I did not mean the focus lock. If you look at the back of a D50 it has a 4 way arrrow button to the right of the screen. If you press it it changes the focus point and there is no way of locking this.

Wheeler: The old rule for full frame 35mm cameras was that for hand holding the shutter speed needs to be at least 1/FL. So to update that to APS you multiply by 1.5. And as you say, the old rule of thumb is just a rough guide.

But I certainly won't argue with you when you say what works for photographing planes. You obviously know far more than I do about that. BTW nice pics!

Leif

I have just picked a link up from another forum that seems to be a good read for anyone whanting to try some aviation photography:
http://airfoto.photosite.pl/

Leif is correct 1/FL will provide an adequate shutter speed for sharp fuselage with some prop blur. However Wheeler is also correct to reduce shutter speed to yield a desired prop blur BUT depending on experience this will dramatically effect the number of 'keepers' but one or two crackers are possible. I have developed a formula specifically to give a certain amount of prop blur as five bladed props do not require as much blur as a single blade to give the ultimate full disc.

Forumla :-

Shutter Speed = (60/rpm)/(360/bdeg)

Where

rpm = prop rpm allowing for any reduction gearbox
bdeg = desired prop blur in degrees i.e. 72 for five blade and 180 for single blade.

This may not be perfect and is subject to real-life experimentation but is certainly good for guidance.

Rob, All I know is light aeroplanes the other stuff I just photograph and thought to do a bit of maths to help people.

Light aeroplane C152:-

Take off 2500rpm
Cruise 2150 - 2250rpm
Landing 1000-1500 depending on how your approach went!

I understand you are close to the Shuttleworth trust could you please provide an indication of warbird prop rpm, maybe you know someone who can provide the answer. I know warbirds have reduction gearboxes but what ratio?

I think I'll stick to photographing mushrooms. You don't need to worry about frames per second, prop blur, buying expensive pro-grade telephoto lenses etc. But I do have to work fast as given a day or two they disappear. :)

BTW Since there are some very capable photographers here, do you think the new Nikon 70-300 zoom on a DX body will be useful for air displays or will the maximum aperture be too slow?

Leif

The new Nikon 70-300 will be more than useful for airshows. I think a zoom to 400mm is perfect but 70-300 is adequate. I sometimes use 70-200 with 1.4X (280mm) if airshow is going to be crowded because of lightweight and compact. Max aperture no problem on normal days but if dull/raining will have problems but would you want to be out in that weather anyway - I know I wouldn't. Solution is to increase ISO, use faster lens or go home :).

Or to put the camera away and watch the display without looking through a camera.

Thanks for the answers. That 70-300 mm lens does look tempting.

Not quite in the flight-photography category, yet, but did anyof our aircraft enthusiasts get to the rolling-out of the Vulcan at Bruntingthorpe, Leics., on Thursday? Any pics?