Xha1 1920x1080?

[Don Palomaki]

The NTSC XH-A1s video recording system is:
HDV (High Definition Video 1080i (which as noted above is 1.33 pixel aspect ratio 1440x1080)
DVC (Consumer Digital Video) in SD (which has non-square pixels in 4:3 or 16:9 screen aspect, 720x480 pixels)

The television system is either HDV at 1080/60i or SD EIA standard at 525/60 fields.

The CCDs have about 1.56 megapixels effective, and use horizontal pixel shift (FWIW: first document by Canon with the XL1) to obtain 1920x1080 output and 1920x1080 stills on the memory card.

It also has a 30P and 24P mode.

It does not record or output 1080P or 720P.

25 Mbps is the data rate recorded to tape, and sets the pragmatic limit on signal bandwidth and thus resoluton, color depth, audio bandwidth, etc. While both SD (DVC) and HDV use the same bandwidth on tape, the compression used is different, thus the roughly 4x higher resolution HDV signal fits into the older DVC standard bandwidth on tape.

As a point of reference, the highest quality AVCHD found on common prosumer camcorders is often 1920x1080 pixels with a 1:1 pixel aspect ratio. Data rates depend on the level of compression selected. The Canon XA-10 allows selection of several data rates up to 24 Mbps. However, rates of 12 Mbps and lower are 1440x1080 with non-square pixels.

Needless it gets complicated as one considers all the options and then factors in the Blu-ray standards just for kicks. (What happened to the simple days of S-VHS, Hi-8, and even MiniDV when the only option was a somewhat lame widescreen 16x9.)

[Maurice Covington]

This gets more complicated for me as I continue to read but I really appreciate the thoroughness of the responses. In the most recent post, it was said that the XA-10 records at 24 mbps which seems to be slower than the XHA1s which was said to record at 25 Mbps. Am I to assume that the faster the Mbps the better quality of the video.

[Chris Hurd]

Hi Maurice,

The XH series cameras record HDV while the XA10 records AVCHD. You have to take into account that HDV and AVCHD are two completely different codecs. You just can't make a 1:1 comparison between them based on bit rate alone as that does not give you any insight as to what is really happening with regard to image quality.

They way they actually stack up to each other is that AVCHD at 24 Mbps is better than HDV at 25 Mbps. I can't recall the AVCHD data rate that roughly equals HDV -- keep in mind that HDV is fixed at 25 Mbps while AVCHD is usually offered at a choice of bit rates -- but I believe it's AVCHD at 17 Mbps that is the most direct comparison to HDV.

The key thing to understand is that bite rate alone doesn't determine image quality. You have to factor in a number of variables, chief among them being how efficient the codec is. That said, the primary advantage of HDV over AVCHD is that it's easier to edit, especially on slightly older NLE systems. With AVCHD, you're going to need a newer, faster computer (unless you've just recently bought one).

Hope this helps,

[Maurice Covington]

This is great!

Thanks Chris, I'll shoot some footage using the two formats as I have both HDV and non Tape based HD cameras to compare the two sometime later today.

[Chris Hurd]

Sounds good, Maurice... you might have to look closely though, as many people (myself included) cannot visually discern any difference between identical scenes shot in HDV vs. AVCHD.

Workflow (in post, tape vs. flash) is the most notable difference.

[Maurice Covington]

Okay with that being said, I'm sure from my posts you can tell that I am not as experience as some of the others on here nor is my understanding as thorough. I am currently shooting weddings, church functions and so on. I charge a somewhat modest rate for my services but have been struggling with thoughts of upgrading to the XF100 x2 and an XF300. I am currently shooting with an XHA1s an XHA1 and an HF-s20. If a trained eye can't necessarily see the difference, is it sensible to even consider an upgrade at this point. I welcome the feedback from everyone.

Thanks again Chris!

[Don Palomaki]

At last with the Canon XA10, 24 Mbps and 17 Mbps are 1920x1080 resolution, while 12 Mbps and lower are 1440x1080 resolution. On the basis of resolution only the 25 Mbps HDV corresponds to 12 Mbps on AVCHD. These would probably be a resonable quality match under good shooting conditions.
However, as Chris notes image quality is more than just bit rate or resolution. A higher bit rate will allow higher image quality, other things being equal, but they rarely are.

A lot of visual image quality is how the camcorder is setup and the viewing system used. It is always best to shoot/edit/produce with the final use inmind.