[ Content | Sidebar ]

Archives for September, 2010

Thames Barrier to Crayford Ness

September 29th, 2010

Yesterday I went for a walk eastwards from the Thames Barrier and into the estuary. Why wasn’t I at work? Because this week I’m having a staycation! As is often the case with my outdoor activities, the weather was grey and miserable. Here’s the Thames Barrier itself:

The visitor centre is quite good. Beyond the barrier the south bank is an industrial wasteland that stretches for mile after mile. Eventually you come to London’s primary sewage works at Thamesmead which proudly boasts the capacity to process the sewage of 1.6 million people. It is endless: with a six foot high concrete wall on one side and giant sludge vats on the other the effect is quite hallucinogenic. After that comes the UK’s first sludge-based power plant. Hours later I came upon Erith, a dismal suburb of Dartford, and rather wished I hadn’t.

I have to confess, I didn’t make it quite as far as Crayford Ness, the official end of the Thames Path extension. With a view like that I decided I wasn’t going to walk any further eastwards and promptly caught the train back to London to go book shopping.

Reducing DVD drive noise

September 25th, 2010

Fan noise from CD/DVD drives can be very loud. It probably doesn’t matter if you’re just reading something off it but if you’re watching a DVD for example, it can get annoying. The fans are required in modern drives when the disc is spinning very fast – e.g. 16x – and by default it spins as fast as it can. So there is a simple solution: slow down your drive! This is easy enough in Linux, but oddly the command you need is eject. For example, to reduce your drive to 4x speed:

eject -x 4 /dev/dvd

The parameter -x is simply the multiplier: pick a low value (except 0, which means full speed). 4x seems sufficient on my device to completely disable the fans.

Qemu resizing blurriness

September 25th, 2010

Are you annoyed when Qemu randomly resizes its window causing all the text to be scaled and blurred? Maybe it’s just my window manager, but here is a trivial patch to disable that annoying feature:

--- sdl.c.old   2010-09-25 13:30:48.000000000 +0100
+++ sdl.c       2010-09-25 13:30:50.000000000 +0100
@@ -102,7 +102,7 @@
 
     //    printf("resizing to %d %d\n", w, h);
 
-    flags = SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_HWACCEL|SDL_RESIZABLE;
+    flags = SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_HWACCEL;
     if (gui_fullscreen)
         flags |= SDL_FULLSCREEN;
     if (gui_noframe)

Waterloo to Greenwich

September 19th, 2010

Yesterday I walked along the next bit of the Thames path from Waterloo to Greenwich. I think this might have been my favourite section thus far: lots of things to see and Greenwich has some interesting museums. There’s also a really good community farm at Surrey Docks.

Unfortunately just past Greenwich part of the path is closed and the diversion doesn’t exactly go though the prettiest neighbourhoods. I had intended to go to the Thames Barrier but it was getting late so I doubled back to the O2 and got the super-fast ferry back to Waterloo.

I had previously believed the Thames Barrier was The End. But apparently there’s a new Thames path extension that goes 10 or so miles beyond.

Here are some photos I took:

The strange world of film cameras

September 14th, 2010

A few weeks ago I found my granddad’s old camera in a box in our attic. Intrigued, I hunted around a bit on the intertubes and discovered it was quite a nice camera in its period. It’s a Voigtländer Vito B produced in West Germany. This is the upgraded model dating from 1956 with a larger viewfinder and a higher quality f/2.8 lens.

Surprisingly in the same box was the original instruction manual so I set about figuring out how it worked. I got a set of prints back today and, astonishingly, they weren’t a complete disaster!

This is the bridge over the Thames at Maidenhead. The Vito B has a fixed 50mm focal length which I initially thought was rather restrictive but I’ve grown to quite like it. The perspective effect is apparently quite close to normal human vision.

The camera is fully mechanical with no batteries or other fancy modern contraptions. This means it makes all sorts of delightful clanking and ratcheting sounds when you use it. The shutter release sound in particular is rather wonderful.

Using it isn’t quite as complicated as it looks. All the controls are on the lens barrel at the front as you can see from the picture below. The first thing you do is guestimate the distance to the subject. There was apparently a clip-on rangefinder for calculating distances, but I haven’t been able to find it if my granddad ever had one. The diamond indicates the selected distance and the clever scale to either side indicates the distance in front and behind the subject that will be in focus for a given aperture size.

The next task is to measure the light level and set the red arrow to point at the correct EV value. In the same box I found a selenium light meter that, when calibrated to the film speed in use, will give you an EV reading. I don’t know how old it is: it is certainly newer than the 1950s. I’m not really sure I trust the values it gives, especially as selenium’s sensitivity to light decreases over time, but it seems to have functioned adequately.

You set the exposure value by pressing in the metal knobs on the side and turning. When the knobs are released the aperture and shutter speed dials and locked together and increasing the aperture size decreases the shutter speed and vice versa, supposedly ending up with the same exposure. This works a bit like the shutter/aperture priority mode on my normal camera. I am rather amateurish when it comes to this sort of thing so setting these values is a black art. I normally picked something that seemed reasonable and sanity checked with my LX3 forced to the same ISO as the film speed.

This one ended up a bit over-exposed but I didn’t really have time to fiddle. Three of the photos didn’t make it back: the thumbnails are marked “underexposed” and the negatives are ominously blank. But all the others looked all right so a 33/36 success rate isn’t bad.

The lever on the right selects self-timed and flash synchronisation mode. Various sources on the internet say the clockwork timer mechanism was notoriously weak and activating it now may jam up the shutter mechanism.

The photos were developed by Fuji Digital Imaging Service in Burnley who seemed very friendly and were highly recommended on the internet. In addition to the prints they send you a CD of high-quality scans, which is where these images came from.

Apart from the single-use cameras I used as a child I’ve only ever had a digital camera, so there’s something a bit odd about having to wait a week to see the results. The time consuming manual configuration and the thought of each shot costing 18p certainly force you to think about what pictures you take. In contrast to my usual snap-happy style :-).

This is what the back of the camera looks like: no LCD! The lever on the right is used for winding on the film. It also tensions the shutter release button, which is in the top right. The dial on the top left pops up when you push a small lever and this is used to wind the film back into the canister. I really like the viewfinder! I’ve never seen the point of them up to now, but I really have enjoyed using this one. Looking into it you can see overlaid frame lines although there is a parallax problem if the subject is close. Unfortunately I found it very difficult to use with my glasses on as it appears to do some magnification, so I usually just took them off.

It’s difficult to describe but many of the photos have an old-fashioned grainy appearance which I like. This is Wolvesey Castle in Winchester.

I find it pretty amazing that this camera is over fifty years old yet still functioning perfectly. I wonder whether computers will still support JPEG or SDHC in 2060? Will they still make Li-ion batteries? Playing with this has been awesome fun and I’d encourage anyone else to if you happen to find a vintage camera lying around. Last picture:

Back to Winchester

September 5th, 2010

As you may or may not know, I used to live in Winchester while I was doing a placement year at a certain large American mega-corporation. I hadn’t set foot in the place for over four years, so I decided to go back and visit yesterday as it’s only an hour by train from where I currently live.

Of the places I’ve lived in so far, Winchester is easily my favourite: it’s charming, compact, full of history, surrounded by beautiful countryside, and in all respects superior to the drab towns of the Thames Valley commuter belt where I’ve ended up. Even the Stanmore estate, an area with a poor reputation where we lived, is relatively pleasant by the standards of most towns.

The weather wasn’t too great but I managed to hit most of Winchesters major attractions and museums. For the first time I went on a guided tour of Winchester college (a very prestigious public boys school), which was certainly worth the £6 fee. Also noteworthy is the St. Cross almshouse where you can still go to the porter’s lodge and demand your “dole” (ale and bread for the poor). Although I think now you might not get dole without paying the entrance fee.

Anyway, the point of this rambling post is that Winchester is an excellent town which you should most definitely visit if you haven’t already. Here are some photos I took with notes.

A bug for Blodgett

September 4th, 2010

What is it? Where does it come from? Where is it going? Here it comes out of the undergrowth!

Seriously, I have no idea what it is! I’m sure I’ve never seen one before.

This is my first foray into macro photography and I don’t think it was wholly successful. Still, this next one is quite good though, probably because the most of the bug is actually in focus. You can see the sucker-things it uses to propel itself along. A bit like a caterpillar. Is it a caterpillar variant?

I’m wondering if using aperture priority mode might have helped, but that sounds a bit advanced. Maybe using the “spot” autofocus mode would be good too? Anyway, here is the bug’s head. (Well, it moves in this direction.)

And this is its bum. Not sure if the blue thing is a fancy-coloured tail or a dangerous stinger.

Speaking of strange creatures, I was reading on the train home about the sad fate of the giant Steller’s Sea Cow.

Maidenhead bridge from an exciting new angle

September 4th, 2010

I’ve been living in Maidenhead for a whole year now but just last weekend I discovered that what I thought was a private island in the Thames is actually open for several months a year. So here’s what I thought was quite a nice picture of Maidenhead taken from the bridge to the island: