Sky Watcher Equinox Pro 80mm OTA

Sky Watcher Equinox Pro 80mm OTA + Tele Vue TRF-2008 field flattener + QHY10 camera & William Optics 66mm OTQ with T7C guide camera + TS OAG/flip mirror on HEQ5 Pro & focus points on both scopes with these cameras 20/9/2019

Sky Watcher Equinox Pro 80mm OTA + Tele Vue TRF-2008 field flattener + QHY10 camera & William Optics 66mm OTQ with T7C guide camera + TS OAG/flip mirror on HEQ5 Pro & focus points on both scopes with these cameras 20/9/2019:


Focuser slippage in my Sky Watcher Equinox Pro 80mm OTA

Last night I found a significant slippage problem on my Equinox 80.

I have managed to solve this after reading relevant internet resources. There is a small hex screw just behind the locking thumb screw that can be tightened to prevent slippage but this needs to be done carefully and in very small increments to prevent excess pressure causing damage to the focuser tube.

Internet resources:


Photos of my own Equinox 80 today when I adjusted the focuser tension, showing the hex screw being tightened:

Absolute frustration! Astrophotography – when it all goes wrong!

After my initial successes, tonight was a total disaster.

My HEQ5 Pro refused to align properly – even though it said it had successful alignment it sent the scope all over the sky when I did a GOTO. I ended up factory resetting it and this improved things…..but not enough to find Andromeda Galaxy or M81/M82 with GOTO. Ended up manually star-hopping to them.

My Sky Watcher Equinox Pro focuser slips too much – to such an extent that it keeps losing focus. I will need to ask Lee to look at it. I ended up giving up on it and changing to my Sky Watcher DS Pro 72mm.

This meant I had to re-focus the scope – my one success tonight was the first successful use of a Bahtinov Mask.

However this means that the TS Flip Mirror/OAG won’t obtain focus in both camera and eyepiece at same time – I need a shorter adapter TS Flip mirror to scope to create more back focus behind it. So tonight I used the scope with the finder eyepiece out of focus. Camera was in focus though.

Once I got all working and found M31 and was ready to image, suddenly the QHY10 was no longer recognised by Nebulosity and refused to reconnect even after switching everything off and on. It had been working all night.

Then clouds rolled in and stopped play.

Very frustrating!


Stacking and processing image of M101 to remove light pollution in GIMP

It is amazing what instructions you can find on YouTube and Google! I downloaded DeepSkyStacker and stacked 7 images of M101 I took last night to create single image with equivalent exposure of 40 minutes and then carried out the instructions at to remove light pollution – results were amazing as you can see below!

(All images below are TIFF files)

This post follows from my previous post & is using images from that session:

First deep sky images with QHY10 camera


I had taken 7 images of M101 “subs” last night – in my previous post I only presented a single frame. Today I stacked all 7 in DeepSkyStacker ( to create single image equivalent total 40 minutes exposure (below):


The following image is my first iteration of applying curves in GIMP:

I then applied curves again to above image each time narrowing down the top and bottom so that it bridged the data seen on the histogram:

Another iteration of curves:

Now when I looked at the histogram the edges of the curves touched the data both sides:

I used despeckle with standard settings in GIMP on above image to get following image:

I now followed the instructions at to remove light pollution.

The first step was to create a copy of the layer and on this copy I used despeckle with largest radius and maximum black and white points to remove stars, then used the clone tool to remove the two galaxies as best I could to create a layer showing image of the background light pollution.

I then used subtract on the layers to remove this light pollution layer from the original image to give following incredible image (seems incredible to me that this can be done so easily):

TIFF version:

PNG version:

BMP version:

First deep sky images with QHY10 camera

I know that the following photos are not very good but they do show real deep sky objects – M57 (Ring Nebula in Lyra) and M101 (spiral galaxy in Ursa Major). I took these photos tonight using my QHY10 camera on my Sky Watcher Equinox Pro 80mm scope on HEQ5 Pro mount. I spend a long time polar aligning the scope and then did three star alignment. The sky was poor with a lot of moisture but I still managed to get my first successful deep sky photos after 4 weeks of hard work.

These images are certainly not works of art and I have long way to go on my astro-imaging journey but I am excited about the start I made today. I have already achieved my objective of being able to photograph a galaxy and show its spiral arms – my next objectives are now to show star formation regions in a galaxy in one of my photos and detail in the wall of a planetary nebula and to successfully image the North Americal Nebula and Horse Head Nebulae. My objectives are predomently observational rather than to create artistic renderings of the night sky. To me, the camera is a tool to help improve my observations of the night sky.


M57 240819@2247 60s.png – original image (single frame, 60 second exposure):

Applying some curves to above image in GIMP:

Cropping the above image and scaling up the image:

M101 240819@2340 300s.png (original image – single frame, 300 second exposure):

Applying curves in GIMP to above image brings out M101:

Greyscale and further curves and a little playing around with contrast and brightness and I was able to bring out the spiral arms in M101 – I felt this was quite an achievement!

I took 7 images of M101 tonight & the following post describes what happened when I stacked those images:

Stacking and processing image of M101 to remove light pollution in GIMP

Re-processing Moon image in Registax

Roger has very kindly reprocessed my recent Moon image in Registax for me.

He comments: “I actually usually find “wavelets” in Registax more useful for sharpening, at least initially.”

QHY10 camera, Sky Watcher Equinox Pro 80mm OTA, TS OAG/flip mirror, Lichfield, August 2019, Andrew Thornett/extra processing by Roger Samworth.


This post follows on from my previous post:

Applying Lucy-Richardson sharpening in GIMP to my previous Moon image

My original Moon image:

Roger’s reprocessed image in Registax:

Settings Roger used on Registax:

Taking my first successful focused photo of a celestial object with QHY10 camera and Sky Watcher Equinox Pro 80mm/TS OAG-flip mirror – photographing full moon 16/8/19

Having successfully obtained focus with the QHY10/Equinox 80/TS OAG-flip mirror, I was then able to also obtain my first “proper” image of a celestial object using the QHY10 camera.

Successfully achieving focus & noting the focal point on Sky Watcher Equinox Pro 80mm OTA on Manfrotto mount with QHY10 camera and TS off axis guider/flip mirror 15/8/2019

The extensive cloud cover meant that the only object available was the full Moon which was able to penetrate the clouds. To photograph this, I had to use the lowest shutter speed setting possible of 1/10000 second and also using an aperture mask to reduce the aperture of the Equinox 80mm OTA by about 70% and the clouds further reduced the brightness of the Moon!! I don’t think the QHY10 was designed with the brightness of the Moon in mind. Settings on Nebulosity were also amp off on the QHY10, gain 0, offset 130.

Focus point = 15.5mm on the scale on the Equinox 80mm for the QHY10 with the TS OAG/Flip mirror also in place.

The following screenshot shows the focused Moon in Nebulosity 4 software, together with settings for the QHY10 on that software used tonight – note that there is colour dispersion due I suspect to low altitude of Moon and cloud present:

I found a process to address the colour dispersion using GIMP2 software using the decompose function which I have described in another post (click on link below) – please could readers let me know of any better process that you are aware of that I could have used tonight. I do have an atmospheric dispersion corrector but it is only 1.25″ fitting rather than the 2″ fitting required for the QHY10 camera.

Decomposing images in GIMP2

This resulted in my successful image of the Moon:


Moon 150819(VII) 15-5mm on Eq80 focus tube-RGB-blue layer after decompose:

Blue frame above with some processing in GIMP2 (single frame):

See following post for further processing of this image:

Re-processing Moon image in GIMP