Tag Archives: footnote

So Soon?

It was a spectacularly lovely morning with the sun beating down from a cloudless sky, and I realised as I set up the tripod for the first exercise of the day, that my D50 was beginning to show its age when it came to its ISO range. Not able to go lower than 200, meant that anything slower than 1/30th of a second was beginning to burn out. This was fine for the two exercises (and anything slower than 1/15th second ran the risk of the moving subject disappearing totally, like it was Paris in 1830-something) but if I ever want to do something like this for people to see, I need to either get a camera that can do lower ISO speeds or – far less exciting – buy some ND filters. There are various things that argue for a new camera – the 3000 x 2000 pixel image isn’t that big any more; I got it in 2006 so it’s obsolete by now; it’s nice to have new gear – but I hadn’t expected to be thinking quite so seriously about upgrading for a year at least…

And then there’s the issue of the two spots that are apparent on the sensor when you shoot something tonally flat, like the sky:

oca-1-1

I can clean the sensor (or pay for someone else to do it), and I can clone them out when they’re annoying, like here. But, ugh. So soon…

how normal is normal anyway, pythagoras?

One  footnote to the first of the introductory exercises is that I finally did the sums to work out the “normal” focal length for both a frame of 35mm film and for my smaller DSLR sensor and was slightly surprised to discover that:

DSLR: 23.7 squared + 15.6 squared = 805.05 or 28.4 squared: – ie the diagonal = 28.4mm

Film: 36 squared + 24 squared  = 1872 or 43 squared – ie the diagonal = 43mm

So, rather than being normal, a 50mm lens is ever so slightly telephoto and the nearest I can get to a normal angle of view with a prime lens on a film camera is my Olympus Trip 35 with its 40mm fixed lens. And on my DSLR I need a 28mm lens rather than the 35mm one I’ve blithely been using for ages now.

So there…