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Gizmofreak Dec 30, 2003 1:31 AM

Action/Sport modes
Hey guys, could someone explain to me how action/sport modes work on digital cameras? I mean I know it adjusts the settings of the camera for optimum picture taking at action or sporting events but how much better does it improve the picture quality compared to those that do not have this mode?

I guess my concern is I have a camera eyed on for what I would like, but it doesn't have action mode on it. Does that mean action shots won't really be the best quality then?

It's tough researching and deciding on all this stuff isn't it?

ohenry Dec 30, 2003 8:45 AM

A sports mode requires faster shutter speeds. I don't know your level of photography knowledge, so forgive me if I'm overly simple in my answer.

An exposure is made up of 3 elements: shutter speed, aperature (lens opening size), and film speed (sensitivity). Generally, the film speed (ISO) is constant during the actual shooting, although with digital cams it can be adjusted on the fly. This leaves adjusting shutter speed and aperature as your variables to determine proper exposure.

Shutter speeds are measured in fractions of a second. Each speed changes the light admitted to the sensor/film by half, i.e. 1/250 admits 1/2 as much light as 1/125, 1/125 admits 1/2 as much light as 1/60 and so on.

Aperature is also a measurement of fractions with regard to the shutter opening in relation to the lens focal length. Again, each f-stop admits 1/2 as much light. f/2.8 is actually a fractional number so is a larger opening than f/4. If you start with 1 and 1.4 and double them, you will come up with the f-stop scale, each doubling the amount of light. 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32

There is a direct relationship between these two parameters. If you increase shutter speed by one stop, you would decrease the f-stop by the same amount (one stop) to retain the same exposure. In other words, taking a picture at f/4 at 1/250 will give the exact same exposure as taking a picture at f/8 at 1/60 (2 stop differences). The primary difference will be the depth of field. DOF decreases with larger aperatures. order to freeze the action of a sports event, you must take the pictures at a faster shutter speed (typically 1/500 or faster). As a result, the aperature must be larger to ensure the proper exposure is obtained.

The sports mode is just an automatic feature that does this for you. If you can manually set your speed and aperature, it is a moot point to not have one.

Hope this helps.

Olivier12345 Dec 30, 2003 9:37 AM

I don't know if it helps the original poster, but it helped me a lot ! :)

thanks, I'm less a newb than I was now !!

Gizmofreak Dec 30, 2003 3:57 PM

hi yah that did help, now i just need to see if those things are adjustable on the camera that i was eyeing, although i hope it will be easy to adjust. I'm kind of a newbie, since this is my first digicam, but i've been waiting to get one for awhile now and have read so much stuff on digicams it's become overload. But I'm eyeing the Canon S400, I like the small ones.

Blues Dec 30, 2003 6:55 PM

To continue with ohenry's reply, that means that for sports action, one of the most important parameters for you is maximum lens aperture (larger aperture == lower F-number). A larger aperture lets in more light, which allows you to go to faster shutter speed, which will stop the action better.

Most digicams can get no better than F2.8, which is actually pretty good. Then Minolta Z1 that I just bought does F2.8 at wide angle, and F3.5 (about 1/2 stop worse) at full 10x zoom. Your choice of S400 will do F2.8 at wide angle (good), but just F4.9 at 3x zoom (about 1 1/2 stops worse).

A larger aperture generally means a physically larger lens (more glass), which is at odds with your wish of a small camera. Life's full of tradeoffs.

You'll also want to look at the ISO settings available. Higher ISO numbers also allow faster shutter speeds. But read the reviews carefully, because most digicams create pictures with a lot of noise when set for high ISO ratings. Again, a smaller camera generally means a denser CCD array, which usually means higher noise when set for high ISO speeds.

I think both these parameters are more important to you than the availability of a sports mode. As long as you have manual exposure capability, you can set things up as you like. Hope this helps.

Gizmofreak Dec 31, 2003 1:27 AM

Thanks guys, this all helps, and it makes sense too :)

I hear the term noise a lot, what is that exactly? As I'm sure it doesn't mean that the camera is noisy.

ohenry Dec 31, 2003 8:17 AM

Noise refers to excess visual trash on the image. Consider it the digital version of grain in film.

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