Why do I decide on certain camera settings?
Look at an example shot (the Heart Attack Grill in Las Vegas, where if you weigh over 350lbs you eat for free).
I used my 50mm f/1.2 lens that night: I wanted small size, good quality, and the ability to open the aperture if needed.
That’s 1600 ISO, f/5.6, and 1/30th sec (in that order).
And here, the menu:
That’s 1600 ISO, 1/60th, f/4. Yum, a septuple bypass burger!
OK, so why those settings?
At night I decided 1600 ISO would be a good starting point. (experience told me this).
Next, I wanted f/5.6 to get depth of field with my 50mm lens (ditto, experience told me that also). I also wanted f/5.6 to be able to decrease that number quickly, all the way to f/1.2 if needed, in case of lower light.
That f/5.6 gave me 1/30th sec with this kind of lighting, which also I knew I could do handheld (I am quite steady). If it had given me a slower speed I would have increased the ISO to 3200, say.
If I had wanted more depth of field, ditto: this was f/8 at 3200 ISO (one stop smaller aperture = one stop higher ISO).
That’s the thinking process. Can you see how it works? With a bit of experience and application of the basic rules of aperture, shutter and ISO, you get there. That’s really all you need.
Note that all three pictures are similar in exposure value, since all three are artificially lit objects that are not far apart on brightness.
My 12-week course at Sheridan College started yesterday night – 20 students who will know all this within weeks. Do learn! And do consider my e-books to help in that. And come back with great pics.