By: Sam Pitts (samsastro.com)
| Telescope / Lens | 35mm f/2 Canon at f/2.8 |
| Mount Type | Piggyback on Losmandy G11 |
| Camera | Canon F-1 with Bright Screen & Angle B magnifier |
| Filters | UV |
| Film | Kodak ED200 (Slide Film) Slide #05 |
| Exposure | 120 seconds; manual guiding FS/78 |
| Processing | Pushed, Scanned – 2400 dpi, Photoshop |
| Date | June 19, 2004 |
| Location | Eagles Rest, south of Dexter, Oregon |
| Conditions | 2500′ magnitude 6 Skies; Clear, steady |
| Telescope / Lens | 50 f/1.4 Canon Lens at f/2.8 |
| Mount Type | Piggyback on Losmandy G11 |
| Camera | Canon F-1 with Bright Screen & Angle B magnifier |
| Filters | 52mm UV |
| Film | Provia 400F (Slide Film) #10 |
| Exposure | 15 minutes; manual guiding Takahashi FS/78 |
| Processing | Slide Scanned – 2400 dpi, Photoshop |
| Date | September 26, 2003 |
| Location | Eagles Rest, south of Dexter, Oregon |
| Conditions | 2557′ magnitude 6 Skies; Clear, steady |
M31 Original imaging information
9/20/2009 10:46 PM Latitude: 43° 31′ 21″ North Longitude: 122˚ 52’ 35” West 4658 ft. Snow Peak S/E of Cottage Grove. OR. Seeing: E Transparency: 7 Telescopes / Optics: TMB 80mm f/ 4.8 384mm Mount : AP1200 Camera: SBIG ST10XME 3.5 hours; LRGB; L=120min (10 & 5 min) RGB 1.5 Hours (3x10min ea.). FOV 133.4′ x 89.5′ Information: Really tried to go deep into M31 and very satisfied with the results from a 3.1” refractor. Hope to add Ha channel in the future. Captured with CCDSoft, processed with CCDStack and Photoshop.
M31 Additional Imaging information
10/23/2022 10:03 PM Latitude: 33° 29′ 01.48″ North Longitude: 116° 43′ 19.24″ West. Elevation: 4321 ft. Jupiter Ridge #4 Observatory, OCA site, near Anza, CA. Seeing: E Transparency: 6 SQM: 20.78 Bortle: 4 Telescopes / Optics: TMB 80mm f/ 4.8 384mm. Mount: AP1200 Camera: SBIG ST10xme CFW10 FOV: 133.4′ x 89.5′. Filter: Astrodon L series E Gen. 2 & 9nm Ha Total time 65 min. Information: M31 image captured with CCDSoft; Subs- L= 5 minutes x 3 (15), Ha= 10 minutes x 5 (50)-20°c. Processed with CCDStack, Photoshop CS6 & PWP8. Add previous data from 9/20/2009 L-2 hours, RGB 1.5 hours + 10/23/2022 65 min. Total 275 min or 4.5 hours.
The Andromeda Galaxy is readily visible from a dark sky location as a fuzzy patch of light covering approximately 3+ degrees or 6 times the width of our moon. Andromeda is approximately 2.5 million light years from Earth and 220,000 light years across. Making it much larger than our own Milky Way galaxy at only 100,000 lights years across. In about 5 billion years both our Milky Way galaxy and Andromeda will collide and begin to coalesce, perhaps evolving into an even larger elliptical type galaxy. This image reveals much detail and numerous globular star clusters and nebulae are visible. Amazing for just a 3.2 diameter refractor, but Thomas Back (TMB) was a primer Telescope Maker and his designs live on.
Images below reprocessed with data captured on 10/23/2022 and previous data.
Click full screen on movie below and view.
M31 movie shows resolution captured with just an 80mm refractor zoomed in to background SC Galaxy PGC 90494/ 2MFGC511
M31-Andromeda Galaxy By: Sam Pitts 10/23/2022 10:03 PM Latitude: 33° 29′ 01.48″ North Longitude: 116° 43′ 19.24″ West Elevation: 4321 feet; Jupiter Ridge #4 Observatory, OCA site, near Anza, CA. Seeing: E Transparency: 5 SQM: 20.78 Bortle: 4 Telescopes / Optics: TMB 80mm f/6 @ f/ 4.8 384mm Mount: AP1200 Camera: SBIG ST10xme CFW10 (KAF3200) FOV: 133.4′ x 89.5′ Filter: L=135min (10 & 5 min) RGB =1.5 Hours (3x10min) Ha= 5x10min (50)-20°c Information: Captured with CCDSoft Processed: with CCDStack, Photoshop CS6 & PWP8 Total exposure time = 275min / 4 ½ hours NOTE: Data from 9/20/2009 included with new data taken 10/23/2022.
By: Sam Pitts 2001
This depends on your eyepiece’s magnification and apparent field of view, along with the telescope being used. The eyepiece has a focal length indicated in millimeters. The longer the focal length of an eyepiece (25mm-50mm) the lower the power (magnification) and the wider the field of view. This assumes we are using the same telescope with a fixed focal ratio (f/10) and length (fl/2000). The higher the power or magnification the shorter the focal length in millimeters, resulting in a smaller field of view (FOV).
To determine the magnification of an eyepiece, divide its focal length into the focal length of the telescope’s objective lens or mirror. 8″ f/10= 2000mm focal length (fl).
Telescope: 8″ f/10 – 2000mm fl (focal length)
Plossl Eyepiece 32mm with 50° FOV (apparent field of view)
Magnification 2000mm ÷ 32mm = 62.5x
The field of view with this setup is determined by eyepiece magnification and apparent field of view 50°. Hold an eyepiece and look through it. The circular view of light observed is its apparent field of view. The diameter of this circle is the apparent field of view measured in degrees. Below is a list of apparent field of views with different types of eyepieces.
Tele Vue ® Nagler™ 82°
Tele Vue® Radian™ 60°
Meade® Ultra Wide 84°
Erfle 60°
Orion® Ultrascopic™ 52°
Plossl 52°
Orthoscopic 45°
Kellner 40°
To find the actual field of view, divide the eyepiece’s apparent field of view by the magnification on a particular scope. Using the example above (8′ f/10 scope ).
50° ÷ 62.5 = 0.8°
The 32mm Plossl on an 8″ f/10 (2000mm) telescope will render a true field of view of 48 arc minutes or 8/10 of a degree. Remember the moon is approximately 1/2° (30′) in diameter. Wide field of view lenses may suffer from aberration near the edges due to astigmatism. The stars may be slightly distorted near the edge of the field of view.
A 32mm Tele Vue Nagler 82°, with the same telescope, would have a FOV of 1.312° or 1° 18′ 43.2″
A 32mm Kellner 40°, with the same telescope, would have a FOV of .64° or 38′ 24″
Eyepieces > 32mm are best used with 10″ or larger objectives/mirror and a 2″ diagonal.
Canon F1
Canon 50mm f/1.4 Stopped down to f/2.8
Kodak E200 puhed
8 min exposure
Piggyback Losmandy G11
2 image mosaic/composite/ 3rd image of foreground
| Telescope / Lens | 50 f/1.4 Canon Camera Lens stopped down |
| Mount Type | Piggyback on G11 (Stepper) |
| Camera | Canon F-1 with Bright Screen & Angle B magnifier |
| Filters | 112mm UV |
| Film | Kodak E200 (Slide Film) |
| Exposure | 10 minutes; manual guiding FS/78 |
| Processing | Push 1, Scanned – 2400 dpi, Photoshop |
| Date | July 2003-Milky Way; Diamond Peak 8/2006 |
| Location | Panther Creek, south of Veneta, Oregon |
| Conditions | 1200′ magnitude 6 Skies; Clear, steady |