What makes it special is the ability to get enlargements of the area photographed, with greater definition, without compromising it with additional noise as would happen oversampleing a 200% crop, and in some cases also allows you to get more signal/detail in that area.
Taking a cue from what little I’ve found on the internet about the Drizzle, this is the function that takes advantage of the algorithm called “The Variable-Pixel Linear Reconstruction” which was originally developed at the Space Telescope Science Institute to process Deep Field images from the Hubble Space Telescope.
Drizzle is a linear algorithm for reconstruction of downsampled images from dithering (*), basically allows you to work in pixel mode doubling the size of each image (triples if you choose the drizzle 3 x).
To take effect, the Drizzle, you must have raw data that have these requirements: Downsampled images: If the images are already well sampled, the Drizzle won’t give you great benefit. Images with Dithering: Drizzle is absolutely necessary and without proper dithering the rebuilding process is not working. Many images: Drizzle requires more images than a handful of images that a wide field astrophotography. The more the better, but generally you should acquire at least 20/30 images to get good results.
[ * ] -For dithering applied in astrophotography, also as a function of driving software, means that every single shot has the exact same field resumed (FOV), but always present a small shift, a drift that then generates the final image darker sides those borders. See also: http://dslr-astrophotography.com/dithering-optimal-results-DSLRs-astrophotography/
We could call it vulgarly a crop more powerful, but also a little as if the photo shooting increased three times without carrying those annoying aberrations than a “teleconverter” optic, although of excellent brand you would bring back.
A little like giving hormones to the telescope:) or one of his “second life” warning though, this type of processing actually produces the benefits in the image only if it was taken with perfection to the native focal, I mean focusing great Chase very good, otherwise the image produced in drizzle also amplifies these faults!
This is the pubblication of Space Telescope Science Institute about Drizzle:
And here are some examples to better understand what we’re talking about, before without drizzle to campio full (APS-C) and then Drizzle 2 x:
To learn this technique of elaboration, I suggest you my TUTORIAL “Deepskystacker e Drizzle Function”:
Thanks for viewing and bye 🙂