OT: Ghosting Hands (interview)

gdstaples wrote on 1/4/2006, 7:08 PM
I recently shot a talking head interview in medium light conditions with the Z1U.

If I remember correctly the camera was set to medium gain at 1/200 at around f/4.0. When this guy talks, he moves his hands a lot and in some cases I get ghosting that appears around his hands when they move - almost like video lag. The footage was shot at 1080i - HDV.

I have tried rendering in progressive mode with no improvement. What can I do in the future to prevent this? I was using an Arri Fresnel 650 (softbox) with bounce for fill. You would think this would be sufficient lighting to prevent this type of situation. I needed to go medium gain and fairly wide open for ambient conditions as the background was quite interesting and too large to light for an interview.

Any tips or suggestions would be appreciated.

Duncan

Comments

richard-courtney wrote on 1/4/2006, 7:13 PM
Are you using the lens steadyshot function?

I had a problem taping closeup Christmas lights, steadyshot was causing what
I thought was a spider web inside the lens. Turn it off.

Original coatings on the lens or have you cleaned the lens lately?
gdstaples wrote on 1/4/2006, 10:13 PM
Lens is clean and steadyshot is on. It almost looks like the shutter speed was too slow - like the Matrix hand motion effect. I would think 1/200 would be fast enough.
mjroddy wrote on 1/5/2006, 9:24 AM
Sorry I can't help you with your problem. But I had a question: Why use mid DB and a shutter of 200? Why not use 0 db and something slower? I have pretty good luck with 60. I thought 200 was more for outdoor use. I'm just trying to learn more and more.
Re-reading your description, I guess I had to be there to see your BKG and such to know why you made the choices you did. I'm thinking that's the only way I would understand the trade-off's you made to get the right exposure.
Your ghosting problem is odd, though...
Coursedesign wrote on 1/5/2006, 9:40 AM
Use ND next time instead of squeezing the shutter.

At this point you could try putting some motion blur on his hands, it's probably rescuable.

But, is the final product meant to be shown on an interlaced or on a progressive screen?

This sounds like a deinterlacing problem, especially if you are seeing this on your computer screen as opposed to on an interlaced monitor.
gdstaples wrote on 1/5/2006, 2:07 PM
Here is a small sample rendered in progressive mode:

http://staplesphoto.com/fm/test_hands.html

So I should use a slower shutter speed than 1/200 CD?

The results are visible on the master tape as well so it was something captured via the camera.

Duncan
rmack350 wrote on 1/5/2006, 2:48 PM
Yes, you should use a regular shutter speed. If you had then the hand movements would be a blur instead of a stacatto-looking sharply resolved shot. Because you used an abnormally high shutter speed you captured very clear images of the hands moving. High shutter speeds are nice for freezing raindrops or getting clearer images of a football in the air but normally not so good for natural looking action.

Steadyshot probably didn't help either. You don't need it for tripod/doll/crane work.

Rob Mack
Coursedesign wrote on 1/5/2006, 3:02 PM
It's called strobing for a reason.

Add motion blur to those hands, it will make it look much better.
gdstaples wrote on 1/5/2006, 3:22 PM
Do I do this via a mask or can I just apply motion blurr to a targeted area?

Good info guys. Live and learn on the shooting end. Definately a lesson learned.

Duncan
Coursedesign wrote on 1/5/2006, 5:05 PM
I never used Vegas for this.

There are several AE plug-ins to do this semi-automatically (depending on footage).

I've got ReelSmart MotionBlur, this can either add or remove motion blur, not bad for $100 or so.

It is conceivable that this can run inside the free Boris Graffiti LTD in Vegas, or in one of the other "gaskets" that interface to After Effects plugs.
gdstaples wrote on 1/5/2006, 6:13 PM
I've got AE. Any tips on what plugins work best?
Coursedesign wrote on 1/5/2006, 7:04 PM
ReelSmart MotionBlur.

gdstaples wrote on 1/5/2006, 7:10 PM
Thanks CD.