a7s Zebras

[mojo43]

I have a question about zebras on the a7s. I have been testing out the 100+ setting. It seems that the 100+ setting is displaying anything over 100 IRE. But when I import my footage into my editor those places aren't blown out. They are just over 100 IRE, but can be under 120. I thought that anything over 100 should be blown out?

[smon222]

Great question, I was wondering about that myself. I switch between 100 and 100+ but I don't see much of a difference. Could someone explain Zebras as they pertain to the A7s. Its different somehow.

[dhessel]

I could be wrong but I believe the IRE scale is for video levels. Video levels translate to 16-235 rather than 0-255 for full 8bit. Therefore it is possible to record above IRE 100 without clipping. 

[mojo43]

I lost you there. Are you saying that the A7s records 16-235 or all cameras record that?

[dhessel]

It varies depending on picture profiles but camera can record 0-255, 255 would be 108 IRE if I am not mistaken.

[mojo43]

I am really confused. 108 IRE sounds about right. So when zebra 100+ shows on the display, it doesn't mean that it is clipping. It could be, but maybe it is between 100 and 108. Correct?

[dhessel]

That is right It doesn't mean that it is clipping, it could be but doesn't have to be. The value would be over 100 IRE, if it is between 100 IRE and 108 IRE it won't clip in the file, if it is over 108 IRE then you will see clipping in the file. That is my understanding but I am fairly new to the whole concept of video levels myself.