Instruments
Telescopes, mounts, cameras
Scopes, mounts, and cameras I actually use. The numbers are from the maker. If I wasn't sure, I left the field out. Notes on each photo are still sample text, but the gear names are these.
Telescopes / optics
Air-spaced triplet apochromatic refractor
Sky-Watcher Esprit 80ED
- Aperture
- 80 mm
- Focal length
- 400 mm
- Focal ratio
- f/5
- Image circle
- 33 mm with the included field flattener
- Focuser
- 2.7 inch dual-speed linear power
Ships with a two-element thread-on field flattener. Sky-Watcher lists the tube at about 4 kg.
Four-element Petzval apochromatic refractor
William Optics RedCat 51 III
- Aperture
- 51 mm
- Focal length
- 250 mm
- Focal ratio
- f/4.9
- Focuser
- Internal WIFD rack-and-pinion
Flat field to a full-frame sensor, so no separate flattener. William Optics lists the optical tube at 1.77 kg.
Two-element ED apochromatic refractor
Sky-Watcher Evostar 72ED
- Aperture
- 72 mm
- Focal length
- 420 mm
- Focal ratio
- f/5.8
- Focuser
- 2 inch dual-speed Crayford
Sky-Watcher lists the tube weight at 2.0 kg and the tube length at 420 mm.
ED doublet refractor
SVBONY SV503 102ED
- Aperture
- 102 mm
- Focal length
- 714 mm
- Focal ratio
- f/7
- Glass
- S-FPL51
- Focuser
- Rack and pinion, 1:10 reduction
SVBONY’s 102F7 specification. A separate reducer is not part of this listing.
Astrophotography lens
Askar ACL200
- Focal length
- 200 mm
- Focal ratio
- f/4 to f/22
- Aperture
- 50 mm at f/4
- Optics
- Six elements in three groups, including ED glass
- Coverage
- Full frame
Built-in adjustable aperture and an integrated flattener. Askar lists the weight, with ring and dovetail, at about 1.8 kg.
Compact apochromatic refractor
Askar FMA180
- Aperture
- 40 mm
- Focal length
- 220 mm, or 180 mm with the reducer
- Focal ratio
- f/5.5, or f/4.5 with the reducer
- Optics
- Triplet objective with dual ED glass; sextuplet with the reducer
The FMA180 name is the reduced configuration. The reducer is part of the kit and is spaced for a 55 mm back focus.
6 inch Ritchey-Chrétien
GSO RC6
- Aperture
- 150 mm
- Focal length
- 1350 mm
- Focal ratio
- f/9
- Optics
- Hyperbolic primary and secondary, no corrector lens
The long tube in the set. Used in the sample log for galaxies, globulars, and the Moon and planets.
Mounts
Strain-wave equatorial mount
ZWO AM3
- Mount head
- 3.9 kg
- Payload
- 8 kg without a counterweight, 13 kg with one
- Drive
- Strain-wave gear and synchronous belt, 300:1
- Periodic error
- Under ±15 arcseconds, 288 second cycle
- Modes
- Equatorial and alt-azimuth
- Latitude
- 0° to 90°
- Saddle
- Losmandy and Vixen
ZWO’s AM3 manual. Light wide-field rigs do not need the counterweight.
Strain-wave equatorial mount
ZWO AM5
- Mount head
- 5.5 kg
- Payload
- 13 kg without a counterweight, 20 kg with one
- Drive
- Strain-wave gear and synchronous belt, 300:1
- Periodic error
- Under ±20 arcseconds, 432 second cycle
- Modes
- Equatorial and alt-azimuth
- Latitude
- 0° to 90°
- Saddle
- Losmandy and Vixen
ZWO’s AM5 manual. This is the original AM5, not the later AM5N.
German equatorial mount
Sky-Watcher NEQ6 Pro
- Payload
- 18.2 kg
- Mount head
- 16 kg without counterweights
- Drive
- 1.8° stepper motors, 64 microsteps
- Resolution
- 0.144 arcsecond
- Slew
- Up to 3.4° per second
- Hand control
- SynScan
Sky-Watcher’s EQ6 Pro specification, the mount sold as the NEQ6 Pro. This one is fitted with a Rowan belt modification on the motor transfer gears. The belt kit’s effect on periodic error is not listed here.
Cameras
Cooled colour smart camera
ZWO ASI585MC Air
- Sensor
- Sony IMX585, colour
- Format
- 1/1.2 inch, 11.2 × 6.3 mm
- Resolution
- 3840 × 2160
- Pixel size
- 2.9 μm
- ADC
- 12-bit
- Full well
- 40 ke−
- Guide sensor
- SC2210 mono, 1920 × 1080, 4 μm
- Onboard
- 256 GB storage, dual-band Wi-Fi
Imaging, guiding, and control in one body. ZWO lists cooling of 30–35°C below ambient. The smaller pixels are the ones used on the RC6 for the Moon and planets in the sample log.
Cooled colour smart camera
ZWO ASI2600MC Air
- Sensor
- Sony IMX571, colour
- Format
- APS-C, 23.5 × 15.7 mm
- Resolution
- 6248 × 4176
- Pixel size
- 3.76 μm
- ADC
- 16-bit
- Full well
- 50 ke−, 73 ke− in expanded mode
- Peak QE
- 80% (colour)
- Guide sensor
- SC2210 mono, 1920 × 1080
- Onboard
- 256 GB storage, dual-band Wi-Fi
The deep-sky camera. ZWO lists the cooling temperature as −30°C to −35°C. Read noise is given as 0.9–4.2 e−.
Where the mount goes
Places named in the sample log. The Bortle figures are estimates for those sites, not measurements from a meter.
Bortle 8
Terrace, Kondapur
Home base in the sample log. Emission nebulae, the Moon, and planets when they clear the neighbouring roof.
Bortle 4
Ananthagiri Hills, Vikarabad
The usual dark-site drive in the sample log. Broadband galaxies, clusters, and Milky Way fields.
Bortle 6
Moinabad outskirts
Closer than Ananthagiri, darker than the terrace. Used in the sample log for Cygnus and other fields that need an early return.
Bortle 7
Osman Sagar road
A western horizon with less clutter. Lunar portraits and bright planets in the sample log.