An inventory of most of my gear, at least the gear which I use most.
Focal Ratio or f/stop is the focal length divided by the aperture.
A scope with a focal length of 700mm and an aperture of 80mm has a focal ratio of 700mm/80mm = 8.75
Determining Magnification: Telescope Focal Length / Eyepiece Focal Length
For example a 19mm eyepiece in the 8 SCT which has a focal length of 2032mm: 2032mm/19mm = ~107x
Focal Length: 400mm
Focal Ratio: f/6
Weight: ~4 lbs
Model: SVBONY SV503 102ED F/7 Refractor
Focal Length: 714mm
Focal Ratio: f/7
Weight: ~8.75 lbs
Focal Length: 700mm
Focal Ratio: f/8.75
I got this used, it’s a great scope especially for visual observing. Fantastic on Jupiter and Saturn.
Model: SCT 8
Aperture: 8″ (203mm)
Focal Length: 2032mm
Focal Ratio: f/10
Weight: ~13 lbs
Model: SCT 6
Aperture: 6″ (152mm)
Focal Length: 1500mm
Focal Ratio: f/10
Weight: ~9 lbs
Astro-Tech AT66ED with SV305 camera attached, SVBONY SV106 Guide Scope with OSSAG camera attached.
This is my primary EAA setup. Most of the EAA images in my Messier Log and M81 Group Log have been captured with this setup.
Model: SV106 Guide Scope
Focal Length: 240mm
Focal Ratio: f/4
Weight: ~1.7 lbs
Celestron CG5 Advanced GT
Control: NexStar Hand Controller
Payload: 30 lbs
My work horse… I have two of them. Will likely upgrade one day, but for now they handle most of what I throw at them.
Payload: 25 lbs
Got this mount when I purchased the Stellarvue 80mm. Light, great grab and go. Handles my AT66ED and my Stellervue 80mm refractors well, also works great with my 6″ SCT.
Tele Vue Nagler (82 degree Apparent FOV)
7mm, 9mm, 13mm 16mm
Tele Vue Panoptic (68 degree Apparent FOV)
The 19mm Panoptics is probably my favorite.
Tele Vue Radian (60 degree Apparent FOV)
Williams Optics SWAN (72 degree Apparent FOV)
SWA (70 degree Apparent FOV)
Astro-Tech Series 6 Wide Field
8mm, 12mm, 17mm
Not sure what the apparent FOV is on these. They were inexpensive and are no longer available, but these are great for planetary viewing.
Determining optimal sub-exposure length
Where R = camera read noise and P = light pollution rate
ZWO ASI294MC Pro
Sensor: 4/3″ SONY IMX294 CMOS
Resolution: 11.7Mega Pixels 4144X2822
Pixel Size: 4.63µm
Read Noise: 1.2-7.3e
Max Exposure: 2000 seconds
Weight: 14.5 oz
Cooling: Regulated Two Stage TEC
SVBONY SV305 2MP CMOS Color Camera
Sensor: 1/2.8″ CMOS IMX290
Resolution: 2 Mega Pixels 1920X1080
Pixel Size: 2.9 µm X 2.9μm
Read Noise: .7e-
Max Exposure: 1800 seconds
Weight: ~0.3 lbs
Atik Titan CCD Mono Camera
Sensor: Sony CCD ICX424
Pixel Size: 7.4 µm x 7.4 µm
Guide Port: ST4
Weight ~0.7 lbs
This is an older camera and has been discontinued.
Orion StarShoot Auto Guider (OSSAG)
Sensor: Micron MT9M001 CMOS
Resolution: 1280 x 1024
Pixel Size: 5.2 µm x 5.2 µm
Guide Port: ST4
Weight: 4.4 oz
Dew Heater: Dew Buster Dew Heater Controller
Focus Mask: Bahtinov Focus Mask for Telescopes with Dew Shield or Front End Diameter from 2.5″ to 4.5″ – This mask works great on both my AT66ED and my Stellarvue 80mm.
Meade F/3.3 (SCT)
Celestron F/6.3 (SCT)
SVBONY .8 Reducer/Flattener for 102mm Scopes
102mm Refractor – Looking at the AstroTech AT102ED. I really like my AT66ED but would like some more aperture. For the price the AT102ED looks like it will fit the bill. I decided on the SVBONY SV503 102ED F/7, this is pretty much the same scope as the AT102ED. The reason I picked the SV503 102ED over the AT102ED was the price and availability.
A better camera. I am having a lot of fun with the SV305 for sure, but I think I would to eventually have something a bit more sensitive. Looking at the ZWO ASI 183MC Pro. Will take me a bit to save up for it so something else may come along, but I think the ASI 183MC will be a nice upgrade from the SV305. 02/27/2022: After some research I have ordered the ZWO ASI 294MC Pro from Astronomics. I decided on the 294MC due to the sensor size and the sensitivity. This camera should provide great FOVs across all my scope focal lengths. I debated on the cooled (Pro) and un-cooled version, and decided on the Pro (cooled). This way if I decide to do some more astrophotography work it should be pretty well suited for that as well.
A set of tube rings for the AT66, either the Parallax 75mm tube rings or the AgenaAstro 2.9″ tube rings. I want a more solid way to mount it and some additional mount points. The adjustable rings I have work great but I am not able to easily mount anything else to the scope when they are on. Currently I have the SV106 mounted on it using the finder shoe, and that is really not the best way to do it.
A ZWO EAF. This would be a nice to have. After initial set up the only thing I have to go back to the scope for now is to adjust focus.