What's the skinny on the "non-HVX" codecs?

S

StingrayPictures

Member
Okay, so I'm pricing out the 200a today when sales dude starts talking about how much his buddy loves his new Sony XDCam EX1 (I know sales dude, and he is a Panasonic fan all the way)...naturally I give the camera a look-see. I'm all about the HVX, but I want to know what is lost in the compression when compared to DVCPro HD. It's pretty tempting to want to have 3 times more record time on the cards, and to be honest have never come across (nor can find) any info regarding how networks deal with the Sony codecs (For instance, how Discovery HD still classifies HVX footage into their HDV criteria --- is this Sony codec not much better than HDV?). Also, it felt and looked like a pretty sweet camera, loved the functions, the 1080p --- but what does this recording format equate to in Panasonic language? Is it "true" HD? (aka is it broadcast quality?) Sorry if this sounds elementary, I just kinda lost interest in Sony when, well, the HVX came out! Anyone wanting to talk me into the 200a please start ranting now...I always have suspicions with Sony, but the camera seems pretty sweet...
 
The sony uses a Long GOP (group of pictures) which is why it's compression rate allows for longer recording. Instead of individual frames that are independent of each other, like in DvcPro HD (AKA HVX200/200a), the ex1's frames rely on each other and are not independent.

A good example to see this compression and long GOP is to compare shots with say the hvx and the ex1. On still shots (no camera movement) the ex1 is going to look gorgeous as I'm sure the hvx will too. But if you were to have any medium to fast camera movement the difference between codecs will be easier to see. If you were following a football player as he runs down the feild each frame of the hvx would be, given a high shutter speed, very clear and detailed. But do the same with the ex1 and the subject looks pretty good but the background has lost a great deal of resolution and may even have artifacts and macro-blocking. This is because of the codecs. the ex1 has to base each of its frames off of a "i" which is created, I think, every 15 frames. Whereas the HVX is "i" frames every frame.

To answer your broadcast questions. Usually bigger companies like discovery only allow between 10% and 20% of a show be shot in HDV (or HVX but there is more to that). But the HVX is not HDV it is DVCPro HD, a professional codec, but still they feel that it is an inferior camera that can't produce the images they are looking for. This is wrong in my opinion. Yes the image quality with more expensive cameras is better, but if you know what you are doing behind the camera and in post then they may never notice the difference. I think there was someone on dvxuser that once said he had produced an entire show for a broadcast company on the HVX. This company did not accept HDV or HVX footage and when they saw the program they said something to the effect of "This is the kind of quality we are looking for! Not something shot with a cheap DVCPro wannabe." That second line may be a little exaggerated but you get my point.

In short the HVX is broadcast quality and is a 1080p camera. The 200a from what I hear has some great improvements over the 200, like a better more light sensitive imager which reduces noise and has better res.

Sorry for the long answers and anecdotes but I hope you found some answers in them.
 
Appreciate the info, especially on the long GOP...does HDV not use pretty much the same type of compression? I've stayed faaaar away from HDV as I am already aware of the interpolating or whatever it does between every 15th frame or whichever...also I had missed it initially but found the thread that Barry Green had posted regarding his test on the EX1 --- after I posted my question...the whole rolling shutter problem seems pretty scary. Your mention of the HVX being a 1080p camera does confuse me, but this issue always confuses me. I thought that the HVX only shoots up to 1080i (and I know it has the 1080i24p setting or whatever they call it)...
 
There compression is only similar in the fact that both codecs use it. But the HVX's DcvPro HD codec compresses each individual frame independently and the EX1 compresses them as a group of pictures 15 frames long. This results in the different bitrates 100mbps (Mega bits per second) for the HVX and only 35mbps for the EX1 at it's highest quality.

It shoots 1080p the same why it and the DVX shoot 480p. It does this by capturing progressive frames with pulldown in the case of 24p and embeds it in a 1080i codec. So the frames are progressive which means no interlacing which means full 1080 Progressive frames. It is a bit confusing but it is 1080p if it wasn't then you would see interlacing lines during movement. Remember this: All of the HVX's footage is captured at 1080P and then recorded to the set format ie. 1080, 720, or 480.
 
I shoot daily with both cameras. They are both great for certain things and suck for certain things.

For sit down interviews and scenes with low camera motion (no fast pans), the EX-1 blows away the HVX in sharpness, resolution and lack of noise. The EX-1 has a much higher resolution chipset than the HVX, physically larger chips, a much better lens and lcd.

For scenes with high speed camera motion or strobes, flashing lights, the HVX blows away the EX-1. CCDs and the HVX's shutter do not suffer from the same motion artifacts that the CMOS chips and rolling shutter in the EX-1 produce. IMHO, the colors on the HVX-200a blow away the EX-1 colors. The HVX-200a has a much more filmic image to me. I find the menus and ergonomics of the HVX-200a superior to the funky menus and ergonomics of the EX-1.

There are about ten billion posts on this website arguing why one of these cameras is superior to the other. Honestly, I really dig them both, either of them can produce feature film quality imagery if you have the talent to create the images for the camera to shoot.

The Sony, generally looks like really nice, clean and smooth video.
The Panasonic reminds me of pretty nice looking Super 16mm film.

Different strokes, I am happy with both of them for certain situations. I have been shooting green screen with the EX-1 and the ReflecMedia ChromaFlex and it keys just fine even though the camera only has 4:2:0 color space. It's extremely high resolution makes up for the lack of color space. The HVX does pretty well on green screen as well.

Dan
 
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