HPX500 vs. HDX900

With 4:2:2 there would be a loss of color resolution but not a loss of luminance resolution, correct? So therefore, if only one chip receives light the luminance resolution will be standard definition too.

This might be helpful here:

Color resolution is measured in "lines of resolution" over a given distance span just as is regular resolution (luminance resolution) where each "line of resolution" equals one color change.

Changes between a light and a dark shade of the same color are luminance changes and are not affected by limitations in the color resolution.

http://members.aol.com/ajaynejr/vidcolor.htm
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Aah yes, this I think must be the point of confusion.

Luminance is simply the luminance of each color - all luminance is of one or more colors.

Notice that there is no "Luminance" sensor, just a sensor for (the luminance of) each color.

RGB video is simply the lumiance of R, G and B - there's no seperate luminance channel.
Then when you convert it to Y, Cb, Cr, (Component video) for recording, then you have Y - which is simply the sum of all the colors (but still dependant on them) and then CB and Cr which are just calculated signals to show "color difference" - It's just a different way of storing the data, but it's stil the same data.


Also keep in mind that the lack of blue and green on a red subject, doesn't mean that the resolution isn't there, it just means that it's value is "0", and thefore black - it's dark, but it doesn't mean it's not there!

- Mikko
 
But if you are recording a deeply saturated red object, how do you get 1920x1080 resolution if two of three sensors are not receiving any light at all? You don't. And so in practical terms unless all three chips are being used to their fullest you are not getting true 1920x1080 resolution.
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If you want to get pedantic, then yes -- if you imaged an object that was exactly the exact same identical hue of red or green or blue as the Beyer filter separates it out, or the prism splits the light into, then yes you'd get the resolution of the one sensor (or of the pixels in the Beyer pattern).

What are the odds of shooting that exact wavelength of light? Pretty slim.

In practical terms, there's always some crossover. Always -- or at least 99.99999999999999999999999% of the time. And when that crossover happens, it'll be detected by the other chips, and voila - the full imaging block is used.

Video isn't recorded in RGB anyway, every pixel undergoes a YUV conversion, where each individual pixel gets 60% of its signal from green, around 29% from red, and around 11% from blue (or thereabouts).

As Mikko demonstrated, a "true" 1920x1080 single-chip design isn't "true 1920x1080" for any color channel. It's 960x540 for red and 960x540 for blue.

So that's all meaningless. Just look at the images. The XHA1 is about the same speed (not more sensitive) and about the same noise level (just different texture to the noise) as the HVX is. But it has to use interlaced chips to get there. You get more pixels (but not any noticeable sharpness increase, and a different noise texture). You can't do true variable frame rates with it, because it's coming from an interlaced chipset. The HVX allows true variable frame rates because it's a progressive chipset, but because it's progressive they had to employ larger pixels to get comparable sensitivity and noise performance.

(BTW, nothing wrong with being pedantic, I get that way all the time. But there's a difference between observing what's theoretically possible to happen, and acknowledging what actually happens. I'll acknowledge that in most circumstances long-GOP works just fine -- but there are certainly some circumstances where it utterly fails. And I'll acknowledge that in the extremely vast majority of cases pixel shift works great, but there is a rare exception of shooting under pure single-color conditions where it won't work).
 
There could be crossover 99% of the time but if it happens in certain areas of the frame and or in varying degrees of exposure your resolution will still be somewhat compromised, right?

Why is it that when I film someone wearing a red shirt the shirt is pixelated? Is this 4:2:2's fault or pixel shift?
 
marco0782 said:
There could be crossover 99% of the time but if it happens in certain areas of the frame and or in varying degrees of exposure your resolution will still be somewhat compromised, right?
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Only on those elements where it's that single pure color.

Why is it that when I film someone wearing a red shirt the shirt is pixelated? Is this 4:2:2's fault or pixel shift?
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Most likely 4:2:2. It's really noticeable on 4:1:1 or 4:2:0.
 
Hi,

The diference in image betwen hpx and hdx are:
dynamic range HPX 8.5 stops / HDX 10 stops
less noise in HPX
special gamma curve four night shooting in HPX, but HDX have a much more natural tones
HPX more sensitivity 1stop

HDX have the varicam CCD and less quality optical block
More control, beter DSP, less artifacting from pixelshift to go 1080 from a 720 ccd compared of HPX senzor. The crhomatic aberacion in HDX it four some low cost lens. not work in the big glases no need, ans so on.

I attach 2 test frames, first one a comparacion "out of box" and my one cinelike 2 setup, at the end some CC. Second one with difrent cinelike2 setup. no CC.
Canon HDCg series lens. The first image have a big mjpeg compresion.

Gabriel Bordas
 

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Thanks Gabriel--

Finally someone getting the discussion back on topic. :)

A couple questions for you:

Which camera are those pictures from?

And where are you getting those stats (like the dynamic range comparison)? Is that something that someone else published somewhere? Or is that from your own experience with the two cameras?

It looks like I'll be using the 900 for a project next week (that I was originally asking about). But in general I'm very interested in the 500, b/c of P2, b/c of cost, and b/c of low-light, which I tend to do a lot of (night-time cityscape stuff).

Thanks,
Kevin
 
I am cutting a trailer for a feature that was shot with a Varicam with ziess glass and I just picked up an hpx500 with a fuji 17x lens today! After staring at varicam footage for the past 2 weeks and looking at a few quick rolls from the hpx500 today, I am blown away with the quality of the HPX500! I can tell you that the Varicam does have more dynamic range (in the highlights especially). The highlights in the varicam (and surely the HDX900) seem to roll off to white nicely. With that said, The HPX500 still has great useable dynamic range and is on par in terms of sharpness (the hpx500 might be sharper).

The funny thing with us film/video/data/resolution/pixel freaks is that we forget why and who we are actually making content for. I have made up my mind, that it does not matter if you shoot with an hpx500,f950,varicam,hdx900, ect. Your client or audience (narratively speaking) will not notice any difference. (for 95% of your productions, it might be different if your work is on a 100 foot screen) But what they will notice is "my production crew shot with a big HD camera" You guys know how silly it is.

The problem is in the producers and cast/crew/investors (even me). is that We make choices based on politics and marketing. The Hpx500 is not marketed as a flagship camera for panasonic. Thats the Varicam's job (and soon to be the HPX3000's) But anyone with their head screwed on can see that the difference in between the varicam (40k for the body alone) and the HPX500 (20k for a kit with 4cards, evf and lens), is not a 20-40k difference in aquisition quality.

You pay a lot for that V.

Well, This turned into a rant and I am sorry.

Bottom line:

Shoot with what ever you can, focus on lighting and composition more than datarates and pixels.
 
HPX vs HDX

HPX vs HDX

skillimon said:
Trying to sort out a new camera purchase.
Setting aside all the issues related to P2 vs. tape, how do these two cameras stack up,camera to camera? Picture quality, low-light capability, easy of use. Any experiences or comments helpful.
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I use both cameras and own an HPX. There is no question that the HPX is a little noisier and softer then an HDX. You get what you pay for. The HDX is also better in low light, it's rated F11@2000 lux and the HPX is rated f10 but I think the HDX is better then F11. That being said I love my HPX because of its ability to shoot DV,DVCPRO, DVCPRO50 and DVCPROHD and variable frame rates, wow. You CAN overcrank (slow mo) an HDX by shooting 60P or 30P and applying software that panny provides called 'variable frame rate converter'. It looks great but you can only do 24P, 30P, and 60P, no undercranking and its time consuming. With an HPX you can playback in camera and see the effect instantly. The HPX sure is a bang for your buck with it recording versitality, 2/3" chip and mount, variable frame rates, pre-record function (HDX also has) and interval recording (for timelapse) which I love. I am happy with the HPX and look forward to upgrading to a 2000 or 3000 some day. Don't think I will go back to tape.

Mike Brand
mbrand@lafayettehillstudios.com
 
It's the little things that make a difference for me. I haven't been on the 900, but I have been on many many tape based cameras over the last 10 years and the biggest unexpected thing is the simple joy of hitting the little red button and instantly recording with no roll-up. That is just so insanely awesome especially in the type of work I do.
 
Mbrand--

HDX900 lower noise/more sensitive? Did you get that the right way? That's backwards from what others are saying (and intuitively backwards given the higher pixel density on the 900).

I really wish Panasonic would make a better effort to explain their product lines, making conversations like this pointless. They have a product range that spans $45K, and a "compare" feature on their site that is entirely worthless.

-Kevin
 
I yelled at both cameras for about 10 mintues after a shoot last week and the -500 burst into tears... it's definatly more sensitive.


- Mikko
 
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