How do I properly set up white shading, black shading and flare on a ENG Sony Camera?

Mike Krumlauf

Mike Krumlauf

Award Winning Filmmaker
What tools and steps can I take to properly align my lens to my sensor so i know they are all talking to each other correctly to minimize any artifacts or Chromatic A. in the image.
 
I think it's a pretty involved process to set-up a lens profile, properly. I have seen the basic process written out.

Roger Macie may have created a lens file for one of my lenses for my old D50WS Betacam, back in the day and he did a lens profile for one of my W/A's on one of my VariCam's. I can't say that I really noticed a difference, though. But kinda depends on the glass...
 
Mike Krumlauf said:
What tools and steps can I take to properly align my lens to my sensor so i know they are all talking to each other correctly to minimize any artifacts or Chromatic A. in the image.
Click to expand...

It's a pretty involved process. A bit of a big topic for the confines of a single post. It's not difficult if you know what you are doing, like most things I guess. Have a look at the following couple of videos if you need some pointers. Especially the first video for white shading and flares. These adjustments though won't have any affect on CA as that is not an electronic phenomena. CA is an optical artifact, the product of lens design and refraction and has a fair bit to do with how a particular lens responds to a particular sensor. That's why ALAC and CAC circuits were introduced to Sony and Panasonic cameras to work in conjunction with the CA aberration files stored in the lens file bank in each lens.

ENG Essentials -- White Shading & White Offsets
https://www.youtube.com/watch?v=Mi0BBVqmUgs

The second one is also useful to understand the gamma adjustments of a camera.

Gamma Matching
https://www.youtube.com/watch?v=VFKquFICHz4

I've used these video in training years back and they seemed to help students understand what the processes involved were. They are a few years old but still very current in their application.

Basically black level adjustments and offsets are done the same way as the whites in the first video but with a capped lens. You adjust the RGB Black levels for minimum RGB carrier levels. In laymans terms as fine and thin a line as possible on each of the RGB black levels. To do all this you will need a good WFM and vector scope. You don't need to have the "white sphere" as described in the first video but you will need a very evenly lit white surface., I used to use large art cards used for painting. Taped or pinned to a wall or cork board or similar. I know some people who have used large clean whiteboards. Light really evenly with a couple of soft boxes if possible. I then used to run an exposure meter across the cards top to bottom and then left to right and adjust the lighting so that I had the evenest spread of light across the art card that I could get. You will also obviously need a "chip chart" as seen in the video to see the correct waveform patterns on the WFM. If you can hire one of the Tektronics Diamond displays it will make your adjustment life much easier. It goes without saying it is pretty essential to have the service manual for your camera to hand if you don't know which pots to adjust.

Camera Set Up with the Tektronix Diamond Display
https://www.youtube.com/watch?v=ynrkjFkcfg0

Edit:
Showing my age! When I say 'pots to adjust.' I mean if you can't pull signals into shape via the menus you may have to go back adjusting the analogue RGB pots on the camera boards. Trust that isn't needed.

Happy tweaking!

Chris Young
 
Last edited:
You must log in or register to reply here.
Back
Top