Gain vs Exposure vs the Histogram

[John K]

Hi guys,

with a new monochrome Skynyx 2.0 camera I am trying to get a better hand at the relationsihip between image quality and Gain vs Exposure and what I should be seeing in the Histogram.

With the SPC900 webcam I simply adjusted things to capture what seemed "right" on the screen capturing in AVI format. If it looked right on the screen, then it looked right for processing. However, capturing in non-AVI formats is different. So some questions I have are:

* What is the real relationship and compromise between Gain vs Exposure? - Sure, too much gain results in too much noise, but does a shorter exposure mean the seeing "freezes" more effectively and this offsets the higher level of noise? For a Skynyx 2.0, have people found an optimal gain setting or compromise level e.g. 75% etc?

* What should the histogram objective be? - Have never used a histogram to set the capture settings before, so what should it look like?

Look forward to your advice and comments.

John K.

[Alchemy]

gain increases the electronic signal ...multiplies it (and the noise)
exposure is just that the length of time to expose,

i find the settings i use are determined by firstly shutter speed to freeze to a point usually 1/75 sec or quicker( this will depend on focal length to some degree), then adjust gain to suit, then gamma if its too contrasty which might need you to reset the gain alittle bit.if you are running your frames through something like registax you will find processing will blow out the highlights if you set the time for the white end of the histogram ..ie highest value 255,.... try 200 and adjust to suit ...its going to be a bit of a suck it and see experimentation but thats how i would aproach it.