Star trail help

[coltonomor]

Any tips or tricks for star trail photography? I thought I understood it but then I tried it and my photos came out noisy and a little blurry. The foreground of the long exposure was fine and clear but the stars came out blurry and noisy. Any recommendations for ISO, aperture, time of the exposure, ext would be appreciated.
https://m.flickr.com/#/photos/95048358@N08/13092485325/

 

[Aloicious]

what settings/equipment were you using, what method were you using to attempt focusing it?

 

[Judobreaker]

:addpics:

 

[Austin Greene]

1. Go to Youtube. Watch a tutorial. There was a very good link to a video posted in a topic with the Beyond the Basics part of this forum.

 

[D-B-J]

Looks like you have camera shake there. Either your tripod wasn't settled or it was windy, but that's definitely as a result of camera movement. Typically, this is how I approach star trail photography. I wait for a nice clear night, grab my tripod, wide angle, cable release, etc, then head to the location. I typically start with an exposure of 30s at ISO 1600 and f2.8, and adjust from there. I take 50+ 30s images once I get the settings right, and then stitch them together using starstax (free application I found online). Also, I usually shoot around 3300k WB, and that keeps the stars at a nice and cool blue. I've found this strategy much more successful than one really long exposure, but that's just me.

Best,
Jake


Sent from my iPhone using Tapatalk

 

[pgriz]

I'm showing two images that I took recently.

The first is a stack of 31 stills (ISO 800, 24mm, 30 sec, f/4.0) using the freeware "Star Trails" (Startrails application). Each photo was shot with the long exposure noise reduction on (which means for every exposure, there is a corresponding dark frame), which is why the trails look like they have gaps (the gaps are the dark exposures). Those setting enabled me to reach stars of magnitude 8.0 (at a time when naked-eye visibility was around 5.5). Noise reduction was applied to the individual frames prior to stacking, and a final noise-reduction pass was made after stacking. My camera is the Canon T1i, which is not particularly good at higher ISO levels.


The second image is 1 still (ISO 800, 10mm, 301 sec., f/4.0), showing the amount of skyglow recorded with a 5 minute exposure.


The second image makes it clear that to try and get star trails with a long exposure is doomed to failure, with skyglow rapidly building up and ruining the image. The solution is to use relatively short exposures to minimize skyglow, and then stack them to achieve the star trails.

The alternative is to find true dark sky locations which allow much longer exposures before skyglow still ends up showing up.

Sky location I used was found using this site (Dark Sky Finder). Sky transparency, etc. can be found here: (Clear Sky Chart Homepage).

 

[Gavjenks]

You can help combat skyglow by shooting "flats" - exposures of a similar amount of exposure (ideally similar time, but during a critical sunset, you don't have time to take two identical shots before things change, so instead you might jack up the ISO a whole bunch), with a t-shirt or similar over the lens to remove all detail and get only low spatial frequency light patterns. You get a basic pattern of ambient brightness, which you can then use as a mask in photoshop to counteract the glow pattern.