Which DV cam works best with chromakey? at DVinfo.net

Ted Bragg · October 29th, 2003, 01:18 PM

I'm looking for a DV cam that can shoot greenscreens with as little signal noise as possible.

We'll be lighting the screen with even light, and lighting the foreground actors seperately (I forget what the light artists call that...)

We might audition different cams, but from ya'lls experience, what's the best cam for shooting greenscreens?

We're shooting indoors, controlled lighting, all plate work is done in post...not doing any live keying on this..

Don Donatello · October 29th, 2003, 01:31 PM

BEST ! stay away from 4:1:1 format = dv25 ...if you do use dv25 format use a camera like sony DSR 500 or better ...

digibeta does very good .. dvcpro50 also does very good ...

you might check with your effects persons as i find depending on the project they prefer PROGRESSIVE frames over interlace - which then leaves you with panasonic 900 24p camera that can shoot 30P ( and 24P ) and can also shoot dvcPro50 (4:2:2)

Ted Bragg · October 29th, 2003, 09:33 PM

Ouch. The Panny 24p is pricey, but it DOES have those nifty cine-gadgets...

It'd be the most expensive part of this production.

Hmmm.

Maybe we should shoot a presentation reel on what we've got now (Pana DV53), get funding and then go get the 24p...

In a pinch, we could rent the digibetas at the cable co. but I don't have any editing gear to handle footage from those...

You're right; my CG guy's face lit up when I mentioned progressive...

"Yes! Yes! Please give me progressive! No interlace! nooooo interlace!"

:D

Don Donatello · October 30th, 2003, 11:11 AM

you did say BEST ...

does your pan53 do frame mode ?

you can make do with what you have ... try frame mode type camera ... do test before shoot and have your effects person play with it so he can make suggestions what is working and what is not ..
when effects person apply chroma key you may not get the whole background ( look at mask) so apply a 2nd/3rd chroma key fx on the area's you didn't get with 1st chroma key then render out a MASK for later use to put in background plate ...

Julian Luttrell · October 30th, 2003, 02:25 PM

here's a completely different approach that I use to give excellent quality colour keys.

Use an analogue camera. That's right, I use an old 1980s Ikegami HC230 colour camera (I bought it for £350 on Ebay), together with an old early 1990s DPS Perception PVR card (bought for £500 on Ebay).

With this pair I avoid the low chroma bandwidth of DV25 (and DV50) cameras, and can capture at 13.5MByte/second. Result - lovely smooth chroma variations, no blockiness, and excellent keys.

The downside? Well, the other crew members do tend to look askance at this old kit...

Julian

Glenn Chan · October 30th, 2003, 05:29 PM

According to Adam Wilt's DV FAQ you can get keys from DV that are as good as betaSP provided you apply chroma smoothing/interpolation. Some NLEs and keyers do this while others can't.

Julian Luttrell · October 30th, 2003, 11:04 PM

I'm not suggesting you go via an analogue tape format (such as BetaSP) - as you point out this has the same or lower quality than DV25.

Instead take an analogue component feed direct from the back of the camera and capture/digitise that to the computer. That gives (in this camera's case) 600 TV lines - a LOT better than BetaSP!

I'm not the only one thinking this way - you might ask yourself why companies like ReflecMedia use just such an analogue setup when demonstrating their greenscreen/bluescreen keying systems.

Regards,

Julian

Glenn Chan · October 30th, 2003, 11:19 PM

Ok I get you now. Skip tape entirely and capture uncompressed or some other computer format.

Mike Rehmus · October 31st, 2003, 07:34 PM

The biggest difference in 25 Mhz DV will be made by the keying software. If you use one of the packages that converts the video to 4:2:2 and then applies the key, you will get better results.

DV25 is pretty much DV25. DV25 format is the limit. Some cameras can deliver close to that limit.

If I had a choice, I'd go rent a D-9 (heck, I'd like to own a D-9 camera along with one of the decks). But you still will have to have something better than a straight DVC5 editing package to take advantage of it.

Bill Pryor · November 1st, 2003, 10:12 AM

Every program we do these days has extensive keying. I shoot all studio stuff with a DSR500WS, and usually it's 16:9. I've found that the keying is about the same as it was when I was shooting Betacam SP, but sometimes it's a little more difficult to get a great key. With Betacam, loaded into Avid Media Composer via component, I got pretty good keys using the Avid keying software. Now with DVCAM, loaded via firewire into an Xpress Pro, the Avid keying isn't so wonderful...so we started using Ultimatte, and it works fine. Recently, however, we started experimenting with Boris and, believe it or not, we are getting perfect keying with Boris, and it's more flexible than Ultimatte.

Ted Bragg · November 2nd, 2003, 06:05 PM

<<<-- Originally posted by Mike Rehmus : The biggest difference in 25 Mhz DV will be made by the keying software. If you use one of the packages that converts the video to 4:2:2 and then applies the key, you will get better results.
-->>>

This is encouraging. Which apps can convert footage from 4:1:1 to 4:2:2?

If I can use existing DV25 cams and then use software to bump it up to a workable frmat, then great!

Mike Rehmus · November 2nd, 2003, 06:55 PM

The Canopus real time cards convert. Don't know about others. It may be that After Effects does starting with version 6.

Glenn Chan · November 2nd, 2003, 07:01 PM

FCP3 with filters, FCP4's chroma smoothing filter, and the good keying programs all convert from 4:1:1 color space to a higher color space.

October 29th, 2003, 01:18 PM	#1
Ted Bragg Regular Crew Join Date: Jun 2003 Location: Houston, TX Posts: 105	Which DV cam works best with chromakey? I'm looking for a DV cam that can shoot greenscreens with as little signal noise as possible. We'll be lighting the screen with even light, and lighting the foreground actors seperately (I forget what the light artists call that...) We might audition different cams, but from ya'lls experience, what's the best cam for shooting greenscreens? We're shooting indoors, controlled lighting, all plate work is done in post...not doing any live keying on this..

October 30th, 2003, 02:25 PM	#5
Julian Luttrell Regular Crew Join Date: Oct 2002 Location: Cambridge, UK Posts: 164	Another way... here's a completely different approach that I use to give excellent quality colour keys. Use an analogue camera. That's right, I use an old 1980s Ikegami HC230 colour camera (I bought it for £350 on Ebay), together with an old early 1990s DPS Perception PVR card (bought for £500 on Ebay). With this pair I avoid the low chroma bandwidth of DV25 (and DV50) cameras, and can capture at 13.5MByte/second. Result - lovely smooth chroma variations, no blockiness, and excellent keys. The downside? Well, the other crew members do tend to look askance at this old kit... Julian

October 30th, 2003, 11:04 PM	#7
Julian Luttrell Regular Crew Join Date: Oct 2002 Location: Cambridge, UK Posts: 164	Analogue... I'm not suggesting you go via an analogue tape format (such as BetaSP) - as you point out this has the same or lower quality than DV25. Instead take an analogue component feed direct from the back of the camera and capture/digitise that to the computer. That gives (in this camera's case) 600 TV lines - a LOT better than BetaSP! I'm not the only one thinking this way - you might ask yourself why companies like ReflecMedia use just such an analogue setup when demonstrating their greenscreen/bluescreen keying systems. Regards, Julian

October 31st, 2003, 07:34 PM	#9
Mike Rehmus Wrangler Join Date: May 2002 Location: Vallejo, California Posts: 4,049	The biggest difference in 25 Mhz DV will be made by the keying software. If you use one of the packages that converts the video to 4:2:2 and then applies the key, you will get better results. DV25 is pretty much DV25. DV25 format is the limit. Some cameras can deliver close to that limit. If I had a choice, I'd go rent a D-9 (heck, I'd like to own a D-9 camera along with one of the decks). But you still will have to have something better than a straight DVC5 editing package to take advantage of it. __________________ Mike Rehmus Hey, I can see the carrot at the end of the tunnel!

November 2nd, 2003, 06:55 PM	#12
Mike Rehmus Wrangler Join Date: May 2002 Location: Vallejo, California Posts: 4,049	The Canopus real time cards convert. Don't know about others. It may be that After Effects does starting with version 6. __________________ Mike Rehmus Hey, I can see the carrot at the end of the tunnel!

October 29th, 2003, 01:31 PM	#2
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	BEST ! stay away from 4:1:1 format = dv25 ...if you do use dv25 format use a camera like sony DSR 500 or better ... digibeta does very good .. dvcpro50 also does very good ... you might check with your effects persons as i find depending on the project they prefer PROGRESSIVE frames over interlace - which then leaves you with panasonic 900 24p camera that can shoot 30P ( and 24P ) and can also shoot dvcPro50 (4:2:2)

October 29th, 2003, 09:33 PM	#3
Ted Bragg Regular Crew Join Date: Jun 2003 Location: Houston, TX Posts: 105	Ouch. The Panny 24p is pricey, but it DOES have those nifty cine-gadgets... It'd be the most expensive part of this production. Hmmm. Maybe we should shoot a presentation reel on what we've got now (Pana DV53), get funding and then go get the 24p... In a pinch, we could rent the digibetas at the cable co. but I don't have any editing gear to handle footage from those... You're right; my CG guy's face lit up when I mentioned progressive... "Yes! Yes! Please give me progressive! No interlace! nooooo interlace!" :D

October 30th, 2003, 11:11 AM	#4
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	you did say BEST ... does your pan53 do frame mode ? you can make do with what you have ... try frame mode type camera ... do test before shoot and have your effects person play with it so he can make suggestions what is working and what is not .. when effects person apply chroma key you may not get the whole background ( look at mask) so apply a 2nd/3rd chroma key fx on the area's you didn't get with 1st chroma key then render out a MASK for later use to put in background plate ...

October 30th, 2003, 05:29 PM	#6
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	According to Adam Wilt's DV FAQ you can get keys from DV that are as good as betaSP provided you apply chroma smoothing/interpolation. Some NLEs and keyers do this while others can't.

October 30th, 2003, 11:19 PM	#8
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	Ok I get you now. Skip tape entirely and capture uncompressed or some other computer format.

November 1st, 2003, 10:12 AM	#10
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	Every program we do these days has extensive keying. I shoot all studio stuff with a DSR500WS, and usually it's 16:9. I've found that the keying is about the same as it was when I was shooting Betacam SP, but sometimes it's a little more difficult to get a great key. With Betacam, loaded into Avid Media Composer via component, I got pretty good keys using the Avid keying software. Now with DVCAM, loaded via firewire into an Xpress Pro, the Avid keying isn't so wonderful...so we started using Ultimatte, and it works fine. Recently, however, we started experimenting with Boris and, believe it or not, we are getting perfect keying with Boris, and it's more flexible than Ultimatte.

November 2nd, 2003, 06:05 PM	#11
Ted Bragg Regular Crew Join Date: Jun 2003 Location: Houston, TX Posts: 105	<<<-- Originally posted by Mike Rehmus : The biggest difference in 25 Mhz DV will be made by the keying software. If you use one of the packages that converts the video to 4:2:2 and then applies the key, you will get better results. -->>> This is encouraging. Which apps can convert footage from 4:1:1 to 4:2:2? If I can use existing DV25 cams and then use software to bump it up to a workable frmat, then great!

November 2nd, 2003, 07:01 PM	#13
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	FCP3 with filters, FCP4's chroma smoothing filter, and the good keying programs all convert from 4:1:1 color space to a higher color space.