HVX200 Sensitivity?

D

Drew Harty

Member
Hello,

Does anyone know what the sensitivity of the HVX is? And is that sensitivity for DV, HD progressive or interlaced or are they all the same? I am trying to get a fix on what the exposure factor will be going from a 60i SD camera with a F/11 @ 2000 Lux standard sensitivity to the HVX shooting 720 30p.

Also, can you transfer footage directly from a P2 Store to a stand alone hard drive?

Thanks,

Drew Harty
 
Drew Harty said:
Hello,

Does anyone know what the sensitivity of the HVX is? And is that sensitivity for DV, HD progressive or interlaced or are they all the same? I am trying to get a fix on what the exposure factor will be going from a 60i SD camera with a F/11 @ 2000 Lux standard sensitivity to the HVX shooting 720 30p.

Also, can you transfer footage directly from a P2 Store to a stand alone <a style='text-decoration: none; border-bottom: 3px double;' href="http://www.serverlogic3.com/lm/rtl3.asp?si=24&k=hard%20drive" onmouseover="window.status='hard drive'; return true;" onmouseout="window.status=''; return true;">hard drive</a>?

Thanks,

Drew Harty
Click to expand...

I believe the HVX is a full two stops darker than the dvx100.
 
Yes, it's less sensitive that the DVX, and from my limited experience (9 days), this changes slighty when you swith modes (or, is there something wrong with my camera?). I'm not sure exactly what the sensitivity is, but two full stops seems a little off --- maybe a stop (or stop and-a-half?).
 
I was shooting in a dark bar today and needed a bunch of light shooting WFO and still had to drop the shutter down to 1/24.
 
Acordinng to all the group tests the HVX has an equivelent exposure index of 320 ISO. That is the same sensitivity as the F900. The DVX is about 500-640. One stop more sensitive.
 
The DVX has been a full two stops faster in my testing as well. You definitely need ample light to feed the HVX! :)
 
Hvx has only 25% smaller pixels than dvx, so it should be only half a stop slower, if it would use the same quality ccd's than dvx. There also should be some advancement in ccd technology over the years...
 
HVX = 518,400 active pixels per frame. DVX = 345,600 active pixels per frame. HVX CCD is 16:9-shaped, and it's not necessarily identical in surface area to the DVX. HVX CCD is the same size as the Canon and maybe a hair smaller than the Sony, and the JVC 1/3" CCD is smaller than all of them, so 1/3" CCD sizes (especially in 16:9) are far from standardized and equivalent.

So DVX has 2/3 as many pixels, but if the chip is a bit smaller, it would probably mean HVX pixel size is half the size of a DVX pixel. Which means, generally, 1 stop slower.

And that's what we're finding in practice: 1 stop slower, when comparing progressive to progressive.

In interlaced the DVX is another stop faster because it gains sensitivity due to row-pair summation when interlace scanning. The HVX doesn't do that; it's all-progressive all the time. So it can't benefit from row-pair summation.

I think the numbers add up.
 
Barry, last time you told that hvx has 550k and dvx 410k pixels. Active size does not matter. Both has 1/3" chips, so their chips diameter should be 6mm.

If these cameras are really not 1/3" cameras, that's very new to me and I'd like to hear some more about it.

Dvx: 4800x3600/410000=42 (sq-micrometers per pixel)
Hvx: 5200x3000/550000=28

14/42=33% (=2/3 f-stop)

Ok, I miscalculated before.

But the important point still is that hvx's ccds are less sensitive _per area_ than hvx!
I think this is really significant. I can think of two reasons: technical research in ccd tehcnology has stopped in a way that sensitivity does not get any higher anymore or camera panasonic has used some cheaper older generation chips, which are even less sensitive than couple of years old dvx chips.
 
toke lahti said:
Barry, last time you told that hvx has 550k and dvx 410k pixels. Active size does not matter. Both has 1/3" chips, so their chips diameter should be 6mm.

If these cameras are really not 1/3" cameras, that's very new to me and I'd like to hear some more about it.

Dvx: 4800x3600/410000=42 (sq-micrometers per pixel)
Hvx: 5200x3000/550000=28

14/42=33% (=2/3 f-stop)

Ok, I miscalculated before.

But the important point still is that hvx's ccds are less sensitive _per area_ than hvx!
I think this is really significant. I can think of two reasons: technical research in ccd tehcnology has stopped in a way that sensitivity does not get any higher anymore or camera panasonic has used some cheaper older generation chips, which are even less sensitive than couple of years old dvx chips.
Click to expand...


Who cares. Go make a movie. That's what matters.
 
pretopost said:
Who cares. Go make a movie. That's what matters.
Click to expand...
Thanks, I better hurry.
If ccd sensivity halves every couple of years, I can't afford to make any movies in the next decade...

Seriously speaking, I think hvx200 is the first camera ever by any manufacturer that has less sensitivity by pixel area than models before.
Maybe it makes very easy to bring new enhanced hvx200a to the market very soon...
 
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