How do I Know if I need gain?
 

Hello, This must sound like a dumb question but here goes. I own a PD170 and my question is how do I know when I need to use gain. This is what I do now please tell me if this is the right procedure. First I ask the camera what the exposer should be by pointing it at a common light source and pressing the iris button. If it tells me it needs f2 or higher I go with it. If it is F1.6 I assume it might need gain. Then I ask how much gain by pressing the gain button. Is the the best way to determine if I need gain? I don’t want to use gain if I don’t have to. Please advise.

Al Ioimo

you use gain, when you need a brighter image, i always try to stay away from using grain because, well it makes the image grainy, but sometimes you have too.

well first I have to say that my experience with sony cameras tells me that when using gain on the 150/170/250 series the image doesn't really start to SHOW degradation until you rach about 18. I've gone up to15 and the image has held together very very well. Do I like t odo that? No but if I'm in a situation that I feel needs some gain to help get a decent workable image I use it. As far as when to know to use it and how much I use a very simple process. I set the zebras to 70% and go for something white. If I'm not seeing any bars then I know it needs help. It also comes with experience-looking at the lighting thats there and having experience to be able to say to yourself "the image needs help." For the most part I use a 35w on camera light with a softbox and I can tell you that in ALMOST every wedding reception I do, once they turn the lights down, I use gain-generally 9db will do the trick for me but I've have to go to 12 and even 15. Again the image is not degraded to the point of breaking up but it can be right on the edge.
If I'm shooting a corporate seminar with ony stage lighting then I depend more on a production monitor than anything else but I also use the zebras-again generally set to 70%.
I guess for me it's really more of a 'feel' thing than anything else but I'm not afraid to use the gain control-and sometimes even a slightly degraded image is better than a very very dark image.
Just my $.03 worth (adjusted for cost of living)
Don

I use the Zebra setings too, but I use the em at 100% and step down if I see the Zebra's. I rarlely go above 12db in Gain and try not to exceed 9 even thought the camera does an amazing job at both.

Ezra

Gain after Iris completely open?
 

The gain is used (increased) only after the iris is completely opened, correct?

Is there a situation where you might turn up the gain before opening the iris???

Just a question...

You have to keep in mind how much zoom you're using, since at full zoom you shouldn't drop your iris below f2.4, but if you're staying wide you can go to f1.6. If you're using different magnifications for different shots, you may want to leave it at f2.4 and up your gain, even if you could open the iris more at your current zoom. Also, my VX2100 shows a little vignetting at f2.4 at full zoom, so I wish I could go to f2.8 and +3dB gain to get rid of it, but the VX2100 doesn't have the separate gain control.

There may also be times when you want more depth of field, and are willing to use a little gain to avoid opening the iris all the way. My VX2100 is also a little softer wide open, but again I don't have the option of trading aperture for gain.

-Terence

Al:

You said "point at light source" ??? Sounds like you are using the camera as a source light meter. Everyone responding is assuming you mean point at subject, and you are taking readings from that.

In Auto, you set the gain will be set by camera, along with F stop and Shutter speed. You can also limit the gain to be applied in menu under AGF.

In manual, with VX2000, which I assume is same as PD's, you set your shutter speed, then activate exposure dial. Using zebras, with the setting you prefer, dial exposure to the point that you aren't blowing out highlights, and you are getting shadow detail. Sometimes you sacrifice one for the other....