How do the stars in this photo appear without star trails even at a long shutter speed?

Question

I found an image of the night sky taken by James Sainty at http://500px.com/photo/11615131.

It has the following EXIF metadata:

Camera Canon 5D Mk II
Lens Canon 16-35mm L
Focal Length 16mm
Shutter Speed 140 sec
Aperture f/4
ISO/Film 1600

As I know there is a rule of "600" and night sky photographing, which says that if I don't want to shoot star trails, the max shutter speed should be 600/Focal Length. In this case, based on this rule, shutter speed should be 37s. But it is 140s, and there are not any star trails.

How could it be? Is this rule incorrect or are there some other aspects to it?

Image taken by James Sainty

Where did you get that 600 rule from? Are you sure it doesn't mention anything about ISO or aperture? — BBking, Dec 03 '12 at 23:41
@BBking: since the issue is freezing motion, not exposure time, ISO and aperture logically wouldn't come into it. (It sounds similar to the traditional rule for hand shake, except for the rotation of the earth.) — mattdm, Dec 04 '12 at 00:21
It could be that it's a composite image? One for the milky way and the second for the foreground? — Peng Tuck Kwok, Dec 04 '12 at 03:53
@BBking I saw it on a couple of sites related to astrophoto. For example - http://digital-photography-school.com/how-to-shoot-the-night-sky-introduction-to-astrophotography. Third point of article describes it. — Sergey Litvinov, Dec 04 '12 at 11:07

score 16 · Answer 1 · edited Apr 13 '17 at 12:43

I initially marked this as a duplicate of How can I avoid star trails without an expensive tracking mount?, but on reflection, I think the answer here is simply the assumption in that one: to get a night-sky exposure longer than 30 seconds or so, you have to track the motion of the sky, and a fancy tracking mount is the way to do that.

It looks (from the shadows) that the tree is lit by a burst from a flash; it's effectively a double-exposure (the tree frozen by the quick flash burst, the sky with the natural light at long exposure). The photographer confirms that he uses this technique in comments on another similar photograph.

Thank you for your answer. I had not thought about tracking mount... — Sergey Litvinov, Dec 04 '12 at 11:10

score 8 · Answer 2 · answered Dec 04 '12 at 00:28

8

1) He used a rig to track the motion of the stars.

2) A flash for the trees.

3) some PP to make local adjustment to the color temperature of the trees.

My guess.

answered Dec 04 '12 at 00:28

Sleeper Smith

191
4

1

Color temperature is easier to adjust on spot by gelling the flash as needed. – Imre Dec 04 '12 at 08:15
Thank you for your answer too, but I accepted @mattdm answer, because he was first, and his answer has more details. – Sergey Litvinov Dec 04 '12 at 11:13

score 7 · Accepted Answer · answered Sep 11 '23 at 21:34

7

A little late to the party here, but as the photographer in question I thought I'd weigh in. It's a single exposure. I used an external speedlite flash to "paint" the tree - with several bursts from different angles. Then used PP to adjust the colour temp. The confusion is quite rightly from the shutter speed - that EXIF input data was a manual input and should've said 40 seconds (so sorry!) It is a little longer than had I wanted, but I needed the extra seconds to get sufficient exposure - if you look closely you'll see trails beginning towards the edges. Hope that helps... many many years on!

answered Sep 11 '23 at 21:34

James Sainty

86
1
1

Hehe, a great read, thanks for chipping in! :) – blobbymcblobby Sep 11 '23 at 21:39
Hi James, welcome to Photo-SE. It's always great when the actual photographer comes in and answers about their shot! Thanks! =) – scottbb Sep 11 '23 at 22:22
So, just to verify, you didn't use a tracking mount, right? That is, you were using a fixed tripod head? – scottbb Sep 11 '23 at 22:30
1

whoa, thanks for the information! i wasn't expecting to get an answer from the author here especially 11 years later, so its definitely a good surprise :)) – Sergey Litvinov Sep 12 '23 at 15:24

How do the stars in this photo appear without star trails even at a long shutter speed?

3 Answers3

Linked