Image Enhancement The Lagoon and Trifid Nebulas Here is an example of the hidden beauty in a long-exposure deep-sky astrophoto that can be brought out with the proper processing techniques. The contrast and color were increased and enhanced in the original stacked image. It was shot with a simple 70mm refractor and stock Canon 1000D (Digital Rebel XS) DSLR camera.

This beautiful area around the Lagoon and Trifid nebulas is located in the constellation of Sagittarius.

The Lagoon Nebula is a gigantic cloud of dust and gas that glows red from the emission of light by ionized hydrogen. It is also an amazing stellar nursery.

From a dark site, M8 is visible to the unaided eye as a small bright patch above the large Sagittarius star cloud in the Milky Way. Bok globules, small dark knots which are condensing protostellar clouds, can be seen embedded throughout the nebula.

Taking its name from the dark lane that runs through the center of the nebula, just to the west of open cluster NGC 6530, the Lagoon nebula is a beautiful sight in any size telescope.

M20, the Trifid Nebula, is another remarkable object, seen at the top of the frame. It is a complex of red emission and blue reflection nebulosity about the size of the full moon, intersected by three dark lanes, from which the Trifid gets its name.

M21, to the upper left of the Trifid, is a rich open cluster comprised of some 70 stars with a large brightness range and strong central condensation. It is approximately 13 arc minutes in diameter and shines at magnitude 5.9. It is located 1/2 degree to the northeast of M20.

Eighth-magnitude globular cluster NGC 6544 can be seen glowing golden in the lower left corner of the image.

Image Data

• Lens / Scope: Stellarvue SV70ED ED doublet refractor
• Focal Length: 336mm
• F/stop: f/4.8 with William Optics 0.8x Telecompressor / Reducer
• Exposure: Stack of twenty-six 1-minute exposures (26 minutes total exposure)
• Mount: Orion Sirius polar-aligned German-equatorial mount
• Guiding: None
• Camera: Unmodified Canon EOS 1000D (Digital Rebel XS)
• Mode: Raw
• ISO: 1600
• White Balance: Custom, set on sky background
• In-Camera Noise Reduction: Off
• Filter: None
• Temp: 65F
• Start Time: 3:26 a.m.
• Date: April 28, 2009
• Location: Steelmantown, NJ
• Calibration: Master Dark and Master Bias
• Processing: Calibrated and Stacked in Images Plus. Contrast, color adjustments, enhancements in post processing in Photoshop.