babuci opened this issue on May 15, 2009 · 6 posts
babuci posted Fri, 15 May 2009 at 1:37 AM
I have a problem. Do you see the dark "highlight" almost black on the edge of the red petals? Looks like a postwork went very wrong but this is an original capture. What cause it and how can I avoid it?
Set up is: 2 cold white light either side, the righside of lamp a bit far away then a left.
F/9
1/20 sec
iso 100
I used different WB all picture has it this difault.
Any help please...thank you
girsempa posted Fri, 15 May 2009 at 3:51 AM
I can hardly see those darkened edges, Tunde... I have to try very hard to see what you're talking about :o)
So, while it's not that visible to me, maybe a few questions can help solve your 'problem'...
Did you try this with another lens? Perhaps a different lens could be better (or worse) in juxtaposing or resolving the red edges against the green background (think of red-cyan fringe or chromatic aberration...). I did some red-cyan fringe correction and it does seem to have an effect on some edges, but not all...
Did you try with a wider aperture? Maybe diffraction at the edges is causing the red 'overlay' against the green... Although f/9 shouldn't be too much of a problem.
Did you try a different color setting in your camera (muted colors, saturated colors, etc...)..?
Do you have the same problem with a less color-contrasting background (say yellow or brown)..?
And what if you reproduce this shot with only natural light with a few reflectors added..?
We do
not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs
ǝʍ
TwoPynts posted Fri, 15 May 2009 at 10:22 AM
Geert covered this pretty well. For me, it isn't a distraction. It is only noticeable because you mentioned it. I'm guess it is the redflowers close against the green. Perhaps if they were moved forward somehow and the green was farther behind, out of focus a bit. Also, some more diffused lighting could also help the issue.
Kort Kramer - Kramer Kreations
Onslow posted Fri, 15 May 2009 at 12:23 PM
I am guessing Geert was possibly correct when he mentions diffraction.
In simplified terms the red/green boundary is falling across more than one pixel array on the sensor. There being twice as many green as red or blue pixel receptors it is going to be virtually impossible to get a perfect transition. Your camera then decides what colour the image pixel should be by guessing from the data it receives from nearby receptors.
Using a larger aperture should help with your type of camera. The trade off is you will lose some depth of field and will need to experiment to get a happy medium which gives you results you like.
And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies
live;
Their heads are green, and their hands are blue, And they went to
sea in a Sieve.
Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html
babuci posted Fri, 15 May 2009 at 4:56 PM
Thank you guys, I will try to capture it again with the advised set up by Geert and use a macro len this time instead of the 17-85 lens. ( I am not bother with a kit lens) see if any better.
seeyus Tunde
bclaytonphoto posted Sat, 16 May 2009 at 4:14 PM
I agree with Kort here..