Gain Switch tutorial or help????

G

gossamer

Active member
I searched "gain" and found a lot of posts with the word "aGAIN" in them, but nothing with gain. So, I DO know that I DON'T know how to use the search function. :o

Can someone give me a primer on the "Gain" switch. What is the effect with it at various settings. I read somewhere here that depending on where it is the blacks will be more or less black.

What setting accounts for more black? (I ass-u-me lower settings account for blacker blacks but...)

okay, this whole post is sounding like a scene from Spinal Tap so I'm done.

Any help is, as always, appreciated.

"There's no sex and drugs for Ian."
 
Re: Gain Switch tutorial or help????

The gain is a button that could be taped down . . . I asked once about it and the big boys said that besides adding grain & noise it wont be helpful. What it does in actual fact is increase the sensitivity of the CCD to light, giving you a better picture when in the dark but . . . you gotta a price to pay, which is the grainy image you then are left with! Just like film stock. Same deal . . . you might want grain , well then that is a different matter, but I was told . . . if you want a clean pic, dont touch the gain!
 
Re: Gain Switch tutorial or help????

Gain is an electronic amplification of the video signal. Every 6 db of gain accounts for a doubling of brightness in the image. So gain at 0db = the regular picture from the CCD's. Gain at 6db means the signal's been modified, electronically amplified to be twice as bright. Gain at 12db means it's another twice as bright, and gain at 18db means it's ANOTHER twice as bright.

So theoretically, 18db gain would give you a picture 8 times as bright as the CCD by itself (CCD x 2 x 2 x 2).

But it's all electronic trickery and tomfoolery, there's no new information hitting the chips, it's just digital manipulation (sort of like "digital zoom", but for brightness).

So normally you'd go in the menus and assign the Low setting on your gain switch to represent 0 db, the Mid setting to be 6 db, and the High setting to be 12db. Then leave the switch set on Low at all times, for no gain.

Gain is not always a total no-no... sometimes it's what you need to "save" a shot. And you can use small increments with no real bad side effects... 3db or 6db of gain can look just fine. By the time you get to 12db it starts getting noticeably grainy and noisy, and 18db is very grainy and noisy... but hey, if you're trying to emulate 500ASA 16mm stock, maybe that's a good thing! ;D
 
Re: Gain Switch tutorial or help????

THANKS Barry! I've copied and pasted more of your posts into my "DVX Bible" than you can imagine.

If I ever publish it I'll be sure to send you royalties or something. At least a beer.
 
Re: Gain Switch tutorial or help????

[quote author=gossamer link=board=Events;num=1090512538;start=0#4 date=07/22/04 at 11:49:47]THANKS Barry! I've copied and pasted more of your posts into my "DVX Bible" than you can imagine.[/quote]
You too, eh? ;D
 
Re: Gain Switch tutorial or help????

To gain or not to gain, that is the question. LikeBarry said, it all depends on your shooting situation. As an example, in the wedding industry, it's a complete MUST many times. You can't set up lights or control lighting in a dark church. The same with many receptions where the client decides they just want "candlelight".

I usually never go past 6db, although sometimes I will use 9db.
 
You must log in or register to reply here.
Back
Top