Do you guys ever shoot paying projects at 12db gain. I do not set my gain over 6db even on my EX1 most of the time its set at 3, 0 and -3

Hi Brian,

I have shot in 12 dB in the past, but I'm backing it off to 9dB. You can certainly get by with using less gain on the EX1. It's just one of the benefits of spending that much money on a camera.

I try to avoid using 12 db gain at all costs. My gain settings are -6, 0 and 6 on my Z7.

-6 DB, thats interesting. When would u really use that?

Martin, when you have adaquate lighting, using -6 db gain allows you to open the iris more without using as much ND filter to get the correct exposure. ND filters reduce contrast so using -6 db gain instead of additional ND can be a real benifit.

So Greg, next time the ND indicator is flashing I could try to reduce gain in the negative range instead of using ND filter and expect better contrast?

That is the way it is supposed to work. The image just seems to have a little more punch to it.

Thanks, I really don't care for images using the ND filters. Great new tool to try!

I don't know what this means Jeff. You 'don't care for images shot through the internal NDs'? You'll have to explain further, but it sounds like you may have a faulty filter in there.

I haven't done a controlled experiment but I don't think this is true at all. The whole point of an ND is that it is "Neutral," that is, all frequencies of light are reduced equally, which should not have any effect on contrast. I'm guessing the placebo effect is at work here...

Be interesting to do a side by side and post screen grabs.

I think the images look a tad flat when I use the ND filter. Maybe I'm wrong, but I'm open to trying something different. It doesn't cost anything.

Yes, it could be a placebo effect since ND filters are supposed to be neutral. When I first started video taping many years ago, one of the best shooters I have ever known told me that ND filters reduced the overall contrast of a scene. But he didn't provide any documentation to prove it to me. According to one technical source, "most ND filters are only specified over the visible region of the spectrum, and do not proportionally block all wavelengths of ultraviolet or infrared radiation." It has been well documented that some current camcorders images are affected by IR contamination. I don't know all of the answers. But maybe that could have something to do with why the images seem to look a little better to my eye, with -6db gain.
for the image?

I might be mistaken but I seem to remember on a training dvd I watched a while ago it talked about ways of dealing with situations where you would use various settings to avoid using the ND, but I can't remember the details.

When you switch an ND (or two) into the light path you're adding extra elements to the lineup of 15 or so you already have. Extra elements always up the flare levels by tiny amounts and in some cases can alter critical focus at the film plane. The NDs are way out of focus though, so even if they collect dust and debris it's not a problem

But it's a hit worth taking rather than screwing them onto the front of the lens, where their failings and effects become far more obvious on film.

tom.

Hmm... Interesting discussion but I think you guys are missing something pretty fundamental here:

Less light = less contrast

whichever method you use for reducing the light level you can't change the physics.

Black = no light - that doesn't change regardless of any other settings.

So, the contrast ratio is between 0 (black) and whatever your maximum light output/input is. When you reduce the amount of light (whether it be via ND filters or electronically, you are reducing the maximum amount of light - but the minimum amount of light (0) remains the same. Ergo, you are reducing the contrast. That's why night shots (using natural light) are always less contrasty than normal daylight - regardless of how much gain you use.