So new random question: At a basic technical level I get what shutter speed, aperture, and ISO do in relation to each other.
What I'd like to read into is how to more quickly gauge (assuming a consistently Low and unchanging ISO for daylight shots around 64) what combination of shutter speed and aperture work for making for determining the elements of the frame I want in focus and not blown out and gauging the lumens on the various textures.
Any recommended reading on these concepts and what principles to follow?
"the elements of the frame I want in focus" -- you are referring to a concept called Depth of Field or DOF. For example, a given setup might have a DOF of 5 to 10 feet; this means that everything within that distance from the lens is in focus (technically: acceptable focus, not perfect focus), while everything outside of that range is progressively out of focus; stuff at 11 feet might be a little blurry, while stuff at 200 feet is way blurry. (This is all based on planes, not raw distance; all focus distances measure the distance to a plane parallel to the camera's sensor, except in the case of fancy cameras and lenses that let you tilt the lens, which I will not address here.)
DOF is determined by 4 elements:
1) Sensor/film size. The smaller the sensor/film, the more in focus everything will be; i.e., the DOF will be greater. This is why most digital cameras, phone cameras, etc. have effectively infinite depth of field; almost everything that you can see is in focus. It is hard to do the "selective focus" thing where you have, say, a person's face in focus and the background blurry. This is because their sensors are so small. Going up to larger sensors such as those in DSLR's makes it easier to get a narrow DOF.
2) Aperture. All else being equal, a larger aperture (smaller number, in f-stops) will generate a narrower DOF, i.e., less of the shot will be in focus. (For a lens with a large aperture like f/1.4, on a full-frame DSLR, the DOF could be measured in fractions of an inch.) Stepping down the aperture (making it smaller) generates a larger DOF. This is why, in landscape photography, people usually want to shoot at small apertures like f/11 or f/16, to get more of the shot into focus.
3) Focal length. (I will use 35mm-equivalent focal lengths here, since that's what everybody is most familiar with.) 50mm is considered "normal", this is approximately what your eyes see, i.e. not "zoomed in" or "zoomed out", just plain. Lower than that is considered wide-angle, and longer than that is considered telephoto or "long". A classic wide-angle focal length is 28mm, while a classic telephoto focal length is 200mm. All else being equal, a wider focal length will give more DOF than a longer focal length. A full-frame DSLR using a 28mm lens at f/2.8 might have a DOF in the tens of feet, while the same camera with a 200mm lens at f/2.8 might have a DOF of less than a foot.
4) Focus Distance. Closer focus distance = smaller DOF. Take a set camera, set lens, set aperture, set focal length. Now move the subject close, so the focus distance is 2 feet. This will result in a very narrow DOF. This is taken to extremes with macro lenses where the subject is held only inches away from the lens, and the DOF is measured in millimeters. Take that same camera/lens/aperture/focal length and focus it to 20 feet away, and it will have a very large DOF. In fact, it could be infinite.
Every lens has what is called a "hyperfocal distance" which means that it is effectively focused to Infinity. On a wide-angle lens, this might be 10 feet or less; on a telephoto, it might be hundreds of feet. Hyperfocal distance is saying "everything from this point back to infinity will be in clear focus." Of course, the hyperfocal distance is not just based on the focus distance. It is based on the system as a whole, and incorporates all 4 of the elements above. This gets back to the point I made at the beginning, where you have small sensor digicams with effectively infinite focus. This is because their hyperfocal distance is very short.
That's my primer on DOF. Here is a very good website that you can use to calculate DOF for any set of parameters:
http://www.dofmaster.com/dofjs.html
Ok, now, you also ask about how to quickly gauge exposure. There is the "sunny f/16 rule" which tells you that on a sunny day, you can set your aperture to f/16, and your shutter speed to 1/ISO, and you'll have a good basic exposure. (You can adjust this: for "bright cloudy" days use f/11; "mostly cloudy" days use f/8; "overcast" days use f/5.6.) So if your ISO is 64, use f/16 and 1/64 shutter speed (probably closest your camera comes would be 1/60 shutter speed) to give a first approximation of your exposure. Now, chances are this will not be a very useful exposure. So you can vary your aperture and shutter speed in opposite directions: say instead of f/16, you go to f/8 (a 2-stop difference) which means you can make your shutter speed 2 stops faster, from 1/60 to 1/250. This will limit your DOF a bit (although on a P&S, it likely won't make much difference) and probably make your shot sharper because it will have less motion blur, as a 1/60 shutter speed is prone to blurriness with moving subjects and/or shaky hands. Or take it another stop, f/5.6 and 1/500. Or another stop, f/4 and 1/1000. Another stop, f/2.8 and 1/2000. Playing around with the DOF calculator, it seems that you can get some good blurred backgrounds with this camera at its widest aperture settings, although the best it goes at full telephoto is f/4.5.
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