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Author Topic: corrections  (Read 5476 times)

user

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« on: October 19, 2007, 04:30:55 pm »

the problems/limitations of digital cameras are known to all of us

what I need to know is which is most easily and efficiently correctable and which is most annoying

1. purple fringing?
2. non accurate color reproduction?
3. barrel distortion?
4. blurriness/lack of sharpness?
5. noise?

what?

which can be easily corrected or avoided? either with some photoshooting technics, or with software editing?

thanks
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jerryrock

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« Reply #1 on: October 23, 2007, 02:04:32 pm »

The problems you listed are not unique to digital cameras.

Purple fringing, barrel distortion and blurriness are products of lens quality.

Color reproduction and noise (grain), are also problems associated with film type, ISO speed and developing process.
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Gerald J Skrocki

Tim Gray

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« Reply #2 on: October 23, 2007, 02:48:08 pm »

Quote
the problems/limitations of digital cameras are known to all of us

what I need to know is which is most easily and efficiently correctable and which is most annoying

1. purple fringing?
2. non accurate color reproduction?
3. barrel distortion?
4. blurriness/lack of sharpness?
5. noise?

what?

which can be easily corrected or avoided? either with some photoshooting technics, or with software editing?

thanks
[a href=\"index.php?act=findpost&pid=147269\"][{POST_SNAPBACK}][/a]

1, 4 and 5 depend on the severity of the problem.  eg: lack of sharpeness (such as introduced by the AA filter) is relatively fixable using available sharpening tools.  Out of focus is another problem.  The ease of fixing noise depends on how much: noise at 1600 ISO out of something as new as a Canon G9 is going to be a problem - annoyance is in the eye of the beholder, sometimes "grain" can be a good thing.  'normal' fringing is also relatively fixable in todays RAW converters.

2. color balance is easily fixable, assuming RAW and in an ideal world, you have either a neutral gray in the image, or have shot a gray card.

3. slight barrel distortion is probably the easiest to fix.  Some of the more exotic lenses have a slight "mustache" distortion that is tougher to fix.
« Last Edit: October 23, 2007, 02:49:20 pm by Tim Gray »
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user

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« Reply #3 on: October 23, 2007, 08:44:58 pm »

thanks for your reply

can you fix the slight purple shadow in this photo and post the edited file please?

http://69.93.231.164/PRODS/N2/FULLRES/N2hMULTI3648F.JPG

I really need to see how it can be fixed
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marcmccalmont

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« Reply #4 on: October 23, 2007, 10:14:43 pm »

www.shaystephens.com/ca.asp

It is a photoshop action that I was just turned onto
Marc

[attachment=3628:attachment]
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Marc McCalmont

user

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« Reply #5 on: October 23, 2007, 11:21:57 pm »

thanks but the photo you attached is the untouched/unedited original
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DarkPenguin

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« Reply #6 on: October 23, 2007, 11:36:45 pm »

They're different, dude.  Look harder.
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marcmccalmont

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« Reply #7 on: October 23, 2007, 11:57:33 pm »

Here is a closer look
Marc

original [attachment=3630:attachment]

after PF action [attachment=3631:attachment]
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Marc McCalmont

user

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« Reply #8 on: October 24, 2007, 11:11:46 am »

mmm another person send me this, but I cant find him to send me the full edited file:

http://www.hostmyjpg.com/images/758050375_1.jpg

doesnt it look very much better? all the purple shadow seems gone and the white and black are pure
« Last Edit: October 24, 2007, 11:47:02 am by user »
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marcmccalmont

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« Reply #9 on: October 24, 2007, 12:21:22 pm »

2 more crops that I uprezzed to make it easier to see
Marc

[attachment=3634:attachment][attachment=3635:attachment]
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Marc McCalmont

user

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« Reply #10 on: October 24, 2007, 12:31:01 pm »

mm thanks but again it doesnt seem VERY big improvement, in comparison with the screenshot I pasted before, right?
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meyerweb

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« Reply #11 on: October 25, 2007, 05:33:24 pm »

Quote
mm thanks but again it doesnt seem VERY big improvement, in comparison with the screenshot I pasted before, right?
[a href=\"index.php?act=findpost&pid=148410\"][{POST_SNAPBACK}][/a]

Seems to me the purple is pretty much completely gone. Other color fringing still exists, but I don't think the action was designed to remove those effects.
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user

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« Reply #12 on: October 26, 2007, 11:58:08 am »

is it possible to correct the text line distortion in this:
http://shup.com/Shup/9175/DSC00059.png
thanks
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joedevico

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« Reply #13 on: October 26, 2007, 04:39:25 pm »

"doesnt it look very much better?"

who can tell at that size?

"all the purple shadow seems gone and the white and black are pure"

sure, the levels have been adjusted to make the whites lighter and the blacks darker - but at that resolution, anything would look good. I like Marc's action that he shared with us. Seems to do an excellent job with the "purple shadow" - you could then apply a color balance, curve or levels adjustment to get the "white and black are pure"

jdv
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Joe DeVico
the PhotoGraphic Design Group

joedevico

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« Reply #14 on: October 26, 2007, 04:45:46 pm »

Quote
is it possible to correct the text line distortion in this:
http://shup.com/Shup/9175/DSC00059.png
thanks
[a href=\"index.php?act=findpost&pid=148853\"][{POST_SNAPBACK}][/a]

Options:

1. Flatten the page before you shoot
2. Use a flash or tripod to keep camera movement to a minimum
3. Spend a bunch of time in photoshop fixing the distortion, but forget about the left edge - it's beyond help.

I've shot a bunch of copy work of books and media - and there's definately an art to getting it right. Unless you need maximum resolution, there's also no reason to fill the frame with the media. Then your just introducing lens distortion into the already distorted image.

Unless this book were the last copy lost in a fire, this would be easier to reshoot properly than bother to fix after the fact. It would even be easier to scan the book in multiple passes and merge them in photoshop than bother to try and fix it.

jdv
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Joe DeVico
the PhotoGraphic Design Group
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