Proper Zebra Settings

Kevin Martorana · September 8, 2004

Hi everyone !

Okay...I've been shooting video for 30+ years...and zebra settings are a pretty simple concept. I usually like my zebra to begin showing up at 98%...so I know I'm getting close to full 100% and (depending on the camera) can push the exposure depending on the scene.

NOW...the 900 has got me confused a bit. When I put the gamma into Filmlike2, and light a standard interview...expose where I think should be correct...my b&w viewfinder looks correct. Detail in darks and the correct exposure on the skin. Problem is...on a color monitor...this is not the case....I'm usually 1/2 to 1 full stop overexposed !

So can someone explain...that this is because of the gamma curves ? They're allowing me to "push" the exposure more ?

In that same senario...I don't even get zebra...until I'm so far overexposed....the person's face is totally blown out.

Yes...i could set a zebra at 70% for face...but I've always found that to be disturbing when looking at facial features and performances.

THANKS !

David Mullen ASC · September 8, 2004

If you are setting the zebras at 98 or 100, then you only expect to see the zebras on white objects. So how are you setting the exposure? Based on what?

Shouldn't you set-up your b&w viewfinder and color monitor to bars so that they match in terms of brightness? And are you sure your large HD monitor is properly terminated (if using the three analog HD cables instead of an HDSDI connection)? An unterminated monitor will look about a stop "hot".

Obviously if your zebras are set to 98 or 100 IRE, you wouldn't see the zebras in the face until you overexposed them to be nearly white.

Either you need to set your zebras to 70 IRE and expose so that the hotter spots of the (caucasian) face are showing zebra stripes, or if the zebras are set for 98 or 100 IRE, you need the subject to hold up a grey scale with a white bar and set the exposure so the white bar is showing zebra stripes.

With DCC (auto knee) on and gamma set-ups being used, you will tend to hold more detail in bright areas so less of the frame will hit 100 IRE, but obviously a white object next to a normally exposed face will probably be at 100 IRE.

Anyway, there shouldn't be a discrepency between the brightness of your eyepiece and the monitor, or else how are you going to judge exposure?

John Ealer · September 9, 2004

Filmlike2 Gamma has a very flat knee, exposing for the highlights based on IRE alone could likely be throwing you off and lead to overexposure.

To test this, switch to STD gamma and see if your method of judging exposure seems to work.

J

September 9, 2004

what about going for both zebras? 1 at 80 and the other at 100 or 98--this way you can set skin tones and watch for clipping in whites too? i am around the varicam,f 900 , the dvx 100 , and the sdx 900--usually i get from the guys that have been shooting beta for many years is--MAN IM A WHOLE STOP OR 2 OVEREXPOSED!!! --they will say it looks ok in their vf--but the ref monitor looks blown out--ill find out that their zebras are set at 95,98, or 100--then begins the process ok pleadin with then to drop down their zebras--i usually get the vf looks ok argument--but you are telling the vf to look ok with only showing zebras at 95,98, or 100--so if you are zebra'ing then you have no headroom for correction--

what do yall think--i would love feedback to help people out

Kevin Martorana · September 9, 2004

Hi. guys....

Well...first of all..for David. There is no HD monitor...since this is a SD camera.

I've done some tests...setting Zebra 1 to 70% for skintones...and it does help...if you're shooting interviews.

There is a great difference between Filmlike 1 and STD setting in the gamma. Almost 2 ful stops !

Bottom line...this is alot like shooting film...and a light meter or scope is helpful when shooting.

In the old days of 60i video...you could rely on your eye with a B&W viewfinder...and grayscale images. With the latitude of this camera...you have to much more careful.