Removing gradients in Photoshop CS6

[Amra]

I wanted to share this tutorial I found on Youtube by Doug German 

I've been having problems fixing gradients for a long time, I used GradientXterminator a bit but once the trial ran out I didn't bother purchasing it.

As I didn't want to pay the hefty price of the GradientXterminator plug-in, I found this video randomly today, it was very helpful and the method worked beautifully.

I used it on some old data of M37 and it worked well, super simple & quick method. 

Original:

After gradient removal:

Hopefully it will help somebody. If I have problems with gradients again and have forgotten this method I'll just look into my post history & bookmarks.

[sandyshaw]

God I hate gwadients, I always get the worst kind of gwadient.  I now use a SW LP filter which makes things much easier

[swag72]

While we are talking about gradients, I found this tutorial absolutely brilliant - It removed gradients that DBE wouldn't touch. I've used it a couple of times now - absolutely excellent http://www.corius.net/?page_id=395

[sandyshaw]

Could this be automated in photoshop actions and also removing bright spots (stars) over a specified threshold value?

[Amra]

While we are talking about gradients, I found this tutorial absolutely brilliant - It removed gradients that DBE wouldn't touch. I've used it a couple of times now - absolutely excellent http://www.corius.net/?page_id=395

Thanks a lot, seems very useful.

[sandyshaw]

How safe is this to use on nebulae?

[Amra]

Could this be automated in photoshop actions and also removing bright spots (stars) over a specified threshold value?

I'm not sure, but for this particular M37 I didn't even remove any bright spots, but then again the image isn't very bright & uber detailed. Would be useful if you could do that.

[Alien 13]

I have found that some gradient removal tools work with some images but not others so i use my own methods but basically uses the standard way of creating a gradient mask but is then inverted and used with a standard blend mode.

Alan

[sandyshaw]

I have found that some gradient removal tools work with some images but not others so i use my own methods but basically uses the standard way of creating a gradient mask but is then inverted and used with a standard blend mode.

Alan

This method on the video uses the images own gradient mask (Colours and gradient), wheras if you make your own gradient, it maybe (probably will be) less accurate. At least with this method you are using the gradient in the image itself, not a hand made one.

[Alien 13]

This method on the video uses the images own gradient mask (Colours and gradient), wheras if you make your own gradient, it maybe (probably will be) less accurate. At least with this method you are using the gradient in the image itself, not a hand made one.

I create an inverse gradient from the original image but do a few tweeks to it this has completely removed the need to take flats anymore.

Alan

[sandyshaw]

I create an inverse gradient from the original image but do a few tweeks to it this has completely removed the need to take flats anymore.

Alan

And how do you deal with the stars and detail?

[Alien 13]

And how do you deal with the stars and detail?

I use a combination of dust and scratches and gausian blur but not too much the brighter objects are removed with a clone tool.

Alan

[sandyshaw]

I use a combination of dust and scratches and gausian blur but not too much the brighter objects are removed with a clone tool.

Alan

So it is basically a similar technique of the video except using an inverted blurred mast?

[Alien 13]

So it is basically a similar technique of the video except using an inverted blurred mast?

Yes but i do change the overall level otherwise the combined image tends to set the background to zero.

Alan

[sandyshaw]

So what is the best way to deal with nebula and galaxies in the images that seem to match the colour of the light pollution?

Using this technique is great when you just have blobs of stars, but gas / dust details are eaten alive with it.

[Alien 13]

So what is the best way to deal with nebula and galaxies in the images that seem to match the colour of the light pollution?

Using this technique is great when you just have blobs of stars, but gas / dust details are eaten alive with it.

Anything bright will show as a lighter patch on the de noised layre i just use the brush and eye dropper tool to paint out the brighter bits with the surrounding darker area.

It works better sometimes if you blend the two layres with less than 100% opacity this does leave some gradients behind but the image can be merged and the process repeated rather than doing it all in one hit.

Alan