"P" Mode vs. Av Mode

[Master Mason]

Actually as Mark pointed out, at least in Canon products when you move to any of the auto zones you also lose the ability to shoot in RAW. I guess their thinking is if your shooting in Auto, your not going to be post processing. But that's just my guess.

 

[MarkBarbieri]

These are the shooting modes listed on DPReview's Preview of the Rebel XSi:

Auto
• Program AE (P)
• Shutter priority AE (Tv)
• Aperture priority AE (Av)
• Manual (M)
• Auto depth-of-field
• Portrait
• Landscape
• Close-up
• Sports
• Night portrait
• Flash off

There is a Program mode and a Portrait mode. The former is one of the "Creative Zone" shooting modes and the latter is one of the "Basic Zone" shooting modes. With the "Basic Zone" modes, the camera controls lots of features like the flash, the autofocus mode, and the drive mode. It also disables custom functions, exposure locking, bracketing, and RAW. "Basic Mode" assumes that you want the camera to control most things for you. "Creative Zone" assumes that you want to be in control.

There is nothing inherently wrong with the "Basic Zone" (or spouse modes as they are sometimes called) settings. It makes it much easier to get decent results out of your camera. You are leveraging the expertise of skilled engineers to pick reasonably appropriate settings.

The problem is that those engineers aren't there when you are taking the picture. They don't know what is happening when you are shooting or what you are trying to do. Most people that get even moderately serious about photography eventually switch to the "Creative Zone" modes for most or all of their work. In fact, the professional series cameras from Canon don't even have "Basic Zone" modes.

There is nothing that the "Basic Zone" modes do that is magic. You can do all of the same things with the "Creative Zones" if you know how.

My recommendation to a new shooter is to use the "Basic Zone" only until you learn how to reliably operate your camera in the "Creative Zone." If you are picking up a DSLR for the first time and are shooting something really important to you, it's safer to start with the "Basic Zones." Just don't limit yourself and your camera by staying there.

 

[MarkBarbieri]

Haven't been shooting in RAW (don't kill me)...takes up WAY too much room on the card, and I haven't seen a tremendous amount of difference in shots yet.

In one sense, you have been shooting RAW and you just don't know it. When you press the shutter, your camera captures a RAW image. If you are shooting in RAW mode, it writes that image to your card. If you are shooting in JPG mode, it converts the RAW image to a JPG and applies some adjustments to things like sharpening, saturation, white balance, and contrast while it is doing the conversion. When you shoot in RAW mode, you do the same thing, but you do it on your computer long after you take the shot.

If you take a RAW picture and convert it to a JPG using all of the same settings that the camera uses when it converts to JPG, the pictures will be essentially identical. What RAW allows you to do is to second guess some of those adjustments. It also allows you to take advantage of improvements in RAW to JPG conversion that get developed later.

So everyone shoots RAW. Some people spend the extra writing time, extra file sizes, and extra processing steps to convert from RAW to JPG on their own terms. Others are willing to give up that extra control and shoot in JPG for the speed and convenience. Even some professionals (usually when timelines are extremely tight) shoot in JPG. Most serious photographers, however, pay the extra price to keep the RAW files.

 

[handicap18]

In fact, the professional series cameras from Canon don't even have "Basic Zone" modes.

Same is true for Nikon (D100, D200, D300, Dh series and D1, D2 and D3 series) and the Pentax K10D & K20D also don't have those modes.

 

[AlienBrain]

Doesn't P mode make adjustments to always have your exposure in the middle of the scale? I thought that was one of the complaints with P mode, because sometimes, depending on your metering method, a middle of the road exposure will under or over expose your picture. e.g. a dark object with a bright light surrounding it or vice versa.

 

[MICKEY88]

Doesn't P mode make adjustments to always have your exposure in the middle of the scale? I thought that was one of the complaints with P mode, because sometimes, depending on your metering method, a middle of the road exposure will under or over expose your picture. e.g. a dark object with a bright light surrounding it or vice versa.

program mode, aperture priority, and shutterpriority, actually any mode other than full manual will expose for 18%grey, so yes in highkey or lowkey situations the exposure will be off,,

snow scenes, the camera will automatically darken to turn the bright white grey...

a portrait of a woman in a black gown in front of a black backdrop, the camera would lighten to turn thigs grey, that's why it's a good idea to know how to use exposure compensation if your camera has it,

with the snow scene you would go +1 to force the camera to give more exposure turning the snow white.


the other scene would be -1 exposure compensation to force the camera to give less exposure to make the dress etc black raather than grey

 

[MarkBarbieri]

Doesn't P mode make adjustments to always have your exposure in the middle of the scale? I thought that was one of the complaints with P mode, because sometimes, depending on your metering method, a middle of the road exposure will under or over expose your picture. e.g. a dark object with a bright light surrounding it or vice versa.

Program mode doesn't affect the metering. You will get the same exposure level (brightness or darkness) whether you use Program, Aperture Priority, or Shutter Priority (or even Manual if you adjust it to match the camera's meter reading).

Let me try an example with a picture. This picture was taken at an ISO of 400, with a shutter speed of 1/125 second, and an aperture of f/5.6. The "effective" focal length was 45.5mm.

The moment I clicked the shutter, the camera's meter determined how bright the scene was. In order to properly expose the picture, three things had to be weighed - the ISO, the aperture, and the shutter speed. I already set the ISO to 400.

Based on the amount of light the meter determined was present, the correct values for the exposure would be:

f/22 - 1/8s
f/16 - 1/15s
f/11 - 1/30s
f/8 - 1/60s
f/5.6 - 1/125s
f/4 - 1/250s
f/2.8 - 1/500s

If I was in aperture priority mode and wanted minimal DOF, I might have chosen f/2.8. The camera would have picked a shutter speed of 1/500s. I might have wanted a large DOF and picked an aperture of f/22. In that case, the camera would have picked 1/8s.

If I was in shutter priority mode, I might have wanted a high shutter speed to freeze any action and picked 1/500s. In that case, the camera would have picked an aperture of f/2.8. I might have wanted a low shutter speed to allow for some motion blurring and picked 1/15s. In that case, the camera would have picked an aperture of f/16.

With Program mode, the camera has no idea what I want for DOF or for freezing or showing motion. It picks something the engineers thought would be reasonable. First, it determines what shutter speed would let a typical users get a decent shot without using a tripod. The longer your zoom, the higher the shutter speed it tries to pick. In this case, my effective focal length was 45.5mm, so it was trying to get a shutter speed at or faster than 1/45s.

It would also try to pick an aperture that it thinks would be sharp for that lens. It usually likes to pick apertures two stops smaller than the maximum for the lens and tries to avoid apertures smaller than f/11. So for this lens, that would be the range between f/5.6 and f/11.

If you look on the chart, there are two combinations that would make it happy - f/5.6 + 1/125 or f/8 and 1/60. Anything with a slower shutter speed might be too slow for me to hand hold. Anything with a wider aperture would not be optimal for my lens. It can't always pick something optimal, so it picks the most reasonable of the choices that it has.

The important thing is that Program, Aperture Priority, and Shutter Priority are all picking from the exact same list of acceptable combinations of f/stop and shutter speed. They'll all be same lightness or darkness. The metering mode (spot, evaluative, center-weighted, etc) determined how light or dark things should be. With Program mode, it picks from any valid pair of values on the list. With Av or Tv, you pick one value and it picks the other value from the list of valid values.

The list of valid values is different for different levels of light and ISO. If things are brighter or the ISO is higher, you get faster shutter speeds for the same apertures. If things are darker or the ISO is lower, you get slower shutter speeds for the same values.

 

[Zoesmama03]

I shoot 99% in Manual. I did aperture priority for 2 1/2 years on my p&s when I got my DSLR the first thing I did was turn it to M where it stays. I was so excited to have the "control" that I haven't really messed with anything else. I'm working one exposure right now. I've learned to read from the histograms more and picked up the "metering" in camera too, finally. The pieces are coming together.

I do have my lens on auto but at first I was doing it manually but for my dd who moves A LOT it works better.

 

[SrisonS]

I use Av mode pretty much all of the time; unless I need some stop action shots, or long exposures....then I'll use Tv.

 

[Dcanoli]

I use Av mode pretty much all of the time; unless I need some stop action shots, or long exposures....then I'll use Tv.

Same here, and I was wondering when you'd pop in and give your two cents!

This has turned out to be a great thread and has evolved into a learning thread IMHO! I passed the link on to my two friends, one of which I know has read it.

I know they are still thinking that P helps them focus on things in the "front" verses in the background, and that's what their goal was in snapping shots of the children.

However, is that a P mode advantage or is that a function of something else that could be obtained in AUTO mode?

I mean if the advantage of shooting in P mode is control of flash, metering, and ISO, then it seems like beginners and non-serious photo enthusiasts might choose to stay on Auto.

Right?

If these girls shot in AUTO, would the camera still focus on what is in the front of the shot versus the background?

 

[labdogs42]

If these girls shot in AUTO, would the camera still focus on what is in the front of the shot versus the background?

Yes.

I also think that someone was trying to tell them to use Portrait mode (denoted on a canon by the picture of a person's head), not the Program mode. I know the portrait mode sets a shallow depth of field on purpose to draw attention to the foreground. In contrast, the landscape mode (the mountain scene) has a deep depth of field for landscape shots. If these ladies are amateurs wanting to shoot pics of their kids, the green auto mode might serve them best or the portrait (ladies head) mode. If their kids are running around fast, they should try the sports (running guy) mode.

 

[Dcanoli]

Okay, you hit the nail on the head. Exactly what I was thinking.

But, I am telling you guys...one of the girls' in-laws had given (yes, I said GIVEN) her a Canon EOS, and when I switched it to P, the screen said PORTRAIT.

Screwy, huh? I'll have to look at that again....just to make sure it wasn't a twilight zone minute!

So, now--I got it...if they want to take normal, every day shots of their kids--AUTO or Portrait, not PROGRAM mode.

Now....I'm gonna try and talk them into Av and Tv modes!

 

[handicap18]

If these girls shot in AUTO, would the camera still focus on what is in the front of the shot versus the background?

It depends on how the focus points are set. If it is set for something like closeest subject. Then the camera will look for something it thinks is closest. It doesn't always choose the right spot.

 

[Dcanoli]

I think that's a whole other thread--choosing where the camera focuses and metering.

 

[jann1033]

Okay, you hit the nail on the head. Exactly what I was thinking.

But, I am telling you guys...one of the girls' in-laws had given (yes, I said GIVEN) her a Canon EOS, and when I switched it to P, the screen said PORTRAIT.

Screwy, huh? I'll have to look at that again....just to make sure it wasn't a twilight zone minute!

So, now--I got it...if they want to take normal, every day shots of their kids--AUTO or Portrait, not PROGRAM mode.

Now....I'm gonna try and talk them into Av and Tv modes!

what screen are you talking about? i just tried p and portrait and it doesn 't say anywhere i can see what mode you are in. i even looked in my manual thinking i've been missing something the past almost 3 yrs i have used this ( rebelxt) camera...and it doesn't say it anyplace i can find... i don't remember it doing that on my film eos either, maybe it was one of the picture styles you saw rather than the shooting mode??
and not to throw in another subject but it also would depend what focus point or points you have set as to where it focuses, ie if you have the left point set and try to focus on something in the foreground right, it's going to focus on what is behind the left focus point.

 

[Dcanoli]

what screen are you talking about?

The screen on the back of the camera.

I don't have the camera here with me, and I only played w/her camera once, but when it came on, it was either on P already or I moved it to P and the screen said Portrait mode.

Your screen doesn't show what mode it's in when you change it? When I turn my Pentax on, whatever mode it's in comes up on the screen, sort of a "status" screen. Then, when I turn the dial, the new information flashes on the screen to tell me what mode I'm now in.

 

[jann1033]

The screen on the back of the camera.

I don't have the camera here with me, and I only played w/her camera once, but when it came on, it was either on P already or I moved it to P and the screen said Portrait mode.

Your screen doesn't show what mode it's in when you change it? When I turn my Pentax on, whatever mode it's in comes up on the screen, sort of a "status" screen. Then, when I turn the dial, the new information flashes on the screen to tell me what mode I'm now in.

no, it tells you the meter, drive, ad, wb, about the card, the image quality, shtter flash, exposure, apertrue battery in the small lcd and on the large lcd in portrait/auto it tells you if the beep is on, red eye and quality ( ie raw) in the first screen, scrolled through the other 3 and nothing about auto mode there either.
nothing in the view finder either..
however it does tell you if you are in B&w mode which is why i though it's possible you saw portrait and thought that was what the p mode meant where in reality it was the picture style "portrait" which basically tells you the sharpening etc. ( that is under parameters in my camera and you scroll to get to it on one of the screens)...unless they changed something in the later models it' doesn't list the mode,av what ever on the screens, guess they figure if you can't tell by looking at the dial you have more problems than an icon in the screen could solve. i know they changed the lcd in some of later models and got rid of the lcd small screen. but don't know what camera you are looking at.
edited as
ever curious i just looked it up on dpreview for the xti it does say av, p on the lcd screen etc but there wasn't an example of what it displays in auto, it also says the picture style which is still what i am guessing you saw if it was in p mode, then you could have a "portrait" and a "p", since i am sure you can set the picture style in the semi-manual modes, not sure about the auto modes. but canon hasn't changed it's dials/ icons for yrs so the p has never meant portrait in recent history.

 

[MarkBarbieri]

I never did answer the original question.

For most of my shooting, I use Av mode. I use M when I'm going to be in one place for a while or when I'm using studio lights (and often with on-camera flash as well). I use P when I'm moving around a lot and my mind is not on my photography. I use Tv on rare occasions (although I use it about half the time on my video camera with M being the other half).

There is one time when I switch my camera to full auto mode. That's when I'm letting gators use my gear:

 

[Dcanoli]

...ever curious i just looked it up on dpreview for the xti it does say av, p on the lcd screen etc but there wasn't an example of what it displays in auto, it also says the picture style which is still what i am guessing you saw if it was in p mode, then you could have a "portrait" and a "p", since i am sure you can set the picture style in the semi-manual modes, not sure about the auto modes. but canon hasn't changed it's dials/ icons for yrs so the p has never meant portrait in recent history.

Well, finally! I guess that's the answer to my original question after all! LOL....If you can set PICTURE STYLES in P mode, then maybe that's why it said portrait mode while the dial was on P.

Maybe the mystery is solved after all!