Conditions: no wind, no clouds, seeing not too bad
Setup: Obsession 18" f4.5 Dobsonian telescope with 2x powermate. Lumenera Skynyx 2-2M camera (0.2 arcsec/pixel) with RGB filter wheel. (image)
Acquisition: 9,4,5 msec exposure time with R,G,B filter, 14-bit digitalization. Took 500 frames through each filter.
Processing: Back in 2009 when these images were acquired I processed them using Registax5. However, I could not get satisfactory results when trying to combine them into a composite image with enhanced colors. A week ago, I shot some Moon images with a DSLR and learned that MaxIm DL should be used for making the enhanced color image - not Photoshop. An extra trick is to use MaxIm's 'color smoothing' feature after enhancing the colors. With this new (for me, at least) knowledge in hand I tried reprocessing some old data and started with medium resolution shots of Plato and surroundings. Each image sequence was processed by stacking the best 400 out of 500 frames, NOT applying sharpening and aligning (manually, in MaxIm) to each other. The target here is high SN ratio rather than resolution. Using Maxim DL the color saturation was then boosted (3 x 200%) and 'color smoothing' applied to reduce artifacts. Use MaxIm for this, not Photoshop (see why here). Now I have a low-res, color enhanced image. To get a high-res mono image I used the green channel with best 10% stacking and applied wavelet sharpening.Finally, the high-res image was colorized in Photoshop using the low-res color data. Some tweaking of levels/curves etc. was done in the end according to my personal, aestetic preferences. I can't wait to try more of this in higher resolution!!
Here's my main page where you can see more of the pictures I have taken so far.
Comments greatly appreciated! (mikael@leif.org)
