ASTROPHOTOGRAPHY – Setup

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Current setup – spring 2023

The setup consists of two scopes on two mounts – one for lunar / planetary, the other for deep sky.

1. Optics

Both instruments are refractors: the Takahashi FS-60CB and the FSQ-85ED. The focal length of the FS-60CB varies from 355mm to a whopping 2m; used for photos of the solar system. The FSQ-85ED f/6.2 has a 2°x3° FOV and a motorised focuser; used for deep sky photography. Autoguiding with the ZWO 224MC through the Takahashi GT-40 (40/240mm) carried by the AZ guidescope mount that allows fine movement 6° in altitude and 10° azimuth.

2. Mounts

The mount that carries the planetary scope is the Takahashi Teegul SP3 EQ. This is a tiny equatorial mount motorised in RA only that provides surprisingly good tracking at high focal lengths. Very small, ultra-light setup successfully used to photograph the 2019 total solar eclipse from Chile.

The deep-sky mount is the ZWO AM5 EQ. This is a tiny mount weighing only 5kg that is equipped with a harmonic drive system capable of carrying heavy loads. It is controlled through an app and provides polar alignment even if the pole is not visible. Fully integrated with ZWO cameras, autoguiding included.

The manufacturer provides an error graph (24h) for each unit, guaranteed to be less than 20”. The periodic error is not really periodic, meaning it can not be compensated by playing it backwards. Autoguiding for long exposures (90s+) is imperative for harmonic drive mounts.

3. Cameras

The planetary camera is the ZWO 224MC and the deep sky camera is the ZWO 071MC – both color APS-C sensors. Controlled through the ASIair+ app.

Pixel size and focal length ratio needs to be calculated and thank Gaawd for chat gpt cause now you can ask it to do the work for you and provide clear numbers that can guide you further.

4. Filters

Dual narrowband filter that passes light at both H-Alpha (656 nm) and OIII (500 nm) wavelengths. H-Alpha Bandwidth: 15 nm; OIII Bandwidth: 35 nm.

Neutral density filters with 13%, 25% and 50% transmission.

Anti-light pollution filter.

The ZWO electronic mini filter wheel (5 filters).

5. Controller

The ZWO ecosystem is controlled by the ASIair+ device which handles *everything* from polar alignment to camera control, guiding, aligning and stacking. The interface is an app on your device and it solves plates.

6. Power

Power is supplied by a 220Wh source from Revolt.

ASTROPHOTOGRAPHY – Daytime Moon

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First light for the 224MC from ZWO controlled by the ASI Air plus. Shot through the tiny FS-CB60 refractor at a whopping f/20 on a Teegul III mount.

Exceptionally bad seeing made focus quasi-impossible. Contrast very poor as it was shot during the day. This is a stack of a 90s AVI that I find surprisingly good, considering.

33.3% waxing

Libration was at maximum for the month of February with the Eastern side of the Moon tipped into view. Mare Australis is visible in the SE.

Mare Australis
Libration oval for Feb. ‘23

Among the interesting features south of Mare Nectaris are the Rupes Altai range and the Vallis Rheita.

Rupes Altai
Vallis Rheita

Rupes Altai is a slightly arcuate escarpment bordered by craters Piccolomini to the SE and Catharina to the NW, spanning some 440km. Pictured above is the southern region of the range and the crater Piccolomini with is curious parallel double peaks. The escarpment is a portion of the outer wall of the Nectaris Basin and reaches 4000m heights with respect to the surrounding terrain, considerably more than similar structures such as Rupes Recta and Rupes Cauchy.

Concentric rings forming the Mare Nectaris Basin

Vallis Rheita is 450km long and widest at 30km, formed from a series of overlapping craters that radiate to the center of Mare Nectaris. It is thought to have arisen from secondary events following the Nectaris impact.