Wow does it feel great to have some modicum of success in learning how to stack images.
- Keith’s Image Stacker
- 30 second, 1920×1080 .mov file captured with Nikon D7000, May 10, 2012, 10:35:11pm, David Dunlap Observatory .75 focal reducer [same night as images from this post]
- 175 hand-picked frames.
I went through some trial and error getting Keith’s working. The first image I ever imported was something like 240px wide, and every image thereafter opened at the same dimensions. I trashed the prefs [instead of re-installing] and this allowed me to open the larger files at the correct dimensions. So: in the documentation where Keith notes that the image dimensions will be those of the first file you open, this doesn’t mean per session, it means ever. Computer>Library>Preferences….
Then, when importing, with 1 and 2 threads, Keith’s would hang up at some point. Thanks to John’s computing prowess, I manually imported, and when I hit 175 frames, the software hung up again. I guess that’s the limit for this software. I started over and selected the best 175 frames I could discern in that tiny import frame [previewing the video helped me to confirm a roundabout set of frames, at 24fps].
I identified and selected my best reference frame, and did a Difference Sort – nothing seemed to happen. Then I did a Value Range sort – nothing seemed to happen. So I went ahead and stacked all 175 frames.
I saved as a PICT file [311KB, won’t work for the MacKenzie install], and also exported as 3-channel FITS, and as RAW.
To open RAW in Photoshop: input the export data, use IBM/PC byte order [not mac!], and do not colour manage.
Photoshop won’t recognize FITS format on its own, and a quick web search lead me to this site, where I downloaded the awesomely named FITS Liberator for mac. Of course, it only supports CS3 and CS4, and I have CS5.
Here is a .jpg from the raw file [via .psd, Adobe RGB (1998)].
Tomorrow night I’ll export some tests with fewer frames, and prepare some files for output tests to vinyl in preparation for the MacKenzie Art Gallery faculty-wide exhibition we are installing at the end of the month [curated by the most wonderful Jeff Nye]. More blogging will follow….
Addition, 8 November, 2012. I did a bit of post-processing, here’s a sample from a 22-frame stack of the best frames from those 175 original selected: