CYMG to Luminosity

The Milky Way Galaxy

CYMG to Luminosity

Mosaic Pattern for the Sony IC404AK CCD chip used by the DSI I Color:

Row 1: C Y C Y C Y C Y C Y C Y

Row 2: M G M G M G M G M G M G

Row 3: C Y C Y C Y C Y C Y C Y

Row 4: G M G M G M G M G M G M

The pixels are read by combining Row 1 and 2 for a 1st (odd) A signal, Row 3 and 4 make the 2nd (even) A signal. Row 2 and 3 are combined to produce the B signal. A hot or cold pixels, or a bad filter on the chip that only physically effects one pixel, will generally affect at least two others before the data even gets off the CCD chip in the unit. CYMG filter mosaics provide twice the light sensitivity as an RGB mosaic filter. However, not using a filter mosaic (mono) will be one and one half times as sensitive as CYMG or 3 times as sensitive as RGB. This is a good reason to forget about color images for faint deep sky objects.

Meade's conversion algorithm to luminosity seems to be quite good. I can not say the same for the conversions to RGB components. Performing a drizzle on a RAW image is not going to provide very good results. The CYMG must be converted to luminosity to provide an image that represents what the CCD actually saw.

Unbelievablely, some of the initial and really good images were drizzles of CYMG images. Reprocessing of these images should attain 3 to 4 times the "resolution" or detail.

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