Nice image Mike.
Each has it's own application. And I use both long and loooooooooong exposures for startrails equally, depending on the conditions and what my goals are from the imaging session
Quote:
Originally Posted by iceman
....I should've set it off and left it going in the car.
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That's what I do. Stick the camera in the boot where the temp is closer to ambient, and let it click away.
Quote:
Originally Posted by iceman
.. also with a long exposure you're sometimes guessing on the right exposure length/f-stop/ISO and sitting around for 15-30 minutes hoping you've got it right is a test in patience
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Being completely self taught- trying to determine the right exposure at night used to really confuse me and more often than not I would just guess (and more often than not get it completely wrong) until I read a great little ebook called "Seeing The Unseen" by Alister Benn. It was a lightbulb moment. Now I take a high ISO, 30 second test shot and just work it out from there based on the histogram of the test shot. As an example: Test done at ISO 6400, 30 Seconds and F/2.8. Histogram shows that I am underexposed by one stop. I want to shoot at F/5.6 to get more depth of field. F/2.8 to F/5.6 is two stops (running total 3). And I want to shoot at ISO 400 instead of 6400, which is 4 more stops for a total of 7. 30 seconds times 2, times 2, times 2, times 2, times 2, times 2, times 2 = 3840 seconds or 64 minutes to get the right exposure (I hope my math is right- doing this in my head)
Quote:
Originally Posted by Octane
To circumvent the gaps, I think it is quite easy to find where the pole is using simple Photoshop tools, then, set a centre point at the pole and rotate your stack of images until the arcs overlap any gaps between exposures. That should fill them in (using masks to hide the foreground, if there is one).
It's a little bit of messing about, but, should get rid of the jitter.
H
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This works well if you have a not too wide of a field of view and have the celestial pole in frame or not too far out of frame. But if you are going really wide to encompass both the pole and equator, or you are shooting east or west with a wide angle and the stars are curving in both directions, then this method does not work (or it would work with an awful lot more messing about and a lot more masks).