[StephenHampshire]

Jatrax, with selectable focus points, you can move them with the <> buttons on the rear of the camera, no need to delve into menus. I normally use af-s as I shoot short bursts of 2-3 frames, allow the camera to refocus, shoot ioff another 2 or 3. I will prefocus on the track as I know the oint at which I want to capture the loco - I could use centre point re-compose, but then when the camera refocuses for my second or third burst, the focus will be on the coaches not the loco- sounds complex, but really easy in practice. I do use centre spot/recompose often for static subjects at a reasonable distance. The K5 is not as easy to use as the K20 because on this camera you have to toggle the use of the four-way buttons between focus select and the normal functions, and the LV button is in the wrong place and too easy to hit by mistake.

[dadipentak]

I just assumed it would be too slow to use in the real world and dismissed it as nothing but a gimmick.

Oh no--it's awesome (but I wish it were available for catch-in- focus with MF lenses!)

[TylerD]

It's supposed to be better for tracking moving subjects and such, too. .

Sorry for being thick but is this because in AF C the camera shifts focus from one point to another without you having to move it?

I'm finding this thread really interesting as its helping me start to grasp how auto focussing works, so thanks Philoslothical and everyone else for your help

[RioRico]

Sorry for being thick but is this because in AF C the camera shifts focus from one point to another without you having to move it?

On my K20D, AF.S and AF.C work differently when the shutter button is half-pressed. AF.S will lock-focus on a subject and WILL NOT fire without focus confirmation (the green hex). AF.C will continuously refocus on the subject and WILL fire without focus confirmation.

So AF.C will track moving subjects, but sharp focus isn't guaranteed. One solution is to use AF.C with a Continuous Drive mode. Then you can spray-and-pray (machine-gunning) -- and who knows, you might get some good shots! Stranger things have happened, eh?

[PPPPPP42]

There is a reason why I have all manual lenses except for the one I got super cheap from a friend.
The K20D seems to pick focus points fairly accurately for me since I'm not usually trying to focus on something I'm not at all pointing at, (plus its totally cool to watch it shoot little red dots at all the people in the viewfinder). Never trained with it enough to really use the AF controls effectively though.

Until my camera and I stop getting into occasional disagreements about what in focus actually is I have no need for it to do that for me. Sometimes its good sometimes it changes its mind and decides to screw things up at the critical moment, usually only on the important shots.

Kinda like the arguments at the gun range from the old time shotgun people who can use a pump shotgun rather than a semi auto to hit a mass of clay pigeons all fired at once before they hit the ground. (I use a pump shotgun too)

I firmly believe that someone with a real focusing screen installed in their camera (Katzeye for me) with proper training, experience and instincts can focus just as fast on exactly what they want as the AF system. There are exercises to get much better at doing this near instantly.

Unfortunately modern DSLR's are designed for the other 90% of users so you get short clumsy focus ring throws, crap screens and an AF that needs its hand held to cross the street.

I really only use AF seriously with my one lens because the focusing ring rather sucks, its SO easy to get spoiled and rely on it but then you want to pitch it in the river when it suddenly forgets how to focus that critical one time shot.

[TylerD]

Jatrax, with selectable focus points, you can move them with the <> buttons on the rear of the camera, no need to delve into menus..

StephenHampshire, does this mean that you are selecting different focus points with the <> buttons as you shoot the train coming towards you?

[StephenHampshire]

Tyler - no just keep moving the camera so the focus point is kept in line with the front of the loco - sometimes I will move the point on the hoof once as the train approaches, but not normally as I have set the focus point up to give a classic rule of thirds composition

[TylerD]

Thanks Stephen, so -in continuous shooting mode? - you fire off some shots , then move the camera , then fire off some more shots and so on .Do I have that right? Or do you keep the camera moving as you shoot , I presume not otherwise the image would be blurred.

[StephenHampshire]

Thanks Stephen, so -in continuous shooting mode? - you fire off some shots , then move the camera , then fire off some more shots and so on .Do I have that right? Or do you keep the camera moving as you shoot , I presume not otherwise the image would be blurred.

Yes, that's the way I do it! I also do panning shots, but as the train is then side on, choice of focus point is not so crucial!

U class on the move | Flickr - Photo Sharing!

[TylerD]

Great Stephen , I've got it now, thanks very much! And I love the panning shot , a beautiful contrast between the crisp clarity of the train and the slight blurriness of the steam and background. She looks as though she's really chuffing along!