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-   -   Optura Xi anamorphic question (https://www.dvinfo.net/forum/canon-optura-junior-watchdog/19583-optura-xi-anamorphic-question.html)

Langston Sessoms January 10th, 2004 12:32 PM

Optura Xi anamorphic question
 
I'm about to get an optura xi and i've heard that the 16:9 mode on this camera is great but as far as picture quality goes would i be better off with an anamorphic adapter?

Rob Lohman January 11th, 2004 09:08 AM

If the camera doesn't have native 16:9 chips (and I think it doesn't)
then it is just as if you would do the following in post yourself:

1) crop the picture to a 16:9 ratio

2) stretch it vertically to get back to 480 pixels

In other words, it will be 16:9 widescreen, but you will loose
resolution instead of gain it (what anamorphic is about).

Langston Sessoms January 11th, 2004 11:00 AM

this is from the canon website:

"You can record high-resolution video in the 16:9 format for playback on widescreen TVs. Unlike systems which simply record a vertically stretched picture, the Optura Xi uses the full width of the CCD, retaining image quality and providing a larger horizontal angle of view at the wide end."

Marco Leavitt January 11th, 2004 01:06 PM

This is a really puzzling statement, but if this camera really had a 16:9 chip, I think we would have heard lots of noise about it. There isn't a manual available for download at the Canon site for some reason. There is a brochure, and it doesn't clarify the statement. It more less repeats the statement, but makes no mention of providing a larger horizontal view in 16:9 mode. The fact that Canon says so little about a feature which if it were true would be a huge selling point for this camera, pretty much speaks for itself.

Michael Wisniewski January 11th, 2004 03:21 PM

I think you'll make the image worse using an anamorphic adapter because of the way the Xi does 16:9. The Xi CCD crops the sides of the incoming optical image to get 4:3 and un-crops itself to get the full 16:9 image. The Xi only crops the sides - it does not crop the top/bottom.

There is a good diagram showing this, I'll post when I re-find it.

If you use an anamorphic adapter with the Xi, it will take the full optical image and squeeze it into the cropped 4:3 area on the CCD. That same image, using the built-in 16:9, is spread over a larger, un-cropped 16:9 area on the CCD.

In addition, anamorphic adapters can limit your zoom-thru, add vignetting, cause a distortion in your perspective, and steal additional light in comparison to just using the Xi's lens.

Daymon Hoffman January 11th, 2004 03:24 PM

I think the reason there is no big sing and dance about the Xi's WS mode is because its not a "native 6:9" chip but a 12:9 chip and the camera doing the anomorphic itself. Because we are dealing with SD WS then its all pushed into a 5:4 "container" (720x576 for my MVX3i) and just "squished" and "unsquished" horizontally on viewing. NO dodgey shortcuts like cropping / rez dropping.

If it were "native 16:9" chipped i think most ppl would expect a 16:9 image all the way thru the system to a chip thats 16 by 9 aspect ratio. But for SD i dont think they'll ever bother with that approach and we may only see "true" 16:9 from HD cameras with "need" a natrive 16:9 chip. :)

Langston Sessoms,

I havnt compared it to a 953 but i'm very impressed by its 16:9 capability. :) I'd like to see/find/have the time, know-how to do a resolution test to see what actual resolution its doing in each mode (12:9/16:9) to compare.

Marco Leavitt January 11th, 2004 05:43 PM

So when you capture your 16:9 footage, does it appear stretched vertically, or is it letterboxed? What does the image look like in the flip-out LCD when you're shooting?

Daymon Hoffman January 11th, 2004 05:47 PM

If i capture in 16:9 mode then the played back footage is of WS SD standard. So its 720x576 frame with a 16:9 Aspect Ratio when played back (1024x576). Which is perfect and what you want.

LCD: The only slight negative thus far is that the LCD is a 4:3 and there is no image changing when viewed on it. Meaning... the image (720x576) is "squashed" to fit and fill the 4:3 LCD.

You do get used to shootin gfootage in this mode and beleive me i'd rather this be the only negative then not having WS mode at all, i can assure you. hehehe. ANy other Q's feel free to fire away. :)

Marco Leavitt January 11th, 2004 07:22 PM

I can't seem to find too much written about this camcorder. Does it have manual controls? (Aperture, shutter, gain) I can only find mention of the various auto modes.

Daymon Hoffman January 11th, 2004 07:25 PM

It has a manual shutter mode and a manual aperture mode. No gain AFAIK.

Marco Leavitt January 12th, 2004 07:37 AM

Does that mean you can't control both at the same time? It sounds like you are talking about aperture and shutter priority auto modes.

Langston Sessoms January 12th, 2004 08:38 AM

http://canondv.com/opturaxi/f_manual_controls.html

Tommy Haupfear January 17th, 2004 02:06 PM

I bought the Xi as soon as it came out for its widescreen mode. I'm not a big fan of anamoprhic adapter limitations or the price. The Xi has an extremely high quality 16:9 mode with no apparent loss in resolution.

My only beef with this cam is with its limited contrast ratio compared to other 3CCD cams under $2000. The Xi (or at least the one I had) struggled with blue skies and trees. No matter what the setting it was always inferior to cams like the Panasonic DV953 or Sony PDX10. I already knew the Xi was not that great indoors (low light) but its performance outside of blowing out the sky was unacceptable. My DV953 and PDX10 (and now GS100) handled this much better and I'm not sure if its 3CCD vs. 1CCD, better optics, or an advantage of superior DSPs. There is one other minor complaint of the low quality mode selector switch and the last minute look of the LCD housing (same as with my past Optura Pi).

These frame grabs are 16:9 but still at 720x480 directly pulled from tape. Obviously the VX2000 16:9 is of lower resolution but the sky is what I'm concerned with as I rarely use the VX2000 for anything other than 4:3.

Xi
http://img.villagephotos.com/p/2002-...Widescreen.JPG

VX2000
http://img.villagephotos.com/p/2002-...Widescreen.JPG

These next frame grabs are 16:9 and frame mode and also still 720x480 directly from tape.

GS100
http://www.villagephotos.com/pubbrow...elected=685258

PDX10
http://www.villagephotos.com/pubbrow...elected=441334

Langston Sessoms January 17th, 2004 02:12 PM

was the Xi shot on auto mode?

Tommy Haupfear January 17th, 2004 02:25 PM

Quote:

was the Xi shot on auto mode?
Negative.


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