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-   -   LOOK: HV20 Green Screen Test Footage (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/97139-look-hv20-green-screen-test-footage.html)

Nathan Shane June 22nd, 2007 06:47 AM

LOOK: HV20 Green Screen Test Footage
 
Okay, I've seen a few people ask about using the HV20 for green screen, so I put together a test clip to show how well it can be done. This video is nothing fancy and there is no audio, it's just to show what can be done.

The file format is MPEG-4, 24MB. The render is fair to decent, and while I could have rendered a higher quality file, it would be too large to be practical. This video allows you to see both the original footage and green screen fx at work.

For direct download of the file click the link below:
http://vettaville.com/videos/canon_hv20_greenscreen.mp4

For those that want to go to that webpage and Right-Click Save Link As:
http://vettaville.com/testpage.htm

I used only Sony Vegas for video editing and doing the green screen. The Canon HV20 produces such a sharp image that it is very easy to get good clean and sharp edges around your subject matter (as you'll see in the video). The original footage looks far more impressive than this MPEG-4 allows you to tell, but it's still a decent enough test clip.

Martin Newsome June 22nd, 2007 07:41 AM

real clean image nathan thanx for showing us this much appreciated what were your setting you used 60i or 24p ??????? and if 24p did you use cinemamode ??? and good greenscreen is achived through good lighting also so what was your lighting setup did you use softboxes ??????????


peace n luv

Martin

Joey Atilano June 22nd, 2007 07:47 AM

Wow that looks good, is there any tipd you have for grenscreen in vegas? I tried a few times and have a shadow like you had killed me.

Nathan Shane June 22nd, 2007 08:40 AM

Martin...the camera was set for HDV24p and CineMode, but I just pulled it into Vegas as 60i since I don't have NEO HDV yet to extract the 24p (nor have I bothered to setup the free way everyone else is using to extract 24p).

As far as lighting goes, that was kind of a mixed bag. In my workroom, I like everything to be entirely lit up as though I were working out in the sun, so I have a ceiling fan that holds 4 of those spiral bulbs (generic) which I picked up from Home Depot (or was it Lowes). Those spiral bulbs are called n:vision bright white, and have a color temperature of 3500K (it's actually written on the bulb). I think I have the 75/100w bulbs and they output about 1200 lumens each, or something like that...very bright in here with those alone, but I do need to go buy one of those round photo shades/filter things to hang from that fan to soften the light coming down.

But in addition to that, I also used a couple photographic bulbs, the GE 250w 3200K bulbs. One was placed on the floor in front of me and in front of that I used one of those off-white photo umbrellas to soften the light. Then I also had to use another of those bulbs placed in front (off to the side a little), and you can see the reflection of that bulb on the guitar, and it is also that bulb that is causing the shadow on the green screen. I need more lighting equipment, but make do with what I have currently.

As far as the green screen itself, that's some green fabric (almost like a denim) I found one day at Wal-Mart about a year ago. It's two pieces of fabric stapled to the wall which you can see the seam going to down the wall as well if you look.

Joey...I'll actually have to put together a webpage that shows the filter plugin settings in Vegas, it's too complicated to explain here, but I'll work on that and get it posted for everyone to see. But to give a cliff notes version:

Plugin 1) Color Corrector (Secondary) ~ using Saturate Greens preset, check the Show Mask box (this will help you to see exactly what is taking place to the green screen) then you will need to play around with adjusting the parameters in the Limit Saturation and Limit Hue to fine-tune things to where is just the green screen that is being affected and not your subject.

(followed by)

Plugin 2) Chroma Blur ~ used to smooth out the jaggies around the edge

(followed by)

Plugin 3) Chroma Keyer ~ used to remove the green screen.

The primary plugin to focus on is the CC Secondary...because this plugin will allow you to push/fine tune the greens of the green screen so that the Chroma Keyer plugin has something better to work with. This plugin can actually help makeup for somewhat bad/uneven lighting, because the idea is to manipulate whatever is showing green into something the Keyer can work with. Using the CC Secondary, you can actually make the green screen look like it's fluorescent neon green color...and then you'd would adjust the Keyer for a color range that matches. If you try using the Chroma Keyer alone "without" applying some CC to the green screen first, you will not be as successful...UNLESS you happen to be able to get perfect and even lighting across the entire green screen. And for us home videographers, that's usually out of our budget and with not enough room space either.

Peter J Alessandria June 22nd, 2007 09:32 AM

Hey Nathan - that's pretty impressive. Your greenscreen setup was very low rent -but you still got great results! Good job. (And your choice of backgrounds was also very entertaining :-) )

I may try my own greenscreen setup next week but can you post a larger rez image of the greenscreen so we can see the edges? (BTW - you can buy a roll of seamless paper at any photography store in chroma green for like $39. They come in 54" or 109" widths [by like 12 yards I think]. Great for green screen b/c there are no wrinkles/seams.)

Nathan Shane June 22nd, 2007 09:36 AM

Quote:

Originally Posted by Peter J Alessandria (Post 700976)
(BTW - you can buy a roll of seamless paper at any photography store in chroma green for like $39. They come in 54" or 109" widths [by like 12 yards I think]. Great for green screen b/c there are no wrinkles/seams.)

I had looked at the paper first, but with my room it would have just got torn, and the fabric is more portable too. I also looked into getting a real green screen that was one piece of cloth and much larger and will eventually do that, but in the meantime.

Nathan Shane June 22nd, 2007 11:04 AM

Here are some other useful images to help show what is what for the green screen

Canon HV20 Green Screen - Full Size Image Capture:
http://vettaville.com/photos/CanonHV...ugin_order.png

Canon HV20 Green Screen - Color Correction Mask:
http://vettaville.com/photos/CanonHV...wmask_edit.png

Martin Newsome June 22nd, 2007 12:34 PM

I have proplems with green screen i nvegas all the time much thanks for explaing and putting up the diagrhams Nathan and the explanation about the lighting seeems you have pretty wel lit setup to compensate for the hv20 low light proplem , i had much easier time doing green screen in the previous editing program i owned Ulead Media studio 6 ihad no proplem smooth green screens no jaggies

peace n luv

Martin

David Delaney June 30th, 2007 08:56 AM

You are losing the tuning keys in the chromakey - do you have a DV shot to compare it to?


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