Out of focus characters and greenscreen.

[Thomas Fossgard]

(Please move this post to another section, if you feel it belongs there.)

 

Hello!

 

Currently a student of the polish film school, I have an idea for a shot I very much would like to achieve. It would be pretty straight forward it was shot on location, but I am severely limited in this regard, so we want to build the room in the studio, with a large window with a greenscreen outside.

 

I suspect the question appeals more to the post-crowd than cinematographers, so point me in the right direction if this is the wrong place to ask!

 

Description:

Black screen, sounds of person entering room.

The black becomes a silhouette of a character, with the room, and a window with view over the city in the background.

 

I want the focus to be on the background, and the motions of the character revealing bits and pieces with his movements in the very near foreground. (like keeping your fingers close to your eyes while reading this! :)

 

Possible solutions

1. Find a perfect location in a scyscraper/highrise...

2. Find a room on ground-level, and build a greenscreen/box outside.

3. Using a backdrop (Out of budget to make one specifically for this)

 

and what I'm thinking of:

4. Building the room in studio with a large window with greenscreen outside. Advantages are of course choosing the perfect view from anywhere in post, mood, light, studio-shooting, longer days, almost free etc. I've been pitching the idea for this shot around the school and most say I should blur the characters in post, but I'm sceptical to this as it has to end up beautiful and realistic..

 

Does anyone know how to key an out of focus area? Is there a trick to it? Some filter combination or tool that can do it? It will be mostly silhouetted out of focus foreground..

 

Any tips or pointers most welcome.

 

best regards,

Thomas Fossgard

 

(Available shooting formats range from DV, HDV, DVCPRO HD(HVX), Progressive Digibeta, XDCAM HD, and perhaps the Sony HDCAM 750) All with 35mm adapter.)

[Mike Lary]

Keying relies heavily on edge sharpness. I would create the blur in post.

[Thomas Fossgard]

Keying relies heavily on edge sharpness. I would create the blur in post.

 

Thanks, but I'm aware of this. I should have been more specific saying that.

 

I have to broaden the question a little bit then:

Is there a good way of blurring the foreground in post, or is there a good way of working with a blurred key?

 

I might be chasing windmills into a nightmarish post-production here.. :-)

 

I'm not a compositing expert, but I would guess I'm looking for some kind of overlay/replacement of greens going towards blacks/other dark colors)

 

all help welcome, and please say so if you think it's hopeless!

 

Thomas

Edited January 23, 2009 by Thomas Fossgard

[Tom Hepburn]

Hi Thomas,

 

I would say that's pretty close to hopeless. A blurred edge would be partially the moving object/person and partially the background, the green in this case. I think you'd be fine in getting what you want if you get a good key and blur in post. Certainly you'll have much more flexibility.

 

Good luck,

Tom

[Steve McBride]

You could just blur it in post (as mentioned). I'd use After Effects if you have access to it, just use the Fast Blur filter. AE is also a very powerful compositing program as well as keying.

[Thomas Fossgard]

But is blur the same as "out of focus?" :blink:

(Or as beautiful?)

 

I hope this thread will catch up some speed now, but please don't forget my original question!

 

All the best,

 

Thomas

[Mike Lary]

But is blur the same as "out of focus?" :blink:

(Or as beautiful?)

In the way you described the shot, yes. Holding your fingers close to your eyes and focusing farther away creates a complete blur of your fingers.

 

I'm not sure what you mean by 'beautiful'. You're talking about putting a silhouette (or near silhouette) of a person out of focus. There's nothing to see but a soft edge. There's no falloff of focus on the subject - since focus is on the background. If you were shooting film I could see concern over grain loss/expansion when you add the effect, but you're shooting digital so... what quality do you think you're going to lose by adding a blur in post?

 

To answer one of your earlier questions, I would steer clear of DV and HDV and I would do a test before the actual shoot, all the way through the keying process and visFX. I second the vote for using AfterEffects if you don't have someone to do the work for you - which would be the best choice since you don't have experience with those tools.

[Chris Keth]

Personally, I would find an acceptable location and forget greenscreen. This is not a situation where you have to make the shot a composite so why do it? It shouldn't be that tough to find a good location. People can be pretty accommodating, especially if you play the student card well enough.

Edited January 23, 2009 by Chris Keth

[Jim Keller]

I have to broaden the question a little bit then:

Is there a good way of blurring the foreground in post...?

 

I've used the After Effects "Lens Blur" filter to do this very effectively. I tend to use it more for background objects than foreground, but it creates a very natural-looking depth-of-field effect.

[Karel Bata]

I've managed to composite out of focus elements, but it's not easy. And I wasn't completely satisfied. Keylight is the plug-in to use. With film you need to de-grain the shot before working on it, othewise it just gets noisy, and then add some grain back after. They did that on Sweeney Todd at MPC.

 

Use a soft/hard comp combination. You make a hard key first, with really solid matte, but choppy edges, then make this a bit smaller to keep the edges clear, then blur it a bit, and use that matte as a holdout matte for a much softer key which would have holes in it if you would use it alone. Then create the "soft" matte. It has great edge detail, but does not have full density in the core. The hard matte fills in the solid core of the foreground, and the soft comp handles the edge detail.

 

Might be worth trying as a college exercise, but otherwise... I'd blur in post, or better still find a real location.

 

Best of luck! :)

[Scott Fritzshall]

You can do it either way really. The reality of doing effects is that you very rarely have everything shot in a manner that makes it easy to comp. Lots of times you'll have a two-shot against a greenscreen, where one person is in focus and the other person is out of focus. You can absolutely key this, it's just more difficult. I generally tend to be a fan of getting as much in camera as possible, and in this case if I were doing it, I would just have it shot as if it were the real thing; with the character out of focus. This way you get the true characteristics of the lens; bokeh, distortion, other artifacts that are difficult to replicate. If you're less experienced at compositing, you can shoot it all in focus and defocus this later, but you've got to be careful because slapping a blur on doesn't actually replicate defocus. I don't frequently use After Effects so I don't know what sort of tools it has at the moment, but last I heard, its "lens blur" tool was actually a fancy box blur, which is not at all what you want. I was doing a quick search to find examples of the difference between a normal blur and an actual defocus, and I came across this: http://www.mushly.com/2d-graphic-tutorial/...cus-background/

which looks like utter poop and is a perfect example of how unconvincing it looks when you try to simulate lenses with the wrong tools. Here's a little writeup about bokeh, with some neat image comparisons: http://www.bobatkins.com/photography/technical/bokeh.html

 

Focus is really the least of your worries though. More pressing is lighting. If at all possible, you really want to have your background shot before you do principal photography, so that you know what sort of lighting to match. Mismatched lighting gives away greenscreen shots just as easily as bad keying. Also, you didn't specify camera movement. If this is a lockoff shot, you're fine, but if you've got a camera move, then you're going to need to track the background into the shot- possibly as a 3d track, which can be really difficult if I'm imagining your composition correctly.

 

Final advice: don't do this as an effect if you've never done compositing before or if you don't at least have someone to help you who has. I think it's a great idea for you to learn more about visual effects, but making your student film rely on an effects technique you don't know how to do can be a really bad idea. Try shooting some tests and comping them first to get an idea of what's involved, and what works and what doesn't.

[Karel Bata]

Couldn't agree more about getting the lighting right. And gaussian wouldn't really work.

 

But I'm not so dismissive of other blur tools. Tinderbox gets good press. And check out the features on Red Giant's Composite Wizard -but it is $300.

 

p.s. if you go this route, don't forget to switch on AE's own motion blur. It's easy to forget (and annoying! :angry: )

 

:)

[Thomas Fossgard]

Thanks for the input guys!

 

We ended up shooting the whole thing with a backdrop picture, as the time and resources for keying didn't allow us a bluescreen.

 

Of course a talented and eager post-guy from animation jumped on last minute and want to animate people disintegrating in the nuclear explosion at the end..

 

but anyway, here's the some shots from the first day of shooting!

 

1st year cinematographers Tato Kotetishvili and Joaquin Del Paso on the RED, forgive me for the stills, I just screenshotted them from a medium quality RED-reference file with a "look" setting. The data in the RAW is much better, (yes with fill light in the blacks!)

 

I'm just the director with a serious bug of cinematography sickness.

 

The story and the actors might be bad, but at least it will look good!

 

Best and thanks to all of you

 

Thomas Fossgard

 

CHECK THE PICS:

http://www.flickr.com/photos/24967193@N05/...57616050707145/

[Thomas Fossgard]

 

[Karel Bata]

Nuclear explosion? You never mentioned that! :lol: Wow! That looks really good. "I'm just the director with a serious bug of cinematography sickness." Good way to be.

 

I use flickr too, but I find they're a bit limited (unless I'm missing something about them) and I don't like that everything you put there immediately enters public domain. I often use Photobucket like this page (you'll need password 55555).

 

Make sure to post a link to your film when you're finished ;)

[Nathaly Pinheiro]

On 1/22/2009 at 10:05 PM, Tom Hepburn said:

if you get a good key

English isnt my native language.. When people say that is refering to exposing the chroma evenly? 

 

On 1/27/2009 at 8:13 PM, Scott Fritzshall said:

If this is a lockoff shot, you're fine, but if you've got a camera move, then you're going to need to track the background into the shot- possibly as a 3d track, which can be really difficult if I'm imagining your composition correctly.

This is one of my doubts about green screen. When using tracking marks,  how sharp do they have to look in camera? I undestand I shouldnt be shooting very wide open otherwise they would look blurry but does any one has a visual reference? or an fstop interval recomended