From Portsdown Hill in Infrared
It was a cold but sunny day today. So I decided to take my “full spectrum” converted camera up to Portsdown Hill for some infrared snaps. I thought it might also be interesting to try it on my 120 year old Bausch & Lomb + Beck 101.6mm lens. Whilst this is not a sharp lens, it has the advantage that it was made at a time when colour film was in the realms of science fiction. Which means it has no coating on its glass.
To be honest, this did not have the dramatic effect I had hoped for. Infrared shots tend to be a bit fuzzy anyway. But all the images were soft – too soft in my opinion. It was impossible to achieve a sharp focus using infrared with this lens. I’m guessing this is because the infrared element focusses differently from the visible part of the spectrum?
In any event, on reflection, Portsdown Hill in infrared might have been better on a modern sharper lens. I did manage a couple of snaps of a very large full moon, that I was moderately pleased with. In fact I used one as the article’s ‘featured image’.
Hand-made filter adaptor
I also took a few snaps of the kit I used with a standard µ4/3 camera. I did so because I am rather pleased with my home-made filter adaptor. This basically consists of a 12mm length of 32mm inside diameter uPVC waste pipe. I cut it from an old offcut with a giant tube cutter – for a nice lean even cut. I reamed out the inside a little with a piece of Emery cloth, so it slid over the Beck lens housing with a nice snug interference fit.
I then slid a chunky 40.3mm -> 37mm step-down ring over the end of the plastic tube. This is invisibly held on the tube with a wrap of very thin double-sided sticky tape. It has about 3mm of 37mm male thread protruding from the end of the tube. Which is just enough to screw on a 37mm -> 58mm step up ring. So that now I can mount any of my collection of 58mm filters on the front. In fact, insofar as filters are concerned, this 120 year-old lens now behaves pretty much like all my modern lenses do.
