Some Advice Please !

A few weeks ago, I was trying to photograph seabirds in the air without much success and today I took a few shots of a passing air ambulance whilst waiting for the return of a Dakota that never reappeared

Since there have been some really good images of aircraft posted recently, I thought that I would ask for a few tips.

This one was taken as one of a few, single frame shots using autofocus.

Presumably it makes more sense to set the camera to infinity on the manual focus setting and to use continuous shooting, in the hope that a few will turn out o.k. :




Despite appearances, the sky was lead grey, much of the helicopter was in shadow and it was drizzling, so it has been tweaked a fair bit.

I haven't very much experience of photographing aircraft (I was going to write 'shooting' but that didn't seem right) but I think infinity is too far. There was a time when Pentax lenses had depth of field scales so you could accurately work out what would be acceptably sharp (expect a flurry of posts regarding circles of confusion). An example: 50mm f1.7 Pentax-F @ f16, set to infinity on the focus ring to the right hand side of the DoF scale gives an acceptable sharpness between 2.5M and infinity. At f5.6 this becomes 10M to infinity. Telephotos, of course, have shallower DoF; wide-angles greater and Pentax WAs had a very useful hyperfocal distance marked on the focusing scale - oh happy days. I hope this doesn't sound complicated - it isn't. One touch zoom lenses cant have DoF scales and auto focus would overide it, but it might be worth getting a set of scales, I'm certain I've seen them advertised in AP and switching AF off. Somebody must have them published on the Internet. I once had to sit an exam on the calculation of such things but that was in 1977 and maths was never my strong point and there is no chance that I could explain the principles in detail at this distance.

Ken

Best one I've come across...

http://www.dofmaster.com/dofjs.html

[quote="McBrian"]Best one I've come across...

http://www.dofmaster.com/dofjs.html[/quote

Great link, bookmarked!

I've tried the "set at infinity and rely on massive DoF" tactic in the past. I won't say it doesn't work at all, but it doesn't work at the kind of ranges you typically get at airshows unless you're doing pictures of VERY distant parts of the display. You'd be surprised how accurate the focus point has got to be to get a sharp shot.

I don't really know why this is, I've seen the DoF calculators before, and used lenses with DoF scales on them too. I'm not going to enter into arguments over theoretical distances which should be infocus. I observed one such thread on DePressing Review recently where some guy had taken an incoming Tornado very well indeed and he'd commented how well the AF tracked the plane at about 160kts. He was blasted by know-it-alls quoting theoretical DoF figures and saying the AF performance was nothing to do with it.

All I know is that in my real world experience, shooting aircraft at typical airshow flightline distances, you need to get the focus point right, "infinity and hope" just does not produce the same quality of results. It's hard enough getting a few keepers of planes in flight anyway, using this technique will reduce your keeper rate to virtually nil if the planes are at a realistic distance.

BTW, nice helicopter shot under the circumstances. You've done well to get this much detail on such a flatly lit day.

Duncan

Completely agree with this.

And this. Good choice of shutter speed too.

I find continous focus and lots of practice is best (for birds). But be prepared to discard a lot of near-misses.

And a lot of far-misses.

G

If you have the luxury of a fairly stopped down aperture then I think one could set focus near to (not at) infinity and be sure that everything from there out was in focus. But I think often that luxury is not there, since shutter speed has to be fast enough to freeze action. So in that case one has to nail the focus... not easy.

I think this shot is fine, BTW. Not sure how it could be better in the circumstances.

Thank you for all your replies.

So the answer is autofocus (continuous) with continuous shooting and lots of practice