To err on the side of aperture, or of shutter speed?

If i use P, it will give me an aperture and shutter speed that are both moderate in most cases. Usually not a shallow depth of field, f/8-f/10 in most shooting conditions, and a shutter speed to match.

If i was in Av, and put the aperture a bit wider, the shutter speed would be faster, but at the same time, give me less DOF.

...basically, i could go either way on my aperture, or shutter speed, and still maintain a proper exposure.

My question is:
Is the depth of field the only consideration here? I can get a good exposure a few different ways, but for one consideration when moving away from P... is the DOF.
Are there any other considerations that i need to take into account other than DOF when tinkering from what P would suggest for the proper exposure?

Most lenses are sharper at smaller apertures than wide open.

For a given exposure value (EV) you need to consider the impact of depth of field on the image as well as the shutter speed. Too slow a shutter speed when hand-holding can create an unsharp image due to camera shake. Also, too slow of a shutter speed when photographing a moving subject will produce motion blur. As noted above, lenses are a bit sharper when stopped down a bit from full open, but depth of field is often used as a compositional element to isolate the subject from the background. You can stop down to increase sharpness and depth of field, but beyond a certain point a smaller aperture will result in a loss of sharpness due to diffraction. It's all a compromise.

First things first, get out of P mode and learn to really use your camera. DOF and motion aside you want to be at f/8- f/11 to get the most from you lens. Choose either the sutter speed or aperture first and then find out where the other lies in order to get the exposure you want (don't forget the role of ISO in the equation).

I usually start figuring things out at my lowest ISO to minimize noise. Compromises will have to be made and each shot is different; you want to be the one making the decisions, not your camera, which is why I say get out of P mode.

Av and At modes have thier place and time; if you learn how to use your camera in M mode you will know just when the time arrives to use them.

doidinho wrote in post #5966133
First things first, get out of P mode and learn to really use your camera. DOF and motion aside you want to be at f/8- f/11 to get the most from you lens. Choose either the sutter speed or aperture first and then find out where the other lies in order to get the exposure you want (don't forget the role of ISO in the equation).

I usually start figuring things out at my lowest ISO to minimize noise. Compromises will have to be made and each shot is different; you want to be the one making the decisions, not your camera, which is why I say get out of P mode.

Av and At modes have thier place and time; if you learn how to use your camera in M mode you will know just when the time arrives to use them.

well for the most part, i do try to stay out of P..... except when i'm using a flash in daylight. everything i know about shutter speed has to be changed because of the limitation of 1/200 shutter speed.

i do portraits, and concert photography mostly... and both require the widest aperture possible (if not close to it)... but when using a flash, i cant use 1.8... or even 3.5 for that matter because 1/200 is just too slow....

funk1196 wrote in post #5967266
well for the most part, i do try to stay out of P..... except when i'm using a flash. everything i know about shutter speed has to be changed because of the limitation of 1/200 shutter speed.

i do portraits, and concert photography mostly... and both require the widest aperture possible (if not close to it)... but when using a flash, i cant use 1.8... or even 3.5 for that matter because 1/200 is just too slow....

What you need to realize about using electronic flash is that shutter speed really has no effect at all on the exposure - unless there is significant ambient lighting as well. The duration of the flash burst is far shorter than the shutter speed timing, and so if the flash is the only significant light source you will have the same exposure at a 1/200 second shutter speed as you would at a three second shutter speed.

When mixing flash with ambient lighting, and using manual exposure control (both the camera and flash manually controlled), you can control the exposure from the flash source with aperture and then further control the exposure from the ambient lighting with shutter speed (using the aperture required for the flash) as long as the shutter speed does not go any faster than the "max sync speed".

SkipD wrote in post #5967299
What you need to realize about using electronic flash is that shutter speed really has no effect at all on the exposure - unless there is significant ambient lighting as well. The duration of the flash burst is far shorter than the shutter speed timing, and so if the flash is the only significant light source you will have the same exposure at a 1/200 second shutter speed as you would at a three second shutter speed.

When mixing flash with ambient lighting, and using manual exposure control (both the camera and flash manually controlled), you can control the exposure from the flash source with aperture and then further control the exposure from the ambient lighting with shutter speed (using the aperture required for the flash) as long as the shutter speed does not go any faster than the "max sync speed".

So when shooting flash in daylight, shouldnt i just always use Tv with 1/200 (if not P)?

funk1196 wrote in post #5967341
So when shooting flash in daylight, shouldnt i just always use Tv with 1/200 (if not P)?

The choice of modes depends purely on your intentions.

I would probably use manual mode with the camera and the flash, assuming I was using a flash that I could control manually. Unfortunately, my 420EX has no manual mode. However, my "studio" flash systems are purely manual. I have blended lighting from my studio flash and outdoor scenery quite well several times. In my typical manually controlled setup, the shutter speed is totally dependent on a combination of what aperture the flash lighting requires and what the ambient lighting levels are. Of course, a handheld light meter that can measure both ambient and flash light levels is very important to being able to think through a setup like this.

Without one, you can run some tests & get the same results if you're willing to take the trouble to do it: See post #3
Tips for Xmas Ball Please

I primarily use AV mode. Most lenses perform their best in the f/8-11 range but AV mode lets you prioritize DOF control.

TV mode, or controlling the shutter speed can be important if you're shooting action and want to control the blur of moving subjects. Another approach to add to controlling both those aspects is using the aperture that gives you the DOF you want and a shutter speed to get the result you want and adjusting the ISO to get a proper exposure.

I use aperture mode 90% of the time because unlike some I tend to shoot wide open or stopped down maybe 2/3rd of a stop when shooting people, to control and separate them from the background. I also do this on flowers, messing anywhere from wide open at 1.2 all the way down to 11, using the depth of field preview button to see how the colors and shapes in the background can add to the shot when changed varying the bokeh or eliminating it.

I filled a card at an event last month shooting people and really didn't need to overthink it, I was just having fun with a whole lot of people I know so I put my 5D in P which I rarely do and shot with the 70-200. I was very pleasantly suprised, they were all keepers and the camera actually did some very nice figuring out the focal length needs vs, shutter and stop.

Use whatever works for you, if you shoot enough you're bound to get to know your camera intimately anyway.

Scenics are a different story I'll shoot anywhere from 5.6 to 11 and on some close ups I've pushed it on occasion all the way to 32 but that's seldom.

If it's a really neat scenic type of shot and I'm a little undecided, I'll go ahead and shoot at several different settings, either bracketing the stop/depth of field or shutter if it's windy and the grasses are moving in the foreground. Using the depth of field preview button always helps to make some of these decisions.