Here's a question for you. at DVinfo.net
DV Info Net

Go Back   DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon HDV and DV Camera Systems > Canon XH Series HDV Camcorders
Register FAQ Today's Posts Buyer's Guides

Canon XH Series HDV Camcorders
Canon XH G1S / G1 (with SDI), Canon XH A1S / A1 (without SDI).

Reply
 
Thread Tools Search this Thread
Old January 27th, 2011, 05:53 PM   #1
Major Player
 
Join Date: Mar 2007
Location: Sitka Alaska
Posts: 470
Here's a question for you.

I was looking at the A1 specifications and I found that the HD and SD(16.9) have the same frame size, resolution and pixels.

HD approx. 1.56 Megapixels (1440 x 1080)
SD (16:9) approx. 1.56 Megapixels (1440 x 1080)

They are identical
.

So if I shoot SD (16.9) or HD the quality and file size are the same?

Is this correct? It sure looks that way to me.

Now standard SD SD (4:3) approx. 1.17 Megapixels (1080 x 1080) is not the same. So I'm presuming that the A1 down converts HD or SD (16.9) to create Standard SD (4.3). Correct?

OK,
So why not shoot SD (16.9) instead of HD, since SD (16.9) would be easier and faster to edit?

????
David Rice is offline   Reply With Quote
Old January 27th, 2011, 10:02 PM   #2
Major Player
 
Join Date: Jun 2007
Location: Hamilton Ontario
Posts: 769
Quote:
Originally Posted by David Rice View Post
I was looking at the A1 specifications and I found that the HD and SD(16.9) have the same frame size, resolution and pixels.

HD approx. 1.56 Megapixels (1440 x 1080)
SD (16:9) approx. 1.56 Megapixels (1440 x 1080)
Not sure about the interpretation, or what's been quoted,..... but in the end, SD is going to be 720x480 pixels, regardless of how much the sensor uses internally...
Wheras HDV will output to 1440x1080 pixels...
Peter Manojlovic is offline   Reply With Quote
Old January 27th, 2011, 10:09 PM   #3
Major Player
 
Join Date: Mar 2007
Location: Sitka Alaska
Posts: 470
I just double checked on the Web Site for the A1s. As per their own specs, the camera delivers SD (16:9) approx. 1.56 Megapixels (1440 x 1080).

??????
David Rice is offline   Reply With Quote
Old January 27th, 2011, 11:07 PM   #4
Inner Circle
 
Join Date: Feb 2007
Location: Fairfield, Dunedin, New Zealand
Posts: 3,689
Images: 18
Hi, David...........

Not really my area of expertise, but I'l have a stab at this one, if I may.

I think where this all falls apart is between what the front end can aquire, and what the back end can write to tape, to keep within spec.

The DV spec is pretty specific about what goes on the tape, the compression used and many other thngs as well.

During the front end to back end journey, that aquisition has to be whittled down to what the DV spec allows on the tape, which is 720 X 480 pixels max, no matter what was taken in at the front end.

Does the camera put out a higher resolution picture via the Firewire port during DV capture than is written to tape?

Doubt it, otherwise any system designed for DV wouldn't be able to reckognise it, so it must be down sampled before it gets to that port.

In short, no matter what the specs say, what is going in, is NOT what is coming out, as it MUST be DV compatible in SD mode.

The overall bandwidth used during tape record of both SD and HD is pretty much identical, but there is a huge difference in the compression between the systems, which explains why the data rate is similar even though the data retrieved after is so much higher in HD.

As to your specific question about shooting SD or HD to get editable SD footage, there are about 5,000 posts here that basically say the camera doesn't do as good a job of converting HD to SD as can be achieved in pretty well any decent NLE, so why shoot SD?

If you're pushed for processing power or time, fine, shoot SD. Nearly everyone as posts on the subject say they get better results shoting HD then down converting.

Heck, I'm not going to argue, I've never shot SD on the camera since I've had it.


CS
Chris Soucy is offline   Reply With Quote
Old January 28th, 2011, 03:04 AM   #5
Major Player
 
Join Date: Apr 2006
Location: Sweden
Posts: 244
Hi

Don't know what they mean with the SD resolution, it seems as the info you attatch is taken out of it's circumstances. To make it possible for us to help you must show more of the document or attatch a link to it.

SD can never be HD resolution. A guess is that Canon mean that the whole CCD is used to capture SD. The picture will then ALWAYS be down converted to SD resolution, 720x480 (NTSC) or 720x576 (PAL) and stored that way on tape.

Regards,

/Bo
Bo Sundvall is offline   Reply With Quote
Old January 28th, 2011, 08:06 AM   #6
Inner Circle
 
Join Date: Jan 2004
Location: Boca Raton, FL
Posts: 3,014
David,
I agree with Chris' explanation. THe camera is using the whole sensor in SD 16:9 mode but down sampling it to standard DV format (720x480 anamorphic). You can prove this by recording to your MRC1K or to your computer directly. The resulting files will be 720x480 anamorphic.
Les Wilson is offline   Reply With Quote
Old January 28th, 2011, 08:42 AM   #7
Major Player
 
Join Date: Mar 2007
Location: Sitka Alaska
Posts: 470
Then with the A1 there is no way to utilize the highest capabilities of the senor.
David Rice is offline   Reply With Quote
Old January 28th, 2011, 08:56 AM   #8
Major Player
 
Join Date: Apr 2006
Location: Sweden
Posts: 244
Yes there is. Shoot HDV (1440x1080). If you have need for SD, downconvert in post, nobody will see the difference.


Regards,

/Bo
Bo Sundvall is offline   Reply With Quote
Old January 28th, 2011, 08:48 PM   #9
Major Player
 
Join Date: Jun 2007
Location: Hamilton Ontario
Posts: 769
"Then with the A1 there is no way to utilize the highest capabilities of the senor. "
Yes there is..Learn about lighting and composition...


David.....

If you're planning on outputting to DVD, then stick to SD 16:9..It will save you the headaches of getting a downconvert..
If you're planning on delivering to BluRay or HD web, the stick to HDV 30fps ...

Don't let the theoretical assumptions get in the way of having fun...
Trust us on this...Go out and shoot!!!
Peter Manojlovic is offline   Reply With Quote
Old January 28th, 2011, 09:57 PM   #10
Major Player
 
Join Date: Mar 2007
Location: Sitka Alaska
Posts: 470
I'm shooting HD 30p. I have a friend looking for a backup camera and I suggested he purchase a used A1. That's when we read the A1s specs and noticed that the camera does SD (16:9) at approx. 1.56 Megapixels (1440 x 1080). Why Canon lists it like this in it's specs, I have no idea.

All it does is add to confusion.
David Rice is offline   Reply With Quote
Old January 28th, 2011, 10:14 PM   #11
Trustee
 
Join Date: Jul 2007
Location: Novato, CA
Posts: 1,774
Quote:
Originally Posted by Peter Manojlovic View Post
If you're planning on outputting to DVD, then stick to SD 16:9..It will save you the headaches of getting a downconvert..
If you're planning on delivering to BluRay or HD web, the stick to HDV 30fps ...
I would actually advise against this. As has been already pointed out, the XH and XL canons use the full sensor at all times, whether shooting HD or SD. In order to create an SD picture, it relies on in camera resampling to create the SD signal. The camera just does not have enough computing power to do a good job at this. Go back and read many posts on disappointed XH A1 owners who were shooting SD and couldn't figure out why their SD footage looked so bad, yes, even with good lighting.

You will get far superior results if you shoot HD and use a quality down converting program such as VirtualDub (which is free) to get your SD footage. Most NLE's do a horrible job at resizing video, FCP, Adobe, and Sony Vegas are some of the worst. Yes, there is a longer workflow but it is worth it. I'd advise that you experiment for your self as I did.

-Garrett
__________________
Garrett Low
www.GLowMediaProductions.com
Garrett Low is offline   Reply With Quote
Old January 29th, 2011, 09:30 AM   #12
Inner Circle
 
Join Date: Mar 2003
Location: Billericay, England UK
Posts: 4,711
Quote:
Originally Posted by David Rice View Post
the camera does SD (16:9) at approx. 1.56 Megapixels (1440 x 1080). Why Canon lists it like this in it's specs, I have no idea. All it does is add to confusion.
There's no confusion David. The camera is permanently and always 1440 x 1080. The chips are 1440 x 1080. You can choose to record this to tape as HDV or you can 'shoot in DV' and record 720 x 576 (or 480) to tape.

Of course in this SD mode the camera is still shooting 1440 x 1080 (it's forced to when it's fitted with these chips) it's just that it does the down-conversion from HDV to SD on the fly, between chips and tape.

tom.
Tom Hardwick is offline   Reply With Quote
Old February 3rd, 2011, 11:18 AM   #13
Major Player
 
Join Date: May 2004
Location: Oxford, UK
Posts: 425
Quote:
Originally Posted by Garrett Low View Post
You will get far superior results if you shoot HD and use a quality down converting program such as VirtualDub (which is free) to get your SD footage. Most NLE's do a horrible job at resizing video, FCP, Adobe, and Sony Vegas are some of the worst. Yes, there is a longer workflow but it is worth it. I'd advise that you experiment for your self as I did.
There is at least one NLE that does a good job of down-converting HDV to SD: Avid (used to be Pinnacle) Liquid (v7.2). I've been using it for 4 years and have had the chance to compare DVDs I've made with those made by Adobe, FCP and Sony Vegas systems. Liquid does seem to do a better job.

(Liquid is a bit of a "legacy" product now. It's cheaper, easier to use and all-round better than Avid's own Media Composer, so they've stopped developing it - IMHO, of course!! ;-) Therefore, I keep my eye out for alternatives. I haven't found one yet that makes better DVDs from HDV.)
__________________
Steam Age Pictures - videos in aid of railway preservation societies.
Mark Fry is offline   Reply With Quote
Old February 3rd, 2011, 06:16 PM   #14
Regular Crew
 
Join Date: Feb 2007
Location: Berlin, Germany
Posts: 89
I'm using the A1 and AVID, mostly for SD productions, and this since roughly four years. I tested both ways quite thoroughly, shooting HDV and downconverting, as well as shooting in SD and going straight forward. May be I'm blind and dumb, but I couldn't figure out a significant difference. If you tweak the settings right, the A1 will give you great SD images right away. And you don't waste time with downconverting.
Jan Luethje is offline   Reply With Quote
Old February 3rd, 2011, 06:47 PM   #15
Trustee
 
Join Date: Jul 2007
Location: Novato, CA
Posts: 1,774
Quote:
Originally Posted by Mark Fry View Post
There is at least one NLE that does a good job of down-converting HDV to SD: Avid (used to be Pinnacle) Liquid (v7.2). I've been using it for 4 years and have had the chance to compare DVDs I've made with those made by Adobe, FCP and Sony Vegas systems. Liquid does seem to do a better job.
I have not used Avid for ages (never with HD footage, that shows you how long) but I have heard it does a better job than the others. As I mentioned VirtualDub does a very good job and allows you to chose from a number of resizing algorithms. For HD to SD I usually use the Lanczos algorithm as it retains the sharpest looking PQ.

Quote:
Originally Posted by Jan Luethje View Post
I'm using the A1 and AVID, mostly for SD productions, and this since roughly four years. I tested both ways quite thoroughly, shooting HDV and downconverting, as well as shooting in SD and going straight forward. May be I'm blind and dumb, but I couldn't figure out a significant difference. If you tweak the settings right, the A1 will give you great SD images right away. And you don't waste time with downconverting.
Jan, what settings are you changing to improve the SD quality. I no longer shoot with an XH A1 but when did I spent a long time trying to tweak settings and nothing I tried could make it look better than shooting HD and downresing.

-Garrett
__________________
Garrett Low
www.GLowMediaProductions.com
Garrett Low is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK


DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon HDV and DV Camera Systems > Canon XH Series HDV Camcorders


 



All times are GMT -6. The time now is 02:08 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network