My first attempt at star trails

It's a merging of 112 30 second exposures. I need a few more to close the gaps but it was interesting to do.

A couple of points to note.

The flaring on the right is because the balcony I was on is at the end of our lounge and we had the lights on - they were reflected in the balcony glass - lesson for next time.

The other thing is the line that goes across at the bottom right could be a meteor but I am not sure - this is North facing - any ideas?

I used a program called StarStax to merge the photos and then upped the shadows as much as I could.

In hindsight, I don't think 30 seconds was enough for each exposure.

This is a good effiort. You are lucky to have a north-facing opportunity and clear skies. Why no EXIF data?

As to improvement, it depends upon what you want to end up with. Complete circles take 24 hours! I think less is more: why not try a three minute exposure on its own and work from there. If you use a neutral density filter, you can reduce the number of stars seen and get something more interesting, which would enable you to identify individual stars.

I wonder if the streak on the bottom LEFT was the ISS. You can look up its coordinates on the internet. Polaris is about 53° from your horizon, and the streak was about 45° N of the celestial equator in your last exposure -- I think: check my maths!

David

David,

No exif data because it's a composition of 112 images combined by StarStax and that didn't put any exif data in. But it was taken with my Fuji X-T5, ISO 200, F4.5 and Speed 30 seconds using a Viltrox 13mm lens.

This image was taken at the same time with my Samyang 8mm fisheye lens. Also ISO 200, F4 and 30 seconds. 119 images combined.

And this was one 15 minute exposure at F8, ISO 125 from my Viltrox 13mm which I took on Monday night (with shadows pushed to lighten it a bit).

Sorry! I dont seem to be helping; but I‘ll try again.

The last photo seems not to be in focus (assuming it is on the same tripod as the others). Apart from that, I should have thought that the thing to do is to turn up the highlights (the stars), and turn down the darker areas, for more contrast. (But I may have misunderstood you.)

The original composite that you posted does the job of showing that the starts are circumpolar, but little else. A shorter exposure should show shorter trails, from which it should be possible to identify at least the plough, or cassiopeia, depending on the time of night. In the evening, the plough should currently be at the bottom of the sky.

What happens if you combine half or a quarter of the 122 images you already have?

David

David,

The last photo was taken 2 days before. I don't think it's out of focus.I haven't messed with the photo at all, apart from reducing it in size. I hadn't thought about a shorter time with a wider aperture to compensate so I could find constellations. That may be something I would think about instead of star trails.

I may try your idea of combining a quarter (or less) of the images to see what I get.

The purpose was for me to try out star trails and see whether it was a hobby worth pursuing. I think the photos are nice but I don't think it's a subject I will carry on with. It's sort of a "tick, I've done that, now for something else" moment. That may sound a bit shallow, but it doesn't really grab me for a long term interest. But see my first paragraph.

Alan

Alan,

You have just made me realize why I have never spent time out in the cold photographing star trails! By their very nature they are always bound to be parts of concentric circles, and there is nothing much you can do to make the patterns rectangular or anything else. That may not be a profound statement, but it is not shallow and has the advantage of being truthful!

I wasnt sure about the focus, but it occurred to me a) because the trails looked wider and fuzziier than the other photos, and b) because the horizon on mother earth looked out of focus, and (at f/8 and 20mm focal length) I would have thought that it was pretty much at oo, as the stars are.

I am, however, certain that you must have covered the distinction between speed and velocity at school, as I did, and I am not sure why it came up above! 😁

David

Alan,

I googled "star trails" and, apart from several articles on how to do them which might be worth following up, among the images was this one, which enables the identification of the stars involved. It might be interesting to see if you can do something similar it from your posiiton. There is no chance from here!

David