*Note – Some prerequisite knowledge of Adobe Photoshop and basic digital photography will be required.
I have been fascinated with the night sky since as long as I can remember, going outside and looking up at the stars makes you feel that your problems – no matter how big they are to you, are really miniscule in the grand scheme of things. Last night I had a burst of inspiration for taking some starscapes in my back garden. I then considered making a batch of slow exposures into a movie file.
To do this I used a Canon 6D and a 35mm lens. I set the lens to infinity and then set to manual focus so the camera wouldn’t “hunt” for focus. I then framed a shot against some large trees for with a large patch of sky showing. I set up an automated switch to continuously take 30 second exposures at 1600 ISO. I left the camera running taking shots for just over an hour collecting approximately 130 slow exposed images.
Next I used Adobe Photoshop and specifically the “actions tool”. I recorded the action of adjusting the brightness and contrast option to better bring out the details of the scene.
Then I saved the image to a new folder specifically for smaller images so I wouldn’t ruin my raw files. Next I ran a “batch automate” function with photoshop that did the same exact thing to the next 130 or so images without me having to do anything manually (word smarter not harder I say). See below for a description on how to negotiate the actions sequence.
Step 1. Open 1 file from your batch. As soon as its opened go to “Window –> Actions”
Step 2. When the actions panel opens, click the record new action option. Name it whatever you want to.
Step 3. Make adjustments to your image, I used Brightness Contrast and then adjusted the Curves to better pop the stars.
Step 4. Save for web to a folder of your choosing (better to save it to a new folder to save your raw files)
Step 5. Stop the recording button on actions.
Step 6. Go to “File –> Automate –> Batch”
Step 7. When this is opened select the source folder for the files you want to have the same action applied to, ensure you have the named action selected in the dropdown. Under “Destination” choose the folder you wish to save the adjusted files to. Once that is selected, switch that option to “Save & Close” then finally click “OK”
You will now see photoshop do the same action to all the files in your selected folder, this might take some time depending on how many files you have selected.
Once I had the images shrunk to a reasonable size and better lit, I used a tool called Virtual Dub, this is a free tool available online here. The next thing to do is when you have Virtual Dub installed, go to file -> open video file. Locate only the first image in your sequence and open it, Virtual Dub will literally do the rest as long as your files as sequentially labelled i.e. 001, 002 etc, most cameras will output files with sequential filenames. Once you have your photos in you can go ahead and export your file as a .avi file. et voilà, an awesome view of the night sky in timelapse with minimal effort.
Check out my first quick 10 second clip below…