Physical defocus offsets slices in random directions


Does anybody else notice that physical defocus offsets the slices in various random directions?

It’s quite annoying in a shot with static focus, but makes it completely unusable in any shot with any kind of change in focus depth - which in my experience is every shot.

I’d like to know if this is a problem everyone is having or if there’s a solve that I’m overlooking.

Flame feedback request here to upvote if you have this issue: FI-03200


As much as I want to like most things in Flame, that node is trash. It softens everything, even the focal plane and has confusing controls. Maybe changing the slicing mode from “auto defocus” to “static” changes things, but in my brief refresher I am geting awful results with both as an object moves through the focal plane.

Rant aside, if you (or anyone else reading this) has ever gotten good results out of it, please tell me how. I would like to like it if I can.

Yes. You absolutely have to change from auto defocus to static. Unless you’re comping a still then resampling the z slicing on every single frame will never give a good result. If you could use auto defocus to sample the slicing and then lock it, that would make that feature usable. Same as with the depth position icon. It would be great if you could use that to sample a depth and not have to have a point to sample on every single frame.


  1. The way Physical Defocus handles the layering of things (i.e not blurring background objects in front of foreground objects) functions better than in all the other depth blur options (3Dblur, DepthofFeild, S_ZDefocus).

  2. The lens kernel also seems to function better than in other nodes.

  3. The Focus model “Physical” is great as inputting Focal length in mm and F-stop is a great starting point if you have that information from the shoot.

  4. The “Custom” Focus model is also great as allows separate control over FG defocus and BG defocus.


No, I’ve never got a good result that I’ve used on a job because of the issues with it. The one this post is about. And yes, also the one you’ve mentioned (soft focus plane).

So close to being great but unfortunately totally unusable.

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