M57
Ring Nebula in Lyra

10.1″ f/4.5, Mallincam DS432cTEC with 0.5 focal reducer
Exposure = 1.4 sec, Live Stacked frames = 351, Gain = 95 of 250

A spectacular planetary nebula, the Ring Nebula appears approximately 3 arcminutes across in this view. Slightly oval-shaped, brightest along the upper and lower outer edges, looking somewhat like a smoke ring. The edges on the east and west sides appear to bleed into the background with subtle undulations that seem to be partially transparent. Pretty much the entire spectrum of colours from red to blue can be seen from the outer to inner portions of the ring. The 15th magnitude central white dwarf star is clearly visible in the middle, along with another star to the upper-right and some cloudy knots. Another star is visible to the lower right near the outer edge of the ring, presumably in the foreground. The Ring Nebula is about 2.6 light years across, 2300 light years away, and 7000 years old.

North at 11 o’clock, East at 8 o’clock

10.1″ f/4.5, Mallincam DS432cTEC with 0.5 focal reducer
Exposure = 1.4 sec, Live Stacked frames = 351, Gain = 95 of 250

Full wide field image from the previous image. Shows various background stars; 3rd magnitude Beta Lyrae (Sheliak) is about 50 arcminutes to the north-west outside this field of view.

North at 11 o’clock, East at 8 o’clock

10.1″ f/4.5, Mallincam DS432cTEC with 1.5x Barlow
Exposure = 6 sec, Live Stacked frames = 50, Gain = 140 of 250
(exception: No Filter is 100 frames @ 70 Gain)

Images of M57 using a variety of filters for comparison. “No Filter” displays the greatest range of colours, from reds through to violets; central star is clearly visible. The O-III filter is fully green with no central star. L-eNhance has most colours just not blue; central star not visible again. Astronomik UHC is mostly green and a little yellow-orange on the edges. L-Pro has no blue, less green and more yellow – somewhat similar to the L-eNhance.

Probably the most surprising result of these tests for me is that the L-eNhance which is a dual narrowband filter displays more colours than the Astronomik UHC which has a broader pass around O-III & H-Beta and also above 630 nm and yet it has more focused green colour (O-III) as opposed to the L-eNhance. Ultimately my preference of all these though is no filter!

10.1″ f/4.5, Mallincam DS432cTEC with 1.5x Barlow
Exposure = 6 sec, Live Stacked frames = 100, Gain = 70 of 250

North at 9 o’clock, East at 6 o’clock