A1 Steak Sauce at DVinfo.net

John Wheeler · January 19th, 2007, 01:29 PM

I just had to make that title :)

2 questions

1. What are the chances that there will be an updated A1 in the next year or so that will include more variable frame rates? Like the HVX200?

And also, I've done a little searching and I just get more confused about the capabilites of the A1 and a green screen. I saw several posts that said the color sampling on the A1 is 4:2:0

But straight off of the canon website, this is what it says "The XH A1 has an output with 4:2:2 color sampling which ensures optimal image quality" ....Ok so whats going on? ....And has anyone actually tested the A1 with a green screen and have anything to say about it? or footage to share?

Thanks,

John

Jim Martin · January 19th, 2007, 01:36 PM

Scott Billups tested the H1 vs. the Cinealta and said the Canon keys better than the Sony. I'd assume the A1 is very close to that.

Jim Martin
Birns & Sawyer

Bennis Hahn · January 19th, 2007, 01:41 PM

Quote:

Originally Posted by Jim Martin

Scott Billups tested the H1 vs. the Cinealta and said the Canon keys better than the Sony. I'd assume the A1 is very close to that.

Which Cinealta?

Chris Hurd · January 19th, 2007, 01:48 PM

Quote:

Originally Posted by John Wheeler

But straight off of the canon website, this is what it says "The XH A1 has an output with 4:2:2 color sampling which ensures optimal image quality"

Via analog component video output.

Thomas Smet · January 19th, 2007, 03:29 PM

If you plan on shooting progressive scan then the 4:2:0 is actually not that bad at all.

True progressive 4:2:0 is very clean are basically just has chroam pixels that are the size of 2x2 pixels. This is much cleaner then 4:1:1 because with 4:1:1 you have a chroma pixel that is the size of 4x1 pixels. This means huge holes in the horizontal direction that can be 4 pixels wide. P 4:2:0 is a nice even value that gives very clean results.

Interlaced on the other hand uses 4:2:0 in a different way and has to alternate the vertical samples every other line. This can create a mess if not dealt with well.

Nick Weeks · January 19th, 2007, 03:48 PM

Quote:

Originally Posted by Chris Hurd

Via analog component video output.

What if you are capturing through DV? Will it downsample it to 4:2:0 or 4:1:1:? Even if shot in HD at 24F?

Chris Hurd · January 19th, 2007, 05:24 PM

HD output over FireWire (which is compressed digital) is 4:2:0.

HD output over Component (which is uncompressed analog) is 4:2:2.

Frame rate has no bearing on this. Keep in mind that component video capture does not include audio output... but digital capture by FireWire does.

Kevin Myhre · January 19th, 2007, 05:32 PM

I've been playing around with my A1 and green screen and it seems to look pretty good to me. I don't have any other camera to compare it to but as long as I light the screen right (that seems to be the hard part for me) It looks pretty good. I'll try to post a clip for you because after all someone with more experience than me might think it looks like crap.

January 19th, 2007, 01:29 PM	#1
John Wheeler Regular Crew Join Date: Oct 2003 Location: San Antonio Texas Posts: 85	A1 Steak Sauce I just had to make that title :) 2 questions 1. What are the chances that there will be an updated A1 in the next year or so that will include more variable frame rates? Like the HVX200? And also, I've done a little searching and I just get more confused about the capabilites of the A1 and a green screen. I saw several posts that said the color sampling on the A1 is 4:2:0 But straight off of the canon website, this is what it says "The XH A1 has an output with 4:2:2 color sampling which ensures optimal image quality" ....Ok so whats going on? ....And has anyone actually tested the A1 with a green screen and have anything to say about it? or footage to share? Thanks, John

January 19th, 2007, 05:24 PM	#7
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	HD output over FireWire (which is compressed digital) is 4:2:0. HD output over Component (which is uncompressed analog) is 4:2:2. Frame rate has no bearing on this. Keep in mind that component video capture does not include audio output... but digital capture by FireWire does. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

January 19th, 2007, 01:36 PM	#2
Jim Martin Major Player Join Date: Jul 2004 Location: Burbank, CA 91502 Posts: 949	Scott Billups tested the H1 vs. the Cinealta and said the Canon keys better than the Sony. I'd assume the A1 is very close to that. Jim Martin Birns & Sawyer

January 19th, 2007, 03:29 PM	#5
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	If you plan on shooting progressive scan then the 4:2:0 is actually not that bad at all. True progressive 4:2:0 is very clean are basically just has chroam pixels that are the size of 2x2 pixels. This is much cleaner then 4:1:1 because with 4:1:1 you have a chroma pixel that is the size of 4x1 pixels. This means huge holes in the horizontal direction that can be 4 pixels wide. P 4:2:0 is a nice even value that gives very clean results. Interlaced on the other hand uses 4:2:0 in a different way and has to alternate the vertical samples every other line. This can create a mess if not dealt with well.

January 19th, 2007, 05:32 PM	#8
Kevin Myhre Regular Crew Join Date: Nov 2006 Location: Rochester MN Posts: 68	I've been playing around with my A1 and green screen and it seems to look pretty good to me. I don't have any other camera to compare it to but as long as I light the screen right (that seems to be the hard part for me) It looks pretty good. I'll try to post a clip for you because after all someone with more experience than me might think it looks like crap.