Skywatcher Astrolux Finder Mod

[Les Ewan]

For its price and aperture the Skywatcher Astrolux 76mm f9.2  is a fairly capable instrument. Its let down by its supplied Barlow but  at just over £100 it comes with a pretty good steady full height tripod and altaz yoke.

This set up is hard to criticise given its price however the finderscope really lets what is generally a good piece of kit down badly.

The finder is supposed to be a 24mm  but has a aperture stop behind the  objective which is non achromatic and reduces it to only 12mm. Im actually surprised that a company like Skywatcher allows a junk scope finder into its range. 

It is also very difficult to align using the non sprung adjusting screws and is easily bumped out of alignment.

This finder is very frustrating and could be a hobby killer to newbies.

I found that if all three set screws are rack right up tightly the finder scope can be securely aligned permantly by packing the bracket /OTA contact point with fibre washers(first image).

The aperture stop is easily removed and have done this (third image). It will of course make the abberations on this dire finderscope even worse but it will brighten the image for star hopping.  

 

  

[Les Ewan]

Well I finally gave up on the Astrolux finder. It is usable optically once the aperture stop is removed( I really dont know why Skywatcher fitted the stop in the first place as the finder works much better without it).

However it is so infuriating to adjust and never stays in alignment between uses even with the mods I done previously.

Luckily I had a spare 6X30 finder and bracket kicking about. The stud holes in the tube match the bracket exactly so there was no drilling to be done,(wow something going right for a change)!

I got this scope primerly for solar work and its much easier for this task than a refractor. I took this image of a Sunspot group near the limb yesterday using a Nikon DSLR attached to a Celestron Duel Ultima 21mm plossl.