f/stops, stops, light stops, etc..

[jcospolich]

is there a linear correlation b/w stops of light, regardless of if you're adjusting ISO, f, shutter?

In other words, just talking about brightness (and not clarity, quality, sharpness)....
will each of the below brighten the image similarly (+ 2 stops of light)?
- ISO 100 to 400
- slowing shutter speed from 1/125 to 1/30
- opening aperture from F8 to F4

So taking an exposure at 1/60 f11 would be allowing the same amount of light on the sensor/film as 1/250 f5.6?

This site has always been helpful-
http://www.photonhead.com/simcam/

as has this one-
http://www.uscoles.com/fstop.htm

[jcospolich]

i am slowly beginning to understand how intertwined the settings are, and how one certainly affects the other.

for my interior flash photography, I have been struggling with finding the right settings for a nicely lit picture.

I have toyed around with the following:
- P mode, ISO 200, cloudy WB, FEC +2/3, EC +2/3, auto everyting else. camera usu chooses f4.0-4.5, 1/60
- M mode, ISO 400, cloudy WB, FEC +1, EC +1/3, f5.6-6.3, 1/125-1/200
- Av mode, ISO 200-400, cloudy WB, FEC +1, EC +2/3, f9-10, 1/13

for minimal post processing, usu the P shots, and sometimes the Av shots are okay. M shots still leave a lot to be desired. I know I can play with WB a lot more, but I think that is a subject for me to tackle after I fig out exposure better.

[Digger]

you have the concept and are correct in your conversions. at this point its practice and feel. dont worry you will get the hang of it. since your using flash and in control of the light i would drop your asa some more. i personally like to use as low of an ISO that i can, less grain/noise

[12345Michael54321]

Originally Posted by jcospolich

just talking about brightness (and not clarity, quality, sharpness)....
will each of the below brighten the image similarly (+ 2 stops of light)?
- ISO 100 to 400
- slowing shutter speed from 1/125 to 1/30
- opening aperture from F8 to F4

Yup. Each of the examples you offer represents a change of 2 stops.

Just in case you were wondering, that's 4 times the light. Since a 1 stop change equals twice the light. (Or half the light, if you're moving in the other direction.)

So taking an exposure at 1/60 f11 would be allowing the same amount of light on the sensor/film as 1/250 f5.6?

Yes. Those are equivalent exposures.

Of course, depth of field would differ from f/11 to f/5.6, so the picture might look somewhat different (or maybe not - if everything in the picture is very distant, depth of field considerations can pretty much become irrelevant). But if all you're talking about is exposure, they're the same.

Give yourself a pat on the back for understanding this. It's a fundamental concept, but one of which most people are utterly oblivious.

[jcospolich]

thanks it is starting to make sense. I usu prefer low ISOs, but since most of my paid workends up compressed as heck on MLS and prop websites, I don't see much of a difference with ISO200 or 800.

[PhotosGuy]

for my interior flash photography, I have been struggling with finding the right settings for a nicely lit picture.

This might help:
Fill light at sunset
Here's something that will help you figure light fall-off in your head.