Star Trails

[Slix]

Hi Guys, Has anyone got any hints or tips for shooting Star Trails. I have been reading up a bit about the subject but would appreciate any advice especially regarding equipment suitable for use with my K5iis.

[LennyBloke]

I'm sure someone will come along with more specific advice but I've found that Trial and Error is how to improve with any astrophotography - the beauty of digital being that you can review your results instantly and "tweak" as you see fit.

As a starting point for Star Trails I would do the following:

1. Use a tripod.
2. Use a low to medium ISO setting (High ISO wont benefit you much on a star trail).
3. Use Manual Exposure mode.
4. Use Manual Focus (AF is notoriously difficult on the night sky).
5. Don't assume that the furthest point on your focus ring is infinity (some lenses focus past infinity) - check your focus and if you can "fix" it (a small piece of tape across the barrel to the focus ring will often do it - but not the sort that will leave residue on your lens).
6. Stopping down a lot won't give you any real benefit (in terms of increased sharpness or depth of field) - optimum aperture is often between 1/2 and 2 stops down from the maximum aperture, 1 stop down is probably a good starting point.
7. The slower the shutter speed the longer the star trail.
8. Cable Release and Mirror Up will massively reduce the possibility of camera shake (due to the vibration of the mirror up/down) - you will see this as a slight (or pronounced) jump/jerk at the start/end of the star trail.
9. My preference is to use Prime lenses, and faster lenses give you more light gathering power and will often be higher quality (IQ). Some lenses have more pronounced Coma effects (towards the corners and edges of the image) - you'll need to do a bit of reading if your are going to purchase a lens specifically, but I've had good results with the F28/2.8, F50/1.4, FA35/2.0 - although these may not be as wide as you'd want.

Sorry if some of those may be obvious, but they'll probably be a good starting point.

[ronniemac]

Thanks for all that info, I'll certainly be referring to it if we ever get a clear night sky in Oxford.

[Slix]

A belated thank you to LennieBloke for your advice, I will certainly make use of it.