Good information so far. something to REALLY watch is the setting you have on your light meter. For low light situations, a spot meter is essential. read the area you WANT to see. Remember a light meter will under expose white and over expose dark. You need to make adjustments accordingly. I do NOT recommend automatic settings on a camera for low light exposure. Sometimes auto works, sometimes it doesn't. By taking control, you can get the best results possible for the conditions.
oh.. watch the auto focus too. It takes light for auto focus and the focus assist light does not work at decent distance.
From an old school film guy:
Depends on what you are shooting.
In general, lower ISO is going to give you better image quality. Was especially true with film, also applies to digital. ISO is governed by light level and shutter speed you are going to need. Low light level requires higher ISO. Shooting sports, for example, need very high shutter speed, so usually need a higher ISO. (Also, an old rule of thumb for shooting with a telephoto is that the lowest shutter speed at which you can hand-hold the camera is the numeral one over the focal length of the lens. i.e. a 200 mm lens, 1/200 second shutter speed or faster.)
There are basically two factors that govern aperture; light level and depth of field desired. Less light, wider opening. More light, smaller opening. More depth of field (background in focus), smaller opening. Less depth of field (background out of focus), larger opening. We were also taught that there is a "sweet spot" for a given lens with the least optical distortion which would be somewhere between the widest opening (i.e. f 2) and the smallest (i.e. f 22).
The best advice I have received from several photographers is to shoot digital fully manual, like film. These guys use the camera meter on auto to shoot a couple of frames to get in the ball park and from there shoot fully manual--setting shutter speed and aperture manually and not relying on the camera's meter. May be a little much just starting out. Experiment!
Last piece of advice--don't get hung up on gear. Image quality is mostly about "the glass"--lens quality. And as a great photographer said "learn to see light."
I shoot only on manual as auto just cannot be reliably trusted. Auto is programmed to play it safe, not burning out highlights, so the images are almost always too dark. Use your built-in light meter. Get that marker in the middle of the scale and you'll have a good place to start. This mid-point is your camera's way of telling you its a reasonably good exposure. Then go from there changing your shutter speed or aperture to vary light levels. Photoshop will only give you about 10-15% fudge factor in controlling light levels in post production so do your best to get it right on the snap. Good success!
If you shoot in manual mode and just centre the meter, you are working too hard. Aperture or shutter speed mode can do the same for you with less work. Exposure Compensation will let you tell the metering you want it darker or lighter.
If you shoot raw, you can push the exposure lighter or darker three or four stops, which is probably more than 10-15%. It is best to get it right when you take it but there is a lot of latitude in the software if needed.
Anyone who only shoot in manual outside the studio, will miss at least 50% of the opportunities to get a good shot
I'd be interested to know why shooting on manual causes one to lose 50% of their shots.
I think he is thinking about those fast capture moments where you don't have time to set your exposure for the shot. I think 50% is a big number, but I do see where if you only shoot manual you could miss some shots. I use all the modes on my camera depending on the situation. There are times where I really want to keep the shutter speeds up, so shutter priority, Most of the time I am in manual or aperture priority. I also generally use center weighted or spot metering to make sure my camera is giving me the shot that I want.
I rarely shoot motion so its not much of an issue for me. When I shoot models in motion in the studio I can control the light so its not a factor here either. I figured that motion was what Thomas was referring to. Thanks.