Sunday, 10 July 2011

Amazing place, amazing lens

I thought I'd do another little advertisment for my equipment and holiday. The lens used in this 30 second shot covers from Scorpius to Polaris! This view was from the plinth at AstroPalma looking across to the astrotrak and remote dome. I hired the f/2.8 Sigma 4.5mm 180 degree fish eye from lenses for hire, and it JUST (or maybe not?) focused with my modified Canon EOS1000D. The trouble with modifying a camera is that the removal of glass makes a tiny difference to the focus. Fortunately most lenses focus a bit beyond infinity, but with this one the tiny TINY focal length made the focus point crucial and it only just made it to focus with the ring at full turn. Phew! It is impossible to use live view at night with this lens - no star is bright enough and Jupiter wasn't risen from behind the mountain. I had to find a street light in this dark sky location. Fancy that, wanting light pollution? Mad.


Eric C. Emms FGA DGA said...

How was AstroPalma? How long were you there, what do you 'rent' and how much did it cost?
Interested as one who will be in Canaries (again) next year for observing.
Many thanks

Dr Dan said...

Hi Eric,
Fantastic 7 clr nights, mag 6.0 was my limit though - not as perfect as you might hear (7.0) as there was some saharan dust and we were only at 750m. Perhaps the high dew point (18C) & inversion height contributed to light scatter. V V good comp to UK tho! If you ask 'Joan', the obs has a small chalet for 2 beside it (in his back garden!). €315 for 7 nights plus €260 for 5 night + 1 day session course (Joan's time, full access, can do as you please). I hired 2 lenses from lenses for hire.