DC modes

[DCbeginner]

Can someone explain how to choose PAS or M mode? How do I know which one to use?
Thanks

[PhilR.]

Are you sure it's "PAS" and not P/A/S? Normally it's P for program, A for aperture priority, and S for shutter priority. M is for manual mode. You use P if you do not want to specify any settings, and want the camera to do the work for you. You select A if you want to specify the aperture setting. You select S if you want to specify the shutter speed setting. You select M if you want to specify both.

PhilR.

[DCbeginner]

Yeah, I meant P/A/M/S. Since M can specify both A and S, why need A or S?

[Robert Besen]

With M, you have to set both the speed and aperture yourself, and check the metering or preview to make sure you're getting the exposure you want. With A, the camera will select the proper speed according to the built in meter, and with S the camera will likewise select the aperture. Which one you use depends on a lot of factors, but keep in mind that a higher aperture number (smaller actual aperture) will give you increased depth of field, while a higher speer number will stop action better. Hope this helps.

[ReF]

Yeah, I meant P/A/M/S. Since M can specify both A and S, why need A or S?

because even an experienced photography may accidentally choose the combination of S and A in manual mode.

examples of things that can go wrong in M:

you choose your desired aperture but too long a shutter, causing an over exposure. this is less likely in A if you meter correctly.

you choose a fast shutter speed but accidentally left the aperture at a very small setting, causing an under exposure.



having to choose both the Aperture and the Shutter speed may require some test shots, and sometimes you don't have time for that. I cringe at the thought of having to guess the proper shutter and aperture combination for every shot.