The Ultimate 720p camera.

[Alexander Ibrahim]

Originally Posted by Thomas Smet

The HVX200 ends up using around 40 mbits when shooting 720p 24p.

Actually, the HVX200 uses approximately 54Mbps when shooting 720 24psF. You get 10 minutes on a 4GB P2 card in that mode.

35mbits isn't that much less and it is interframe which makes the compression even better.

The tradeoff is that, while you do indeed get better compression, you are also getting lower resolution. Specifically this codec (XDCAM) is throwing away a lot of time data- and thus reducing temporal resolution.

Images reconstructed from interframe codecs will vary depending on the specific decoding implementation. Intraframe codecs contain all the information in each frame for frame reconstruction. Interframe depends on math and data from other frames to reconstruct a frame. You can do the math "right" several ways... but get different results because the steps along the way are different- or simply because the programmer makes different assumptions about precision in the data.

If you use the same ratio the 720p 24p could look more like it has double the birtate over the HVX200.

Unfortunately, I think that this is irrational exuberance.

The other thing that XDCAM seems to be tossing out the window compared to DVCPRO HD is 4:2:2. I've posted elsewhere that this will make little difference unless your work is going to be heavily posted or displayed in a large format. Of course if that is how you work.... its almost enough to stay with the older HVX200.

I say almost, because the HD/SDI output will give those of us who need all that data some options.

The one thing that XDCAM gains vs DVCPRO HD is that it is a full raster codec. More pixels is good in my book.

I expect that the XDCAM EX is going to be a much better camera than the HVX200, but this is going to be on the strength of its lens system, CA correction and sensor.

If I am proven right and the camera is better it will be DESPITE (as in not in any way because of) the XDCAM format.

Eventually Panasonic will release a competitor that is very similar in specification and records AVC Intra on P2 (or maybe they'll see the light and use SxS... I can dream right?)

[Steven Thomas]

Compared to the rez numbers we ran from the HVX200 and what we're hearing from some preliminary tests, the XDCAM EX resolves close to a 1000 lines. The HVX200 was around 500 lines.

[Paul Curtis]

Don't forget though that downsampling a 1080p to 720 would also effectively get you better colour sampling too. Because that 720p compressed will be 4:2:0 max no matter how it's compressed. For some work that could be advantageous.

Whether it is better to do 720p vs 1080p will probably come down to actually trying things out and experimenting with the camera itself.

In my experience these things are never as simple as the math suggests!

cheers
paul

[Alexander Ibrahim]

Originally Posted by Steven Thomas

Compared to the rez numbers we ran from the HVX200 and what we're hearing from some preliminary tests, the XDCAM EX resolves close to a 1000 lines. The HVX200 was around 500 lines.

Yeah, but that isn't DVCPRO HD's fault, rather that's the camera's problem. That is part of what I expect to be radically better on the XDCAM EX.

To be clear, and getting a bit old school:
I expect the camera portion of the XDCAM EX to kick the ass of the the HVX200.

I expect the recorder section of the HVX200 to be better than the XDCAM EX

On the other hand... I think the HPX500 will shoot better images than the XDCAM EX, and they'll gain the benefit of being recorded in DVCPRO HD.

I have no experience with Panasonic's AVC Intra, but it sounds impressive. As much as it might pain them Sony should adopt AVC Intra, or a similar codec, before Panny gets the idea to make an HVX300 that uses AVC Intra and has a camera section that is competitive with the EX1.

Of course- I think these are the last days of heavily compressed "pro" video. Storage is going to catch up to the needs of video fairly soon. The next generation of codecs will give us greater and greater bandwidth until eventually we are all working in losslessly compressed HD, 2K and even 4K.

[Steven Thomas]

I hear you...
But I'm also hearing XDCAM at 35Mb/s HQ has no visible artifacts.

Having said that, I'm hoping RED will come up with a Mini RED that offers
2K images and sells for less than $8K USD.

[Alexander Ibrahim]

Originally Posted by Steven Thomas

I hear you...
But I'm also hearing XDCAM at 35Mb/s HQ has no visible artifacts.

Visible is the key word. There are artifacts aplenty in compressed video. Do a difference key against the uncompressed version and see what I'm on about.

The important thing is that every tool in the post workflow not only can see them- but can potentially be "confused" by them

Having said that, I'm hoping RED will come up with a Mini RED that offers
2K images and sells for less than $8K USD.

Stop it! I can't handle that much excitement!

Of course given the reality of RED's delivery schedule on RED One I am not too excited about whatever their plans are for the RED Mini.

Also... 2K 16:9 is only a few more pixels than 1080p. I'll take them- but it isn't a huge deal.

Being unable to resist spouting my own RED Mini dreams...

The most exciting thing about a 2K RED Mini for cheap is that they'd likely use a 2K codec derived REDCODE- which is a very good looking codec.

What I really want is a VERY cheap (like $3000 USD- about what a used 16mm camera runs for) 2K camera with a 16mm sensor size (close to 2/3") and PL film lens mounts. Sort of doing to 16mm what they've already done to 35mm

[Ali Husain]

Originally Posted by Alexander Ibrahim

What I really want is a VERY cheap (like $3000 USD- about what a used 16mm camera runs for) 2K camera with a 16mm sensor size (close to 2/3") and PL film lens mounts. Sort of doing to 16mm what they've already done to 35mm

actually a 16mm sensor is closer to a 4/3" "video" sensor size, since video manufacturers use the--what i think is now dishonest--historical way of measuring sensor sizes based on the diameter of a glass tube and the useable area in the center. one reference:

http://www.dpreview.com/news/0210/02...ensorsizes.asp

"The size designation does not define the diagonal of the sensor area but rather the outer diameter of the long glass envelope of the tube. Engineers soon discovered that for various reasons the usable area of this imaging plane was approximately two thirds of the designated size. This designation has clearly stuck (although it should have been thrown out long ago)."

... so a 35mm-wide sensor using this measurement system should be designated 2.5" or almost 8/3" lol.

a 2/3" sensor is closer to 8mm film width. :(

i had posted about this once a long time ago:
http://www.dvinfo.net/conf/showthread.php?t=96091

[Barry Green]

Originally Posted by Ali Husain

a 2/3" sensor is closer to 8mm film width. :(

Yeah, but 8mm film didn't give you 8mm of image either. Lots was cropped off for the sprocket holes. You ended up with about 6mm x 4mm.

For that matter, "35mm film" as used in the movies doesn't get anywhere within striking distance of 35mm, in any direction. The actual size used is about 22x12mm...

In practice, a 2/3" 4:3 sensor is close to the same size as a frame of 16mm film. But a 2/3" 16:9 sensor is not quite as large as a frame of Super16 film.

[Ali Husain]

Originally Posted by Barry Green

Yeah, but 8mm film didn't give you 8mm of image either. Lots was cropped off for the sprocket holes. You ended up with about 6mm x 4mm.

For that matter, "35mm film" as used in the movies doesn't get anywhere within striking distance of 35mm, in any direction. The actual size used is about 22x12mm...

In practice, a 2/3" 4:3 sensor is close to the same size as a frame of 16mm film. But a 2/3" 16:9 sensor is not quite as large as a frame of Super16 film.

oops! i don't know what i'm talking about. barry is right. i forget that motion picture camera film size is != still camera film size:

http://en.wikipedia.org/wiki/35_mm_f...specifications
http://www.dvinfo.net/conf/showpost....3&postcount=10

[Alexander Ibrahim]

Ali Husain;

Check out the frame size specifications on the Wikipedia page for 16mm film here:
http://en.wikipedia.org/wiki/16_mm_film

camera aperture: 0.404 by 0.295 in (10.26 by 7.49 mm)
projector aperture (full 1.33): 0.378 by 0.276 in (9.60 by 7.01 mm)
projector aperture (1.85): 0.378 by 0.205 in (9.60 by 5.20 mm)

and I think you'll agree that a 2/3" 4:3 video camera comes very close to the specifications for 16mm's full 1.33 projector aperture. (8.8mm x 6.6mm)

It's certainly closer than any other video format.

Incidentally a 1" camera is a close match for Super 16mm. Of course, I wouldn't dare to match footage from an old 1" camera- if I could even get a working one- to Super 16. I'd rather match it with a modern HD camcorder.

8mm is an almost exact match to a 1/3" 4:3 video camera

Oh, and RED matches 35mm and super 35 very nicely. :)

[Thomas Smet]

um what does any of this have to do with 720p from the EX1?

Alexander, the only reason why you feel as though mpeg2 isn't good enough is because you have not seen it done the right way. I also write software that deals with a lot of mpeg2 encoding and I know what it is and is not capable of. If you give it enough bits it is virtually perfect. The whole and only point to this thread is that 720p 24p does have a lot of bits to work with which is why it will look so good. Intraframe is kind of a waste because even if you have a solid black frame it still takes up the same amount of space.

Personally I am affended that you said I was irrational. I am pointing out a fact that the encoded video is going to look so much better at 720p 24p due to how many bits it can have. Clearly you have never dealt with mpeg2 quality at this level before. I suggest encoding a SD video at 15mbits/s and taking a look at just how good it is compared to the source. Well that is what 720p 24p at 35mbits will look like. Is it perfect? Of course not but then neither is DVCPROHD compared to uncompressed. They will both end up with typical DCT based compression artifacts. The mpeg2 however may have less of those artifacts due to the fact that it can adjust how many bits to use per frame unlike Intraframe which will always use the same amount of bits.

There is also a huge difference between interlaced 4:2:0 and progressive 4:2:0. Progressive 4:2:0 isn't all that bad even for keying if you have the right tools. I know a lot of people who have used XDCAMHD footage even interlaced from the 350 for keying and they said the results were great. DVCPROHD from the HVX200 is far from perfect for keying and is only nice for those who are too lazy to actually try to capture to an uncompressed or lightly compressed format. DVCPROHD isn't very far from DV in terms of compression artifacts and in fact it gets compressed even harder.

Who told you 24p on the HVX200 uses 54 mbits? Everyplace I have ever checked says 40mbits which is 2.5x smaller then 100 mbits the max for 60p. That is pretty simple math there. Are you sure you are not mixing in the amount of space the audio takes up on the card?

[David Parks]

All:

The Sony XDCAM EX will make may me money the same way my JVC HD100 did. I saw this same back and forth debating between HVX 200, Z1U, JVC 100, and the Canon XH1 last year. Finally, everyone started shooting with their particular choice and made nice pictures. And the debate somewhat subsided.

There are thousands of issues to consider before making a choice on cameras and believe it or not, resolution quality is lower on my priority list than ease of workflow/flexibility. But that's me. There are several options and choices.

The bottom line is that until it starts (Sony XDCAM EX) shipping, everyone is going to make their own choices based on their own production philosophy or in my case "marketing philosophy".

After all, in the final analysis I've never had a client go:
"Man, Long GOP MPEG 2 4:2:0 is inferior to Intraframe 4:2:2." They almost always say, "That's look so clear. I'm glad I hired a professional."

Keeping one foot in the real world.

David

[Seun Osewa]

I agree with Thomas. More bits with slower frame rate equals better video. ;)

[Alister Chapman]

I used HDV before switching to XDCAM HD. Every year I spend many months shooting weather footage. The first year I had my Z1 I shot at 60i, the second year 50i. The difference in picture quality is quite surprising! My 50i footage holds up so much better in post production compared to my 60i material. As this is very similar footage shot with the same camera my guess is that the difference is simply down to more data per frame at 50i. So shooting 720/24P with a EX1 should be ultra clean and robust.

To compare the XDCAM and DVCPRO codecs simply by quoting numbers and saying one is better than the other because it's intra or inter is nonsense. They are very different codecs, born out of different requirements at different periods in time. Both do a decent job, both have strengths and weaknesses. Most people that rubbish long gop codecs have never used them properly with correctly set up edit equipment or don't understand the way modern applications reconstruct the GOP sequence with empty frames around edits to prevent excessive concatenation.

No codec is perfect, despite what the designers or code writers may say. Your best bet is to find the package that fits your needs best. Once you have chosen your system work out how to get the most from it, find out it's flaws so you can avoid them where possible. Then find it's strengths and make the most of them.

[David Parks]

Originally Posted by Alister Chapman

I
No codec is perfect, despite what the designers or code writers may say. Your best bet is to find the package that fits your needs best. Once you have chosen your system work out how to get the most from it, find out it's flaws so you can avoid them where possible. Then find it's strengths and make the most of them.

Alister,

Well said. Once this camera gets into some experienced hands hopefully we'll start discussing how to get the best looks and sharing workflows rather than discussing inordinate specs that don't apply. Hopefully most people on this forum will stay focused on how to get the most out of the EX.