Need advice on green screen & lighiting

S

shawn.w

Active member
Hey Everyone,

I'm going to list my questions with numbers so i can track your responses easier.


1. So This will be my first attempt at using green screen, and i was wondering if anyone had any beginner info for me, especially related to this camera (hmc150).

2. I'll be using the green screen behind subjects that im interviewing, so i probably wont buy that large of a sheet. Any advice on what i should be looking for in purchasing a green screen? Any place more reputable for ordering one online?


3. Other thing im worried about is lighting it evenly. Only thing ive got right now is clamp lights. Any sort of low budget solution to lighting the thing evenly?

4. The room im shooting the interviews in has fluorescent lights above, and daylight from the side, but i could kill the daylight with blinds if i dont want it hitting the green screen. Is that something i should be worried about?

5. Anything else I need to know?


Thanks so much!

- Shawn
 
Beyond lighting the background consistently, you're gonna want to keep your subject relatively far away from the background (the bigger room you have the better). The closer you keep your subject to the actually green backdrop the more green spill you're going to get on your interviewee's hair and skin.
 
There was a very good thread about this, and while doing a search to post the link here i found 3 pages full of good threads just here on the HMC150 section... just search "green screen"
There really is a lot of info on this subject! good luck!
 
Superfresa66 said:
There was a very good thread about this, and while doing a search to post the link here i found 3 pages full of good threads just here on the HMC150 section... just search "green screen"
There really is a lot of info on this subject! good luck!
Click to expand...

whenever i use the search function i just get a plain white screen with the following message:-

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 524288 bytes) in /home/dvxuser/public_html/V6/search.php on line 1155


:embarasse
 
use the WF = search feature?

I'll try searching more for the answers i posted but im not finding too much related to the type of project im doing. Any recommendations on cheep lighting solutions for green screen lighting would be great. Thanks


- Shawn
 
best affordable studio lighting to be found at:
www.imagewest.tv

check out their easy fluorescent kits:
http://imagewest.tv/index.asp?PageAction=VIEWPROD&ProdID=121&HS=1

most people will recommend you use fluorescent lights for greenscreen, but you can always go cheaper with halogen lamps from home depot.

these $400 3-point lighting kits are the best minimal investment you can make and have the perfect soft and diffuse light you want, which also makes them great for HD in general.
 
very good point....don't overlight your greenscreen!
makes the spill worse and actually can make it harder to light evenly.
i've gotten better results by using less light, even one time relying almost entirely on indirect sunlight coming in through a window!

when you use the waveform monitor, zoom in so that the greenscreen just fills the frame, then adjust the lights until you get a nice evenly thin bar all the way across.

the thinner the bar, the more even your lighting.
 
ps. turn the detail down to 0 or lower in your scene file and make sure coring is at 0 or higher.

you don't want to shoot with super sharp contrast enhancing scene files like spark.
they'll create outlines around your subject that will be next to impossible to key out cleanly.
 
awesome, thanks guys these are great tips. Let me know if you think of anymore, even if their basic, as this is my first time using green screen.

Averan, the scene file I shoot on right now is a bit contrasty, i just did some modifications to the scenefile1. I'll make detail and coring 0 as you suggest, but what other options do i want to look out for? Is there a scene file anyone has written up for best green screen use or one of the standard ones shipped with the camera that most people use for green screen? Thanks!

- Shawn
 
here's the latest version of my 'grnscn' scene file:

detail: -2
coring: +2
chroma level: +2
master ped: -7
gamma: b.press
knee: high
matrix: cine-like
skin tone: on

everything else set to 0.

i too would love to know what others are using.
i'm still experimenting with each shoot.
i chose the gamma, matrix and knee by switching between options and watching what it did to the WFM, settling on the combination that gave me the cleaner/thinner signal.

i'm sure that a different combo of settings might work better, especially with a different lighting setup.

i'll post a frame later today from my latest shoot.
 
frame grabs from a bluescreen shoot i did this week using the custom setting i mentioned.
lighting was mostly CFL, 5.6k, with a touch of warm daylight-balanced tungsten hairlight.
shot at 1080_30p.
lost a little color in the jacket with the key that i'll have to replace.
in general, i've gotten better results with the bluescreen than the green so far.

1257301238.jpg

1257301266.jpg
 
Interesting. Why do you think you've gotten better results from the blue screen? Seems to me like that blue is a color that would more closely resemble shades people may wear to an interview shoot. Where as i couldn't imagine anyone wearing anything like the color of the green screens ive seen.

Also, what sorts of lights did you use? Types of lights is something i didnt take enough time to read up on when i was in school. Just checked out the lowel and fresnel kits most of the time heh. You said most people use fluorescent for green screen, the cheapest option for those was like $400? Might not be able to afford that at this point, so my backup would be some halogens from home depot? Any idea what sorts of lights im looking for at home depot? Only thing I would know to ask for would be clamp lights, but im guessing youre talking about something more powerful?

Also if fluorescent lights are the recommended, does this mean you have to shoot at 1/60th shutter speed the whole time? As i reported a problem shooting under fluorescent lights a week or two ago and this was the recommendation. Thanks!

PS. Thanks to everyone, especially Averan, for taking the time to help me though starting up and come to an understanding on this material, this forum has been the best help imaginable.


- Shawn
 
i have a friend who also gets better results with the bluescreen....i guess we're the black sheep in the chromakey flock! =)
i think it has to do more with the hair and skin color. i know all about all the technical reasons why a greenscreen should be better, but i prefer the results i get with a bluescreen better.

i used Compact Fluorescent Lights. if you buy simple 'clamp lights' you can also buy some big 40w CFL bulbs to put in them instead of regular old tungsten bulbs. i was referring to the halogen work lights at home depot. you can get them very cheap and they're very bright. but with chromakeying you really want to have a nice, even, diffuse light....exactly the kind of light that fluorescents produce.

if i'm shooting 30p, then i'm pretty much always shooting at 1/60th shutter speed. its standard operating procedure to shoot at a 180 degree shutter speed.

good luck!
 
So here is what i have in my head for lighting options:

From cheapest to more expensive:


- Clamp lights from home depot w/ any? CFL bulb

- Halogen work lights from home depot

- The "4200 Watt 3 Light EZ Open Softbox Flo Light System" seen as a package 2/3 of the way down this page for $399:
http://imagewest.tv/index.asp?PageAction=VIEWPROD&ProdID=121&HS=1


I suppose another option would be to try to find a cheep lighting kit off ebay? If anyone would like to add to the options i should consider please let me know!

- Thanks

 
one note:
CFLs come in a variety of color temps, with most being warmer, closer to 3.2k.
get the daylight balanced version as close to 5.6k as possible.
 
Will do. Any other cheap kits / lighting options i should run a search on if im looking on ebay or for a deal?
 
if you're looking for a deal, just get whatever you can afford.
you'll find a way to make it work with whatever you have on hand.
its just harder to get a soft, diffuse and even spread of light on the greenscreen using tungsten or halogen lamps, but lots of people do it.
 
hi all,

i do a lot of green screen work and since getting the HMC-151 ive been on a bit of a quest to get good results too.

for my lighting i use just these on their own which i got cheap off amazon:-

http://www.amazon.co.uk/PhotoSEL-LS...ef=sr_1_1?ie=UTF8&qid=1257446771&sr=8-1-spell


and i use this for my greenscreen:-

http://www.warehouseexpress.com/buy...-background-1-5x2m-chroma-green-blue/p1015726


i set my camera up in front of me and put a soft box either side and just behind the lens. i then sit only around 2 to 3 foot in front of the green screen with the camera about 3 or 4 feet in front of me.

the soft boxes are about 3 foot either side of the camera.

the 2 soft boxes are the only lights i use (i shoot in my front room at night......its quiter! lol) and they somehow seems to light myself up nicely whilst also giving a fairly good even light on the screen...........i certainly dont notice any major shadows :)

i manually set the white balance by zooming into a white piece of card whilst sitting in the position that im being filmed at and then use the waveform monitor and 100% zebra function to adjust the exposure until everything is looking roughly in the middle of the WF. then when i move away and just look at the green screen the waveform monitor gives a "fairly" straight line with just a slight bend at the start and end of the line.

i use the 1080 25p PH mode and just use scene file one without any adjusting.

here are the results:-


Before

PIC1.jpg



After

PIC4.jpg




cheers,

scott
 
You must log in or register to reply here.
Back
Top