[slr_neophyte]

I'm a very happy K-x owner, and am loving my camera more and more. My wife just got me the DA 55-300mm...and it's a beauty - I've been having a lot of fun with it. I've been taking photos for about a year and a half now with my K-x, still have my kit lens and a couple manual lenses that I've picked up along the way. Still, I'm very much a novice and some things frustrate me when I give myself time to think about them. Specifically I'm referring to buttons and functions that I really have no clue what their use is. I suppose I could research each and every individual function / button, and try to learn that way, but I'd love to just post a few of them here and get a condensed, 'dummied down' explanation of what each is for, and what situations would require me using them. So, here is my list:

1. The AF/AE-L button
2. Dynamic Range Settings (Highlight Correction, and Shadow Correction)
3. Lens Correction (Distortion Correction, Lat-Chromatic-Ab Adj)
4. Catch in Focus

There are a few others, but for now these are at the top of my list of things that so far I never use, but can't help but thinking there's a good use for them, and should I be using them? And when?

[wildweasel]

Those are all useful features and worth learning how to use.

1 - press the button whilst half pressing the shutter and it will lock the focus and exposure, so you can recompose whilst keeping the correct exposure/focus for the shot.
2 - preserves detail in highlights and shadows.
3 - does what it says - if a lens has, say, pincushion distortion, the camera will correct it.
4 - fires the shutter when correct focus is achieved. It's useful for manual focusing - press shutter and rotate focus ring, shutter will fire when subject is in focus, and for capturing moving subjects, such as plants in the wind, insects, etc.

[metaphiston]

Wildweasel did a great job of explaining what the buttons do, so here are some further ideas about when you might use them.

1. Useful for fast moving action, such as sports photography, where you don’t want a sudden change in the settings once you’ve focused and composed if you’re shooting in a partially automated mode like Av or Tv. Can also be used when shooting landscapes (in Av, for example) to deliberately under or overexpose compared to what the camera has calculated by AE-L at a darker or lighter composition before recomposing to what you want to shoot with the shutter halfway depressed and taking the shot.


2. I almost always have highlight correction switched on, to stop the detail in the highlights being lost. Useful if you are taking a picture with something white in it – like a brides dress, or a swan. Also useful for landscapes to try and save as much detail as possible in a scene with a lot of dynamic range, as it allows more to be done in post processing.



3. To save you applying these in post-processing, but will slow down the camera's burst rate. Most useful for landscape shots, where you will likely not need to shoot off a lot of shots at once.


4. For a moving subject – say a car driving past you, you can have the camera prefocused with the shutter button depressed, and the camera will take the shot at the precise instant the car comes into focus. Useful for sports and events photography. Also can be used on manual focus mode, as you turn the ring the camera will take the shot as soon as it detects proper focus.

[Just1MoreDave]

The AF/AE-L button can be programmed to control AF instead of locking the exposure. You can set up your camera to only autofocus when you hit that button, AF with either that button or a half-press of the shutter button, or holding the button down cancels AF while it's down. I could never unlearn habits I picked up from my old *ist DS. When AF started to do something weird, I used the AF/MF switch on the front of the camera to go to MF. You may find one of those options works better for you.

I use the AE-L button sometimes. It's another button that customizes the camera to the way you work, or you could ignore it if it doesn't help. One use is combined with spot-metering and any mode except for M. Say you wanted to have perfect exposure on someone's face, no matter what lighting was behind them. You could point the center spot at their face, then press the AE-L button to lock the exposure. Now you can change the framing to anything, so the face is not dead center in every shot, and the exposure won't jump around wildly as the center spot meters other things. It's exactly what I need for testing lenses at different apertures. I get a good exposure at f8, then use Av mode to set other apertures. The shutter speed follows along to maintain the same exposure value.

The camera reviews at dpreview have the technical explanation for what is happening when highlight and shadow correction is used. It applies to JPG shots so I don't use it, but it doesn't mean it's not useful.

The lens corrections automatically remove some flaws that your lenses have. The flaws are not always significant or present. Most zooms have distortion that varies at different focal lengths. If you take a shot at a focal length where distortion is low, you won't see a lot of difference between corrected and uncorrected. If you shoot RAW, you can do this processing later in the Pentax software. I find the corrections most useful when you're shooting several shots and combining them into panoramas.

You can use catch-in-focus for handheld closeup shooting. I sometimes set my lens for its minimum focus distance (to get maximum magnification). Then mve the camera back and forth and use catch-in-focus to fire the shutter when it detects focus.