star trails: I would like to get better at star trails. This shot is near a road so the lower left has a lot of interference light from cars. Location was not my primary concern here;...

ebrunner Loc: New Jersey Shore

I would like to get better at star trails. This shot is near a road so the lower left has a lot of interference light from cars. Location was not my primary concern here; but instead, I was working on technique. I'm using the Star Stacker program to stack the images. Does anyone know why I'm getting gaps. I activated the "fill gap" operation in the program. Would love some ideas on how to improve the quality of the trails. This was about 40 exposures at 30seconds. Could be that I need many more exposures to fill the gaps. Right now, I'm perplexed. I think this is better than my previous attempts; but I think it could be much better.

star trails

(Download)

St3v3M Loc: 35,000 feet

I had a similar problem and emailed the Star Circle Academy
- http://starcircleacademy.com/startrails

Part of the email I received -

Judging by the size of the gaps, I'd say you have too much time between exposures for the angular view and direction you are facing.

You can try this trick:
- http://blog.starcircleacademy.com/2011/11/out-darn-gaps

I hope it helps! S-

ebrunner Loc: New Jersey Shore

St3v3M wrote:

I had a similar problem and emailed the Star Circle Academy
- http://starcircleacademy.com/startrails

Part of the email I received -

Judging by the size of the gaps, I'd say you have too much time between exposures for the angular view and direction you are facing.

You can try this trick:
- http://blog.starcircleacademy.com/2011/11/out-darn-gaps

I hope it helps! S-

Thank you for the information. The trick that was mentioned in the article does seem to be a good idea. Of course, it will only work when oriented to the north (which was not the case in my westward looking photo. I never thought about the gaps as being created in the time between the exposures. Gave me a sort of...Duuhhh! moment. The information is valuable and very pertinent. Now I will have to do much more reading and experimentation; but you pointed me in the right direction to start this process. Again, thanks for the information.

Linda From Maine Loc: Yakima, Washington

There is also a specialty forum on UHH that could help:

http://www.uglyhedgehog.com/s-109-1.html

As with full moon photos, I like that you included landscape in your shot. Much more interesting for me than straight up into the sky :) I hope you'll post many more as you work out the technique, Erich.

Pixelpixie88 Loc: Northern Minnesota

Did you use an intervelometer? I use one and do about 100 plus pics. Have one second between the shots. I think the more shots, then you should have less gaps. I've posted one of mine that has about 125 pics. Then stacked in StarStax.

ebrunner Loc: New Jersey Shore

Linda From Maine wrote:

There is also a specialty forum on UHH that could help:

http://www.uglyhedgehog.com/s-109-1.html

As with full moon photos, I like that you included landscape in your shot. Much more interesting for me than straight up into the sky :) I hope you'll post many more as you work out the technique, Erich.

I agree that there is a steep learning curve. I would not want to have just the lines. I think, as you do, that the landscape is interesting. I like using water because the trails reflect in the surface of the lake if it is flat. There will be more, I just hope I get better before I get too frustrated.

ebrunner Loc: New Jersey Shore

Pixelpixie88 wrote:

Did you use an intervelometer? I use one and do about 100 plus pics. Have one second between the shots. I think the more shots, then you should have less gaps. I've posted one of mine that has about 125 pics. Then stacked in StarStax.

I did use an intervelometer. I noticed that it was taking a long time to start the next photo. (THis could explain the gaps as well as too few exposures.) I will have to play with the device so that I have a better understanding of what it is doing. Directions are very hard to understand. I love your photo. Looks really great. You've set the bar pretty high. So now I have a challenge. Thanks for your input.

Pixelpixie88 Loc: Northern Minnesota

If you have any questions on the intervelometer, pm me and I'll walk you through it. I'm sure that the amount of time between your photos, is the problem.
I might say, I really like your composition and the color of your photo. I'm sure that next time, your photo will be perfect!

ebrunner wrote:

I did use an intervelometer. I noticed that it was taking a long time to start the next photo. (THis could explain the gaps as well as too few exposures.) I will have to play with the device so that I have a better understanding of what it is doing. Directions are very hard to understand. I love your photo. Looks really great. You've set the bar pretty high. So now I have a challenge. Thanks for your input.

Linda From Maine Loc: Yakima, Washington

Pixelpixie88 wrote:

... I've posted one of mine that has about 125 pics.

Talk about stunning!!

Pixelpixie88 Loc: Northern Minnesota

Thanks Linda...they are fun to do!

Linda From Maine wrote:

Talk about stunning!!

BassmanBruce Loc: Middle of the Mitten

ebrunner, first off it's a pleasing photo.
As to the gaps, check to make sure you have enough time berween shots for the camera and intervalometer to "synch up" after each shot.
On my rig if I use a 30 sec exposure and 32 sec interval my camera doesn't trip and must wait for the next interval. I was only getting half the programed no. of shots. By switching to 30 sec exposure and 34 second interval the setup worked fine.
Pretty timely thread, I just stacked my first shot this afternoon.

DirtFarmer Loc: Escaped from the NYC area, back to MA

ebrunner wrote:

.... Does anyone know why I'm getting gaps...

The earth moves continuously, so if there's a time interval between exposures there will be a gap. Here's a photo I took, 2 second exposures, 15 second intervals. The gaps are very large since the exposure/interval ratio was small. There will always be a gap when you are taking multiple exposures because there's a finite time between shots.

If your camera has Long Exposure Noise Reduction, be sure to turn it off if possible. That will take a dark frame for every exposure with a length equal to the exposure time, so you will never get more than an exposure/interval ratio of 1/2

daeod Loc: Levittown, PA

I agree- too much time between shots. I am also learning star trails. I set up the camera to 16mm, f2.8, 30 sec. and continuos shooting. Then I hit the remote button and lock in the button. The camera keeps continuous shooting until I unlock the button. Star stacker then does the rest nicely. Get away from the main road and find a little used side road. I found a small park on a lightly used road near my in Bucks County. It is about as dark as be found in the North-east. Good luck! Which reminds my- NO noise reduction!

docshark Loc: Millersville, PA

Can't help with the technical aspect but I love the result.
-Doc

ebrunner Loc: New Jersey Shore

DirtFarmer wrote:

The earth moves continuously, so if there's a time... (show quote)

Good information. Thank you. I had turned off the noise reduction for exactly the reason you mentioned.