My XL1s ISO's
 

I was so curios about using a light meter with my adorable XL1s, so I searched the web but I couldn't find anyone tested his XL1s in the way to obtain an ISO measurement. I found many articles (even on the precious Watchdog XL1s) but no one tells the main thing: a value of comparable ISO on the XL1s. So yesterday I took my Sekonic 358, one Kino Flo Diva 400 (5500K), one Kodak gray card 18%, my beautiful XL1s with 16x manual lens, and made the test. Simply I set the camera on shutter-priority (Tv) of 1/50 (I'm in PAL), 0 GAIN dB, and read the corrispondent aperture value (in my case was f1.6) in front of the gray card; then I put the light meter in front of the gray card to read the INCIDENT light with shutter priority of 1/50. I regulated the light meter ISO's until I found the equivalent aperture value of the XL1s (f1.6). The result? Same values of camera and light meter at ISO 320. That's it. Anyone did the test before? Opinions?

Yes, I did the same type of test and came up with 320.

However, there seems to be some controversy about this subject.

An older thread on this subject is titled: Equivalent ISO for Canon XL1S.

Yes Dan you're right, there are many existing threads treating ISO's theme. I was a bit euphoric to post my "discoverings"...
I think the most important thing is to obtain a reasonable ISO value in order to get light values to compare in the set place. Obvious: I will never open camera's iris following just what the light meter says... I will even put an eye on zebras and to my Sony PVM 9L2...
Anyway: thanks for your reply Dan, bye from Italy...

I've also obtained equivalent ISO speed reading on the order of 320 for the XL1 (at 0 db gain) using a standard gray card. However, given that the photometric curves for a CCD are different than film ...

Of course the video camera is really a light meter, sampling a ~720x480 (NTSC) matrix of the scene and capable of displaying the reading for each sample point (pixel) it on a display (the monitor) so you can adjust for proper exposure optimizing for the highlights and/or shadow details of interest in roughly realtime.