backlight/spotlight

Cees Mutsaers

Cees Mutsaers

Veteran
What does the backlight option do? I thought when you shoot for instance an interview from someone in front of a bright window "backlight" would kind of make some kind of compensation where the luminance of the background is reduced while the person in the front will not become to dark. If I push the user button with backlight I don't see anything happening in the EVF nor the LCD. So maybe someone who used this option can explane me hoe this option is used ? I guess spotlight is the reverse of backlight, right ?

Also when I set the irus (manually) in such a way that the 70% zebra's are visible and only in some very small bright areas the 85% zebras are visible, if I go to FCP and use the "range-checking tools" to check if the luminance and chrominance are within the "broadcast safe range" it turns out that not a single clip fullfills this condition. Does this mean that my 70% and 85% zebra's are off ????
 
Backlight and Spotlight just change the iris to allow for more or less exposure. You have to be in auto-iris mode for it to work.

I don't use 70 & 85, I use 70 and 105. 70 to check for the hotspots on caucasian skin tones, and 105 to check to see that nothing's blown out/clipping anywhere in the frame.
 
Thanks Barry, that makes sense that it only works in auto iris. Since I never use auto iris it is the reason I did not see anything happening.

Concerning the zebra's if I use 85% as upper level wouldn't you expect more problems to fullfill the "broadcast safe range" when you use 105%? Do you adjust the iris in such a way that (in your case) the 105% zebra is just not visible?


Barry_Green said:
Backlight and Spotlight just change the iris to allow for more or less exposure. You have to be in auto-iris mode for it to work.

I don't use 70 & 85, I use 70 and 105. 70 to check for the hotspots on caucasian skin tones, and 105 to check to see that nothing's blown out/clipping anywhere in the frame.
Click to expand...
 
and the reason why I got "overexposure" according to the "broadcast safe range" in FCP is that when I see the 85% zebra's it can as well be even beyond 100 % right?

You say that you use the 70% zebra to check for the hotspots on caucasian skin tones. What do you do in that case ? I guess closing the iris will result in underexposure?

In general how should the zebra's be for a correct exposure?

Barry_Green said:
Yes, I never want to see 105.
Click to expand...
 
Essentially, yes. Skin tones should be around 70%, more or less. When I see zebras on cheeks or forehead I back off. Setting to 105% tells you the other extreme, and usually if I have proper exposure for skin tones but still blowing out I fix the blow out. It might be dimming a practical in the background, adding difusion to a light, or reframing.

John
 
For me if I just see zebras on cheek highlights and then back off a bit that makes it OK.

I only started using zebras with my 301 this year and now I am so used to them, I also do a quick press of the auto button and 9 out of 10 times the exposure is right.
 
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