OT: Full Scan on HVR-A1P

Malcolm D wrote on 7/25/2007, 10:46 AM
Hello
Is anyone with an A1P using this function (on a tripod as Steadyshot has to be off)?
It seems to me that this function increases the used area of the chip from 1440x810 to 1920x1080 so a small improvement in vertical resolution might be expected.
It's probably a trade off as in standard mode the 810 lines is extrapolated to 1080 whereas in Full Scan mode the 1920 is interpolated to 1440 for the tape so which ever mode you use something is being scaled.
I'm just curious whether anyone uses the mode and what benefit they perceive.
Malcolm

Comments

Spot|DSE wrote on 7/25/2007, 11:18 AM
Full scan mode is for display, and bears no relevance to what goes to tape.
Malcolm D wrote on 7/25/2007, 4:56 PM
Sorry Spot
I don't think I agree. The manual refers to recording in this mode.
Maybe you are thinking of the All Scan mode which displays an uncropped picture in the viewfinder with a border around it.
I refer to this link I have subsequently found which discusses the same issue.
http://www.dvinfo.net/conf/archive/index.php/t-52300.html
I have yet to test it but I would expect a different (larger) area captured to tape.
Has anyone played with this?
Malcolm
Spot|DSE wrote on 7/25/2007, 6:00 PM
You're right, I was referring to All Scan.
Full Scan is related to the OIS system on the camcorder. When you have one of the stabilization modes enabled, the camcorder cannot scan the full image, thus reducing full resolution prior to processing. When stabilization is off, the full resolution is achieved.
In any event, a full image is recorded to tape, the difference is in what the processing/DSP of the camcorder receives prior to going to tape.
HTH
Malcolm D wrote on 7/29/2007, 11:01 AM
As I suspected Full Scan mode uses full 1920 x 1080 from chip giving a larger image area with marginally better vertical resolution which would not be visible on other than a 1080 native display.
Possible use would be when lens won't go wide enough and you are using a tripod as Steadyshot has to be off.
Also bragging rights as Canon is not the only HDV camera with native 1920 x 1080 chip(s). A1P is in fact 1920 x 1440 but in normal video mode uses only 1440 x 810 to allow for image stabilisation.
Full chip is only available for stills.
Spot|DSE wrote on 7/29/2007, 11:28 AM
The imager isn't 1920 x 1080, but the DSP output is.
ALL 1080 HDV is 1440 x 1080 at tape. Regardless of imager size.
However, you are correct. Image stabilization modes output 1440 x 810 to the DSP, which then converts the signal to 1440 x 1080 which is recorded to tape.
Since I don't use this small camera handheld, and only on a helmet or tripod, Stedishot is always off.