View Full Version : signifigance of 720 x 486
05 May 2003, 03:21 PM
hi all, i am sorry to repeat the thread, but the last thread wasn't addressing this exact question. i am going to be screening my thesis animation from a beta deck, being projected onto a 30*15 foot screen. Jeremy Birn says that i should render at 720 x 486 to get the widescreen effect that i wanted, with the simple addition of the black bars.
could someone please explain the signifigance of 720 x 486, as opposed to rendering at something like 640 x 360.
05 May 2003, 04:34 PM
720x486 is the NTSC resolution..
so that is the best you can get on a beta recorder..
if you render any smaller you will either have black around all sides or you have to scale to fit the bigger resolution which makes the image look blurred - which is especially when projecting on a larger screen not a good idea (and very especially in THAT size of the screen)
05 May 2003, 04:51 PM
The resolution you need is determined by the device you will use to output to video. That video card (or digital disk recorder, or firewire connection to a DV camcorder, or whatever hardware you're using) is the thing you should read the specs for. There are some differences, such as DV devices that crop a little and use 720x480 instead of the full 720x486 D1 resolution. Basically, find the hardware, read the manual, that tells you the resolution of the hardware.
05 May 2003, 12:18 AM
I didn't see your earlier post, so maybe I'm rehashing things a bit. But...
How you render is dependant on how you're getting your frames to tape...not just what machine you're playing back on.
720x486 is the resolution for D-1 video.
640x480 is the resolution for NTSC analog video.
Because NTSC video MUST use a 4:3 width to height ratio, you can't render out a non-4:3 image file and put it to video. If you do it will get stretched to fit the screen.
To get around this you just need to format your widescreen rendered footage from Maya, to fit within the 4:3 frame.
My guess is you're using some digital means to lay off your video. Something like a DigitalVooddoo card or perhaps an NLE like an AVID or Media 100?
In that case your FINAL images to tape have to be 720x486. The signal comming out of the compositte spigot on the beta deck will be 640x480.
I'm assuming that your widescreen is a 1.85:1 ratio? If that's the case you can do this to get things to tape effectively.
- Render out your animation in the widescreen format you want in Maya. Probably 720x389. (This to fit the width within the D1 frame. But you can always scale larger viceo to fit.)
- In AE, or whatever compositing ap you like to use drop the finished wide images into a 720x540 composition. This will center your 1.85:1 footage within the 4:3 D-1frame.
- To get out to tape properly you need to re-scale the pixels to be rectangular. So scale your 720x540 frame vertically to 720x486 and render. (AE has a function for this built in.) This will make your comp look funny on a computer monitor, but when it gets translated to D-1 it will look fine.
Here's a rough template.
05 May 2003, 12:20 AM
Okay...here's the template:
05 May 2003, 01:07 AM
you guys have all been an extreme help in making my thesis showing go smoothly. i find it really encouraging to know that the cg community is there to support struggling students like myself. it is really very impressive that such knowledgable and experienced people as yourselves would take the time to critique work, and share advice. i am humbled by your kindness and generosity. thank you again.
05 May 2003, 02:04 AM
When you have this composite which is set at 720x540, the fastest and most foolproof way to get it out at NTSC D1 is to drop that comp into a full NTSC size comp (D1 NTSC 720x486 0.9 aspect) and assuming your in AE. Then hit CTrl-alt-F, This will fit your smaller comp exactly into the new comps frame.
When you choose to render, in whatever comp prog you use, make sure you choose the params for D1/DV 720x486 0.9 aspect (its always a preset) and lower fields first (even) as your output. Avids are always lower field first these days.
Even better, go to the avid site and download their Meridian codec and install it, render to that codec. This will give you the cleanest image on an avid. Even the digi voodoo codec wont do as well on an avid import. If you can afford to master this baby on a Flame or Inferno system, bring frames, not a vid file, they can give you an outrageously good 10bit digibeta output.
Once you render to a vid file, you are subject to a codec. They do horrible things in general. If ya gotta go to a vid file, go to your editing systems native codec for best results. As mentioned, the exception is mastering on a flame where you can use your nice high quality frames. Last note, dont go importing frames directly into an avid type system, go to their native codec, then import.
Ok, one last note: Don't fool yourself into thinking that a fancy lossless or 10bit codec is gonna look good once imported into an 8bit avid that does its own crap to your vid in the end. Using a codec native to the editing system gives you the contorl, the system will import this without further messing with it.
Best of luck
05 May 2003, 02:17 AM
Most high-end production work is rendered, composited, and output entirely as a series of uncompressed, numbered image files.
Only use compression, codecs, or animation files if you are forced to (if, for example, you have no output hardware other than a non-linear editor that requires it), but try to keep things in a format like .tif instead if it's allowed by your output hardware.
12 December 2003, 05:31 AM
I have a question relating to ntsc output. Is it acceptable to set render option "by frame" to .8 to render a 24fps animation at 30fps rather than screwing with timeline fps?
03 March 2005, 09:06 PM
okay, I am still confused about the widescreen issue. This is the scenario. I am going to be outputting the finished sequence to DVD. I want the result to be widescreen. I am using 3DS MAX to generate the images. What resolution do I render at and why? (width, height, image aspect, pixel aspect). Then once the images are rendered and composited (using After FX). What resolution should the final images be at? (width, height, image aspect, pixel aspect)
I have posted in other places before and noone can give me a simple answer. I hope someone can help me because I am just about ready to render.
Any help would be greatly appreciated.
03 March 2005, 09:06 PM
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