The Blue Light Effect

[Smalerbi]

Hello All,

The further away the objects are in a real world scenario they appear to take on more of the atmospheric color or what I like to call, The Blue Light effect. You will notice this more on crisp cool winter days when the air quality is very good and it seems you can see forever. Can this be achieved in Vray and if so, how?

Thanks,

Scott

[Dariusz Makowski (Dadal)]

Blue thin fog

[muoto]

could be done easily in post with z-depth no ?

[stevesideas]

Thats the method I would use too. Use a zdepth element...invert and do as a screen layer over the top. Colorise and then adjust opacity to suit.

[Dariusz Makowski (Dadal)]

Thats the method I would use too. Use a zdepth element...invert and do as a screen layer over the top. Colorise and then adjust opacity to suit.

Could add noise to make it even more interesting !

[Smalerbi]

Thats the method I would use too. Use a zdepth element...invert and do as a screen layer over the top. Colorise and then adjust opacity to suit.

Zdepth was my first method, however, it did not provide the desired effect. To get any of the blue color to come into play, you need to have opacity cranked up and then you are dealing with to much haze. On clear cool winter days when the visibility is very good, there is very little atmospheric haze and you are left with the blue light effecting the distant objects.

Thanks,

Scott

[glorybound]

can you post a reference photo?

[crazy homeless guy]

Zdepth was my first method, however, it did not provide the desired effect. To get any of the blue color to come into play, you need to have opacity cranked up and then you are dealing with to much haze. On clear cool winter days when the visibility is very good, there is very little atmospheric haze and you are left with the blue light effecting the distant objects.

Thanks,

Scott

How did you use the Z-Depth? Did you try different methods of transfer and tinting?

[BBB3]

use the Zdepth pass as a mask to composite between two images: the normal render and one with a blue tint and lower contrast. Works fine over here.

[Smalerbi]

How did you use the Z-Depth? Did you try different methods of transfer and tinting?

I’m composting the Zdepth frames in Premiere CS4. The Z-frames are above the regular frames in the timeline and then I set the opacity to screen and then set the opacity % to my liking. I also added a tint filter to the Z-frames but the tinting would effect the entire image and not just the Zdepth so I can only assume I am doing something wrong.

Please see attached photo references. I realize there will always be some type of atmospheric haze, however, you can see how the blue light effects the distant objects.

BB…..Thanks for the information, however, for dummies like myself I would need a bit more information how the 3 elements would be layered in the timeline.

Thanks again.

[BBB3]

I don't use Premiere so I'm not entirely sure how but the following should work:
First load your image and the Zdepth pass into Premiere and put them into a new comp, the Zdepth at the bottom of the stack and not visible.
Then duplicate your render and colour-correct it so that it looks like you would want the background of your image to look (blueish tint, adjust levels by clipping the blacks so that the darker parts of the image appear washed out without the lighter parts getting darker, which would happen if you only lower the contrast).
Then (and that's when I'm not sure how you would do that in Premiere) tell Premiere to use the Zdepth pass at the bottom of the stack as a mask to mix between the two images. In effect, you would be telling AE to let the colour-corrected image appear only in the most distant parts of the landscape. You can then contrast-correct your Zdepth pass to make the image exactly look like you want (the Zdepth is linear whether a real atmospheric haze effect would be cumulative, so the pass will likely need a bit of correction).
The advantage of this method is that the blue tint only appears in the distant parts of the landscape.

[Smalerbi]

I don't use Premiere so I'm not entirely sure how but the following should work:
First load your image and the Zdepth pass into Premiere and put them into a new comp, the Zdepth at the bottom of the stack and not visible.
Then duplicate your render and colour-correct it so that it looks like you would want the background of your image to look (blueish tint, adjust levels by clipping the blacks so that the darker parts of the image appear washed out without the lighter parts getting darker, which would happen if you only lower the contrast).
Then (and that's when I'm not sure how you would do that in Premiere) tell Premiere to use the Zdepth pass at the bottom of the stack as a mask to mix between the two images. In effect, you would be telling AE to let the colour-corrected image appear only in the most distant parts of the landscape. You can then contrast-correct your Zdepth pass to make the image exactly look like you want (the Zdepth is linear whether a real atmospheric haze effect would be cumulative, so the pass will likely need a bit of correction).
The advantage of this method is that the blue tint only appears in the distant parts of the landscape.

Thanks…..I will give it a try. I do have AE CS4 so I guess it is about time I learn the software.

Thanks again.

Scott

[BBB3]

Sorry, I wrote AE when I meant Premiere.

But really, this should be working in any 2D app that can handle masks.