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Author Topic: Chromatic aberation or tree buds?  (Read 5028 times)
Peter Jon White
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« on: June 29, 2005, 11:31:30 AM »
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If so, why is there no color fringing along each branch? There are branches at every angle with no color at all, and none of the color we see is along the edge of a branch. Instead all of the color is clumped. And why none along the edge of the windmill? Why is it in clumps, just like tree buds? Are you saying that all of the color we see is CA? Or is some of it CA and some of it tree buds? If none of it is tree buds, why not, since the photo was taken in late March, when all living trees in the northern hemisphere are budding?
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« Reply #1 on: June 29, 2005, 01:34:20 PM »
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As I wrote to you in a private email, these are not magenta buds because I say so! Why? Because I was there. There were no buds.

Also, anyone who has ever seen a blossom, or CA, can tell the difference, as several members here have indicated, though obviously this is a challenge for you.

This is CA or a related phenomina. Repeat after me THESE ARE NOT MEGANTA BUDS. THIS IS CA!!

Give it a rest.

Michael
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Jack Flesher
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« Reply #2 on: June 29, 2005, 07:12:33 PM »
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Amazing... Less than 24 hours and the "beyond infinity" post has been topped!

PJ: Last time I looked at a tree with pink buds on the branches the buds were NOT translucent, nor did the branches of same appear as splotches of translucent cyan...

You are grabbing at the wrong limb with this one...

 :laugh: :laugh: :laugh:
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Peter Jon White
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« Reply #3 on: June 29, 2005, 10:43:57 AM »
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In his 2003 review of the Kodak DCS 14N full frame DSLR,

http://www.luminous-landscape.com/reviews/...-initial2.shtml

Michael Reichmann claims that this image

*Scroll down the page a little past half way to the image of the windmill and tree and the 100% crop just below.*

displays "absolutely unexpected and appalling CA" (chromatic aberation). But to me it looks like the tree is budding and will in several weeks time have blossoms. The photo was taken in late March, a time when all trees in the northern hemisphere that lose their leaves in the fall show magenta colored buds.

Michael says "I'm stumped. It clearly is caused by a combination of the 14n's sensor and the particular lighting situation found in this particular frame, but I'll be damned if I can explain it. Will all lenses display CA like this with the 14n under certain lighting conditions? Is it only this particular lens or model? Is this problem known by Kodak and will it be fixed in future firmware releases?

Feel free to speculate, but if you find out for sure, please let me know."

Well, I emailed Mr. Reichmann and explained to him that trees in the early spring have buds and that those buds would look exactly like what he's calling CA in this image. But he's adamant that he didn't see buds on that tree. Of course, unless the tree were dead, it would have to have buds on it at that time of year.

Notice that the magenta color is in clumps, just as it would be if we are looking at tree buds. There is no magenta color lining every little branch, as there would be if it's CA. There's no magenta color along the edges of the windmill, as we would expect to see if it were CA. The magenta clumps are there with both bright sky as background and with the windmill as background, exactly as we would expect if the magenta clumps were tree buds, and not at all what we would expect if the magenta clumps were CA.

So my question to all of the faithful is this. Is this tree dead? ;-)Luminous Landscape
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Jack Flesher
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« Reply #4 on: June 29, 2005, 11:02:28 AM »
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That is indeed a perfect example of horrible CA.
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Jack Flesher
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« Reply #5 on: June 29, 2005, 12:12:47 PM »
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Because it has its compliment cyan as well as the red.  CA usually occurs in two combinations; Red/Cyan and Blue/Yellow.

I think what you are seeing as blossoms is clusters of overlapping CA -- note that you can also see through most of those.  To the point there is definitely CA present in the branches.  In the tree branches you can see the cyan fringe along with the red fringe which is traditional CA.  I enlarged the image by 400% to show it more clearly.

As for not seeing it along all edges, I see it on almost every single branch in the tree -- the windmill is oof so the edge is not shapr enough to generate the CA.

400% enlargement:
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Peter Jon White
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« Reply #6 on: June 29, 2005, 12:56:38 PM »
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Jonathan,

I hate to belabor the obvious, but isn't that exactly what we have here? We have specs of magenta. And we have sections of branches with no color fringing along the branches. The branches all show up as one single color, cyan in various shades. But we don't see colors in parallel.

Could anyone please explain to me how this image isn't 100% consistent with what any living deciduous tree would look like in late March, when this photograph was taken?
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Peter Jon White
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« Reply #7 on: June 29, 2005, 02:32:26 PM »
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Michael,

You seem very defensive about this, which only makes me more curious. You said in your private email that you had an image of the tree taken with a different camera that didn't show the CA. When I asked you to email me the image, you didn't reply, which is what prompted me to post this message here and on photo.net. I'm left to wonder whether you don't in fact have the image you claim to have. I'm also left to wonder whether you realize that you made a mistake in your review and are now too embarrased to admit it. There is nothing whatsoever in the image to indicate CA. The image is completely consistent with a living desiduous tree in late March, ready for the buds to blossom. You've made a mistake. You have claimed that a $5,000 camera has some serious but mysterious defect that you readily admit you can't explain. And you won't admit that you've made a simple mistake.

Could you please post the image you claim to have which doesn't show the "CA"?

And if not, could you tell us whether or not the tree was dead? If the tree is dead, then what appears to be blossom buds must be something else. But as things stand, any objective observer who has ever seen a desiduous tree in late winter must conclude that you've made a mistake and are misrepresenting the Kodak camera in your review.

If the tree isn't dead, perhaps you have an explanation for why this tree mysteriously doesn't have any buds on it, and at the same time causes this $5,000 camera to exhibit an otherwise unexplainable "CA" phenomenon.

By the way, have you ever seen a living desiduous tree in March that didn't have magenta buds all over it?
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« Reply #8 on: June 29, 2005, 03:08:11 PM »
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I am under no obligation to provide you with anything.

I am not defensive, I'm simply annoyed. I usually go out of my way to accomodate people with legitate requests, but since I've told you that there were no megenta buds, yet you insist on my proving it to be otherwise to satisfy your disbelief, the answer is a simple NO. Move on!

Now, please stop wasting other reader's time or my bandwidth with this nonsense.

Michael
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Peter Jon White
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« Reply #9 on: June 29, 2005, 04:28:06 PM »
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In your review of the camera you wrote,  "I'm stumped. It clearly is caused by a combination of the 14n's sensor and the particular lighting situation found in this particular frame, but I'll be damned if I can explain it. Will all lenses display CA like this with the 14n under certain lighting conditions? Is it only this particular lens or model? Is this problem known by Kodak and will it be fixed in future firmware releases?

Feel free to speculate, but if you find out for sure, please let me know."

You now state that there were no magenta buds on the tree. But as everyone who has ever seen a tree in late winter knows, all desiduous trees have buds on them at that time. So your claim that the tree had no buds is specious. In fact, it's laughable. There's no need to speculate about what caused the "CA". It's a perfectly normal phenomenon that happens every winter. All trees of this type do it.

You have used your website to discredit Kodak's camera with misleading information. You have refused to supply corroborating evidence to back up your claim that the Kodak camera is subject to this mysterious chromatic aberation anomoly. I've read several reviews of this camera and so far have found no other reviewer who has discovered your anomoly. You're the only one who can't tell the difference between a tree bud and chromatic aberation. You have no credibility, Mr. Reichmann.

Jani,

I have looked closely at the 400% image. I would suggest that next March you go outside and look at a tree.

Good Day.

Peter Jon White
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Peter Jon White
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« Reply #10 on: June 29, 2005, 07:16:17 PM »
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Where do you see any translucency? I see none.
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« Reply #11 on: June 29, 2005, 08:47:43 PM »
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Topic now closed due to it being a complete waste of time.

Michael
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thierrylegros396
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« Reply #12 on: June 29, 2005, 10:52:05 AM »
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Nearly sure it's CA.
Looks just like CA with my 18-55mm shooting trees in strong light.
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Jonathan Wienke
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« Reply #13 on: June 29, 2005, 12:22:57 PM »
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It's definitely CA, as buds would show up as small magenta specks along the tree branches rather than a color fringe along the entire branch. And Michel is probably astute enough to have noticed the buds (if that's what was the true cause of the problem) and accounted for that in his commentary.
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jani
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« Reply #14 on: June 29, 2005, 03:09:44 PM »
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Peter Jon,

I think it's you who are defensive, and simultaneously offensive.

It's obvious that you haven't looked closely at the 400% crop that Jack posted, or you've been looking at it on a crappy monitor.

There are absolutely clear signs of chromatic aberration, with cyan, blue and magenta casts.

The blue casts do not exhibit the properties you claim:

Quote
The branches all show up as one single color, cyan in various shades. But we don't see colors in parallel

Just take a look at the major branch in the lower left corner of Jack's crop.
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Jan
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« Reply #15 on: June 29, 2005, 08:46:40 PM »
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I am putting an end to this thread. It's a complete waste of everyone's time. You're clearly a person who is unable to accept other people's words, or the reality of the situation.

By the way, the 14n was a dreadful camera. No appologies for that. If you believe otherwise, or are defensive about the issue, that's your look out.

Topic closed. If you reopen another one on the same subject you'll be barred from the forum.

Michael
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