First attempt at star trails with the dSLR

[StephenM (Stephen)]

Hi all,

I had hoped to do some long star trails while camping at Lake Cootharaba last weekend. I set up at about 10 pm, and had a nice view over the moonlit lake with Orion and Canis major rising. Unfortunalely i only got about half an hour of 30 second exposure done before the clouds became too thick .

Anyway, I stacked them and here is the result. There's also a little timelapse movie showing the clouds, in the zipped file.

Finally, a question: Does anyone know if there is a plug-in that will let the Startrails software read RAW format images? The jpgs coming out of my Pentax camera seem to generate lots of noise in the resulting star trails image. Any ideas?

Cheers,
Stephen

[iceman (Mike)]

Hi Stephen
Lovely shot.

Startrails only reads jpegs and tif's, as far as I know.

So you could convert your RAWs to TIFs, but I don't know how much better it will be. When you save TIF's from the startrails application, they're only 8 bit tifs, not 16bit tifs.

So I've been converting my raws to jpegs and feeding them into startrails.

[Hagar (Doug)]

Never tried star trails so it's a bit hard to comment but I can say it is a nice image. Keep at it.

[StephenM (Stephen)]

Originally Posted by iceman

Hi Stephen
Lovely shot.

Startrails only reads jpegs and tif's, as far as I know.

So you could convert your RAWs to TIFs, but I don't know how much better it will be. When you save TIF's from the startrails application, they're only 8 bit tifs, not 16bit tifs.

So I've been converting my raws to jpegs and feeding them into startrails.

Thanks very much for the comments and info, Mike. I might give it a test run with tifs next time, just to see if there's an improvement. If not I'll stick to jpgs. It's a shame the software doesn't handle RAW files like DSS does.

How many darks would you normally do for star trails, Mike? I think I used about 10 for this image.

Originally Posted by Hagar

Never tried star trails so it's a bit hard to comment but I can say it is a nice image. Keep at it.

Thanks Doug!

Cheers,
Stephen

[erick (Eric)]

On the question of darks, how do you take them through the night as temperature varies and not end up with gaps in your star trail record - or am I missing something here?

[Bloodbean (Troy)]

Looks nice Stephen,

What was the lens and ISO settings you used? I would probably try a higher ISO if you can to bring out a bit more light in each exposure. Next time hopefully the clouds don't roll in so you can go longer than half an hour. Keep em' coming!

Troy

[iceman (Mike)]

Originally Posted by StephenM

Thanks very much for the comments and info, Mike. I might give it a test run with tifs next time, just to see if there's an improvement. If not I'll stick to jpgs. It's a shame the software doesn't handle RAW files like DSS does.

How many darks would you normally do for star trails, Mike? I think I used about 10 for this image.



Thanks Doug!

Cheers,
Stephen

Hi Stephen. For my recent star trails, I had no darks. But I wish I did have some, because I can see lots of hot pixels in mine.

DSS can now do star trails - have you tried it?

Originally Posted by erick

On the question of darks, how do you take them through the night as temperature varies and not end up with gaps in your star trail record - or am I missing something here?

Eric, you'd have to take the darks at the end and not use ICNR.

If the temperature has varied too much, then they may or may not be useful. They may still get rid of hot pixels.

[StephenM (Stephen)]

Originally Posted by Bloodbean

Looks nice Stephen,

What was the lens and ISO settings you used? I would probably try a higher ISO if you can to bring out a bit more light in each exposure. Next time hopefully the clouds don't roll in so you can go longer than half an hour. Keep em' coming!

Troy

Thanks Troy,

I was using an 18-50 lens (f/4.5) and 800iso. The Pentax images get pretty noisy if I go above 800iso.

Originally Posted by iceman

DSS can now do star trails - have you tried it?

I've just downloaded to most recent version of DSS Mike - I'll give that a go next time!

Thanks again.

Cheers,
Stephen