hvx ccd dimensions

nvsurly

nvsurly

Member
Hey there everyone,

So I've been poking around for awhile looking for this and I've only found info on the dvx as far as ccd size is concerned. It seems to be common agreement that Panasonic is reluctant to release this info (not sure exactly why) but I was wondering if anyone knew the exact "used" diagonal or width/height dimensions on the hvx ccds. By "used" I mean the area of the sensor that's actually used to capture the image during acquisition. At some point Barry Green posted the dvx "used" area as being something around 6mm, when of course a 1/3" ccd if used entirely would measure approximately 8.46667mm diagonally.

Any ideas? I am trying to use these to determine an accurate film back (horizontal and vertical film aperture) in Maya. We have a shoot coming up when we will be using the HVX to shoot elements to integrate with our 35mm background plates.

Can someone point me in the right direction if this has already been discussed at length?

Thanks guys!

-n
 
No 1/3" CCD actually measures 1/3" in any dimension. And no 1/2" CCD is actually 1/2", and no 2/3" CCD is anywhere close to 2/3" in size. I don't know the actual measurements on any of the 1/3" cameras' CCDs, but I can tell you that they all vary; it seems like the FX1's is a hair bigger than the HVX and XLH1, while the JVC HD100 is a tad smaller than either of them, but this can only be really judged by setting them to the same focal length and comparing their respective fields of view.

(and that presupposes that the focal length markings were accurate as well)...
 
Thanks Barry. I don't, unfortunately, have the luxury of (or budget for) comparing different cameras on site... I'll see if I can figure something else out.
 
Having the exact CCD dimensions will not help anyway, as the HVX offsets the trio to up the resolution. So you'd need to know by how much they are offset (and in which axis), then add the diagonal of the offset to that of the CCD diagonal. Sorry to offer more bad news. I'd have thought the best thing to do is to shoot a test target and make measurements from that - as that will automatically correct for format dimensions too. But remember that field of view - effective focal length - varies with focused distance too; focal length is by definition calibrated wtih focus at infinity.

Incidentally the reason why, e.g., so-called 1/2" chips aren't 1/2" in diagonal measure is because of hangover from the days of vidicon tubes, whose active area was at best two-thirds that of the physical diameter.
 
Right, which is why manufacturers will usually refer to a 1/2" CCD as a "1/2' TYPE" CCD, meaning it's of the type of 1/2", but not the actual SIZE of 1/2".

The offset is of no concern though; it's only 1/2 of one pixel offset, so you're talking about 2 microns or so. Nothing to worry about.

I tried to calculate the HVX chip size once, I think I came out with 5.24 x 2.95mm, but I can't tell you what that's based on or if it's even remotely accurate. But it might be as good a place as anywhere else to start.
 
Barry-
How did you calculate those intermediate lens equivalents on page 186 of your HVX book? Did you do it manually per your suggestion above, using both cameras to capture and compare the image? The results don't seem to be proportionally the same. Am I looking at this wrong?

Further, how did you deal different aspect ratios of both devices (1.77778 vs 1.5). Did you end up converting both to 16:9 or is that not necessary? Can you give me any info on your process?
 
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