Low Light: HPX500, hvx200, DVX100 compared (HD vs SD) - question

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filmguy123

Veteran
Ok, so we know HD cameras just eat up a lot more light than their SD counterparts. So now, a 1/3in CCD does not deliver like it did back in the SD-days. I am wondering:

- what size CCD would bring HD cameras back into the SAME low-light quality as their SD counterparts? For example, the HVX200 is much worse in low light than the DVX100. If the HVX200 had 2/3in CCDs (basically, the HPX500), does this deliver the SAME performance as the DVX100... or better? If better, how much better?

- if you were to make a scale for low-light, how would a 2/3ccd HD camera like the hpx500 rank here?

HVX200 = 4
DVX100 = 7
HPX500 = ???


Basically, I want a camera with better low light when I can afford one, at least at the DVX-level, or better, and I am wondering what it will take. Also, do you think because of low-light, that in a few years prices will come down and 2/3in CCDs will become the standard for HD prosumer cameras?
 
This is a good question, but you can't forget a big issue:

Signal processing.

You can have a great low light sensor, but if the signal processing stinks, then its all for nothing. Many of these smaller cameras perform much better than you realize, but in the interest of selling bigger cameras, the manufacturers purposefully put the signal threw inferior processing. The DVX is a good example, it forces you to under expose the sensor because of the way its signal processing is designed. You can get a stronger exposure, but the DSP's processing blows it to bits. You can't really win!

Just something to keep in mind when discussing this.
 
cardmaverick said:
This is a good question, but you can't forget a big issue:

Signal processing.

You can have a great low light sensor, but if the signal processing stinks, then its all for nothing. Many of these smaller cameras perform much better than you realize, but in the interest of selling bigger cameras, the manufacturers purposefully put the signal threw inferior processing. The DVX is a good example, it forces you to under expose the sensor because of the way its signal processing is designed. You can get a stronger exposure, but the DSP's processing blows it to bits. You can't really win!

Just something to keep in mind when discussing this.
Click to expand...

This is where hydra comes in handy, that is, if they ever get it on the market!
 
For raw sensitivity, an HPX500 ranks a half stop faster than a DVX100 when the DVX is in progressive mode, and a half stop slower than the DVX when the DVX is in interlaced mode.
 
Another thing you need to consider is signal to noise ratios. Just plain old being really sensitive doesn't mean anything other than the sensors are really sensitive.

They could be crazy noisy.

You also have to consider the ADC's quality too. This is also overlooked in these types of discussions. You can have a stellar sensor with great sensitivity and a low noise floor, but if you're ADC's aren't very good, they can mess up the signal, introduce, noise, etc.... Also, not all cameras have ADC's that run at equal bit depths either.

I guess what I'm saying is that this is a very complex discussion, and we haven't even touched on formats and compression, which also play a big role. It can make your head spin..... and then theres that whole white balance/channel gain thing/camera's native color balance....... sheesh!
 
filmguy123 said:
So basically, it takes 2/3in CCDs to get an HD camera to roughly the same raw sensitivity as a 1/3in CCD SD camera?
Click to expand...
If you want to maintain the same level of sensitivty using the same sensor technology and processing, the size of the photo sites needs to remain constant, so if you are going from SD to HD, the overall sensor needs to be proportionally larger.
 
THoff said:
If you want to maintain the same level of sensitivty using the same sensor technology and processing, the size of the photo sites needs to remain constant, so if you are going from SD to HD, the overall sensor needs to be proportionally larger.
Click to expand...

Ok, so w/same sensor/processing, and going from SD to HD, what is "proportionally larger"? Would 2/3in CCDs be the basic equivalency then (assuming same sensor/processing) to achieve the same low-light results in HD as one did previously on an SD camera?
 
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