Welcome to Fractal Forums

Hey,

I was playing around with DE Raytracer and original quaternion Julia.
Latest build of package from 3Dickulus, no modified code, everything as is out of the box.

I noticed 2 strange behaviours:

1) It looks like the focal plane is not actually perpendicular to the camera optical path (and the screen rendering).
It's clearly visible on this image:
http://labs.kizny.com/image/120362591875
(http://40.media.tumblr.com/b46d56beea6cfcbc57f2d28ac67e0e5f/tumblr_np84a8Q4iA1r9pq3fo1_1280.jpg)

Sort of weird. Any ideas?

2) Artifacts on the rendered image
Across most of the rendered images I see some sort of artifacts highlighted on the image.
It is persistent across a series of frames and the areas slightly move over time across the image.

(https://photos-1.dropbox.com/t/2/AADAUA-rozI8J9w-rmi-PpAGErsvEeTfd9zXTWRDYb_BDA/12/35017997/jpeg/32x32/1/_/1/2/Julia_Quat_201505331.00349.jpg/CI2q2RAgASACIAMgBCAFIAYgBygBKAIoBw/I1ayastBaRhr8SAjvRFPp20guvFV9z-pOJTqOaTVGrQ?size=2048x1536&size_mode=2)

Any ideas on the reason for it?

Not sure about the DOF. I tried to render a couple of tests (attached) in legacy Fragmentarium, and they looked as I would expect. On your image the orientation is not clear to me, so I can not really tell if it looks wrong.

Many kinds of artifacts may arise. Try adjusting the Dither (perhaps even disabling it) or setting the FudgeFactor to something less than 1. Banding issues also appear routinely. Artifacts can also be caused by specular highlights. Some fractals may also exhibit NaN-values at certain settings (which always result in non-antialiased black pixels).

it looks ok to me for a focal plane that is very thin and an aperture that is large, the math for this is (ciiw) all in the shader.
try making Aperture a bit smaller and InFocusWidth a bit bigger.
do an animation where the object rotates or the camera floats around it and observe the look of the focal plane, when in motion it will be very apparent and may lend a clue if there is something wrong.