Star Trails, my first try

[MPelley]

My first attempt from a reasonably dark location, on the coast in Gran Canaria.

This is 204 exposures, each of 25 seconds at 18mm ISO 800 with Canon 50D.

Only problem was the cloud that rolled around in about 8 frames mid way through the session. Any ideas how to remove them/minimise them?

Thanks for looking and your comments would be gratefully appreciated.

http://www.photoradar.com/files/imagecache/con_full_user_photo/photos/users/mpelley/startrails-dcm.jpg?

[lighthalo]

how did you combine all the pictures?

my first star trails picture, i just took straight up 30 minutes haha, it was quite a bit noisy..

[MPelley]

this was done with a simple (and free) piece of software from www.startrails.de Certainly a lot of shorter exposures allows for pictures with lower noise and, after reading up on here about it decided startrails software and lots of exposures was the way to go.

No, I think I will re-process some the images and drop out the ones with the cloud drifting across.

[NovaTJ]

Very nice! Better than anything I've done and I've been trying for a couple weeks now. All my trails are broken and I think it's caused by the delay between shots. Can you tell me what software, if any, that you used to control the camera?

Greg

[MPelley]

Thanks Greg.

I simply used DPP's remote facility to control the camera. It was tethered to the laptop and I set the camera in manual mode, 25 second exposure. I then set the interval mode in DPP to 28 seconds. This meant the shutter would be open for the full 25 seconds, then a delay of three seconds and the shutter would re-open.

[Cyclop]

Beautiful shot.

[NovaTJ]

That's exactly how I do mine, except I can't seem to get DPP to do an interval of less than 59 seconds, which causes a delay between shots of about 34 seconds. I have to do more reading in the manual. Thanks

[lighthalo]

why did you chose to have a delay between exposures? is it to let the sensor cool down a bit before the next one?

also i downloaded the program from startrails.de, and im unsure of how to use the darkframe subtraction.. should i just have the camera do that after every exposure? or is there a way u can just take a "master" darkframe (?) to subtract?

[MPelley]

I tned to leave a bit of a gap between exposures to allow for the image to be saved and to allow sensor to cool a tad. on a short focal length 3 secs shoudl not show up or creat a gap in the trails.

AS for the software, I have not done any darkfram subtractions...I have simply created the trails from the light frames taken. I am sure others will be able to give you tips on dark frame subtraction which should (as I understand it) reduce noise further.

[chris2683]

Wow that is pretty cool. I have never tried a photo like that before but I might have to now.

[NovaTJ]

MPelley...I read up on the Canon EOS software and found my error. Last night I took 102 images at 25 seconds each with an interval of 30 seconds. That allowed the image to be transferred from the camera to the laptop, cool down the sensor slightly, then start the next image. It worked well. Thanks for the tips.

Greg