This sequence was undertaken as part of an experiment to determine if there would be any benefit in working with a
larger image size. The camera was direct-coupled to a 3mm Radian eyepiece, which itself yields 400X when used
visually with this 1200mm fl, 8" Mak-Newt'. With the afocally mounted camera zoomed to its optical max of 4X, Jupiter's
disk is a whopping 680 pixels wide in a 2048 X 1536 field.
81 individual images were made, but the majority (which were done @ 1 second) had a washed-out, low definition
appearance. 8 images were shot @ 2seconds, with more intense coloration and improved contrast, but the added time
gave the atmosphere more opportunity to smear things around. Only one of the 8 was a "keeper".
The 20 best shots were culled from the 1 second batch and processed with AstroStack, using weighted assignments
(bad, average, or good) for each. The resulting image was then itself re-stacked with the single good bright image, the
former assigned as an "average" quality and the latter as "good". Io was obtained via PhotoShop by "Apply
Image/Blend/Adding" of two images, doubling the signal strength.
The results seem to bear out the wisdom of matching the image scale so as to minimize the exposure time. Also, taking
many images and discarding most but reaping a few real gems! My next attempt will be with a more modest image
scale and comparably reduced exposure times. Focusing with the InterAct LCD screen is now part of my normal
Jupiter was still fairly low in the early morning sky when these images were taken, but
hopefully my technique will improve as it climbs higher.
This composite image was formed as indicated in the sequence below. The thrust of my
effort for this particular session was to determine the effects of gross over-sampling.
|1 of 20 Stacked
Single Bright Image
By the end of the 2001/2002 apparition, my technique (and the "seeing" conditions) were improving. Alas, I have since
moved over to a Canon D60 SLR, and no longer have the benefit of zoom-focus or a real-time large-screen LCD display.
The above image was processed with Images Plus, which automates much of the cropping, stacking, aligniing, and
combining procedures, as well as performing restorative techniques.