Adjusting black and white point - how

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gordonrobb
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I'm trying to adjust existing texture (images) for use in Octane. I'm using the plugin, but it uses the same nodes so I'm posting the question here.

The ColorCorrect node used to have a black point adjustment but now it doesn't

What I want is what OTOY are suggesting is the process for adjusting black point and white point. I don't want to adjust the gamma (which I know how to do). I've found a few different work-arounds that each do something, but each do it differently.

What I'd like is what OTOY are saying is the way to do the following.

Make the blacks less black
Make the whites less white
Control where, from 0%-100% your images constrains it's black/white. So I have an image that goes frm 0% to 100% just now, but I want it to go from 10%-90% (without cutting off what is currently between 0-10 and 90-100.

Help!
Windows 8 Pro | i7 3770 OC | 32 GB Ram | Single Titan (plus Black Edition on Order) | Octane Lightwave |
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BorisGoreta
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You have to mix the texture with the white RGB value to adjust the black point, and white point is adjusted using the power in the texture image node. So you don't need color correction node at all.

Capture.JPG
gordonrobb
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I'll need it for contrast adjustment, but I can just feed your solution into it. Thanks, I'll give that a try.
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BorisGoreta
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There is a contrast adjuster in the Color correction node plus with gamma you can adjust contrast too.
gordonrobb
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BorisGoreta wrote:There is a contrast adjuster in the Color correction node plus with gamma you can adjust contrast too.
yeh, that's what I meant, i'd need to use the colorcorrection node for contrast. It was in response to you saying I wouldn't need to CC node :

Anyway, tried your solution and it works a treat, except for this bloody gamma difference problem with Lightwave.

This is the original....
Normal.png
this is it in Photoshop with the black point adjusted to 128 (50% grey)
128.jpg
this is it in LW with the adjustment to 50% (with your node setup)
50.jpg
To get it similar, I've had to adjust it to 12%
12.jpg
This is ok, but the adjustments I'll lactaully be making with be darker than this, and 1% is a lot at the bottom end in LW>
Last edited by gordonrobb on Mon Jun 15, 2015 5:29 pm, edited 1 time in total.
Windows 8 Pro | i7 3770 OC | 32 GB Ram | Single Titan (plus Black Edition on Order) | Octane Lightwave |
gordonrobb
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Joined: Sat Mar 16, 2013 9:08 am

That's weird. My 128 image looks darker once I've posted it.
Windows 8 Pro | i7 3770 OC | 32 GB Ram | Single Titan (plus Black Edition on Order) | Octane Lightwave |
gordonrobb
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Joined: Sat Mar 16, 2013 9:08 am

Replaced it with a JPeg and that works
Windows 8 Pro | i7 3770 OC | 32 GB Ram | Single Titan (plus Black Edition on Order) | Octane Lightwave |
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