Test Renders - Camera Calibration Settings

[tommyboy]

As suggested by others on these awesome forums, we have been working on Maya-based renders to test camera positions and coverage, lens lengths, and use of noise projection.  There are two aspects that are unclear though, regarding camera calibration:

1) What is the pixel size for these renders, since there is no real sensor?

2) Because Maya's renders are 'perfect', there is no lens distortion to undistort, and the diminishing effects of wider lenses like 24mm cannot be accurately simulated.  Does anyone have a Photoshop or Nuke script that can recreate the lens distortion using the same Brownian model that PS uses to remove it?

Any other tips for making accurate simulations?

Thanks!

[Marcel]

You can run the Lens Correction filter with manual settings, which will allow you to introduce any level of lens distortion you want.

Adding chromatic abberation is not possible with the latest Lens Correction filter, because it uses a method that only corrects based on the actual abberation that is present. The older versions of Photoshop Camera RAW import had a simpler correction method that would 'shift' channels. With this version you could overcorrect (and introduce more abberation). Not sure if that version also had a Filter version of that correction module.

Please keep us updated on your research, we are very interested in your findings.

[Wishgranter]

Hi as i remember V-Ray introduced lens distortion and other lens stuff that mean you can do back all the "problem" of real world lens http://help.chaosgroup.com/vray/help/150SP1/vrayphysicalcamera_params.htm

http://help.chaosgroup.com/vray/help/maya/150R1/camera_extr_attrib.htm 

thsi is for the older version but just search for the new release.......

[tommyboy]

Thanks, we are just using the Maya software render as we have a copy lying around already, no VRay (yet).  Will give Lens Correction a try in Photoshop.

Any ideas on the pixel size?  PS seems to be doing a pretty good job by just supplying the lens length, although sometimes it has greater success than others.  For example it calculates the cx,cy as being quite right of center, while other times not, is that a problem?