Advantages of aperture/shutter priority over 'P' mode?

[yorkshirelad500]

OK, let me check I have this right...When in P mode on my D3100, the camera chooses what it 'thinks' is the best aperture and shutter speed to get a good exposure for a given scene. However, I can rotate the dial left or right to adjust the combination of aperture/shutter speed, all of which will give the same exposure. In P mode I can then rotate the dial to choose a specific aperture or shutter speed, depending on the depth of field I want to achieve, or how quickly the subject is moving and if I want to freeze motion etc etc.

My question is, as I can still adjust ISO, use exposure compensation and choose when to use flash on either shutter priority, aperture priority or on P mode - why is it necessary to ever stray from P mode? Surely P mode is effectively aperture and shutter priority combined into one? ..or am I missing something?

 

[Nawty]

Others will argue differently but I think P mode is better than Av / Tv modes for general shooting, the only time to move to those is when you're in specific type of shooting an need to be sure the settings stay as wide/narrow, fast/slow as you need.

Then, you use manual when you need control over both shutter and aperture which can happen for a variety of reasons (generally because you know the meter won't work in the situation you're in).

 

[Dale_tem]

Av - aperture priority (A)

Tv - shutter priority (S)

I've not used P

I generally use S so I can control the shutter speed to prevent blurring (taking photos of kids).

 

[flossie]

In P mode I can then rotate the dial to choose a specific aperture or shutter speed, depending on the depth of field I want to achieve, or how quickly the subject is moving and if I want to freeze motion etc etc.

um... I've no experience with your D3100, but if you are saying you can fix the Aperture or Shutter value whilst maintining the camera's idea of "correct" exposure (deliberate use of quotes...), you have effectively shifted into Av or Tv/Sv/(whatever nikon call shutter priority) mode...

Personally I (like many people) use Av mode (aperture priority) about 95% of the time, as I want to exactly specify what the depth of field is, and let the camera figure-out the necessary shutter-speed. I then adjust the ISO based on experience, or if the exposure is too long (e.g. blurred people). Sometimes use "auto ISO 200-800" to give the camera a bit more lattitude to play with.

I believe "P" modes will always try to aim to keep aperture around F8, unless it would result in a shutter speed less than ...something or other - 1/50th?? - basically this means that someone who is used to a point and shoot camera will always get a reasonable shot, with most of the image in focus. Or, in short, if you want to get more creative, you will need to venture outside P... go on, give it a go - good luck!

 

[Nawty]

Nope, Program P mode basically means you can shift it either way, one way increases aperture, the other decreases it (or vice versa with shutter speeds). Quite handy really.

 

[HoppyUK]

TBH, there is a lot of prejudice against P mode as being a bit amateurish and only for novices, in much the same way as you're supposed to use manual if you're a proper photographer

What you say is perfectly true, but it's not quite the whole story. The thing about manual is that it locks everything, and the advantage of Av or Tv over P is that it locks one of the settings. In P for example, if you want to shoot at maybe f/16 or f/2.8 for depth of field reasons, if the light changes or you move to a different scene, on P it will change both the shutter speed and aperture and so you have to reset everything again via the shift and/or compensation controls. Basically, it's just easier to go straight to what you want with Av or Tv, in the knowledge that it'll stay there.

All just different ways of doing the same thing. Whatever suits you or the subject

 

[yorkshirelad500]

Thanks...now I get it!!