Star Trail Software?

konraDarnok · 10-09-2009, 08:41 AM

Is there software that can take a long exposure star trail and reverse it digitally?

It should be possible, to take star photos with more dynamic range without the use of a motorized tracking platform.

*Wheatfield* · 10-09-2009, 08:53 AM

A friend of mine has some software that allows stacking and registration of several sky exposures.
I'll email him and post his reply here.

*wildlifephotog* · 10-10-2009, 08:21 AM

For long exposure star trails, no motorized mount is needed. You just use a steady tripod.

There is a program that will allow you to stack many 30 second exposures to make one complete star trail photo.

Startrails application

konraDarnok · 10-12-2009, 07:13 AM

Originally Posted by wildlifephotog

For long exposure star trails, no motorized mount is needed. You just use a steady tripod.

There is a program that will allow you to stack many 30 second exposures to make one complete star trail photo.

Startrails application

No, I'd like to do the opposite of a star trail. Take a long exposure the counteracts the earth's rotation -- or a series of photos. To get a higher dynamic range in the final shot without an extremely fast wide angle lens or a table to rotate the camera.

Like this:

APOD: 2008 July 29 - The Milky Way Over Ontario

*wildlifephotog* · 10-12-2009, 07:39 AM

Your only other option is to shoot a video. Then convert to .avg. You can then stack the frames in registax.

davebris33 · 10-12-2009, 08:53 AM

Originally Posted by konraDarnok

No, I'd like to do the opposite of a star trail. Take a long exposure the counteracts the earth's rotation -- or a series of photos. To get a higher dynamic range in the final shot without an extremely fast wide angle lens or a table to rotate the camera.

Like this:

APOD: 2008 July 29 - The Milky Way Over Ontario

I think i know what you want to do, but as we are constantly moving relative to the stars, i don't think it is possible to take multiple exposures that match up perfectly unless your tripod or telescope has some sort of tracking device...or do you mean many short exposures that are stacked in photoshop or similar? I have done a few star shots and the longest time i have got before a star seems to deviate from a perfect dot of light is about 20 seconds....so i suppose with a camera at high iso, with good noise reduction that does not obliterate detail (mmm) with a fast lens wide open (dodgy, could result in soft image) might be able to take 80 or so .25 sec images and then stack em up in software....i'd go for a tracker, i'm saving for one right now!

good luck tho

davebris33

Raybo · 10-16-2009, 08:03 PM

I don't think it can be done with just software.

You CAN build a barn door mount on the cheap.

Deep Sky Blog: Astrophotography: Barn Door Tracker

*pingflood* · 10-16-2009, 08:19 PM

Deep Sky Stacker will align frames based on the brightest stars; not the same as "reversing" a long exposure, but allows you to stack many exposures without a tracking mount.

*newarts* · 10-17-2009, 04:43 AM

Originally Posted by konraDarnok

Is there software that can take a long exposure star trail and reverse it digitally?

It should be possible, to take star photos with more dynamic range without the use of a motorized tracking platform.

Yes it is possible to undo star trails by deconvolution, but in practice it is more difficult than one might first think. I think software named RotnStack will allow this for a single long exposure frame.

I suggest you google search for "deconvolute star trails" "astrophotography"

See: CS448 Project: Removing Motion Blur