Graduated filters creating a dark line - cleaning up white backgrounds

[andreasandrews]

I thought it might be an optical illusion, however I've done some tests using a colour picker in photoshop and I can confirm that I've started noticing something strange when using the graduated filter which causes darkening to appear just after where the grad. filter ends.

When lightening one part of an image using the grad. filter, you would not expect another part of the image outside of the selected area to go darker, which is quite strange.

This was noticeable when making the edges pure white on a slightly off white background with the exposure and brightness settings on the grad. filter turned up all the way.

Has this ever happened to you? Any suggestions no matter how wild as to what could be causing this to happen?

 

[b_gossweiler]

Can you post a screen shot of what you see?

What should be happening is that everything before the beginning of the Graduated Filter should have full effect, between the beginning and the end of the filter you should see the graduation, and after the end of the filter you should see not effect at all. See this example with Exposure -4:




Beat

 

[andreasandrews]

Can you post a screen shot of what you see?

What should be happening is that everything before the beginning of the Graduated Filter should have full effect, between the beginning and the end of the filter you should see the graduation, and after the end of the filter you should see not effect at all. See this example with Exposure -4:

View attachment 1803


Beat

I When I tried using the same colours as you I didn't have an issue, so here is a screen grab showing what happens on the certain image where I'm noticing this issue:

 

[RikkFlohr]

It is the abrupt transition and extreme positions of your sliders that do this. A +1 Exposure and 0 Brightness is probably sufficient to blow your white seamless to pure white. At the beginning of your gradient you have[FONT=Trebuchet, Verdana, 'Lucida Grande', 'Sapir Sans', Tahoma, sans-serif] +4 and +200 at the mid point you have +2 and +100. Your distance from mid-point to no effect is too short and your gradient too steep, resulting in a hard transition.

Dial it back to +1 Exposure and no Brightness and see if that doesn't look better. Your transitions will be much more gradual.

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[Chris_M]

Or, since the chairs appear to be the same photo pasted 3 times,
there appears to be no fuzzy edges, so I reckon it would be quicker and easier to simply cut out the chair, or mask out the background,
then copy 'n' paste to a blank white background canvas in Photoshop as many times as required resulting in zero transition problems.

Unless of course the shadow is important, which complicates things then.

 

[Mark Sirota]

I see the tonal inversion near the end of the grad. Do you, by chance, have a lot of Clarity applied, and does the inversion disappear if you zero it out? What I'm thinking here is that Clarity is enhancing the border between the white and grey areas.

Similarly, if you back off on the strength of the Exposure and Brightness adjustments (so that the top area is still pure white, but just barely so) does the tonal inversion decrease? I'm thinking it will.

 

[andreasandrews]

Thanks, I would normally do things in a very subtle and smooth way with like you said just a little bit of an exposure increase dialled into the grad, and no brightness. In this case didn't want smooth transitions, but I didn't expect the image tones to become darker which is the issue here.

I used clipping path on all 240 images now whilst retaining the shadows so it's no longer an issue, but the mystery still remains.

 

[andreasandrews]

Fantastic! I think you've made a very good point there... the Clarity is being re-applied so to speak in relation to local or other adjustments in the image and due to the difference between the tones after applying the grad this is happening. This makes sense to me. I'll have to verify that this is the case, but I know that I have indeed applied some if not slightly above the default amount of clarity on these images.

I shall experiment with the amounts on the Exposure and Brightness and study the effects it has on the tonal inversion.

 

[andreasandrews]

The time it was taking in Lightroom to use local adjustments to get this effect turned out to be a little faster than what I would expect doing clipping paths in paths in Photoshop, but even just spending just 5 or so minutes would have taken too long for 240 images, so I outsourced to India where it was done cheaply and in 1 weekend keeping all the shadows in too, which was great.

 

[Victoria Bampton]

Sorry I didn't see this thread before. Er, yes, outsourcing it would have been my suggestion too. I don't know about you, but I don't have the patience to clean up 240 white backgrounds! I can't think of plenty of other ways to spend that time!