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> Blue Screen Help Needed!
whorfin
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post May 24 2007, 10:00 PM
Post #41
Christopher,

There are a couple of ways to interpret your post. This reply assumes that the "it" referred to in your post was compositing green screen footage (the topic of the entire thread), not the more specific topic mentioned in my last post (uncompressed HD on the cheap). If this assumption is wrong, let me know.

> Would Adobe After Effects do the job?

Apparently, yes... depending upon the quality of the video, how well After Effects works on your computer with the captured footage (i.e., do you need a new, powerful PC?), how much effort you put into setting up your green screen (especially lighting), *and* the time invested in working on the footage in After Effects (if there are problems).

> and how do I do it in Adobe After Effects?

I haven't done any Green Screen work myself... yet... so I am not qualified to answer the question. Pretty much everyone else in this thread is more qualified to discuss this than me. If you have access to a good library, or can use interlibrary loan, try to find books on After Effects, Digital Video, and Cinematography... or use the internet to learn more. If you have questions about After Effects, look for user forums for that program. Hopefully the links below will help for now.

http://www.philipwilliams.com/greenscreen.aspx

  There are links to tutorials on this page. Which I got from:

http://www.google.com/search?hl=en&q=A...G=Google+Search

Thinking of taking Morning Star live action?? If you haven't already, check out the "Behind the Scenes" featurette for the Fan Film "Grayson". Its not Star Trek, but it demonstrates what can be done when someone thinks real hard about making a Fan Film.

http://theforce.net/fanfilms/nonsw/grayson/
http://en.wikipedia.org/wiki/Grayson_(film)
http://www.untamedcinema.com/


What follows is probably *way* too much hypothetical thinking on the topic than you intended in your original question, but I tend to be very detailed in my answers. Ignore it if you want.

In terms of the acutal filming, here is my *utterly* *inexpert* advice. Whatever you use for your green screen -- assuming you don't buy a professional one -- make sure it is smooth and painted evenly (don't neglect the floor). Light it according to whatever guides you can find on the subject (at least one PDF on this topic was linked previously in this thread - http://studio204.tlt.psu.edu/tutorials/lightingtutorial.pdf ). Try to keep you actors 10 feet or so away from the screen and light them seperately if at all possible. Use an appropriately colored "green" screen if your characters don't have green makeup or costumes that cause keying problem. If they are green and there are problems, try a different blue colored backdrop instead and film with that. If both green and blue characters are in the same scene, you could try the orange color referenced earlier in the thread. Unless, of course, characters with ordinary skin tones or redish costumes are *also* in the scene ['Thalek' probably just blew an antenna off thinking of keying that], in which case you'll have a *lot* of fun with your project (such as finding another color that works, endlessly tweaking the keying in After Effects, or shooting them all seperately and adding them all back in... like in Star Wreck 6 -- check their FAQ or Behind the Scenes web page). Avoid frizzy hair and diaphonous clothing... unless you want to buy Ultra 2.

When you do the filming, *if* you are going to have complex scenes where you individually add in multiple actors or objects (like Star Wreck 6), you need to mentally compose the filming of each segment mathematically. What does that mean? It means if in the final composited scene one actor is over there looking in one direction and another is over there looking a different way, you need to take these relative positions and directions into account when you film them individually. Instead of, for example, just having both of them look over your shoulder. Use trigonometry and map it out ahead of time... at least if you are not getting satisfactory results. Similarly, your Computer Graphics generated "virtual set" needs to be created using these calculation, preferably set to emulate a lens similar to what is actually in your camera (don't ask me how). If you don't want to do the calculations, take the actors or stand-ins somewhere that you have room enough to pose them the way you want the scene to work out, use a tape measure to get distances, and use a digital camera or a drawing to figure out approximate angles. Don't move the camera while filming for compositing (not one bit, including zooming) *unless* you are interested in figuring out how to do motion tracking and/or rotoscoping (see Star Wars Revelations audio commentaries and documentaries to learn about this hassle).

Also, the actors need to be lit seperately in accordance with how the final composited scene is supposed to look (i.e., light sources in the computer graphics generated room or conventional lighting for filming purposes... whatever... need to be taken into account and adjust your on set lighting accordingly as the actors are positioned, if necessary). Similarly, if one character is supposed to be in the foreground and in focus and one character is in the back ground and slightly out of focus (or vice versa), you may need to take that into account or you could lose the 3D feeling of the scene. I have no idea what having an actor slightly out of focus will do to green screen compositing (under various programs). I would guess it would be a *bad* thing, so it might be best to do that digitally in After Effects during compositing (don't ask me how). Anyway, this is only an issue if actors are seperated by a noticible distance in the composited image.

The more effort you invest into figuring out how everything should be done ahead of time to achieve exactly the image you desire, the closer you will come to achieving that goal. If what I've explained above doesn't make sense, or is too much information, I suggest trial and error -- learn by doing. Something is usually better than nothing, and if not you can always erase the tape.

So, to summarize, "yes".

Regards,

Whorfin
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whorfin
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post May 24 2007, 11:13 PM
Post #42
John,

Check this out...

http://www.philipwilliams.com/greenscreen.aspx

  Specifically:

http://www.philipwilliams.com/chromatutorial.aspx

The keying of the clear glass is quite impressive, the toy-in-frentic-motion somewhat less (to a non-professional like myself, at least). Perhaps this has something to do with the commentary at the bottom of the links to the merchant sites in the last post I made back to you regarding Ultra 2 (I'm wondering if Adobe has integrated it into its products)? Does this compare to Ultra 2? Any Star Wars glasses or Speeder Bikes handy? 8)

This link was as close as I could find to the dead link on the page (the site owner evidently moved the guides to their own website). Interestingly, it raises some of the points I made earlier, except *concisely*.

http://www.fxguide.com/fxtips-242.html

The following article had several interesting points:

  Blue/Greenscreen Tips
http://www.greatdv.com/post/bluescreen.htm

"Some folks claim that blonde hair keys better against blue. If you're recording in DV format (say, with a Sony DCR-VX1000) you'll find that green works just a bit better due to its higher luma content."
"Use a live analog chroma keyer straight off the camera whenever possible. This is still the highest quality, fastest technique, since you're keying the uncompressed camera signal at 4:4:4 sampling."
"If an analog keyer is available, but you must still record to tape and composite later with AE or other software, here's a great tip: replace the actual green screen with a solid electronic green through the keyer. That way, the software won't have to wrestle with 200 shades of green in the digitized image -- and the software controls can be used to fine-tune edges instead."

You may already know all of this.

At the bottom was a link to this page, which has some interesting statements as well:

http://www.seanet.com/users/bradford/bluscrn.html

"Red, green and blue channels have all been used, but blue has been favored for several reasons. Blue is the complementary color to flesh tone--since the most common color in most scenes is flesh tone, the opposite color is the logical choice to avoid conflicts. Historically, cameras and film have been most sensitive to blue light, although this is less true today."
"Green has it's own advantages, beyond the obvious one of greater flexibility in matting with blue foreground objects.  Green paint has greater reflectance than blue paint which can make matting easier. Also, video cameras are usually most sensitive in the green channel, and often have the best resolution and detail in that channel. A disadvantage is that green spill is almost always objectionable and obvious even in small amounts, wheras blue can sometimes slip by unnoticed."
"Sometimes (usually) the background color reflects onto the foreground talent creating a slight blue tinge around the edges. This is known as blue spill. It doesn't look nearly as bad as green spill, which one would get from green."

Studio Depot? I picture this huge store filled with everything movie makers need, conveniently located in almost every suburban neighborhood.

The entire site has potential, but "Post Production" seems to be most on-topic here:
http://www.greatdv.com/post/post.htm

Sorry if I am rambling. Its about 2:30am here.

Goodnight & Good Luck,

Whorfin
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Thalek
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post May 25 2007, 04:13 AM
Post #43
The blurry key is as impressive as the glass.  Watch some of our sword work that wasn't filmed on location:  the rapidly moving "swords" turn green because the keyer can't handle the blur.

I haven't had a chance to study all the links, but yes, this plug-in for After Effects appears to have some of the strengths of Ultra 2.  Whether it works the same way or is based on the same algorithms, I really couldn't say.
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whorfin
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post May 26 2007, 11:21 PM
Post #44
John,

> The blurry key is as impressive as the glass.  Watch some of our sword work that wasn't
> filmed on location:  the rapidly moving "swords" turn green because the keyer can't handle
> the blur.

I suspected as much, but with my ignorance on the topic...

I haven't been able to view all the images as I managed to get my super-slow dialup connection up and running to supplement what little broadband time I have (hence why I was posting at 2am).

And of course, as the guy points out, this was with a less-than-stellar Mini-DV camera, improper lighting, and inadequate green screen. But was it significantly harder to do (i.e. lots of tweaking required)? [Thinking out loud.]

> I haven't had a chance to study all the links, but yes, this plug-in for After Effects appears
> to have some of the strengths of Ultra 2.  Whether it works the same way or is based on
> the same algorithms, I really couldn't say.

Sorry, that's my version of thinking out loud, asking question that don't have easy answers. Rhetorical, ultimately? While you might want to check out those other links when you have time, here's what I've figured out about the current Ultra situation. Adobe bought Ultra 2, and are *selling it* ($499 I think) on their website (along with the virtual sets). They are advertising the upcoming Adobe Ultra 3, and I think they mention it's features (or the whole product) being in their next top-of-the line studio version of Premiere (whatever they call that uber-bundle). Presumably though, the screen shots on the websites I had links for are the currently available version (a year or more old, I guess), which shouldn't have Ultra technology. Of course, diaphonous fabrics might not fair as well until the full Ultra injection occurs. I don't know if they bought all of Serious Magic (like DV Rack) or just that product.

So, the good news is that Ultra is now part of Adobe, who of course have lots of money to stick into developing it. The bad news is that they could decide to stop offering it as a seperate product and bundle it with Premiere or After Effects or their Uber-Bundle only. Also, they could make it less effective with competing products... I guess. That Ultra 3 is scheduled as a seperate product is a good sign. Probably, the switch to Adobe would make new Mac or Linux versions less likely to happen than from a more independent company.

BTW, one of the websites in the previous post has "sister website" that is a online VFX school. Money is involved in taking these courses ($300 a term), but some resources seem to be free (such as the podcasts).

http://www.fxphd.com

They do have a "Help Desk" section of their forum for non-members. There is some useful info in it, such as this one on Shake:

https://www.fxphd.com/lounge/showthread.php?t=2704

Regards,

Whorfin
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Thalek
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post May 27 2007, 02:42 AM
Post #45
They're planning on Ultra 3?  Good!  Because when the Photoshop CS3 or whatever it is called comes out with the Ultra plug-in in July, they will no longer be offering Ultra 2 as a separate product.  :-(

I suspect they bought the other products of Serious Magic at the same time.  Whether they intend to continue offering them for sale, or just consider them something else they had to buy to get the Ultra technology, I coudn't say.

Well, back to bed with me.
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Wolf one
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post Jun 13 2008, 06:51 PM
Post #46
QUOTE (Thalek @ May 27 2007, 05:42 AM) *
They're planning on Ultra 3?  Good!  Because when the Photoshop CS3 or whatever it is called comes out with the Ultra plug-in in July, they will no longer be offering Ultra 2 as a separate product.  :-(

I suspect they bought the other products of Serious Magic at the same time.  Whether they intend to continue offering them for sale, or just consider them something else they had to buy to get the Ultra technology, I coudn't say.

Well, back to bed with me.

Well Been pondering can i pull off a blue screen shot?, well there is a garage pull everything out of it got room(unlevel floor thought) roof leaks i could get the basic shot , but the "Keying" of the Bridge,Med-Bay,Flight Deck
fighter ETC. how does one make the images to put into the green screen shot?
(yes i have taken notes from this post) my pc is an 1.7 ADM 30gig hd 500 front side bus would this run the apps for the green screen and keying or will i need to "upgrade" to a better computer?
William"Wolf One"Mellott
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Statik
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post Mar 15 2009, 01:22 AM
Post #47
For those who are interested in doing their own greenscreen on the cheap, here is a workable solution:

1. Get any cheap DV camcorder. I'm using an old Sony Digital 8 which has only 300K resolution, I think.
2. Go to your local dollar store and purchase several green table cloths that are as close to digital green as you can get.
3. Watch your local hardware store flyers for sales on 2-head halogen work-lights on a tripod. Buy 2 or three.
4. Download Blender 3D from http://www.blender.org/download/get-blender/
5. Download the greenscreen plugin from http://paprmh.googlepages.com/greenscreen

There are several tutorials on lighting and such for greenscreen on youtube.com. Here are links to a video and the source I did using the equipment above, except that I didn't have the worklights. The results would have been better with them.

Short video overlay of greenscreen kid and a zoom-out - http://statikonline.com/Slides/Seth_Grows.mpg
The DV source for the greenscreen - http://statikonline.com/Slides/seth_green_source.dv

My Youtube channel with some other green-screen and blender videos I've done.
http://www.youtube.com/user/Greydesk

Statik
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STRequirius
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post Apr 4 2009, 12:49 PM
Post #48
Which program is better for keying? Sony Vegas or Adobe Premier? I want to know before I buy premier.
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post Jun 11 2010, 03:33 PM
Post #49
For strictly photography with Blue Screen, what camera would be best ?

It was mentioned the Areak filming room was small. How small ?
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