XDCAM EX1 on the road blog

Hi

I don't touch Pro res and actually edit everything in xdcam ex timelines with no problems at all. Including lots of grading.

I dont use a monitor with my ex1 and have no problems. Look at my kew gardens film. No monitor was used to get focus.
Best

Phil
 
Philip, when you shot that segment on the protestant family, was the interview scene set up deliberately so that only the woman's face was in focus? Her body seemed to be a little bit out of focus, If I'm not mistaken. I was just curious if you set up a very narrow depth of field deliberately or if the LCD did not prove perfect for pin sharp focusing.

My guess would be the former, because her face was in perfect focus.
 
spa_edwards said:
cheers lads.

I will be spending the next couple of days trying to read all of the posts. two questions i would like to put forward that i cant seem to find the answer to-

1) The colour sampling rate of both cameras - does it matter that the sony is 4:2:0 and not 4:2:2 like the panasonic, what is the pros and cons of this?

and
2)Ive read that the sony p2 cards records at a rate of 35mbs while the panasonic records at 100mbs, does this mean that the sony camera loses quality in recording at 35mbs. this is very confusing for me at the moment. so confusing it is to me, that i cant construct a descent question. lol.


I understand that they might be amatuer questions but if i dont ask - i will never know.

many thanks
steve edwards
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Good questions...


#1, 4:2:0 vs. 4:2:2 For most shooting, 4:2:0 might be good enough. However, if you do a lot of Greenscreen or Bluescreen work, you'll need the extra color resolution that 4:2:2 offers. Greenscreen and Bluescreen work can be done with 4:2:0, but it seems to be easier and works better with 4:2:2.

The 4:2:0 results in 12 bits per pixel, while the 4:2:2 results in 16 bits per pixel. So, the 4:2:0 gives us less data we need to compress, but we have a slightly rougher color resolution. Not a big issue with most shots.


#2, 100Mb/s vs. 35Mb/s The 100Mb/s system on the Panasonic P2 compresses each frame as a separate frame all to itself. Thus, what happens in the frame before or the frame after, has no impact on the current frame's compression. Thus, excessive movement or changes between the frames has NO IMPACT on the compression quality.

The 35Mb/s system used by Sony uses MPEG Long GOP (Group Of Pictures). MPEG records a key frame and then looks for the differences between this frame and the other frames. Now, if there isn't an excessive amount of changes between the key frame and the other frames (within the GOP), the system works very well and generates a lower bit rate than the P2 system. As for quality, given the higher horizontal resolution at the 1080i mode (1920hx1080v), the Sony system can be sharper. Panasonic DVCPRO100 is 1280hx1080v. However, if there's compression noise, the Panasonic system would be the better system.

The potential problem with MPEG is that IF there are lots of changes between every frame, the CODEC can't deal with all the changes and compression noise will appear on the video. This may appear as little blocks the appear and disappear between each GOP OR as an overall blocky look.

The big question is, "How likely will this happen?"

At 720@24, 25, & 30p, it appears that it's not very likely to occur.

At 720@60p, 1080@30p, and 1080@60i, we really don't know for sure. I haven't seen anyone using the camera in those modes who has posted any information on it.

If your videos are of slow/medium moving things, chances are this is not going to be an issue. However, we are still waiting for the results from those who shoot lots of fast action at 720@60p, 1080@30p, or 1080@60i.

The Long GOP of the Sony system does give us more minutes per GB of memory, BUT we operate with an increased risk of seeing compression noise.


Bob Diaz
 
FrankC said:
I think the HVX has had it's day (as short as it was).
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Still LOTS of great footage being posted thats shot on the HVX.
The HVX didnt become any less capable because the EX1 came out.
They arent really on the same playing field anyway, its like comparing a Filet to a Sirloin, ones obviously better, but they are both still very tasty :)
 
The HVX is still a superb camera. Would I have sold it if I didn't need the cash to buy the EX1? No.

For everyone who still has an HVX, you have a superb camera there. For me I needed different things, better lens, sharper image, bigger sensors, better low light, longer recording time. I need my workflow and my camera to operate like my full size cameras. This is the only "small" camera I have used that lets me do that.

Should people buy an HVX today rather than an EX1? I would say no. Mainly because I think it is a superior product. BUT, the HVX makes sense for some people who are bought into P2. It is surely a foregone conclusion that Panasonic will lose customers to Sony with the EX1 but they will respond with a replacement that can take up the new challenge. Now that camera should be pretty special!
 
Cheers for your reply bob, it was very useful.

Just wondering that if i was to use the ex1 "overcranking" system with the variable framerates, would i experience compression noise when using this? many thanks.



The potential problem with MPEG is that IF there are lots of changes between every frame, the CODEC can't deal with all the changes and compression noise will appear on the video. This may appear as little blocks the appear and disappear between each GOP OR as an overall blocky look.
Click to expand...
 
I would say the chances of compression noise are lower when overcranking.

The EX1 actually increases its datarate at higher fps, so at 60 fps overcrank, the camera records 2.5x the data per second compared to 24. In other words, it maintains the amount of data per frame that it records.

And since the image changes frame to frame are only 40% of what they would be at normal speed (on average), the codec is taxed far less when overcranking.

No one has been able to show any visible macroblocking (compression noise) on the EX1 in any test footage I have seen. It's not to say that it can't happen, but the codec is very good and hard to break.

Also, the 35Mbps rate, according to what I have read, can be exceeded by the EX1 codec for short bursts (up to 50Mbps I think) for particularly difficult frame sequences.
 
Agreed, matthew77.
The footage that convinced me was taken from the back of US aerobatics ace Patty Wagstaff's plane doing some pretty outrageous (15G) moves - and nary a macroblock (nor a CMOS vertical smear) in plain sight.
Now if only someone besides Red can get some wavelet compression going...
 
I really enjoyed your series. You're probably limited on time, but it would have been interesting to see a bit more of each family. How much post corrections did you do?
 
rockoblm said:
I really enjoyed your series. You're probably limited on time, but it would have been interesting to see a bit more of each family. How much post corrections did you do?
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yes it would have been nice to have made them longer but i was given max running times for them. Their interviews were so fascinating. Wish I could have made them longer.

Everything was graded in post, is that what you meant?
 
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Just wondering that if i was to use the ex1 "overcranking" system with the variable framerates, would i experience compression noise when using this? many thanks.
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cheers for the reply, but i think i must have meant to say - would i experience compression noise with undercranking?

love the work philip
 
Thought the catholic one was particularly good. Almost brought a tear to my eye when the man was talking aout his baby who died 40 minutes after its birth. Really excellent stuff Phil.
 
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