View Full Version : Chromakey and the H1


Kevin Martorana
December 8th, 2007, 08:02 AM
Well...got done shooting an all HD chromakey video and all I can say is we're delighted.

In our studio...set up the H1 and ran the HD_SDI output directly into our Avid upstairs. We captured live video/audio into the Avid at 220mbs.

We also recorded HDV at the same time as a "tape backup"...

I have not tried to take in a quick segment of the HDV footage to see how well it keys....but...the footage in the AVID Adrenaline looks ...well ...spectacular.

I put two jpgs here for you to see...

Please note...the jpg with the key is a quick comp from AE...(our artist is doing SFX on the footage...and there is a slight keying issue in the lower left corner)...but the AVID keyed these beautifully with little or NO tweaking.

I was impressed with the edges, hair...etc.

Another PLUS for the HDSDI output of this camera !

Joachim Hoge
December 8th, 2007, 03:58 PM
Thanks for posting the pics Kevin. Very impressive. I havenīt tried the HD-SDI out yet. Did you use the 20* lens?

Kevin Martorana
December 10th, 2007, 07:46 PM
No...we used the 6x lens...
We have a small studio and needed to see two pieces of talent at the same time....so the 6x was a must.

Joachim Hoge
December 12th, 2007, 01:57 PM
Looks great. I just bought the 6x myself from a member here at DVINFO. Should arrive next week.

Kevin Martorana
December 12th, 2007, 08:18 PM
We just did a quick test with the "backup" HDV recordings we did on this job.

Digitized into AVID...and tried the chromakey. First try was perfect....chromakeyed perfectly !!!!

We could see the compression artifacts from the HDV on the monitor...but seriously...WOW...amazing. I can't believe the 25mbs HDV tape chromakeyed that easily.

Proves two things....1. If you needed to do a chromakey with just HDV recording, it will work nicely.

2. If you need to keep the HDV as a backup/emergency restore...there is no question the recording will "cover your butt" !

Joachim Hoge
December 14th, 2007, 12:45 AM
Hi
Just a quick question;
You said you have a small studio, how far away from the blue screen did you manage to place the talent?

I can´t see any blue spill light at all. Very nicely done

PS What frame mode did you use?

Matthew Roddy
December 14th, 2007, 11:07 AM
Finally,
Something I can contribute!
I read these forums so often and never have something to offer, but on this matter, I have some experience.+

I've shot about 10-15 hours of HDV on a chroma key green using the H1.

My feelings are mixed - again, using HDV, not HD-SDI.

First, I get a fairly prominent dark "ring" on the subjects left, camera right. It's really irritating, but subtle enough that no one has complained - except me. I attribute it to chromatic aboration (sorry if I butchered the spelling), but I'm not tech savvy enough to really call that.
I use either Keylight (After Effects) or Serious Magic Ultra 2 for my keying and get really nice results.

I try to keep my subject at least 10-12+ feet away from the backdrop; I use amber back light on both sides (I've over-done that a couple times, so be careful) to help the key and I keep the camera about 10-15+ feet away from the subject, using the stock lens.
I also turn the camera 90 degrees on it's side, so I essentially double my resolution. This allows for some nice 3D camera motion in Boris Red or After Effects.

CA aside, the H1 does a great job, and HDV, with the right tools, is not a problem to key.

Christopher Glaeser
December 14th, 2007, 11:11 AM
CA aside, the H1 does a great job, and HDV, with the right tools, is not a problem to key.

Post a link to a short clip (before keying). This may not be CA and we may be able to suggest ways to improve the lighting.

Best,
Christopher

Kevin Martorana
December 16th, 2007, 09:22 PM
To answer a few of those questions and comments...

Our studio is only 24' by 20' wide. So it's small.
We have a 20x20 bluescreen that was streched on pipes and then spring clipped to stands...with sandbags at the bottom.

We hung kinos from our ceiling...there is a drop ceiling...which we popped out the tiles and hard mounted the kinos for maximum amount of height.

The kinos were 4' four bank lights. We used 3 of these to light the blue screen. Also....KEY POINT....our Gaffer...Mike Confer did a great trick. He lit the blue screen with 5600 kinos...while the talent was lit 3200k....Talk about making blue ....BLUE. It was awesome !

Also...talent was literally only 3-4 feet away from the backdrop.

Everything was shot at 60i.

When I get back into the office this week...I'll post a "behind the scenes" shot of the studio...and you can see how tight it is.

Kevin Martorana
December 18th, 2007, 03:51 PM
here's the studio shot...

You can see...not alot of "head room"...and talent was not far from the backdrop....