Sunday, 26 October 2014

the Roulettes

 Yesterday (well and today too) we had the Gold Coast 600 race (because we lost the Indy har ha ha ha) and as part of the circus we also had the Roulettes doing an air show at the start of the "big race".

I happen to live quite close to where the event is (Main Beach , Gold Coast) and so get a great view of it all.

Even better I live on top of a hill in the area and get an excellent "back row grandstand" overview of it.

I have found in the past that my Canon FD 300mm f4 lens does a fantastic job of aircraft at that range. The shot to the left here is "straight out of the camera" with no cropping to make my lens seem to reach further.

Given that its a 70's mechanical camera lens whacked onto the front of my GH1 I'm happy. Actually I've had it for a five years now and remain happy with it.

Just by way of comparison, here is a shot showing 100% pixels (its a 4000x3000 pixel image capture, so naturally it won't fit on a 1200 pixel wide screen right?) that top aircraft.

which all things considered (you know, like atmospheric losses {shimmer and such}, it being hand held...) I've got to say that I don't think that you'd get that much better with any other lens no matter how much you spent on it.

My technique for this is to focus on something about half a mile away (hat tip to the UK and American readers, as I usually use metric. ... and yes you can see the difference in focus on something further away at f4) and lock it down with my "rubber band" technique.

I then set in f5.6 so that I can get a DoF that covers almost everywhere the aircraft will be in (its called Hyperfocal Distance). Eg, from this online calculator.

So you can see that the amount of blur will trail off gently as they get further away (further than 2.6 Km anyway by which time the combination of atmosphere and distance will soften that loss). To put a perspective on that graph's "Blur" (which is the Circle of Confusion, excellent tutorial there) the value of 0.01 is the minimum discernable size in a 8x12 print and I reckon that the combination of this lens and camera will not attain such. So vrom 300 meters to 2km it won't really change the image.

Anyway, there's more to a good picture than just sharpness and maths right?

I liked this shot (even though it was further away)

and when pixel peeping you can see heat shimmer is already eroding the quality (no matter what focus or what lens I had, even if I'd had a SciFi Anopticon)

Anyway, some other shots from the day ...

It was nice to see the Roulettes


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