Star Trail Photo Simulates Long Exposure

**LeoTaylor** · 03-23-2009, 11:43 AM

Awhile back there was a thread about using a program from Germany called Startrails (www.Startrails.de) to simulate long exposures of the night sky. At the time I had nothing longer than 30 minutes to show. It took this long for me to be at a dark site with a clear sky. Star Trails are intolerant of even a single passing cloud.

This was taken at a Boy Scout Camp in Goshen CT. I waited until the Scouts were asleep. The camera took 212 thirty second exposures using a Pentax K100D, Vivitar 19mm F3.5 lens, Bogan tripod, Pentax AC supply, and Pentax manual cable release. I set the camera to Manual, Continuous, no NR, and locked the remote. I then went off to do some imaging with my K110D. This is just shy of a two hour exposure during which the Earth rotated 30 degrees. Long exposures bring out the color in stars.

Things I could have done better would be to include some foreground scenery and take some dark frames. It was 3 AM, I wasn't thinking clearly.

This type of photography is easy to do once you have a dark location to set up. I should note with this wide lens NO stars appeared in the viewfinder or LCD display. The sharp dots are too small to see without Zoom. I had to focus by setting the lens to infinity which would not be accurate enough for a longer focal length lens.

Attached Images

Last edited by LeoTaylor; 03-23-2009 at 11:47 AM. Reason: fixed url

Jim Royal · 03-23-2009, 12:08 PM

Great shot. I had never considered the idea of multiple long exposures combined into one massive long exposure. It suggests possibilities other than star trails, too.

About the wiggle at the clockwise end of the trails... that happened at the end of the sequence?

**LeoTaylor** · 03-26-2009, 10:40 AM

Originally posted by Jim Royal

About the wiggle at the clockwise end of the trails... that happened at the end of the sequence?

I was hoping no one would ask that.

I don't know. The camera seems to have shifted diagonally, the curl appears in the upper right and lower left. The tripod was unattended for all but the first and last frame, No one was in that area of the camp. My only guess is the ground was muddy when I set up and frozen solid when I returned. Perhaps a leg of the tripod moved slightly as the mud froze. That could cause a diagonal movement.

The longest single frame star trail I've taken was 20 minutes with a K1000 in 2002. That was only 5 degree rotation and still the sky glow was bright. Same manual focus 19mm lens!

heliphoto · 03-26-2009, 10:58 AM

Originally posted by LeoTaylor

I was hoping no one would ask that.

I don't know. The camera seems to have shifted diagonally, the curl appears in the upper right and lower left. The tripod was unattended for all but the first and last frame, No one was in that area of the camp. My only guess is the ground was muddy when I set up and frozen solid when I returned. Perhaps a leg of the tripod moved slightly as the mud froze. That could cause a diagonal movement.
...

Funny - I've never had to worry about frost heave in any of my photography

. Cool star trails - someday I'll do this. Seems like a good use for the interval feature on my K20D.

**LeoTaylor** · 03-26-2009, 06:04 PM

Originally posted by heliphoto

... Seems like a good use for the interval feature on my K20D.

The K20D Noise Reduction may bite you. I don't have one but understand from many threads on this forum that for long exposures that is the only Pentax DSLR that can't turn off NR.

**Digitalis** · 03-26-2009, 07:21 PM

yes, star trails can be a lot of fun...it's just a pain to get them focused correctly.

03-23-2009, 11:43 AM	#1
LeoTaylor Site Supporter Join Date: Feb 2007 Location: Connecticut Photos: Gallery Posts: 679	Star Trail Photo Simulates Long Exposure Awhile back there was a thread about using a program from Germany called Startrails (www.Startrails.de) to simulate long exposures of the night sky. At the time I had nothing longer than 30 minutes to show. It took this long for me to be at a dark site with a clear sky. Star Trails are intolerant of even a single passing cloud. This was taken at a Boy Scout Camp in Goshen CT. I waited until the Scouts were asleep. The camera took 212 thirty second exposures using a Pentax K100D, Vivitar 19mm F3.5 lens, Bogan tripod, Pentax AC supply, and Pentax manual cable release. I set the camera to Manual, Continuous, no NR, and locked the remote. I then went off to do some imaging with my K110D. This is just shy of a two hour exposure during which the Earth rotated 30 degrees. Long exposures bring out the color in stars. Things I could have done better would be to include some foreground scenery and take some dark frames. It was 3 AM, I wasn't thinking clearly. This type of photography is easy to do once you have a dark location to set up. I should note with this wide lens NO stars appeared in the viewfinder or LCD display. The sharp dots are too small to see without Zoom. I had to focus by setting the lens to infinity which would not be accurate enough for a longer focal length lens. Attached Images Last edited by LeoTaylor; 03-23-2009 at 11:47 AM. Reason: fixed url

03-26-2009, 10:40 AM	#3
LeoTaylor Site Supporter Join Date: Feb 2007 Location: Connecticut Photos: Gallery Posts: 679 Original Poster	Originally posted by Jim Royal About the wiggle at the clockwise end of the trails... that happened at the end of the sequence? I was hoping no one would ask that. I don't know. The camera seems to have shifted diagonally, the curl appears in the upper right and lower left. The tripod was unattended for all but the first and last frame, No one was in that area of the camp. My only guess is the ground was muddy when I set up and frozen solid when I returned. Perhaps a leg of the tripod moved slightly as the mud froze. That could cause a diagonal movement. The longest single frame star trail I've taken was 20 minutes with a K1000 in 2002. That was only 5 degree rotation and still the sky glow was bright. Same manual focus 19mm lens! Attached Images

03-26-2009, 07:21 PM	#6
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	yes, star trails can be a lot of fun...it's just a pain to get them focused correctly. Last edited by Digitalis; 05-15-2009 at 06:12 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Night Long exposure and small star trail	ismaelg	Post Your Photos!	1	08-23-2010 07:40 PM
Night Star Trail.	xedent	Post Your Photos!	3	07-09-2010 02:24 PM
Star Trail Photography	rustynail925	Photographic Technique	15	03-09-2010 11:12 AM
Star Trail Software?	konraDarnok	Digital Processing, Software, and Printing	8	10-17-2009 03:43 AM
Moon and first star trail shot	jbrowning	Post Your Photos!	9	02-14-2008 08:41 AM

03-23-2009, 12:08 PM	#2
Jim Royal Senior Member Join Date: Oct 2006 Location: Montreal Photos: Gallery Posts: 179	Great shot. I had never considered the idea of multiple long exposures combined into one massive long exposure. It suggests possibilities other than star trails, too. About the wiggle at the clockwise end of the trails... that happened at the end of the sequence?

03-26-2009, 10:58 AM	#4
heliphoto Veteran Member Join Date: May 2008 Location: Region 5 Photos: Gallery Posts: 2,539	Originally posted by LeoTaylor I was hoping no one would ask that. I don't know. The camera seems to have shifted diagonally, the curl appears in the upper right and lower left. The tripod was unattended for all but the first and last frame, No one was in that area of the camp. My only guess is the ground was muddy when I set up and frozen solid when I returned. Perhaps a leg of the tripod moved slightly as the mud froze. That could cause a diagonal movement. ... Funny - I've never had to worry about frost heave in any of my photography . Cool star trails - someday I'll do this. Seems like a good use for the interval feature on my K20D.

03-26-2009, 06:04 PM	#5
LeoTaylor Site Supporter Join Date: Feb 2007 Location: Connecticut Photos: Gallery Posts: 679 Original Poster	Originally posted by heliphoto ... Seems like a good use for the interval feature on my K20D. The K20D Noise Reduction may bite you. I don't have one but understand from many threads on this forum that for long exposures that is the only Pentax DSLR that can't turn off NR.