M27 with MetaGuide and C11 on CGE at f/10.5
This image was captured with a C11 on CGE at prime focus and a Canon 20d. Guided with MetaGuide and a guidescope. Note the faint double star just in from the left edge, and right of the bright star. This double star has approximately 1.9" separation, and the stars in the image are roughly 2.5-3.0" FWHM.
- CGE mount with C11 at f/10.5 (2930 mm f.l., 0.45"/pixel)
- Stack of 24 4-minute frames at ISO 800 on un-modified Canon 20d
- Arithmetic averaging - no sigma combine or sharpening/deconvolution applied
- Guided with MetaGuide and a Lumenera SKYnyx 2-0m video camera attached to TeleVue Ranger (70mm f/6.8) with 2x Barlow
- PEC enabled, using old averaged run created with PECTool (free)
- CGE mount polar aligned with built-in polar alignment procedure - one iteration. No drift align
- Processing done in Iris, and stacking done using 1-star alignment, with no field rotation
- All software freely available, except final color adjustment in Photoshop (but no sharpening)
- The combination of mid-range mount, commodity camera, and free software make this a very cost-effective image, with the downside that it is limited by thermal noise and doesn't capture red efficiently due to the built-in filter of the 20d.
Single 4-minute frame, with dark subtract and contrast enhancement. Note the double star is evident even in a single image.
Wide field view of Cygnus, including M27. 17-40mm f/4L Canon Lens at 35mm and f/5.6. Note North American nebula at upper right. M27 is on the left side, above Albireo, but not obvious in this reduced image.
Close up of above image at 1x1 shows M27 clearly, with its two lobes evident. This is with a 6.25mm aperture and f/5.6 (35 mm f.l.), vs. the C11 image at 279mm aperture and f/10.5 (2930 mm f.l., or 83x longer).