>>3854950that's an ok start
so generally we try and keep our ISO as low as possible right?
so why don't we shoot at ISO 100 all the time? well things in our environemnt and our subject will give us constraints with shutter speed and aperture
Here's an example:
say im shooting a concert, and I want to make sure I'm freezing motion, so I don't get any motion blur. I need to use a high shutter speed, somewhere around 1/500th of a second.
Im shooting with an 85mm f1.8 prime. Now I'm pretty much gonna keep my shutter speed as is, but to make sure I get more light in, I'm gonna open up my aperture. I probably wont shoot wide open at f1.8 because the depth of field will be a bit too shallow, so I stop down to f2.8. Now, I point my camera at the stage and the lightmeter in the viewfinder is telling me I'm underexposed by about 5 stops, and my ISO is set at 100 - because my shutter speed and aperture are set, I'll raise my ISO 5 stops to 3200 - and boom, I've properly exposed my photo.
Don't just think about it in terms of amount of light, but also understand what else shutter speed and aperture do for you.
>>3854958use shutter priority if you care about controlling motion blur, and want your camera to compensate differences in exposure by changing the aperture for you
use aperture priority if you care about controlling depth of field and want your camera to compensate differences in exposure by changing the aperture for you
You can also shoot in manual mode, control both aperture and shutter speed, and turn on auto ISO and let the camera change the ISO to expose the image for the shutter and aperture settings you've selected.
