little choice. Luckily, the band was itself paying tribute to the 70-year history of Blue Note Records, and capturing the moment in B&W probably made sense even if not not made necessary by the horrible stage lighting. So instead of the above, the version I am using is this:

01-24-2009, 10:00 PM   #22
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QuoteOriginally posted by woof Quote
Look at the supposed "CA" All of it in all of the pictures. CA is normally a fringe along the border of the thing to which it is associated. See the other pictures posted by people in this thread who really are showing extreme CA.

Thanks...

Seaain
Looking at this latest set, I am starting to swing toward the sensor. Except for the green one, they look more like Purple Fringe to the extreme. If you camera is producing these effects, I think the consensus is correct - send it in for repair.
01-25-2009, 07:20 AM   #23
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QuoteOriginally posted by Canada_Rockies Quote
Looking at this latest set, I am starting to swing toward the sensor. Except for the green one, they look more like Purple Fringe to the extreme. If you camera is producing these effects, I think the consensus is correct - send it in for repair.
[QUOTE=Marc Sabatella;462608]Yeah, that looks like a sensor issue to me - I don't normally see anything that bad, either.

QuoteOriginally posted by Peter Zack Quote
This is a sensor issue I'm sure. I have owned and used the 50mm, Sigma 105mm and the Tamron. none of these lenses have ever produced images anything like this even in tough conditions. The camera needs to go back or into service.
Thanks guys. When the other body comes back, out this one goes.

Seaain

01-25-2009, 09:29 AM   #24
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Maybe this is why the camera was "refurbished" before you got it?
01-25-2009, 09:59 AM   #25
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QuoteOriginally posted by laser_red Quote
Maybe this is why the camera was "refurbished" before you got it?
That's what I was thinking as well. It might not have been fixed and never went through any QC.
01-25-2009, 07:56 PM   #26
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QuoteOriginally posted by Peter Zack Quote
That's what I was thinking as well. It might not have been fixed and never went through any QC.
Sigh... quite possible. The tech's may not have been able to reproduce it and for whatever reason they accepted it back and replaced it. I'll see if I can't find out when I service it.

I got it for a song, and it does have a US warranty, so all should be well. I have to wait for my other K10D to return from the shop before sending this out. In the meantime I've been shooting and there is NO way this is anything but the camera. These artifact simply occur too often in too many situations where I have never seen anything like this.

Thanks again.

Seaain.
01-25-2009, 10:22 PM   #27
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Well I'd make sure you keep all these examples of the issue and create a disk of images. Use titles with the lens used and add a Word file with a describtion of the problem. Send the disk in with the camera. Good to know you have nailed the problem down.
01-26-2009, 02:26 AM   #28
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QuoteOriginally posted by Peter Zack Quote
This is a sensor issue I'm sure. I have owned and used the 50mm, Sigma 105mm and the Tamron. none of these lenses have ever produced images anything like this even in tough conditions. The camera needs to go back or into service.

I agree, Peter. I've owned a number of Tamron lenses and have never seen anything this horrible either. In fact, I don't remember ever seeing anything this bad with any DSLR lens, regardless of manufacturer.

stewart
01-26-2009, 03:58 AM   #29
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Well, I'm pretty sure it's the sensor, as you cannot see CA in the "branch-on-branch" areas right next to the green and purple parts...

If you had a really bad case of CA, then all the image would be impacted.

To check for this, just underexpose a shot where it appears... If it stays, that's the lens, if it disappears, then it's an overloading sensor/converter...
01-26-2009, 07:11 AM   #30
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QuoteOriginally posted by dlacouture Quote
Well, I'm pretty sure it's the sensor, as you cannot see CA in the "branch-on-branch" areas right next to the green and purple parts...

If you had a really bad case of CA, then all the image would be impacted.

To check for this, just underexpose a shot where it appears... If it stays, that's the lens, if it disappears, then it's an overloading sensor/converter...
On underexposure it disappears entirely, though on the "bonus" shot above even on a perfectly normal exposure it appeared to some small degree.

Frankly, it is so sensitive and apparent after actually trying to use the camera, that I know it has to be the sensor. My other K10D is fine in these situations.

Thanks!

Seaain
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