Generalising

Some photographs from the snowfall in Cambridge earlier in the week:

Every now and again, I find myself with a pile of telephoto shots of something which was very hard to focus on properly, where I want to select the best few images and crop them for display. If I’ve made a hundred images, this can get very tedious – I have to manually zoom in on each one to see how sharp it is before comparing it to the next.

Tedious, repetitive, tasks. Surely, this is something a computer can do for me? Lo and behold, imagemagick saves the day…

convert -crop 1024x768+1632+1040 *.JPG -set filename:f 'crop_%t.%e' +adjoin '%[filename:f]'

..takes a series of 4288×2848 pictures, crops out the centre 1024×768, and drops this into a seperate file called crop_FILENAME. Skimming through these is far quicker…

I know, I know, trivial solutions. But it saves me a lot of time. And as a result:

…pictures of the woodpecker outside my living-room window, shot with a D90 and an old manually focused f/5.5 300m lens.

It works! I had almost two hundred frames to run through to find these (which may explain why they waited a month and a half for me to get around to it…)

Things you never quite expect to see in suburban English cities: crayfish carefully picking their way across the road.

The first photo feels like I should edit in some 5mm-tall people fleeing the monster.

Photography was suspended briefly for a car to drive over it. (Literally: the wheels passed several feet to each side) The driver couldn’t see what was in the road, but guessed we were photographing something small and fragile, and looked at us with a very guilty expression as she passed…

I used bellows for the first time today – a bizarre-looking Heath Robinsonish contraption, but they worked. The camera was a modern dSLR, the lens a standard Olympus OM-mount 50mm, and the bellows unit emerged from a Soviet factory sometime in the 1970s. (It still has the factory inspector’s slip, signed in Cyrillic…)

These photographs were all taken in natural light with the bellows extended to around 350mm; I haven’t yet calculated the effective magnification, but from counting threads, my best estimate is that the field of view is on the order of 8mm across. The main problem was successful focusing – even at f/8 or f/11, the depth of field is still very low, and it’s possible to watch the area in focus travel up and down a surface as you move the lens.

These are all “horizontal” shots, with the item held up vertically in front of the lens – the bellows is set up for a tripod mounting, but it’s a very light tripod and the camera doesn’t lock on the mount firmly, so there’s a good bit of vibration in the system. Next time with mirror lock…

The rear of a cork-based tablemat.

Cotton weave on a (very worn) teatowel.

The tip of a pair of nail-scissors.

A horde of (quite bold) ducklings at Hinksey Lake this afternoon:

I particularly like the one picking its way through the daisies, though the exposure is a bit off.

Three photos of a coot from last week, testing the new lens on an unexpectedly sunny day:

All three taken at 150mm, uncropped, at f/5.6 and 1/320s. I’m quite pleased, on the whole; this does feel better quality than the older 150mm lens. The focus isn’t quite right, but I think that’s the camera autofocus being set wrongly – I still need to work on this!

Step 2, I suppose, is now sell the old one on ebay and recoup the cost…

Whilst playing with my webcam tonight to try to get the mike to work – which I can’t, because I screwed up the audio settings somewhere, and it’s a real slog to get them back to normal – I noticed it was manually focused, and some quick experimentation confirmed that it could focus down to a point very close to the lens.

Sitting on the other side of the room is an old 260mm f/4 lens mounted on a tripod – it’s heavy enough that it needs the tripod mount on the lens rather than the camera body, and when I was done with it the other night I just left it there.

The webcam is just the right size to poke its lens inside the back of the larger one, so it was the work of a minute to fiddle the two focus rings and produce this:

…which is all very nice, and makes me feel I’ve sort of achieved something, but, well. It’s a camera lens, it has a real mount, I could wire up a real camera and get a photo which is about fifty times the size and without the lens barrel in it. From a practical standpoint, this is not the greatest of achievements.

I’m sure it must be useful for something, but right now I have no idea what. Perhaps I could tape them together and point it at the bird-feeder in the garden…

I recently got a working internet connection back, and have gone through a month’s worth of pictures. One small bit I’m quite pleased with:

The International Space Station, with the new camera and an old (and quite rickety) 420mm-equivalent manual lens. I am looking forward to seeing what a good lens can manage with this.

An earlier attempt with the old camera:

I have been without any working internet connection for a couple of weeks now, so no photographs of the last trip yet. Have some old ones, instead, for the 11th; these are from a trip to Normandy earlier in the year. Three national war graves; three approaches to commemoration.

(…below the cut…)

So, after my debates in parts one and two, I went to source a cheap E-620; after spending hours poring over various retailers, I tracked down a good-condition used one for not unreasonable money in NYC, which could be posted up.

Then someone said, why not look on ebay, if you’re considering second-hand? So I did, again thinking about delivery to New York… and then it occurred to me to actually look on the UK site. Where I promptly found one with a pair of lenses (14-42mm and 40-150mm), used but well-cared for, at about what I was looking at paying in the US and without any of the potential tax worries.

Which was, on the whole, a perfect combination. So, I bought it, and it turned up on Wednesday, and it’s great. I have not had much chance to take it out, but what use I’ve had out of it feels pretty good.