Myles, I can tell you that you are 100% correct. The first three were taken at the January Temora airshow and the Neptune was taken from Bald Hill, Stanwell Park NSW where the local hang gliders/organ donours like to jump off the cliffs.

Thanks Tony, I`m sitting here quietly turning green with envy at your list of camera gear.
Simmo

Chris, I was quoting a poster and moderator on Pentaxforums.com named Mike Riley. Mike regularly posts some excellent airshow pics, and one day a noobie asked how he had so much success - he posted a long explanation based on the premiss that infinity was a lot closer than you think and your camera will focus on infinity almost all the time.
I took that with a grain of salt and carried my own rough experiment. At Albion Park aerodrome at the HARS hangars - the three hangars are a total length of 210 metres. I pre-focused on The Illawarra Fly a tourist attraction on top of the escarpment many mile away without re-focussing I then stood at the Eastern end the hangars and took photo along the line of the hangars and found that ground equipment near the western end of the hangar were sharp. It seems with my set up K20d and 55-300 anything that is approximately 185 - 190 metres away the camera will focus on infinity. You are correct it is possible to focus past infinity and nothin will be in focus. I only have a 300mm lens and I think that for longer lenses 400 or 500 infinity will be further away - but it seems to work for me.
[IMG]http://i125.photobucket.com/albums/p78/baldrick1946/_IGP1467.jpg[/IMG]
[IMG]http://i125.photobucket.com/albums/p78/baldrick1946/_IGP1409.jpg[/IMG]
[IMG]http://i125.photobucket.com/albums/p78/baldrick1946/_IGP2361HDR.jpg[/IMG]
[IMG]http://i125.photobucket.com/albums/p78/baldrick1946/HG4.jpg[/IMG]
Simmo
Simmo

Ancly, it`s worth considering that at most airshows the crowd line is far enough away from the aeroplanes that the camera will be focussing on infinity all the time. If you prefocus on infinity switch to MF you might have more luck.
Simmo

Have been trialling it for about three weeks, but somehow when I get home with a camera full of pics I always seem to click on Silkypix.

The grip (third party) was always on my K100d, it just felt so much better. Needless to say the K10d and K20d are always gripped too.

Hullo Patrickt, I just went through adding more info to that forum and I don`t think the MSN handle is required, I don`t have one and I had no problem logging on.
Simmo

Pictures to exe is excellent as is Proshow Gold and even better Proshow Producer. Producer is a bit pricey but worth it.
Simmo