smoothing out in-camera auto-iris shift

Hey all --

I am working on a total guerilla-style DV feature.

Some of the footage was shot using regular old consumer camcorders.

There are several instances where they would shoot scenes where the camera is hand-held around the room, part of the room having a big bright open window in it. So whenever the camera is pointed on the person standing in front of the window, the auto-iris feature on the camcorder adjusts to the leaves outside, leaving the person's face dark. Then the camera would move to someone else not standing in front of the window, and the auto-iris adjusts for that person's face.

Some shots have to be continuous here, so I am looking for some sort of filter that is designed to level this sort of thing out more or less overall. Right now I am using the color-corrector and the brightness filter and keyframing as much as I can. Very time-consuming, and almost impossible to nail it just right. There probably isn't anything that will do this, but I thought I would throw it out there...

thanks for any suggestions!

best
karl

Rule #1 in shooting...or one of the BIG rules anyway. TURN OFF ALL AUTOMATIC CAMERA SETTINGS! No autofocus...no auto iris. ALL manual. Then you expose for your characters, and if you hit the blown out window, that will cause a huge halo around the subject, but you can still see his/her face.

It would be best to put a filter on the window...but I get that you are a guerilla.

BUT...since you did this already...the best thing to use would be the 3-way color corrector. You can keyframe color correction so you can correct when the iris changes. Or razor at a mid point, correct each scene appropriately then add a cross dissolve.

You should get the ENCYCLOPEDIA OF COLOR CORRECTION by Alexis Van Hurkman. He has a section and TUTORIAL on how to do this.

Amazon.com


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
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Thanks Shane, I'll check it out.

For the record, I DIDN'T SHOOT THIS STUFF. AT ALL.

I wasn't on the set or anything.

I'm just the editor.

Like I said...

Wearing my Harbinger of Doom hat for a minute, as the iris goes down, the contrast goes down with it. If the window was bright enough, there is no face--or it's so distorted as to be unusable.

You get the "Close Encounters" look where the face is a featureless blob in the middle of a bright flare frame.

You'd be amazed at the number of "guerrilla shoots" that were carefully planned.

"How come when they shot guerrilla you could see faces and hear everything clearly. Then, when we shot guerrilla ......"

Koz

[Wearing my Harbinger of Doom hat for a minute, as the iris goes down, the contrast goes down with it. If the window was bright enough, there is no face--or it's so distorted as to be unusable. ]

Oh, it's sometimes worse than that. As you keyframe, pay attention not only to contrastm but Whites, Mids, and Blacks. I have seat time doing AAI -- (yes, just how it sounds) Anti-Auto-Iris -- and it's a bitch. I switch form Visual to Numeric, of course, where the Time Graph appears, and keyframe there. Start a KF right at the first perceived frame of change, and another at the last.

For best accuracy, the same advice as for color correction, don't do this on anything but a real NTSC broadcast quality monitor or NTSC-calibrated flat.

If you don't attend to all the luminance values in the image you get less than smooth results-- and sometimes keyframing is not symmetrical. It's trial and error but you can get the hang of it after a few and it's often worth the trip.

- Loren
Today's FCP keytip:
Set Video In & Out separate from Audio with Control I & O !

Final Cut Studio 2 KeyGuide? Power Pack.
Now available at KeyGuide Central.
www.neotrondesign.com

OK, thanks guys. I suppose this situation needs that special filter called "Ass Plus Chair."

Thanks for the advice!

And Koz -- I hear ya, but I am absolutely certain this one was not "planned." The only thing that was planned for this project was for someone to sort it out in post.



later
karl

[OK, thanks guys. I suppose this situation needs that special filter called "Ass Plus Chair." ]

Yup, but you should be able to semi-automate the keyframing in a rough manner by simply copying attributes from your first successful AAI. Then tweak to taste.

- Loren
Today's FCP keytip:
Set Video In & Out separate from Audio with Control I & O !

Final Cut Studio 2 KeyGuide? Power Pack.
Now available at KeyGuide Central.
www.neotrondesign.com

Use the Foundry's Furnace Plug-ins for Shake. They have a flicker filter that works awesome. it's EXTREMELY pricey (although they do have a 30 day free trial or you can rent it by the day) but it is worth every penny! We had some film that was x-ray flashed and using a combination of Furnace filters we got rid of it.

[www.thefoundry.co.uk]