My first light with the Meade ETX 90, beautiful waning gibbous Moon

This post was originally published on my old blog dedicated to amateur astronomy.

Last week I bought an used Meade ETX 90 (90mm Maksutov), the fork mount was broken so I bought only the OTA to be used with my Meade LX85 equatorial mount. The OTA also had a problem with the 90° flip mirror mechanism to change the focuser image position, it was stuck on the upright 90° position, which is not only a bad place to fix a DSLR but it also makes the visual/AP change process a complicated one. I’ll manage a way to fix this mechanism ASAP, but in the meantime I’m using the DSLR in the upright position.

Another issue I had was my LX85 counterweight is way too heavy for this kind of payload. I had an old EQ1 mount with a smaller weight ideal for it, but the shaft role was smaller than the size of the LX85’s shaft. So I went to a local metal workshop (Acej) and asked them to enlarge the shaft hole for me, they couldn’t do it better, I got it as a perfect fit for the bigger shaft and then was able to balance the payload. Thanks to Andre Figueirêdo for helping me with subjects around 90mm Maksutovs and for giving me the Acej reference. He’s a really talented local astrophotographer.

That aside, I can say it’s superb equipment for planets and the Moon. Had an incredible night with Catarina gazing between Jupiter, Saturn and the Moon. I got really happy watching her faces and expressions while gazing through this scope, I think it’s a night I will never forget. The weather was also surprisingly comfortable.

She went to sleep around midnight, this time I was switching from visual to photography.

I also had brought my notebook to the garden and I was willing to use it to control the camera and the mount, but the Camera->Computer connection is a tricky one. 10m long USB cables are far from the ideal, but it works. Unless you’re passing through the USB device to a virtual machine. The problem is that my notebook runs Linux, and I haven’t yet got lucky with DSLR/mount controls on it. I always do it on my Win10 desktop, but it’s a desktop, I can do it only inside my office, not in the garden. So for that I had a virtual Win10 running on my Linux notebook. Controlling the mount from it works OK, but the DSLR will keep disconnecting every minute.

I’m yet to manage a solution for this,  but for the night I ended up not using the computer, just the DSLR itself and the mount handheld controller.

No fancy/cool techniques were used in the shots, just straight-forward single light frames and Photoshop editing, so definitely those equipment can do a lot better. Also mind that even larger magnifications can be achieved when using a 3x barlow lens, which is a plan for the future.

When I was about to wrap up for the night, my neighbor  appeared and we started talking about telescopes.  I soon invited him to come in and observe (keeping safe distance, as we both observe Covid-19 quarantine) and I think he enjoyed it a lot. He told me he owns a small refractor and that he’s studying astronomy, how cool? He said he’s starting his career on software development but programs since 2014, so we also spent a lot of time talking about IT.

Then I packed the stuff and got up back to the office, performed a really quick/crappy edition and called the night.

Author: Fernando Schuindt
License: CC BY 4.0
Camera: Canon EOS 600d
Lens/Telescope: Meade ETX 90 (OTA-only) (90mm aperture, 1250mm focal length, f/13.88, Maksutov-Cassegrain)
Location Name: Aracaju - Sergipe, Brazil
Location Aprox. Coordinates: 10°58’31.0”S 37°04’26.0”W
Other Gear: Meade LX85 GEM, Canon EOS to M42 adapter, M42 to 1.25” adapter.
Full Resolution Images: https://photos.app.goo.gl/GG4DzQkPTRJuuFJQ7

Composition: 1x Light Frames @ 1/160” ISO800 f/13.88
Processing: Photoshop resize, Camera Raw Filter
Timestamp (Local Time): 07-11-2020 01:19:51
Timestamp (UTC): 07-11-2020 04:19:51
Theme: Waning gibbous Moon 78.06%

Composition: 1x Light Frames @ 1/100” ISO3200 f/13.88
Processing: Photoshop resize, Camera Raw Filter
Timestamp (Local Time): 07-11-2020 01:11:47
Timestamp (UTC): 07-11-2020 04:11:47
Theme: Waning gibbous Moon 78.06%
Other gear: Celestron Omni 2x Barlow

Composition: 1x Light Frames @ 1/160” ISO3200 f/13.88
Processing: Photoshop resize, Camera Raw Filter
Timestamp (Local Time): 07-11-2020 01:13:18
Timestamp (UTC): 07-11-2020 04:13:18
Theme: Waning gibbous Moon 78.06%
Other gear: Celestron Omni 2x Barlow

Composition: 1x Light Frames @ 1/25” ISO3200 f/13.88
Processing: Photoshop resize, Camera Raw Filter, crop, manual background noise removal
Timestamp (Local Time): 07-11-2020 00:58:06
Timestamp (UTC): 07-11-2020 03:58:06
Theme: Bonus picture, Saturn
Other gear: Celestron Omni 2x Barlow

Gear: