08:00 PST — Start of the final day at AIC. Last night included a demo of Light Buckets, an on-line telescope service. Charges add up quickly as it is from $80 to $175 per hour. Next year’s conference is set at the end of October. It will be larger, they have reserved the upstairs room. Bigger and better.

Ray Gralak Advanced Image Combine Techniques CCD usage, starting in 90s. CCD stacking led to great dynamic range, DDP made it visible, but artifacts in the image came out. These are cosmic ray hits, hot/cold pixels, bad columns, satellite trails, plane trails, and asteroids. Four raw image types: Bias, Dark, Flat, and Light frames. Dark and Bias frames may change over time. Data collection tips: Take all frames at the same temperature, take the same number of darks as lights, use light frame duration for darks, dither your lights and flats, flat frames should be at or near focus and at the same orientation of the light frames, a flat for each filter. Workflow: Create master Bias, master dark, subtract bias from each flat, normalize and combine flat frames, subtract master dark from light, apply flat, align and combine.

Combine methods: Average, median, min / max clip, sigma, SDM. Average, good SNR, but artifacts remain. Median, best noise rejection, but lower SNR. Min/Max, rejects most artifacts, but leaves some, must have >6 images. Sigma Clip, strong noise rejection, requires >10 images to work best, does make errors to reject good or not reject bad. SDM, calculates mean and median, then looks at standard deviation of all pixels, if STD is above a certain number, it uses median, otherwise uses mean. Multiply a sigma factor to select “certain number,” if sigma factor is zero, all pixels are rejected and the mean is used. Lost of detail on settings (I took a picture).

09:00 PST — Wolfgang Promper Making the Most of Your Site This is a topic for me, about imaging from an urban location. I get it! We should image where we can do it more often. Normalize background: Equal pixel counts on background in each channel. Interesting, he cuts out of Maxim and pastes into Photoshop. Gradient Xterminator as primary gradient removal, then manual tweaking of the image. High pass and threshold to find the stars (SSRO has instructions). Add stars as new color channel with cut and paste to use the channel as a selection, expand and feather selection by 2 pixels, 2 pixel minimum filter to reduce size of stars. Use extensive selective color to balance nebular color. DDP 100 lower than auto. “After a lot of processing and versions you often find that the first version was the best.”

09:32 PST — Break

10:00 PST — Door Prizes! Art won a telecompressor!

10:30 PST — Conference Over