Equipment for Astronomy

First light Orion Premium Linear Binoviewer with Orion UK Dobsonian 10 in telescope 20/3/19

First light last night with my new Orion Premium Linear Binoviewer used on my Orion 10 inch Dobsonian telescope. What excited me about his binoviewer when I got it was that it claimed not to need any in focus – an issue that has meant other binoviewers I have tried only work if a Barlow lens is also used which means they only work at high magnifications. The whole point (in my view) of using Dobsonian telescopes are the immersive wide angle views – and you need the wide angle at least initially with an object to find it in a Dob when you are star hopping!

Great news! The Orion (USA) Premium Linear Binoviewer does come to focus in my Orion UK (different company) 10 inch Dobsonian. In fact I needed to use a 35mm extension tube – although that is common too with eyepieces in this scope so does not imply that the binoviewer increases out focus. So I think the manufacturer’s claim that no extra in focus is required seems to be supported on this test.

I had more of a problem bringing images of the Moon and a couple of stars together with my two eyes in the binoviewer – I put this down to lack of experience. There were times when the Moon images did come together and then suddenly the Moon would be significantly brighter.

Mind you, I am being a bit unfair on the binoviewer here. Due to the Moon being located awkwardly behind a tree, I had to place the scope in an awkward position to get a view and my own body was somewhat awkwardly positioned too – so that it wasn’t easy to view properly through the binoviewer.


Orion Premium Linear Binoviewer

My best purchase from the Practical Astronomy Show. These binoviewers differ from other makes in that they do not require any extra in-focus. You never see these on sale….but this one was around £100 off new price! I have tried binoviewers before but the need to use a Barlow lens in order to obtain focus on my Newtonian telescopes has meant that they weren’t very practical. I decent read a review in one of the astronomy magazine about this binoviewers and the reviewer was so impressed he bought one!

I tried it today on my Orion 10″ Dobsonian telescope. In order to get focus, I had to use an extension tube plus my Tele Vue Paracorr – the latter has a long tube and I can pull it out quite a distance to act as an extension tube. All of this suggests that I will easily obtain focus on the night sky.

At the Practical Astronomy Show I purchased a pair of discounted APM ultra flat field 18mm 65 AFOV eyepiece and I already had a pair on Tele Vue Nagler 7mm eyepiece.

The view of the trees at the bottom of the garden was amazing! This the first time I have ever had a proper binocular view through a telescope without any sense of strain on my eyes! Both pairs of eyepiece worked well. I can’t wait to get out under the night sky. Only problem is this could work out really expensive on eyepiece with my having to buy a second one to accompany some of those I already have…..



Always worth having a bag of eyepiece caps so if you see any being sold cheap I recommend you purchase some spares in 1.25 inch and 2 inch varieties for both ends of the eyepiece. Below is my bag – the cheap 18mm eyepiece did not come with caps so good job I had some spare.

The attachments I used to obtain focus – this was opposite of in focus = out focus – as I was focusing on the trees at the bottom of my garden which are closer than infinity.

The Tele Vue Paracorr is one of my best ever purchases – so useful!

Adding Sky Watcher finder scope style mounting shoes to Orion UK 10″ Dobsonian telescope

My trusty and well used Orion 10″ Dobsonian telescope does not have Sky Watcher style finder scope shoes – a nuisance as I would like to use a finder scope with it and also attach my heated laser finder device which has Sky Watcher style finder bracket.

So today out came the glue gun and I attached two finder shoes to the tube. If the glue gun turns off with time not to be strong enough then I will bolt them on but hopefully this won’t be needed as not much weight on them.

The other advantage of using the glue gun initially is that I can change position of the finder shoes if it turns out they are not in the best place in practice.


I chose a rather cold day to do this!

OK so in the next picture it looks a mess. However, once the glue has cooled I will then be able to tidy it up and I would rather put a bit more glue on so that my stuff does not fall off the scope, including my bargain from the Practical Astronomy Show – right angled 9×50 finder scope with illuminated eyepiece for only £45, which I bought especially to put on this scope!


Purchase from Astrofest – Orion UK eyepiece tray

I have just installed a great £20 Accessory I purchased at European Astrofest 2019 – an aluminium eyepiece tray to compliment my aluminium Dobsonian mount base on my Orion UK 10″ Dobsonian telescope. Hitherto, I have been putting eyepieces on base below the scope with risk they fall off if I forget they are there and pick up mount to put it away at end of observing session. This new arrangement is much safer! I have drilled extra holes to install at front but there are also already holes available to install it both sides instead so I will see which I prefer in practice.


See also:

European Astrofest Day 1 – 8/2/2019

Astrofest 2019 Day 2 – 9/2/2019

Video from European Astrofest 8-9 February 2019

Making our own image intensified eyepieces

Making our own image intensified eyepieces

Andrew & Damian


This entry is a copy of an entry made in November 2009.

The commercial versions of these eyepieces cost £1500 ($2000) upwards…….here we describe how we made one for £50 ($80) plus some spare SLR lens/extension tubes lying around the house.

The main differences that we are aware of between the commercial versions and ours are:-

(i) Theirs has a higher resolution – not that we noticed at the eyepiece!

(ii) Ours has more distortion of the field – oh well you can’t have everything!

(iii) Theirs are a lot lighter…no getting away from that – our version requires a sturdy telescope/mount and 2 inch focuser.

What we are less sure of is:-

(i) Any difference in brightness? Possibly but the image intensifier we used is a 3 stage generation 1 intensifier that gives pretty bright images

(ii) Fun level – ours delivers on the fun side

(iii) Both image intensifiers can be used with an SLR lens without the scope – probably the best bit

(iv) Ours gives you the enjoyment and sense of achievement of having made it yourself

(v) Price difference – this is one aspect of ATM where there is still a really big difference in price between the ATM version and the commercial version!

Please note we accept no liability for damage or injury incurred from following our instructions (its just what we did) and we make no guarantee that this will work for you. Please let us know if you find a better way of constructing your eyepiece so we can update this website. You will need to source components – a difference image intensifier should work but you will need to modify the instructions. Plus – please note neither of us have had a chance to compare our version with the commercial versions.

We hope you have great fun making your image intensified eyepiece!

The two files below are both PDF files:



Andy & Damian


Observing Log 2/2/2019 @ 18:45-3/2/2019 @ 03:30. Damian and Andrew. Photos taken through the eyepiece

All following photos are through the eyepiece, mostly of the Orion Dobsonian telescope used during this session, but a few from the Tek 140 scope. Photos include photos through Explore Scientific or Ethos eyepieces, and through our homemade image intensified eyepiece on the Orion.

All photos were taken using Samsung S7 smartphone hand held next to the eyepiece.


Hubble Variable Nebula: The following two photos were taken through the image intensified eyepiece on the 10″ Orion Dobsonian Telescope:

M42 Great Orion Nebula: Image intensified eyepiece:

M42 Great Orion Nebula: Explore Scientific 20mm eyepiece on Orion Dobsonian:

Crab Nebula:


Double Cluster in Perseus: Image intensifier:

Double Cluster in Perseus: Explore Scientific Eyepiece:

M82 in Ursa Major: Image Intensifier:

M81 in Ursa Major: Image Intensifier:

The Eyes Galaxies at the end of Markarian’s Chain: Image Intensified Eyepiece:

M13 in Hercules: Image Intensifier:

Telescope sale

Hi folks,

am having difficulty handling these scopes now so am downsizing and selling these to a good home!!

9.25″ Celestron SCT with StarbrightXLT coatings. Including:

Antares F6.3 focal reducer

Antares 2” tube with twist grip

Celestron 1.25” star diagonal

Celestron 1.25” Visual back.

Celestron 9×50 R.A.C.I. illuminated finderscope.

Feather Touch focusser

JMI electrical focuser attachment for feather touch.

Telrad base

Vixen mounting bar, (has been on Skywatcher HEQ5Pro.)

Extra mounting bar on top.

AstroZap flexiheat Dew shield and controller.

Bahtninov mask.

£700 for tube and accessories.

Skywatcher 200PDS Newtonian Reflector. Includes:


Telrad base

Dew Shield

Skywatcher motor drive, can be easily connected / disconnected

from Dual speed Crayford with turn of allen key.

GSL 35mm extension tube.

Bahtinov mask.

£200 for tube and accessories.

If interested contact me on 01283716285 or see meat RAG on Friday.

Pete Hill



CCDSPEC Spectrometer/QHYCCD 6 camera – effect of turning on the fan

When I last used my CCDSPEC spectrometer with its QHYCCD6 camera, I was concerned about the number of apparent hot pixels appearing on the image. OK – it did not matter as the nature of the spectrum meant a few hot pixels were neither here nor there but still I wanted my new kit to work properly!

….Then I noticed that I had not been turning on the fan – so tonight I took pictures of the night sky (without telescope) using Nebulosity – with and without fan turned on the QHYCCD6 camera. The effect of cooling by this method is dramatic for these 30 second exposures as you can see below.

NB The spectrum of the night sky is just visible in the middle of each picture (30 second images).

All images from tonight’s session, including FITS files can be downloaded here:

QHY6 camera on CCDSPEC spectrometer – spectrum images of LRO night sky (30s exposure) without telescope – taken on 13/01/2019


With fan TURNED OFF:

With fan turned ON – only a couple of hot pixels remain:

Dark frame of fan turned ON: