How do I avoid artifacting in my images

[FloridaMike]

I am uploading to a stock agency and getting rejected because of artifacting when viewed at full size and need some help!

[autofocus]

Mike, are you shooting everything at the camera's highest resolution setting?...are you reducing the image size to upload?
Shooting in RAW, and converting to TIFF may help keep the resolution high...just some suggestions, but not sure if any of this will solve the problem??

[kencaleno]

I'm with Shutterstock for the past 4 years, so I believe I can help you-

Fist of all, In camera:

Lowest ISO
Highest resolution
Correct Exposure
Good Glass

Color fringing-This is caused by the inability of a lens to focus red,green, and blue light waves at a single point-The answer is an expensive apochromatic lens,whic has doublet elements to counterract this effect.

To eliminate in Photoshop:


Two Methods:

1. (Takes abit of time,but does a good job)

Ctrl+J select brush tool and click on the quick mask tool.
Choose a brush size to match the width of the fringe.
Draw all the areas that have fringing. When done, click icon next to quick mask
Select> Inverse.
Image> Adjustments> Hue/Saturation and pick the color closest to your fringe color Click eyedropper on the fringe color on your image.
drag Saturation slider to the left until the fringing goes.
Select> deselect
Save

2. Quick method for fringe elimination

Using lasso tool select area with fringing
Image> adjustments> Hue/Saturation
De saturate fringe color
Select> Deselect
save


Noise: ( This is the BIG one)

(Chroma-colour noise)


- Image> Mode> LAB Colour> Channels
Channel “a” Gaussian blur 5 pixels
Channel “b” Gaussian blur 5 pixels
Channel “lightness” Filter> noise> despeckle
Image> Mode> RGB colour

(Luma -Grainy noise)

-lasso area and apply smart blur at default setting (For small areas)
-Or Ctrl+J
-Smart blur-Then eraser tool to expose background features


To avoid Sharpening "haloes"
( It pays to downsize to minimum of 4 megapixels before uploading,this hides some artefacts,and if sharpening needs doing,do it then.)

Like This:
ctrl+J
Filter>Other>High Pass - set to radius of 4 pixels
Blending mode "Soft Light"
Flatten and save

Regards, Ken

[dcclark]

Can you specify what kinds of artifacts you're seeing, or upload an example image?

My first bet is, you may be over-compressing your images (setting the jpeg quality to be too low) -- but that's just my first bet.