Letus or No Letus for Green Screen Shoot?

A

andrew00

Well-known member
Hey,

I'm going to do my first music video on a green screen shoot in two weeks time. I am going to shoot on my camera, Sony EX1. I also have a Letus Extreme, currently with two lenses - Nikon 50mm f1.4 and Nikon 105mm f2.8 (manual).

I was wondering if people would recommend using the camera without adapter or the camera with Letus + lenses?

I don't know which is best for the green screen.

Oh and as a second question if anyone knows, the shoot is pretending it's in a wood so would it be wiser to tell them to paint the screen blue as to avoid any issues with scenery that might be grass coloured, aka green!
 
No need for a 35mm adapter when shooting green screen. Turn the sharpening down on the camera though.

If you've got greenery as props or set dressing against the screen, then you'd want to look at something other than green, blue being the next best suggestion. If you're adding the greenery in post after the shoot, then shooting against the green screen is fine.

cheno
 
We got into that question for a serie's pilot where the main actor is in front of the camera and the background changes at each joke (he visits appartments). Backgrounds are photo-realistics 3D plates, so the goal is to make the green screen integration the most realistic as possible.

We made some tests with and without mini35 (Sony EX3 bare vs Sony EX3 + SG Blade (RR2) + Nikon 24mm).

We definitely used the adapter solution for many reasons :
- With a few meters between the actor and the greenscreen, the slight defocus from the mini35 helps the key, especially with Sony EX series.
- When the actor uses his hands in front of the camera, you can actually feel the DOP, which helps the realistic effect with the defocused 3D background.
- The tests with bare lense made the actor way too sharp and in-focus while the background wasn't. Integration wasn't nice.

Here is a small test we made with a simple background. You can actually see the vfx breakdown after the scene. And also, it is in french : http://player.noside.fr/appart1

Screenshot :


We used -3db gain and sharpening off (around -20) on EX3. We also got small chromatic aberation because of the SG Blade, which we removed in post. The new optics should solve that.

I think it depends on what you're going to shoot, but for our project, the SG Blade helped a lot !
 
Nomalz said:
We got into that question for a serie's pilot where the main actor is in front of the camera and the background changes at each joke (he visits appartments). Backgrounds are photo-realistics 3D plates, so the goal is to make the green screen integration the most realistic as possible.

We made some tests with and without mini35 (Sony EX3 bare vs Sony EX3 + SG Blade (RR2) + Nikon 24mm).

We definitely used the adapter solution for many reasons :
- With a few meters between the actor and the greenscreen, the slight defocus from the mini35 helps the key, especially with Sony EX series.
- When the actor uses his hands in front of the camera, you can actually feel the DOP, which helps the realistic effect with the defocused 3D background.
- The tests with bare lense made the actor way too sharp and in-focus while the background wasn't. Integration wasn't nice.

Here is a small test we made with a simple background. You can actually see the vfx breakdown after the scene. And also, it is in french : http://player.noside.fr/appart1
Click to expand...

Wow that's cool, makes for a nice smooth keying effect. Thanks for the info, I'm interested in seeing if anyone test how this works with other cameras.
Click to expand...
 
Make sure you have alot lights to light the green screen and actor. The trick is to light everything evenly so the post processes is easier. The adapter makes things harder, not impossible but I find while lighting for the adapter it makes things harder then they need to be (The lighting needs to be even on both actor and background, depends on what you want). Use green paint it is easier to key out easier, in my opinion.
 
I also recently used the SGBlade (RR2) for some green screen work and found that it helped make the scene look more realistic. I didn't find it any harder to key than it would have been without the 35mm adapter.
 
Nomalz - Your keys are very clean! What keying program did you use? I am green screening a lot of shots in an upcoming documentary. They also need to be realistic.
 
We don't use an all-in-one plugin or software. Our vfx artist does the compositing in Nuke, but it involves multiples passes to get this kind of result. In example, there is a special work for all the arms movement to keep a nice motion-blur effect.

Sorry not to be able to explain more but I don't know much about it. :)
 
This is very interesting. I never do compositing myself so I wonder whether it is technically difficult to composite something that is out of focus. Wouldn't that create a mixing of the green in to the keyed elements? This is a good question for Jim Arthurs in Texas who has done lots of compositing with the Ex, HVX and other cameras.
 
Tested, tried and true, avoid film adapters when shooting green screen, this is a digital domain concept, and any focus blur or soft edges will break the key. Add shallow depth of feel digitally on the background or on the foreground (subject) in Post. No one will tell the difference afterwards.
Cheers
 
DEPTH OF PHIL said:
Tested, tried and true, avoid film adapters when shooting green screen, this is a digital domain concept, and any focus blur or soft edges will break the key. Add shallow depth of feel digitally on the background or on the foreground (subject) in Post. No one will tell the difference afterwards.
Cheers
Click to expand...


From my experience (tested, tried and true) I have to disagree with such a blanket statement. I have suceessfully done green screen compositing both with and without an adapter. There are times when its appropriate to use an adapter and it's not about getting DOF in a composite.

Here's why/when I use an adapter - If i've shot my entire project with an adapter, cutting in composites that that were shot with a bare lens just won't have the same texture as the rest of the project. You can try and match it in post, but it's never exactly the same. Not to mention it adds additional time to the edit trying to achieve that same texture. Just make sure that your DOF isn't too shallow so that edges of your foreground subject will be sharp and not interfere with the keying process. It takes a little planning, but the results are worth it.

If you still want to add DOF then, as you suggested, you can do that in post. It's about maintaining the texture.
 
Valid point, and when shooting green screen with a film camera or Red One , that is especially true,
I admire your patience, but i do think there are times to lose the adapter, this is one of them!
In my experience, lets say with a HVX or EX series, which both produce superb film looks without adapters, it was not worth the time to add the adapter. Now you can certainly use filters on the raw camera to soften the look of the foreground and light it and make it more filmic , especially if you are shooting 24p 1/48 shutter to get most like film. It is about texture but it is also about lighting the subject to appear seamless with the background, to emerge that subject into the background. Adapter's & external lenses won't always allow us to do what we need to do with "moody" lighting options.

The purpose of the adapter is to create a shallow depth of feel, which is digitally put in via the background anyway. For example, 50mm is not to shallow but will limit your wide angle shots, and 24 mm wide may have softer edges , etc... But on a naked camera without adapter it will allow you so much more control and latitude over the green screen process and it's garbage mattes and in most cases yield the best key. As always, you have valid points here but i think a big part of it will be based on your tools on the set vs. the tools you have in post. If it is a complex VFX shot or just simple shot. If the subject is going to move around between multiple marks then tracking focus, no mater how slight will be pain and the edge key will be tricky!

For me after working at FOX TV so long doing compositing, i would do it in post because that's my backyard so to speak, and i need to produce results a.s.a.p

Nice to talk to u again . Did u go to Cine Gear?
Cheers
 
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Nope, I wasn't afforded that luxury :)

Years ago, a fellow helicopter pilot used to do the post work on the TV series, Pee Wee's play house as his day job during the pre and post digital video era. He used to tell me that it wasn't possible to pull a good Chromakey on the format I used (and could only afford) back then, 3/4" SP. Never tell me that something is impossible to do.... LOL. Back then, we didn't have things like Affter Effects, Commotion, Combustion, etc. We barely had computers! Another friend of mine and I managed to pull some really good live keys (with some modified live switching equipment) and recorded them to 3/4" SP.

Then, much more recently, someone told me you couldn't pull a good key using a 35mm adapter. I don't have to tell you what happened next.

Point being is that in the field of Digital Imagery, can't or impossible just takes longer and/or more imagination. Sometimes there's actually a valid reason to do what might seem counter intuitive.
 
Couldn't agree more, out of experiments comes the knowledge and results that one can never get from following the usual procedures. He sounds like all the wonderful " Film Guys "we met at Cine Gear. These guys know their stuff, How's the Blade hanging, i heard they have the new achromat fix out now?
Cheers
 
Yes, and ordered mine the moment it was available. I haven't really seen too much of an issue with the current optics, but I think it's important to have the best possible optics on an adapter.

Using the blade has been a real pleasure. I pretty much only use RR2, indoors or out. I really like the overall look from that GG.
 
Well it was really for the infamous EX series i believe, but Wayne did say it improves all cameras.
How much stop do u lose with rr2 and deep do u need to focus on the gg ,
Have you done green screen work on the Blade or Letus?
Cheers
 
According to the comparison chart, RR2 loses 1 stop compared to 0.7 for RR1 and 0.4 for RR3. All I know is that I don't have much trouble providing enough light with a minimum of two 650W tungsten lights indoors.

I use the flip module so the least I can zoom in is 73 on the A1.

I've shot green screen with the bare A1, with my DIY Mid-Format adapter, and the SGBlade. I've never used the Letus.
 
I just hate to take the adapter off, so I shoot everything with it on. Camera f4 and lens f4.
 

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