G1 Component vs. SD-HDI

[Peter Ferling]

I know this has been discussed before, but no conclusive result has been released yet (at least that I could find). Now that the G1 is out, I'm sure it's a question on everyone's mind. Is having the G1's SD-HDI really worth it over the A1's component? I'm not sure where the value is. For a little more would it make sense to get an H1 for the sake of the lens to take better advantage of the SDI image?

[Chris Hurd]

I don't think you're going to see any noticeable difference in the lenses between the G1 and H1. The primary advantage of the H1 lens is its interchangeability. In terms of optical quality, the H1, G1 and A1 are pretty much equal.

The big advantage of SDI on the G1 is that it carries everything: not only video, but audio as well as TimeCode. And that's only in the G1, not the H1. The SDI output on the H1 is video only.

Likewise, component output on all three cameras (H1, G1, A1) is video only. No audio. No TimeCode. Plus, it's an analog signal, subject to generation loss. It's also subject to noise and interference over cable runs of any distance. SDI is shielded and allows for very long noise-free cable runs.

Keep in mind also that there's more to the G1 than just SDI. There's also a dedicated TimeCode jack, so the camera can receive TC input from another source while sending SDI output at the same time. Plus there's a GenLock input for live multi-camera switching.

You'll have to ask yourself if you can live with uncompressed analog "video only" output from the component video terminal. If that answer is yes, then you don't need the G1. If you think you can use the "everything including the kitchen sync" single-cable advantage of the SDI output, plus a dedicated TC input/output jack, plus Genlock, then the G1 is for you.

[Jay Stebbins]

The A1 only sends 60i through the component feed...

from the Canon press notes thread...

http://www.dvinfo.net/conf/showthread.php?t=79410

[Peter Ferling]

I didn't think about the TC and genlock, (I'm having information overload here. Being in a rush as right now I don't have any working cams and jobs just around the corner). I do 2 cam shoots often. I need to see how to control both cameras simultaneously and shorten my edit time. I have some lighting gear and software upgrades I may pass in favor of having two G1s if I know it'll make life easier for me in that regards.

If the glass is same quality on all three models, and the G1 options are more than the H1, it kinda kills the need for that model. Realistically, I'd have to slap down more than my budget on a real quality lens for the H1 then, (if such exists).

The G1's release seems early than I expected and was willing to get A1s. Now I have to think this over. Thanks Chris.

Jay, if the A1 only has 60i on the component pipe, then I quess it's 60i at the sensors, and the 24f is part of the compression. Is there 24f at G1's SDI?

[Stuart Brontman]

Now all we have to figure out is a way to grab the SDI-HD signal and get it into a laptop in the field. If there's a way to do this along with Cineform Prospect HD (short of buying a Wafian - ouch, they're expensive and not portable), I'm in!

Stuart

[Philip Williams]

Originally Posted by Peter Ferling

<snip>if the A1 only has 60i on the component pipe, then I quess it's 60i at the sensors, and the 24f is part of the compression. <snip>

I'm not 100% positive, but I think you can extract the 24P from the 1080i component stream, its in there with some pull down I think.

[Barlow Elton]

For FCP users, there is a Nattress plug-in that will extract pulldown. There's also Cinema Tools doing "inverse telecine" but it takes a bit of trial and error to figure it out.

[Pete Bauer]

F-Mode is recorded to tape in true 24fps (or 25fps or 30fps) HDV, but the output for both analog component and for SDI is 60i, which it has to be in order to be NTSC compliant and viewable on monitors and TV's. The HD-SDI is 2:3; up-to-date NLE's can pull it down to a 24fps or 30fps timeline.

If you only want to sync the timecode between two cameras, you can do that on XH A1's by setting them both to free-run right before your event using the technique Chris outlined here:

http://www.dvinfo.net/canonxl2/articles/article11.php

I did a little test a while back with 2 XL H1's and found that timecode drift between the two cameras was about 1 frame per hour, so that should do pretty well for most events.

If you want SDI or Genlock then the XH G1 is your choice.

[Peter Ferling]

Pete, that's excellent information! Thank you.