View Full Version : Z1 shoot this weekend


Eric Bilodeau
February 1st, 2005, 03:32 PM
Hi guys, I will have a Z1 to be able to test it this weekend and I will shoot a 2-3 minutes short and a few tests. I will keep you updated on it as soon as possible.

Eric Bilodeau
February 2nd, 2005, 12:34 PM
I will also shoot head to head with a DVX100a and I will shoot a resolution chart, I will post the results of the chart tests as well. My short involves some compositing so it will be nice to see how the camera reacts to blue, red and green screen (I will test the three of them). I wonder if the actual tools for correcting chroma artefacting in 4:2:0 can correct an interlaced 4:2:0 signal? Frederic (Haubrich)? are you aware of that?

Frederic Lumiere
February 3rd, 2005, 12:20 PM
Eric,

Should be. But it's 4:2:0 color space so chroma keys are always difficult.

I HIGHLY recommend Reflect Media. Their product is incredible for chroma keying.

Frederic

Eric Bilodeau
February 4th, 2005, 08:57 AM
Frederic, do you have a link to their website and/or product?

Bryan McCullough
February 4th, 2005, 09:26 AM
http://www.reflecmedia.com/

Barry Green
February 4th, 2005, 09:57 AM
Test it first if at all possible. We just did an extensive shoot with it, and found it lacking in several ways.

The main thing about it is, you don't have to light the screen itself, the LED ring lights it for you. So you don't have to spend time lighting the screen and getting it "even", and you don't have to worry about spill onto your actors. And, you don't have to have a large space to get distance between the screen and your actors.

However, this cloud has a gray lining. Meaning, there's a gray shadow/halo/outline around everyone! The screen is gray, and only turns green when the LED light bounces off it. But the LED's are not perfectly aligned, so some gray shows through around everyone, and the outline is bigger the further away they are from the screen. We found we had to keep the actors as close to the fabric as possible to try to minimize the gray halo.

Second thing is: you can see every wrinkle, every crease, every seam. The screen is not a magic even flat screen... you still have to key around all that. For $7,000 we expected more of the "magic" you see demonstrated at NAB etc., but it isn't.

Finally, you have to keep the cameras a good distance away from your subject, or the green LED light will affect them. On some close-up shots we started noticing that our actors had green teeth and a sickly tone to their skin. It's reflected light from the LED system. So you have to back up and zoom in to minimize that. Which means the system would be almost completely unusable for macro photography stuff.

In all honesty the footage doesn't look any better than we'd have gotten using a conventional greenscreen. It's just a different way of getting there.

For the cost of the system, I think if you were going to drop $7,000 (the guy who bought it bought the biggest fabric they offered) to try to improve your keying, I'd think you'd get much better results from using Ultimatte and renting a 4:2:2 camera.

Just my opinion from a 3-day shoot on it, others' mileage may vary.

Eric Bilodeau
February 4th, 2005, 10:39 AM
Very interresting, so it is not as magic as expected...

If you have images of the results (unkeyed of course) I would love to see that...

Jim Arthurs
February 4th, 2005, 12:03 PM
<<<-- Originally posted by Barry Green : Test it first if at all possible. We just did an extensive shoot with it, and found it lacking in several ways. -->>>

I completely agree with Barry. I have a pretty deep background in matting, and have used virtually every method out there over the last 20+ years. I own a transmission bluescreen I bought in the '80's, back when we did this sort of thing on an optical printer and using a painted or fabric background just wasn't pure enough to pull a good matte.

I know there are people that really dig this "ring o LED" system, but it is inherently flawed. I used to do true front projection, and did some work with reverse front projection back in the day. A fuzzy ring of LEDS off-axis to the lens is just asking for trouble.

The only way this system CAN work is if a single super bright blue LED is bounced into a 60/40 beamsplitter on-axis with the lens, this would hide the shadows behind the subject if adjusted properly, but all the rest of Barry's points still would be in effect.

Want a large, good screen and have the space to hang it? Buy a length (12' wide by maybe 24' to 36') of the least expensive linoleum you can buy, turn it over, prime the backside and paint with blue or green paint from...

http://www.digitalgreenscreen.com/

Hang it from the wall, draping down onto the floor. Pull the end out from the wall, creating a smooth "cove". Lit properly, you can get a seamless perfect floor to wall transition.

As to HDV and bluescreen/greenscreen... well, I'm VERY skeptical. Oh, you'll get a "key", but nothing I've seen yet is a quality comp. I will do some tests with my Z1 (coming today!), but I think the only hope is by running the camera "live" out the component outs into a NLE and by-passing the MPEG encoding. Even then, that funky chroma fringing lens of the FX-Z1 might be the ultimate limiting factor...

Regards,

Jim Arthurs

Jasenn Robertson
February 5th, 2005, 08:43 AM
I was watching the keying section of the Total Training AE series the other night and they used a Chromatte set-up for all their shots. One important thing they said was to set up your iris for high reflectivity with just the curtain and then bring in your talent and light the talent accordingly. This might eliminate some of the creases and shadows in the curtain.
Thanks for all the comments on this, I was wondering if it was a worthwhile system to use in the studio we're building at my church (limited depth). I was also curious how this same system would work at 1080i resolutions.
They also recommended turning down the sharpness setting of the camera you're using, as that adds noise around the edges of the subject.

Eric Bilodeau
February 6th, 2005, 04:10 PM
Ok. We shot friday night. We used CF24. It looks very nice on an HDTV set. The CF24 looks buggy on the LCD but we had a SD (with component in) monitor and it looked okay, quite like the 24p in the DVX or the XL2. Of course 24p WILL be a little jerky but it is to be expected and it is no different from other camcorders.

The first major bug is the following: the AIC (Apple Intermediate Codec). It clearly "destroys" the image, a lot of compression noise gets added in the process. Especially when color correcting. I will try our old method (m2t to Quicktime uncompressed, edit, then, in the end, back to the camera using the AIC and imovieHD).

More to come soon.

Eric Bilodeau
February 7th, 2005, 12:27 PM
As I have two seperate subjects to cover, I will start a post-prod thread called "AIC-M2t and compression problems" and I will cover production in this one.

Eric Bilodeau
February 14th, 2005, 12:50 PM
Okay, so far here are my findings:

We had the contrast at 15 (goes from 0 to 15), on the SD monitor it looked okay but in a HD monitor we understood the contrast setting augments the edge enhancement witch is very bad. I recommend using 0 for contrast for those having problems with edge enhancement.

Also, the depth of field seems to be narrower than the DVX100 at the same settings, probably due to the higher definition of the image.

There is a hiss in the audio coming from my external microphone. I did not test a lot of configurations though.

I have stills of test charts for 60i, 24p, 30p, 50i, 25p that I could post here for everyone to see. So far, the interlaced versions resolve without an itch the 800 lines of the chart, the progressive modes are clearly 540p (one field is dumped and an interpolation is made from the remaining one). The lines fall around 600.

More to come

Chris Hurd
February 14th, 2005, 01:11 PM
Eric, if you care to email some stills to me, I'll be happy to host them for you. Many thanks,

Eric Bilodeau
February 18th, 2005, 09:09 AM
All right,

A condensed page containing the charts is available at:

http://www.hdvinfo.net/articles/sonyhdrfx1/bilodeau1.php

Thanks Chris and Jeff!

Chris Hurd
February 18th, 2005, 09:50 AM
Eric, if there's anything that needs to be added to that page, just let me know!

Guillaume Tremblay
February 18th, 2005, 11:25 AM
It's not the contrast but the sharpness that was too high. I'm the one responsible for the mistake. Sorry Eric! :)

Eric Bilodeau
February 18th, 2005, 11:42 AM
Ah... yes, you're absolutely right, it's the sharpness :) I don't know why I wrote contrast...

Eric Bilodeau
March 3rd, 2005, 09:44 AM
Ok,

The examples are now posted on the forum at this adress:

http://www.hdvinfo.net/media/ebilodeau/

Description of the files:

AIC_compression.mov
The compression degradation example in DV (for easier viewing on a tv)

still_stairs.ts
The shot used for the AIC compression example, a low light, already artefacted (lightly) shot.

The following 3 shots are examples of motion from cine frame 24, they are extracts from shots used on one of my shorts.
CF24_motion1.ts
CF24_motion2.ts
CF24_motion3.ts

Thanks to Chris and Jeff once again for hosting them :)