Scanned Negative Color banding

[BullMike]

I wasn't really sure how else to explain this. Not sure if it is from a fingerprint. But it looks like colored banding, not unlike a tree ring. I have gone into the RGB channels and looks perfect when I select only "Blue". Is there a way to correct this?

Any help would be greatly appreciated.

Mike

[andrewrodney]

Re: Scanned Negative Color banding

Neutron Rings. Got to oil/gel mount the film and they and a ton of dust and scratches disappear. Don't even try to fix this after the fact, a nightmare. You have to fix it as you scan the image.

[BullMike]

Re: Scanned Negative Color banding

Thanks for the quick reply. I really appreciate it.

I am in the middle of touching up over 1k negatives that my father shot between 1965 and 1985. The negative in question was from around 1980. I have a handful of pictures with this particular artifact on it.

I'm using an Epson 4990 and have been extremely happy with the results.

Again, thanks,

Mike

[crazyfly1]

Re: Scanned Negative Color banding

Hi Mike, I'm not familiar with the issue that Andrewrodney describes but I trust his judgment.
If you are unable to rescan or just want a quick fix then you've already found your solution. The blue channel. The picture you posted is little more than a thumbnail. If you want to repost it so we can work on it and give you our results as an example then use the save for web function in PS and just use the jpeg size slider to cut the image size until it says it's under 100k. Then repost.
Anyway, if you go to "create new fill or adjustment layer" icon at the bottom of the layers pallet and choose "channel mixer", check the box for monochrome and then lower the red and green sliders (I lowered them to -15) and raise the blue slider (I used 150). Now set that layers blend mode to luminosity. You should see the banding disappear.
Again, it's really hard to tell with the image size you posted. You may also try adjusting by color channel to see if you get better results that way. Don't worry about the color shift, it will go away when you change the blend mode.

Welcome to Retochpro!

[BullMike]

Re: Scanned Negative Color banding

http://niagarafalls.smugmug.com/photos/i-KZs5Ssh/0/X2/i-KZs5Ssh-X2.jpg

This is a link to a jpg of the original scan.

Thanks in advance.

Mike

[Tony W]

Re: Scanned Negative Color banding

I think Andrew meant to say Newton rings?

The effect in my experience is usually seen on slide films that are glass mounted. The contact between the film and glass causing the effect that will vary over time depending on temp. and humidity. In this case IMO it is best to remove the film and remount in glassless holders.

If these are negatives then are you scanning by contacting neg to scanner glass and using a glass on top to flatten? Unless you use ANR glass then you risk forming Newton rings. AFAIK the Epson 4990 uses glassless film carriers that will not be troubled by this problem. If you are not using the carrier is there any particular reason?

Even though it may be possible to remove the effect in pp it will be a pain and potentially lessen the quality as the blue channel is quite likely to carry most of the noise in your scan

[BullMike]

Re: Scanned Negative Color banding

Some of the negatives are very warped, and because of the design of the film holders, there can be some contact with the glass.

[Tony W]

Re: Scanned Negative Color banding

Contact with the glass is where the problem lies. Have you tried flipping the film so emulsion is facing the opposite way to your original scans? Obviously you will need to flip it back in your editing application after scanning to show the correct orientation - it may just help

Failing the above suggestions you may want to investigate buying ANR glass http://www.betterscanning.com/

[BullMike]

Re: Scanned Negative Color banding

Thanks very much guys. Thanks CrazyFly. I'm just learning some of the photoshop effects and I found the blending mode you suggested easy to follow, but it unfortunately did not remove the banding.

I'll have to be a little more careful when scanning.

[crazyfly1]

Re: Scanned Negative Color banding

Mike, you are right. Being able to work with the original made a big difference. This is what I came up with. I didn't use the channel mixer, I used the calculations and apply image commands.

[BullMike]

Re: Scanned Negative Color banding

I would be grateful if you could explain how you used calculations and apply image.

Mike

[crazyfly1]

Re: Scanned Negative Color banding

New layer, Open calculations, settings I used were Source 1: background,grey, Source 2: background Blue, Blending: pin light, Result: new channel. Click OK. Go to the channels pallet and make sure rgb is selected.

Go to apply image and I used Layer: background copy, Channel Alpha 1 (this is the channel you created in the calculations step) Blending normal Opacity 100, check preserve transparency (just in case you've done prior work) leave mask unchecked. Click OK. Change layer blend mode to Luminosity. Hold the alt or option key and click the add layer mask icon at the bottom of the layers pallet.

Select the brush tool and set the foreground color to white, now paint over the banding on the face and suit coat. Make sure your layer mask is still selected and add a Gaussian blur to the mask, I used a setting of 14 here.

Go ahead and merge those 2 layers and create a new copy layer. This is the last step to clean up the color. Switch the blend mode to color. Apply another Gaussian blur, I used 4.5 here. Create another black layer mask and paint in the effect over the color banding on the face and suit coat.

That's it. If you create a snapshot and flip back and forth between the original you'll see you darkened the face ever so slightly. I don't think it's enough to bother with but you could brighten it with a curves or levels layer if you feel the need.

Hope that helps, feel free to ask questions for clarification if my steps are confusing.