19

I enjoyed reading the fascinating story of how a climber took an amazing long-exposure photo of his climb up, down and around a Peak District landmark.

See: "Blazing a trail! Climber takes spectacular light streak images during Peak District trek"

I don't doubt that he has produced a beautiful picture, but there is some alarm bells ringing in my head wondering if the light streaks were really created by his head-lamp as he performed his arduous journey.

So I'd appreciate if you could take a sceptical look at this image:

Light Trail

How long would it take to create an image of those stars that streak in that fashion and is it possible to travel the distance marked by the climber's headlamp in that time?

So are those lights the fleeting wisp of a hand torch, Photoshop or the climber's head lamp?

Oddthinking
  • 140,378
  • 46
  • 548
  • 638
JW.
  • 524
  • 3
  • 10
  • As the stars would complete a full revolution in 24 hours can work out exactly how long the exposure was by measuring the angle the stars' arc subtends. In my phone I can't see enough detail to work it out, but that route doesn't look that long. – Rory Alsop Nov 15 '12 at 08:06
  • 1
    This may be challenging for the "no original research" policy. I look forward to seeing how that might be handled. – Oddthinking Nov 15 '12 at 12:04
  • Star trails take about 4 minutes to move 1 degree. I'd say the trails in the pictures (without accurate measuring devices) look about, at most, 1-2 degrees (for reference, full moon is about 0.5 degrees). It's hard to judge the scale so hard to judge whether the whole thing could be done in the 10 mins or so these calculations suggest. Would it be a bad answer if someone produced a more accurate version of this? – matt_black Nov 15 '12 at 13:17
  • 4
    @matt_black - I think it is closer to 10 degrees witch would give about 40 minutes. That is more possible I think. It is hard to judge with the view being toward the polar though so it distorts it. – Chad Nov 15 '12 at 14:49
  • 1
    There are more details of the climb and the photography here - http://danarklephotography.yolasite.com/nightsoloing-at-stanage.php – Tom77 Nov 15 '12 at 15:18
  • 1
    so that's 12 minutes then - 20m high climbs - yep, seems reasonable! – Rory Alsop Nov 15 '12 at 16:00
  • @Tom77 So the answer is yes it is plausible. Interesting question for this site: had the photographer not provided the detail, would an answer based on logical estimation (like mine above) be acceptable? – matt_black Nov 15 '12 at 19:03
  • Yup, I measure 4-5°, so 16-20 minutes total. If the climb was at all longer, I'd say he probably would have done a composite exposure. – Stuart Robbins Nov 16 '12 at 01:40

1 Answers1

11

These pictures are ostensibly made by using a head-mounted light as well as a secondary light pointing toward the camera.

The photographer (Dan Arkle) has a number of similar photos on his website as well as a very detailed explanation of the technology and techniques used.

enter image description here

In addition, you can see an extensive "making of" documentary that was shown on BBC1's "The One Show" showing both the process by which these photos were made (including head-mounted camera footage) and the cameras used.

In several of the individual shots on the video you can distinctly make out a human form climbing along with the lights.

enter image description here

Whilst I agree that it would be perfectly possible to have faked all of the above, it stretches the bounds of credibility to imagine that that's the case.

Richard
  • 1,802
  • 1
  • 16
  • 25