Eclair Cameras: AZ Spectrum video assist, preliminary

[Wade Ramsey <wramsey@bju.edu>]

I finally did a bit of checking on the AZ Spectrum color video assist just installed on our ACL-1.  These are just some preliminary observations, we haven't actually used it under fire.  

First, it has a 3 position switch for exposure control: (1.) AGC On, Iris Off; (2.) AGC On, CCD Iris On; (3.) AGC Off, CCD Iris Off.  The first two seem to be identical in operation.  Switching between them makes no visible difference in any lighting situation I tried it in (sunny exterior, lighted interior ranging from 20fc to 80fc.)  With either of these settings the video image was   too hot until the camera started running, which reduced the exposure, making it usable.  The image was nicely visible, but color info was lacking due to too much exposure.  In the Off position, the color was nicely saturated, but the video image was dependent upon the lens setting.  If exposing for EI 500 film the monitor needed to be brightened up;  if exposing for 200 or 100 it was nearer normal.  

So for fast films the AGC will probably need to be on to be sure there is a fully visible video image.  For slower films, turn it off for better color.  At least this is what appears to be necessary.  As I said, we haven't used it in production in varying lighting conditions yet.

With wide lenses the image was strongly vignetted, due to too much transparency of the finder screen, as I noted in my previous message.  Bernie is going to fix this, now that he has an improved system.  The video assist system, of course, is not responsible for this, it is a function of the finder screen.  The beamsplitter in the video assist is 50/50, which darkens the finder significantly, making a bright screen a necessity.  

BTW, eric, in case you aren't aware of it, a video assist reads the finder screen, so you also have the cross hair and other reticle markings (frame line, TV safe action) on your video image.  It also records any groundglass texture that is visible on your screen.  The AZ Spectrum unit is not flicker free, so you get a strong flicker when the camera is running.  This is not really a problem for the purpose for which video assist is intended, but is another aspect that I think would be undesirable for off-line editing of the image, as you mentioned.





Wade K. Ramsey, DP
Dept. of Cinema & Video Production
Bob Jones University
Greenville, SC 29614

--^----------------------------------------------------------------
This email was sent to: elroro@propagandaindustries.org

EASY UNSUBSCRIBE click here: http://topica.com/u/?a84xYK.bdbHPA.ZWxyb3Jv
Or send an email to: eclairacl-unsubscribe@topica.com

TOPICA - Start your own email discussion group. FREE!
http://www.topica.com/partner/tag02/create/index2.html
--^----------------------------------------------------------------