why is it easier to take shots of a tank with out a painted back?

i was first made aware of this by jer, then when i asked tigah about it he agreed. so thought this might be th best place to talk about it. does anyone have thoughts as to why this would be the case.

lighter backgrounds mean more effective light reaching the camera's sensor. this allows the camera to better evaluate exposure, and generally leads to higher shutter speeds (helping to eliminate shake). that's my take anyway. I'm sure 05xrunner has the correct opinion.

awwww whats the matter...shouldnt you have just pointed them to your write up

i disagree.

first of all, theres spot metering which allows the camera to only focus on the subject and ignore the background so the argument for for light for a correct exposure is irrelevant. second of all, if you have a bright background, the camera might choose the shutter speed to correctly expose the background, not the subject making it dark and under expose.

if you have spot metering and correctly exposed the shot to the subject, the bright background would be over exposed ruining the picture.

if shutter speed is an issue, then use a tripod. if no tripod, then up the iso (tho not advised unless no other option)

i prefer to shoot with a dark background. lot less distractions in the back highlighting the subject (which is what you want to do in the first place)

It's simply Reflected light, try using a polarizer. No backround no reflection blasting at the lens... Keep in mind this is not something that will alwaysbe the case but typically speaking is.

The light meter in a camera is a dumb machine. For the most part it works to make things a happy medium or neutral tone (in B&W this would be called middle grey). If you take a picture of a light subject the camera will tend to under expose and likewise a dark subject will tend to over expose. As a result automatic exposure settings are not really that reliable, they can work well in a lot of situations, but they will not work in all situations. This is why many cameras have exposure compensation controls, these allow you to look at the subject and decide what the camera is going to do and fix it.

To answer your question, most painted backs are are dark color and reef tanks are lit by strong light. This creates a strong contrast between light and dark and your camera will likely try to make the black a bit lighter (grey) as it cannot recognize that it should be black. As a result the lighter subject (coral) is over exposed. With a non-painted back the tank will have a more even graduation on light to dark (in general).

there's nothing about this in my write-up, silly goose.


if you say so, but generally I try not to contradict myself when making a point. also, the only time my backgrounds are blown out is if I want them to be. I don't remember seeing tigahboy's backgrounds blown out either. I also don't think I have trouble isolating my subjects - again, same with tigah.

wfournier's explanation fits better, and is more along the lines of what I was thinking. I mentioned shutter speed and camera shake, not because I have an issue with it, but because a lot of others do, and having a lighter background helps in this respect. eliminating camera shake is generally a first step in improving photos, before talk of exposure and spot metering come into play.

but what do I know, I'm no expert.

lulz

hey guys thanks again for taking the time to awnser the question.