Depth Pass PS lens blur question

[mattjgerard]

OK, I've posted about my love of the depth pass, and now I'm having an issue that I can't pinpoint. See the attached pic, the left is with the focus point on the silver quick disconnect connector in the back. See the green area where the red arrow is pointing, that is a nice blur, the blur bleeds and expands outwards. On the middle pic, the focus point is the light itself, and the blur on the QD connector isn't expanding outwards, its cropping at the edge of the transparency.

In this image, the white is a background layer, and the objects are cut out using the render with transparency option in KS. I've also tried this by merging the white background with the objects so the lens blur is applied to a flattened image, but I get the same results. So I think its and issue with the depth pass layer.

The only thing goofy is that in KS, I had to set my F-stop to 80 to get a reasonable dof, but I'm not sure if that setting affects the depth pass at all. i don't think it does, but it might speak to why the depth pass isn't' working for some reason.

Also, instead of using my PS action that I made last week, and that Richard so politely informed me that it was outdated already I use the HDR toning function in PS, and I get the same result as my old method. So, its not how the exr is being processed.

I'm out of troubleshooting steps at this point!

[richardfunnell]

Make sure that you never have objects free-floating in space. You want to either add a ground plane, or maybe for that angle a ground ramp so that your entire view is taken up by geometry. When there's only free-floating geometry you'll get problems since your solid background color creates areas of intense contrast that the Lens Blur does not handle well.

Sorry for terrorizing your posts!

[mattjgerard]

Terrorize away, good sir! I am learning more and more on these forums. I learn more by interacting and talking to people, which is why I was so envious of my co-worker getting the green light to head to RenderWorld this year. Being the new guy on staff doens't put me at the head of the line for that stuff But if there is anything local, I get to go to that.

Thanks for the tip, I will go try that now and report back. It makes sense, and I'll play around with it as well.

On another note, I was looking at the LensCare PS blur filter from Frischluft (spelling?) do you know if  that plugin can use a depth map? Their filters are legendary in the video world, and it looks a mite better than the PS lens blur.

Thanks Richard!

[mattjgerard]

After some playing around, I did get this to behave properly by using a ground plane as you suggested. i had to fight a little with ground shadows, as I didn't want any, but could not get rid of them unless I dropped the ground plane all the way down, but then I lost the geometry for the background, and thusly defeated the purpose of the whole deal.

So, I dropped the ground plane a little, rendered with with the ground plane on a different render layer, and removed the ground shadows in post using the cutout of the ground plane render layer as a mask for the main objects. That got me my "floating on white" look that I need, then I applied the new depth pass which had a nice looking gradient on for the background, as the ground plane should and the blur on the connectors bled over beautifully. So, you are correct in stating that the lens blur effect doesn't play well with high contrast areas of the depth pass, and even might improve its effect a bit with some simple matte painting work in PS if things aren't looking right.

Thanks richard, this is a great community, and I really appreciate your help!

Matt