Lewis Saunders, thx as always. Your insight is always much appreciated. The lentil.xyz plugin looks like a great solve for me in Houdini fir near term.
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We had a very long discussion about DOF here… Physical Defocus
I can recommend frischluft.com - Lenscare Description …well worth the money and the only way to really get DOF correct for 3d rendered assests with a z-depth matte.
Have a good read through the link on the forum, I think I went through everything. I used the LensCare matchbox on the robot job and it did an excellent job.
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For those interested in DoF as related to sensor size,
I found these PDFs from Panavision really helpful to understand what’s going on.
They also have a video series called Panalab. The Five Pillars of Anamorphic are worth a watch.
Another site to check out is yedlin.net
Steve Yedlin has posted a bunch of interesting research there that bridges the VFX and camera worlds.
Cheers-
Andy D.
Panavision PRIMO 70 The Look.pdf (1.9 MB)
Panavision Sensor Size FOV.pdf (1.6 MB)
Panavision Sensor size Perspective.pdf (871.8 KB)
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Revisiting this post. Tried all the different DOF nodes I could find except Frischluft. Checked out @imag4media ’s web pages too (many thanks)
The thing I’m missing is something easy. My experience with depth of field is a single lens reflex camera. It would be lush if the physical defocus had field of view and lens size ganged together. Surely the one is dictated by the other and the ratio is the neg size. I don’t know, it all just seems to be overly complex.
I want some things blurry. Some things not. Choose how harsh to feather in between and gain up or down.
If you got a zDepth (either from CG or Action) then what you want is Physical Defocus node.
Check out the docs on it. It’s really versatile and pretty quick.
World Scale is the one I change to taste.
Look at slices to see falloff.
I usually use it using FoV that I’ve generated from the cam data:
degrees(2 * atan(sensorHoriz/(2 * focalLength)))/lensSqueeze
Plug in your own values for sensorHoriz, focalLength and lensSqueeze.
I plug these into the appropriate fields w expression link in Physical Defocus. (Sometimes also Physical Glare, Lens Flares and Action can source the same data)
Hope that helps.
A
Physical defocus was definitely getting some nice results. It was annoying that FOV and lens size were two values. Maybe I needed more slices. World view I couldnt wrap my head around.
It made me yearn for my Olympus OM 1.
When you say docs: you mean the online manual in flame help?
To get FoV from action, you can make sure using Cam3D and make sure the filmBack is correct for the sensor that you are matching. Then if you put in the focalLength on that camera, it’ll output the FoV. FoV is a linkable channel, but focalLength isn’t. Or just use the wonky expression to give you that same data.
Docs: online manual or the helpful vids on flame learning
FORGOT to mention:
Action FilmBack is measured in inches which is annoying.
That’s why I use my wonky expression.
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