Rigel Systems A-line / Aline 1.25″ Collimation Cap



The Rigel Aline Collimation cap offers a convenient and affordable means of collimating a Newtonian telescope.

If you simply look down the focuser drawtube it is hard to tell where to place your eye. If you look Into Your telescope through an Aline and you will see a bright white circle surrounding your eye’s pupil, making it easier to center the primary and secondary mirrors.

Fits firmly into the focuser and features a convenient highly reflective inner surface.

Includes instructions.

User comments

“Very easy to use, makes misalignment obvious instantly. I find it much simpler to use than any Cheshire or combination eyepiece with crosshairs.  If the primary mirror is centre marked then it’s a doddle. I’d note that the hole on the cap is slightly off centre yet no matter how I turn it in the focuser the ‘off centre’ reflection stays within the centre mark of the primary mirror so it works fine for me.” – Tamas

“Cheap, easy to use and very effective. My new scope needed a slight adjustment which only took a couple of minutes with this collimation cap. Highly recommended.” – Gary

“Simplicity itself. Having tried the laser tool that turned out to be useless as couldn’t collimate that tool ad incoherent light I tried the Cheshire tool. Having looked at a useful YouTube item on collimation discovered the Collimation cap. After receiving this tool I was able to accurately collimate my reflecting telescope in minutes. So much value in a modestly priced tool.” – George

“Does a good job – Easy Collimation checks and adjustment of my SW200PDS.  Simple and easy to use collimation cap, saves making your own and this comes with very good reflective underside to make collimation alignment easy in mirrors. I use this for very quick check before each viewing session” – Michael

“Really good!  I’m new to astronomy so finding out that my newtonian needed collimating at first frightened me, so after much research I discovered a laser collimator and paid a small fortune for it and it just complicated maters, so looking for a simpler answer to collimation I came across the Rigel Aline and was surprised on exactly how simple it was to use and the results were fantastic and at a tenth of the cost of the laser.  I couldn’t recommend the Rigel Aline enough” – William

“Collimation made easy – i lived in fear of collimation , then i bought a collimation cap, so straight forward to use, i highly recommend this cap.” David

“Better than a laser – I have a premium Premium Cheshire also, but this thing is actually better at a 6th of the price for quick collimation. I use it on a Sky-watcher 200p Dob, and all that is required (once you have your secondary square) is to point it at some blue sky and make sure the cycles are concentric.  Love it!” – Johann

Questions?  Call us on 1300 ASTRODOG or just use the form!

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Additional information

Weight .5 kg
Dimensions 22 × 9 × 10 cm