P Mode question

Discussion in 'Help and Feedback' started by Hyubie, Apr 18, 2012.

  1. Hyubie

    Hyubie Unique like everyone else

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    (Before I start, yes yes yes, I should start using A mode, S mode, or even M mode. :rolleyes:)

    I have been using the P mode quite often when walking around town. I prefer not to concern myself much with the right combination of aperture, shutter and ISO when we're on our trips - what with the two kids running around, thinking about where to go for lunch/dinner, any spot I missed, etc. (Or call me lazy :biggrin:) Also, isn't P supposed to mean "Professional" ? :tongue:
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    Kidding aside though, I am generally satisfied with the results, and switch to A mode only when I am consciously controlling the depth of field or I really want to hit that sweet spot and I know the light is good. My question is - how come when I'm in P mode, the camera more often than not sets the aperture wide open? I noticed this on the E-PL1, E-PL2, and even the Panasonic G3. I don't think I've had duds with all three models? (I mean what are the chances all three are duds?)

    And I don't mean indoor shots - I mean morning-noon-afternoon strolls, with the sun usually at its strongest. If not wide-open, it's usually just up to about three stops. It's very rare that it goes up to beyond 5.6, and I would say 80% of the time it is from f/1.7 to about f/4 (for the Panny 20mm). I'm also on auto ISO, max limit of 1000. I tried it just now, cloudless spring Boston noon sun (I don't think it gets brighter than this), and it's setting it between f/3.5 to f/5.6.

    Is this a common/expected occurrence? Thank you.
     
  2. sprinke

    sprinke Mu-43 All-Pro

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    I've wondered the same question, and my conclusion is that there are tiny gnomes inside the camera that are always pulling the aperture blades open.
     
  3. fredlong

    fredlong Mu-43 All-Pro

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    I would guess it's to keep the shutter speed up and ISO down.

    Fred
     
  4. Armanius

    Armanius Mu-43 All-Pro

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    That'd be my guess as well.

    On the topic of the "P" mode, which I have never really used in any cameras, are there any real advantages of using "P" over aperture priority?

    At least on the GF2, they both look the same to me! Turn the control dial to change the aperture, while the shutter speed is fixed (1/60 for the 20/1.7 lens) assuming the ISO is set on auto.
     
  5. Hikari

    Hikari Mu-43 All-Pro

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    P = Perfect

    Some manufacturers would publish their program lines. Check your manual and that should indicate the criteria for programmed exposure. Of course with Auto ISO, that gets a little tricky.
     
  6. Hikari

    Hikari Mu-43 All-Pro

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    When you do not want to be bothered with either aperture or shutter speed settings. Like when drunk at a party. P = Party mode
     
  7. Armanius

    Armanius Mu-43 All-Pro

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    LOL!

    But then, how does it differ from "auto"?
     
  8. Ned

    Ned Mu-43 Legend

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    Bumping up ISO is always a "last resort" to keep the shutter speed up. When the light starts to get low, the camera first slows down the shutter speed until it reaches a pre-defined point where the camera will not go any slower (to avoid shake and blur). Once it reaches that point, it then needs to retain the minimum shutter speed by opening the aperture wider to let more light in. Once the aperture is opened up as wide as it'll go, if the camera still needs more light to retain the minimum shutter speed, then that's when it starts bumping up the ISO.

    iAuto is simply an automatic Scene Mode selector which picks a scene mode for you based on what it sees in the frame - ie, a face could mean a portrait, a moving object could mean sports, low light could mean night scene. If you are in iAuto or a manually selected Scene Mode, then the minimum values for different factors may change, though the general process is still the same. For instance, in sports mode the camera will stop at a faster minimum shutter speed before moving onto the second step of opening the aperture, or for group shots it may have a defined maximum aperture where it'll stop early and move onto the last step of bumping ISO (to maximize DOF).

    So the general process for dealing with failing light is... slow shutter as much as needed... reach minimum shutter speed, start opening aperture... reach maximum aperture, start bumping ISO.

    Honestly, the camera's methods are not very different from my own. The difference is that I have better judgement of what's really in the scene and what my purpose is for the photo.
     
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  9. Armanius

    Armanius Mu-43 All-Pro

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    Thanks for the explanations. I suppose one day I might venture to something other than A, S or M!
     
  10. Hyubie

    Hyubie Unique like everyone else

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    One diff is that P will not fire the flash unless you pop it up.
     
  11. Ned

    Ned Mu-43 Legend

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    Tsk, tsk... you always have to bring S & M into the conversation, don't you? :biggrin:
     
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  12. Luckypenguin

    Luckypenguin .

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    I found that that there was a noticeable difference in how the GF1 approached P mode compared to the other four m4/3 cameras I have used. The GF1 definitely seemed to shoot at very large apertures even in good light. I figured that it was compensating for having a smaller sensor. The GH1 in particular seems to lean towards a philosophy of choosing smaller apertures which I generally prefer, but sometimes it goes to the point where it will start to choose apertures like f/11 or smaller in brighter conditions even though there is the shutter speed available to choose wider apertures. At this point I'll start using the program shift or switch to A mode to get more optimal aperture values.
     
  13. Ned

    Ned Mu-43 Legend

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    Yes, and there was a time (for Olympus it was the "Blue Auto") before Intelligent Auto (aka iAuto), when manual vs. auto flash control was pretty much THE only difference between Program and Auto. Now with iAuto though, it has the ability to change to different scene modes, and that's the new defining feature. Program is like one general-purpose scene mode, while iAuto can use them all.
     
  14. Armanius

    Armanius Mu-43 All-Pro

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    Hahaha. That's what my fiance says!

    Just kidding!!!
     
  15. Hyubie

    Hyubie Unique like everyone else

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    So, back to the question - is this behavior to be expected in :43: bodies, even in the brightest natural light I can get? Is this, as Nic said, to compensate for the sensor size?
     
  16. Warren T.

    Warren T. Mu-43 Veteran

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    whoever did the computer programming for "P" mode with the Lumix 20mm decided that the lens should be used at widest aperture as often as possible. It annoys me, and it's why I always shoot in "A" mode when I use my 20mm. I would rather control my own aperture than have the "stupid" computer program do it in "P" mode. :)

    I don't know how the Program curve works for other prime lenses because the 20mm is the only native prime that I own.

    I often use "P" for my native zoom lenses, and their programming seems to be fine.

    --Warren
     
  17. Ned

    Ned Mu-43 Legend

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    If you are in bright light and the camera is not trying to compensate for low-light, then individual manufacture settings can vary widely. The general procedure for dealing with lower light is what remains the same across brands (though the actual minimum/maximum values vary), and this is where you will always see the aperture opened before the ISO is bumped.

    However, in brighter light one camera may choose to speed up shutter speed while another may choose to stop down the aperture to deal with the increasingly bright light. That's a manufacture preference, where they have to choose how to balance it. Obviously, on any camera once it reaches maximum shutter speed it'll have to start stopping down the aperture irregardless of priority.

    If you are in iAuto or Scene mode, then again this choice will vary with a preference to dropping shutter speed for action or portraits and a preference to stopping down aperture for groups and landscapes.

    Your camera's Program mode is probably geared more like the action/portrait modes... speed up shutter first until maximum shutter speed is reached, then start stopping down aperture. You mentioned compensating for sensor size, and that could very well be a big part of the manufacturer's choice in this sequence of priorities. Stopping down aperture last means shallower DOF which is certainly the "trend" in photography.
     
  18. Hikari

    Hikari Mu-43 All-Pro

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    You should not be in an auto when you are drinking.
     
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  19. WT21

    WT21 m43 Boom-a-rang Subscribing Member

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    I think this behavior for P mode is preferred. Difraction sets in quick on these small sensors, and many of these lenses are at their best around f/4-5.6. Maybe Oly knows that, and factors that into their P mode algorithm?
     

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