Exposure weirdness

disjecta

disjecta

Lucky Duck
There has been criticism before about the way Canon HDV cameras handle highlights and I have to say, based on my own tests, these comments are well founded.

From what I have seen so far, there is nothing eloquent about how the XHA1 handles highlights, even with the knee set to low. It goes from exposed to blown out in a single step.

What is a little confounding is that I always use zebra stripes to judge exposure and I've usually been able to record what I am seeing exactly how I want it.

I currently have the zebras set to 100, just like I had on my DVX and I am very careful about not letting certain areas clip. When I look at high contrast areas of my shots (for example, a tree on the horizon with a bright sky behind), I am seeing lots of clipping. This was clearly not happening when I was looking through the viewfinder, no zebras, good exposure. This should not be happening so I am thinking I will need to bump down the zebras to 90 or even 80 which seems weird to me.

Has anyone encountered this strange behavior?
 
I think the viewfinder, like the LCD, doesn't display the correct exposure so you wouldn't be able to tell visually without zebra.
 
disjecta said:
I figured out that I need to set my zebras to 80%.... thanks :)
Click to expand...

Learned that the hard way. So much of my first shoot has blown out portions of the frame.
 
Disjecta,

I have seen your shots and they are amazing! I just got my A1 and still learning it and setting it up. I am having the same problem with exposure either being underexposed or overexposed and I was wondering exactly how you use your zebras for exposure. Setting it at 80%, should I be seeing any zebras when shooting? or should I make sure not to see any zebras to get proper exposre. I'm new to using zebras in general. Also do you shooting in 0 db or -3db and what shutter do you generally use? I'm getting some noise in my video, especially in dark spots.

Thanks for the info!
 
You use the zebras as a general guide. Sometimes you have to intentionally blow out an area of the frame to properly expose something else. Sometimes you want to retain detail in a brightly lit area and you use the zebras as a guide to retain as much detail as you can without making the rest of the frame too dark. Generally when you see zebras in your frame, that portion is going to register as white with no detail. At 80%, it may not be blown out completely.

It's just such a subjective thing. I don't use them as hard and fast composition tools, just as a guide and reminder to what is approaching over exposure.

Here's a basic description: http://www.mediacollege.com/video/camera/viewfinder/zebra-stripes.html
 
Last edited:
80% is standard on the HVXA1, but you need to work with it to get a 'feel' what parts do you want to be blown out, to make a reference. You learn that, and can do that with 90% or 100% too, you learn how to read the image, and the parts that ar blown out and how that finally shows in the image. For skintone I prefer 70%.

I returned to 100% and see the levelmeter in the LCD as a guide. Keep it for a longer time on one level and learn. I filmed two swans -swimming in the sun- and the white swans had both a part that was blown out.
Indeed the knee was set for low, but the step to blown out was hard and sudden. Maybe with a lower setting ( 80%) I would have more headroom in the whites but even then, its hard to make a white swan shine in the sun.

BTW: I have set the LCD and viewfinder setting for Peaking and Magnitude in black&white, so you can't fool yourself.
 
Last edited:
this scares me.. i was not aware the knee was so weak even in low..

hmm, im also noticing this in my footage now that i look at it.. I guess there is n oway around this? Must one just lessen their exposure?

i guess i just dont see this as a solution because lowering the exposure will darken the image, but the transition to blowout white will always be harsh, even in low?

:( :(
 
I figured this out QUICK on the A1. What I did was set my zebras to 80 and then adjusted the LCD settings until I sound a fine balance between what my trusty field monitor displayed and what the footage looked like after being imported into FCP. Now, everything is all good.
 
You need to learn yourself a way to interpret the zebra and what it does in real world. You can learn it with 80% but you can't see the blown parts differ from the true white parts in the sky. You need 100% for that. Having both (70 and 100 % ) is best but... the white clipping is there, just a little beter with low knee, but it's not something that bad, reflection on a white curved surface -like the swans- could be enough to clip white on any 1/3 " videocam.

Adjusting the LCD would not help here. [edit] I think I was shooting with peaking for focus on, so no zebra that time, that is the main problem : no zebra and peaking together.
 
Last edited:
Jay Rodriguez said:
I figured this out QUICK on the A1. What I did was set my zebras to 80 and then adjusted the LCD settings until I sound a fine balance between what my trusty field monitor displayed and what the footage looked like after being imported into FCP. Now, everything is all good.
Click to expand...

care to share your LCD settings? :)
 
You must log in or register to reply here.
Back
Top