Fixing banding on white background

M

maddop

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31
Name
Paul
Edit My Images
Yes
Hi all,

I've recently placed my first order with Loxley and they've since called back to advise my pictures had some banding on the white background so they've destroyed the prints and cancelled the order. They suggested i fix the background and reorder.

Its great that they've done that but now i'm not sure how to fix the problem.

My images are all shot on white background... i didnt have the lighting set up correctly so it wasnt a consistant white throughout!!! my bad!

I've tried inverting the image in photoshop to identify any banding but couldnt see anything other than a consistant color... my screen is profiled using spyder3.

Any ideas... thanks,Paul
 
banding could mean anything
look at the image at 100% in photoshop and see if u can spot anything.....it may be that the gradient of white isnt uniform, this can happen with severe editing.......wont show up till you look at it full size
had a similar one i messed up and the sky had several colour bands of diff shades of blue......could only see it when i looked at it 100%

Gary
 
If you have PS it can literally be a 1 minute job dependant on how bad it is and the areas of transition but like has been said we could do with seeing the image. If you could I would suggest posting the image, a 100% crop and a link to a full sized file.
 
Yeah sure, i've loaded 2 version

(small version for display here)
smallexample.jpg


Here is the link to the full version (incase the shrinking has lost quality or whatever)
http://maddop.co.uk/examples/img61and122.jpg

thanks.
 
Hi Paul

I have had a similar problem where imperfections in the white background do not show on my monitor. When the images were transferred to my laptop they clearly showed up when tilting the screen to view from a different angle.
 
It says we don't have permission to view the image when we click on the link and the image doesn't show in the thread.
 
Should be ok now guys, i've turned hotlink protection off on the site. thanks.
 
Access forbidden on that link.

Visible banding - there's always banding, what's important is whether you can see it - in light areas is unusual, it's much more common in low tone areas. It's partly the eye's sensitivity at low light levels and partly a logarithmic kind of thing. Sort of. Very common in TV, especially CG where smooth grads are common because the bit range is narrow in YUV, which is what's ultimately finding its way onto your screen.

It's caused either by there not being enough bit resolution in the image or by changing gamma or contrast beyond what's sensible. For example, consider a grad in the image where it smoothly transits pixel values 1 -> 2 -> 3 -> 4 ..... -> n. If you increase the contrast in that range, you'll go from 1 value increments to something much larger. The eye is very sensitive when doing side-by-side comparisons and banding becomes evident quite quickly.

Did you do any CC or contrast adjustments?

Remember, you're moving into a different colour space. But even so, if your colour profile is set properly it should be fine, especially in light areas.
 
naked eye on my monitor cant see anything
open in photoshop and adjust levels.....middle slider to the right and i wonder of thats what they mean.......bands appear around the child to the left

Gary
 
kimaldis - thanks for the detailed explanation. I did perform some contrast adjustments.

hdseven, good spot. i've adjusted the middle slider and I see plenty of bands throughout the background... i'm guessing thats what they're talking about. It must be showing up on the prints somehow... i'll have a play and try to fix it. Might take some time though... :(
 
  • I used lasso to select each child.
  • Inverted the selection
  • Selected "Refine Edge" then changed feather to 1px and "output to" to "layer mask"
  • Then I clicked on new adjustment curve
  • Then I dragged the mask from the picture layer to the adjustment layer and answered YES to replacing it.
  • Then I clicked to adjustment curve in the top right corner and nudged it to the left till the background was white.

This gives you the white background without altering the overall exposure.

Full sized image link available if you want it
 
Using the magic wand with a tolerance set to 1 you can see there is a mismatch in the white - particularly the child on the left. Could this be what they are picking up on?

Edit: already answered.
 
Is it usual for Loxley to spot this?

I've just used Loxley for the first time. Shots were colour against a white backdrop.

When I examine the prints I can see banding, which I now know I can check in PS (using a levels adjustment and the slider).

I wonder why Loxley treated the OPs images in the way they did, but in my case printed them anyway?

OP did you selected the option to colour adjust?
 
the thing about looking for banding by adjusting levels is that you need to remember that it's about visible banding. There's always going to be some kind of banding in shallow grads but you have to asses whether you're actually going to see it or not. Changing levels will bring forward the invisible as much as the invisible and it can be misleading.

Of course, moving from screen colour space to print space also shifts the balance to some degree and that's where printing becomes a pain.
 
kimaldis said:
Of course, moving from screen colour space to print space also shifts the balance to some degree and that's where printing becomes a pain.
Click to expand...
You should convert to the right profile for the printer/paper combo and not apply it, if any colours are out of gambit you will see and can adjust before sending off to print
 
I didnt request any additional editing from Loxley but i did specify that it was my first order in the additional comments box...

Thanks for all the pointers folks... i'm playing around with them now. Still learning but you've helped me move in the right direction. Cheers.
 
Just to show what i mean about checking with threashold, as you can see ( if i've done this right ) your image had next to nothing that was pure white. The second image is after a little levels adjustment.



 
Kimaldis, they are Jpeg files. Saved used SaveAs in Photoshop CS5 with full quality. Print profile was sRGB (requested by Loxley).

Corbystock, thanks for the screen prints. I did try this and all of my images show as pure white using this method... i'm confused now.

I've never had this issue with other printers but they use different profiles.
 
maddop said:
Kimaldis, they are Jpeg files. Saved used SaveAs in Photoshop CS5 with full quality. Print profile was sRGB (requested by Loxley).

Corbystock, thanks for the screen prints. I did try this and all of my images show as pure white using this method... i'm confused now.

I've never had this issue with other printers but they use different profiles.
Click to expand...

That is strange because the second i brought your image ( large file ) up in PS i could see it wasn't pure white even before i checked with threashold i.e the first screen print :thinking:
 
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