London from above, part 1

Sunset over Houses of Parliament

Houses of Parliament with Westmnister Bridge in the foreground. 19:36, 1/6 sec, f/5.6, ISO 4000

This post was written exactly a year ago, but for whatever reason, I never got it posted. With it again being late September, the timings referred to in the post are accurate once more. So I hurry to get it posted.

I went on the London Eye to try to capture a few pictures of London from above during “the blue hour” when it’s dark enough to make the city sparkle like a carpet of diamonds, while there still is some colour and texture left in the sky. Although the pictures I got are “nice”, they are not quite what I had hoped for, and they don’t do justice to the absolutely amazing view I had from the top of the 135 meter wheel.  So this post is about what I learnt from the experience (warning: it gets quite technical and geeky); hopefully there will be a part 2 in the future where I avoid making the same mistakes again.

Evening or night-time photography is normally a quite slow, methodical experience for me. I like to have as low an ISO as possible to get clean, noise-free images and as small an aperture as I can get away with, to get as much front-to-back sharpness as possible. Plus, my 24-70mm lens gives beautiful sunstars at f/16 and below. This in turn means shutter times of several seconds, and thus requires me to have the the camera solidly locked down on a tripod to minimize any risk of movement.  The Eye doesn’t allow visitors to bring tripods, and even if they did, the movement of the wheel itself during a multi-second exposure would most certainly introduce blur. So I had to compensate with high ISO and wide aperture instead.

I bought one of their flexible tickets where you can just show up and get onto the Eye whenever you wish. That allowed me to wait at the entrance and try to gauge the light in the sky in order to decide when to get on. I set the metering to matrix metering, Aperture-priority with a fixed ISO that I varied between 1600 and 4000 during the ride.

View towards the East

Waterloo Station, Shell centre in foreground, Canary Wharf in background. 19:32, 1/15 sec, f/4, ISO 4000

Below I have recorded timings, exposures and light values from the first, middle and last part of the ride. “Light value” is a measure for how bright a scene is, with LV 0 being a scene requiring 1 sec exposure at f/1 and ISO 100. See Wikipedia for a list LV values for typical scenes.

Time Auto exposure settings Narrative Light value
19:02 Sunset (there was a full moon and thin cloud cover)
19:17 1/25 sec, f/4.5, ISO 1600 First shot when I got on the wheel. Skies still fairly light. Too early for ideal “blue hour” shot. 5.0
19:26 1/20 sec, f/4, ISO 4000 Probably the best blue hour shot, with good balance between sky colour and brightness of electric lights. 3.0
19:30 1/15 sec, f/4, ISO 2000 When I was approx at the top of the wheel 3.6
19:41 1/8 sec, f/56, ISO 4000 Last pic, at the bottom of the wheel again 2.6

I bracketed all my shots, but found that the camera’s automatically calculated exposure was pretty good, so the values above are not a million miles away from the “ideal” exposure.

I was in doubt about what aperture to use, so I hedged my bets by shooting first a bracket series at f/4, and then another of the same scene at f/5.6. With the wisdom of hindsight, I should of course have checked the online DOF calculator, which would have told me that the hyperfocal distance for my 24-70mm lens even at f/2.8 would have been between 7 and 60 meter, meaning that at the distances involved, everything would have been in focus, even if I had shot with the aperture wide open and focused on the nearest building on the ground. So by shooting at f/4 or f/5.6, I essentially gave the camera a one to two stop disadvantage which resulted in longer shutter times than necessary (= higher risk of blur) and/or higher ISO (= more noise).

All my pictures have some unwanted reflections. The carts (or pods as they are called) are round, so it’s like shooting the world from the inside of a glass bottle. Normally the way to avoid reflections would be to press the lens against the glass, but with it all being curves, it was impossible to find a place where I could avoid the reflections. This was probably not helped by me having the (petal-shaped) lens-hood on the camera, as that also introduced openings between the petals where light (and thus reflections) could enter.

View towards the East

South Bank Centre, Barbican, St Pauls, Tower 42 and The Gherkin. 19:32, 1/15 sec, f/4, ISO 4000

So all in all, the lessons from this evening out can be summarised as

  • Invent (and bring) a totally flexible lens hood that can be pressed against curving glass to avoid all reflections. Maybe a foam hood, or a contraption similar to a contour gauge? Don’t use a normal petal-shaped hood.
  • Get (and bring) a Gorilla-pod to help hold the camera still, for the exposure times are going to be fairly long
  • Shoot wide open, there will be plenty of DOF even at f/2.8
  • About half an hour after sunset is a good time to plan to be at the top of the wheel. Entry via the “fast track” queue takes only a few minutes, and the wheel takes about half an hour for a full rotation (so 15 minutes to get to the top)
  • Although the wheel moves, 1/8 sec shutter time seemed to be okay
  • Consider using auto-iso, with a minimum shutter at 1/8 and camera in aperture priority set to f/2.8
  • Bracketing is good, but it’s sufficient to aim for a 5-picture series with 1/3 stop interval (or a 3-picture series with 2/3 stops intervals).
  • It wouldn’t hurt to bring a small spray bottle of eye-glass cleaner and a cloth (or maybe just wet wipes?) to get the worst greasy fingers off the glass
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One comment

  1. Tomas, those pics a lovely, especially the last one, that’s just stunning!

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