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Archive 2009 · 5D2: what is going on here???

  
 
Hey.Underpants
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p.2 #1 · 5D2: what is going on here???


I'm going with the marijuana theory. Though it never showed up on any of my cams/lenses.


Aug 30, 2009 at 01:46 PM
AJSJones
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p.2 #2 · 5D2: what is going on here???


Is it possible that at the moment of the shot, some part of the tree, that had been blocking the direct sun, just moved slightly but enough to let the direct sun's rays land on the edge of the lens - a breeze moved the tree branch , for instance?

The grid pattern reminds me of some demosaicing issues I read about with some poorer converter versions. If you process with a different raw converter are the grids as pronounced??

Other than that, how big was the joint?



Aug 30, 2009 at 02:06 PM
Daan B
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p.2 #3 · 5D2: what is going on here???


AJSJones wrote:
Is it possible that at the moment of the shot, some part of the tree, that had been blocking the direct sun, just moved slightly but enough to let the direct sun's rays land on the edge of the lens - a breeze moved the tree branch , for instance?


Not likely...

The grid pattern reminds me of some demosaicing issues I read about with some poorer converter versions. If you process with a different raw converter are the grids as pronounced??

The grid pattern shows up in both LR and DPP.

Other than that, how big was the joint?

Why is it that us Dutch folks are always associated with joints

We also got cheese, dykes, polders, lots of water, wooden shoes, Heineken and blond girls you know



Aug 30, 2009 at 02:14 PM
skibum5
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p.2 #4 · 5D2: what is going on here???


Daan B wrote:
Why is it that us Dutch folks are always associated with joints



well, because all of you are always smoking one?




Aug 31, 2009 at 12:48 AM
Daan B
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p.2 #5 · 5D2: what is going on here???


skibum5 wrote:
well, because all of you are always smoking one?


Souns like y'all are a bit envious because it is legal here



Aug 31, 2009 at 02:22 AM
slrl0ver
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p.2 #6 · 5D2: what is going on here???


Daan,

Check this site, it could be the demosaicing algorithm and sensitivity to flare:

http://www.pages.drexel.edu/~par24/rawhistogram/40D_Demosaicing/40D_DemosaicingArtifacts.html

I'm curious if VNG 4 colors will show a more favorable image.

- slrl0ver



Sep 12, 2009 at 09:59 PM
roger lund
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p.2 #7 · 5D2: what is going on here???


Where you not using the lens hood?


Sep 13, 2009 at 10:05 AM
Daan B
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p.2 #8 · 5D2: what is going on here???


slrl0ver wrote:
Daan,

Check this site, it could be the demosaicing algorithm and sensitivity to flare:

http://www.pages.drexel.edu/~par24/rawhistogram/40D_Demosaicing/40D_DemosaicingArtifacts.html

I'm curious if VNG 4 colors will show a more favorable image.

- slrl0ver


Very interesting info... thanks

My case seems very similair. So, demosaicing artifacts are the cause of the grid like pattern.

Yeah, it will be worth while to see if VNG 4 colors produce a better image. It seems to do the trick with the 40D file.

Only question is: how do I select this demosaicing algorythm in ACR/LR?



Sep 13, 2009 at 10:48 AM
Daan B
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p.2 #9 · 5D2: what is going on here???


roger lund wrote:
Where you not using the lens hood?


Didn't you read the whole thread?



Sep 13, 2009 at 10:49 AM
slrl0ver
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p.2 #10 · 5D2: what is going on here???


Daan,

I don't think you can choose the algorithm with ACR/LR . But you can try to use "dcraw" as an experiment. I think there are several GUIs available, including "Rawtherapee" if you use Windows or Linux:

http://www.rawtherapee.com/

- slrl0ver



Sep 13, 2009 at 11:34 AM
Daan B
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p.2 #11 · 5D2: what is going on here???


slrl0ver wrote:
Daan,

I don't think you can choose the algorithm with ACR/LR . But you can try to use "dcraw" as an experiment. I think there are several GUIs available, including "Rawtherapee" if you use Windows or Linux:

http://www.rawtherapee.com/

- slrl0ver


Right... Unfortunately I am on a Mac



Sep 13, 2009 at 12:20 PM
corndog
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p.2 #12 · 5D2: what is going on here???


anorphirith wrote:
sky move and create flare


We had the answer early on but ignored it. Were you thinking a sudden flash of light was something supernatural? A freak arc inside your camera that somehow did no damage? Let's all get off our keesters and take some pics outside!



Sep 13, 2009 at 12:27 PM
Daan B
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p.2 #13 · 5D2: what is going on here???


corndog wrote:
We had the answer early on but ignored it. Were you thinking a sudden flash of light was something supernatural? A freak arc inside your camera that somehow did no damage? Let's all get off our keesters and take some pics outside!


Sky didn't move. Flare wasn't visible in the VF... only when releasing the shutter. Which can happen I guess... But this wasn't the main issue... The main issue was the grid like pattern which I thought was caused by the flare. But it seems to have been caused by the reaction of the RAW converter (demosaicing algorythms) to the flare. But all of this would have been obvious by now if you would have actually read the thread



Sep 13, 2009 at 02:21 PM
corndog
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p.2 #14 · 5D2: what is going on here???


I did read the thread, all I saw was a bunch of people over analyzing flare. Is this repeatable? Are you concerned about an anomaly? And I did what you asked your first post, I offered my thoughts. Every camera I've owned(which is at least a dozen between Canon and Nikon), has done something weird at one time or another. If it's repeatable or frequent, then start investigating, otherwise make a mental note and keep shooting. I suspect you'll never really know what this is unless you can have one of the Canon engineers look at it.


Sep 13, 2009 at 02:38 PM
slrl0ver
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p.2 #15 · 5D2: what is going on here???


Daan,

Based on this site:

http://www.insflug.org/raw/guis/

These are two free Mac OSX GUI programs that use dcraw:

http://raifra.fh-friedberg.de/Mac/index-en.html
http://www.chocoflop.com/download_en.html

If you don't mind using the command-line, you can download a OSX dcraw binary and try the options manually.

- slrl0ver

Edited on Sep 13, 2009 at 02:42 PM · View previous versions



Sep 13, 2009 at 02:39 PM
slrl0ver
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p.2 #16 · 5D2: what is going on here???


corndog,

Did you even look at the site I posted a link to (http://www.pages.drexel.edu/~par24/rawhistogram/40D_Demosaicing/40D_DemosaicingArtifacts.html)?

It could be exactly what the OP is experiencing. We'll find out if he can try using one of the other algorithms to see if the processed image (de-Bayer'd) looks better or different.

- slrl0ver

corndog wrote:
I did read the thread, all I saw was a bunch of people over analyzing flare. Is this repeatable? Are you concerned about an anomaly? And I did what you asked your first post, I offered my thoughts. Every camera I've owned(which is at least a dozen between Canon and Nikon), has done something weird at one time or another. If it's repeatable or frequent, then start investigating, otherwise make a mental note and keep shooting. I suspect you'll never really know what this is unless you can have one of the Canon engineers look at it.




Sep 13, 2009 at 02:42 PM
corndog
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p.2 #17 · 5D2: what is going on here???


I read it...it looks like over analyzing flare. Did you look at the photo they're trying to fix in that link? Yeah, let's work on the strange artifacts, because then the photo will be amazing.


Sep 13, 2009 at 02:48 PM
slrl0ver
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p.2 #18 · 5D2: what is going on here???


corndog,

I don't think anyone is forcing you to read or post if you don't want to. Some of us want answers to our questions and I'm curious to see if we can resolve the OP's problem.

-slrl0ver



Sep 13, 2009 at 04:19 PM
Geofn
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p.2 #19 · 5D2: what is going on here???


Looks to me like when the mirror started up it caught an image of the sun, previously outside of the frame but included in the lens' projected circular image, and reflected it into the viewfinder (hence the flash) and the reflection of the sun off the bottom of the pentaprism then traced the arc-shaped flare onto the sensor through the 50% transmissive mirror. Just a guess, but it's the best explanation I can come up with. All the angles would have to be just right (wrong?) for this to happen, so my guess is that you'll likely never see it again.


Sep 13, 2009 at 04:29 PM
Breitling65
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p.2 #20 · 5D2: what is going on here???


I believe this is lens not camera, 35L might serve better than this cheapo


Sep 13, 2009 at 04:46 PM
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