Is my setting workflow for 170 bad?

[Richard Zlamany]

I have good success with my new 170 until my last event recording a chorus. A chorus of 75 people stood on risers. The people in the center were lit strongly while the people on the edges were lit much less. The footage came out not so great. The people in the center were washed out.
My settings were auto iris and focus, 60 shutter, and 0 gain. I let the iris adjust the brightness and usually have good results but now I think I may have caused this. What should have I done to my settings to capture the light difference on the chorus group? I ended up recording the chorus in sections to help but I think I could have done better.

[Don Bloom]

It sounds like the risers were lit unevenly with some sort of overhead spots or general lighting and the folks in the middle just happened to be directly under the light. The camera recorded exactly what it saw. There are 2 things you might have done and would want to practice before the next shoot-keep in mind both require close attention to detail meaning really looking at what you have in the viewfinder as far as lighting and exposure go.
Here are the 2 things. The 170 has a SPOTLIGHT button located on the lower left front of the camera. This will help adjust the iris to compensate for the type of lighting it sounds like you were up against-I've never used it as I run my camera in manual mode, but I guess it would work as thats what its there for. The 2nd thing you could do is practice with and learn how to use the camera in manual mode so you can make precise adjustments to the camera as you need. This in my opinion is the best-the auto iris will read only the overall general lighting and things can go wrong as you found out. To manually set the exposure for that type of situation, zoom in tight on the subject, push the auto iris button to ON, let it set on the skin tone, then push it to OFF. Your iris is now set and then zooom out to frame the subject as needed.
Too late for this one but hopefully this will help a bit for the next one. Remeber to practice before the next one and get set up to check out the lighting and exposures well in advance of the next gig.

Don

[Boyd Ostroff]

The basic problem is the limited contrast range of DV. It can't handle such a big range between light and dark so you will need to compromise in a situation like you describe. I run into this all the time when filming our performances.

Generally speaking, you need to expose such that the brightest areas still retain their details. Once you "blow out" the highlights, they're gone. However, if you close your iris enough to preserve detail in the highlights then the sides of the stage will look too dark. The best you can do in this situation is try to raise the dark areas in post.

Don's right - you need to learn how to use manual controls. The auto setting will never give good results for stage shows. Learn how to use the zebra patterns - do a search here for lots of info on that topic. It will serve you much better than auto exposure.

Also, be careful about setting exposure for a wide shot when you're completely zoomed in. At the telephoto end of the zoom the PD-170's lens is rated at f2.4, but at the wide end of the zoom it's rated at f1.6. So if you expose properly when zoomed all the way in, then zoom back out you'll might be overexposed, depending on the setting.

[Richard Zlamany]

Thank you. I'll practice more with the manual iris and the zebra stripes. I like the idea of brightening the dark areas in post. It wasn't all a lost. I recorded the chorus in sections which helped and for dark areas I added gain and lowered it for the bright areas. I also learned some new ideas from you all. Thanks again. :)

I was thinking maybe if I left the gain in auto and capped it at 9 and manually adjusted the iris I would have had better results. Then I would not have noticed the brightness bump up in steps when I pushed the gain up manually.

But then I might be fighting the gain when I adjust the iris. Maybe if I capped the gain at a lower number there would be less of a fight with the gain when the iris is adjusted. I don't know I am guessing. What do you all think?

[Mike Rehmus]

Gain is just about the last thing you want to increase. I trade of ND filters, aperature, gain and then shutter speed all depending on what I'm shooting.

The best approach is to expose for the faces in the brightest lit section and use correction in the post process to handle the darker areas.

Note that this is a compromise and there will be some quality loss in the darker areas.

If you have a chance, check out the stage lighting ahead of time and see if you can get the lighting techs to help you out. Or they may allow you to bring your own lights.

[Richard Zlamany]

Thanks, this place is great. You all are big help.