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01/24/2022 11:23:45 AM · #1 |
I just started in this area and have some questions about my entry:
1. Settings - I ran 30 seconds exposures, f 5.6 and ISO800, were they a good choice?
2. How long would I need to take photos to get continuous lines? At what settings?
3. What lens would I need to get circular trails?
4. There is a short line almost perpendicular to the main lines to the left of the top of Matterhorn, what is it?
5. Is the near horizontal line of dots the space station?
Any other words of advice? I am still in Zermatt and could try it again, we have clear skies till Friday when we leave. The moon is now down to about half.
Message edited by author 2022-01-24 11:32:11. |
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01/24/2022 01:19:08 PM · #2 |
We only have one (old!) tutorial on astrophotography which I don't think addresses your questions, but might be interesting to see what people have done with limited equipment.
Regarding point #3 I don't think the particular lens is critical to getting circular trails; what counts is having your frame centered on Polaris (North Star) so it is fixed and the others rotate around it.
AFAIK Shannon ( scalvert) is the site's current expert in this area ... |
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01/24/2022 02:11:39 PM · #3 |
That's not something I've ever tried, but I'm guessing you need a much shorter focal length.
Coincidentally yesterday I came across this discussion on a different topic where the example photos were circular star trails. The metadata show they were shot at 12mm on an Olympus Camera, so you'd probably be looking at 24mm on your Sony to get similar results.
Oops, I forgot the link.
https://www.dpreview.com/forums/thread/4625984
Message edited by author 2022-01-24 14:12:26.
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01/24/2022 08:20:26 PM · #4 |
Hey Margaret,
I think I can clear up some of your questions, not all. Let's take 'im one at a time...
1.) Given the full moon, your exposure choice was very appropriate. You nicely balanced the landscape lighting with the sky.
2.) When you san continuous lines, I expect you mean that you don't see the ends of the trails. There is no one answer to this question. The best answer is that the total exposure time would need to be greater than the time for any individual star to cross the angle of the frame. That time depends on the direction your camera is pointing, and the angle of view of the lens. Example: with the camera pointe 90 degrees from the north star, a star will move across the sky at about 15 degrees per hour. So if your frame takes in 45 degrees, it will take about 3 hours for an individual star to cross the frame. If you exposed for 3 hours total, you'd still see the starts of some trails and the ends of others. The only way to see no ends at all would be to expose for an entire 24-hour period, if that were possible.
3.) You can get circular trails with nearly any lens. Stars trace a circular path around the north star, so if you lens is pointed toward the north, you will see a circular pattern.
4.) There are two of them, as well as several of what look like un-moving point sources. I can't tell for certain you what they are, however they might be ghost images from ground-based light sources out-of-frame.
5.) The horizontal line is a satellite, the brighter spots in the line are flares (sun reflecting off flat surfaces). Given your location, the direction your camera was pointed and the exact time of your exposures, it would probably be possible for someone with experience to determine which specific satellite. I don't have enough experience to do so. |
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01/24/2022 08:43:51 PM · #5 |
I shot this in 2020 when I was playing with astrophotography stuff.
Kirbic has covered most of it. In addition to circular trails you can get some amazing curved ones too, depending on the orientation of your camera lens direction.
There are a gazillion tutorials on this that only take a short time to review (most in 15 minutes or so).
Here's a few. I'm still looking for the one I used ...
Link 1
Link 2
Link 3
I used a software (freeware) application called StarStaX to put the exposures together.
Message edited by author 2022-01-24 20:54:00. |
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01/25/2022 12:49:19 AM · #6 |
Thanks, everyone, I am still following the links and digesting the info.
Unfortunately I won't get circular trails from here as Matterhorn is in the west, northern star is behind the mountain on the right.
I thought that there are many satellites and the reasons why I only recorded one was the duration of shooting (half an hour) and the backlight from Zermatt so only the biggest and brightest would be visible.
I used 24-105 lens as I did not take my 16-35 to Zermatt but I understand now that was not a problem.
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01/25/2022 07:49:14 PM · #7 |
My attempt at star trails:
Message edited by author 2022-01-25 19:50:30. |
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