SVBONY Red Laser Collimator for Newtonian Marca Telescope Alignment 1.25 inches 7 Bright Levels Triple Cemented Lens with 2 inches Adapter

I've used this to collimate my dobsonian telescope, and it has increased the telescope's image quality. It's a permanent addition to my backpack of telescope parts, and doesn't take much space there either (although, it's easier to fit when outside of its box). Connecting this to the focuser is easy, and when turned on, the laser shows up clearly, and has different levels of intensity.I did notice that the dot that gets reflected back is less of a dot, and more of a wider circle, but it's still easy to tell when it's centred. It functions well for my purposes.

This device arrived with easy to understand instructions and was easy to calibrate my telescope mirrors. Great proct! Highly recommend!

Good range of brightness levels. Came reasonably collimated (adjustable). Works great with the Barlowed laser technique. Really easy and effective!Brightness: quite dim on the lowest setting to quite bright by the 4th or 5th.Collimation/alignment of the laser itself. I setup a fixture using Legos (great suggestion I read online), placed it on a granite countertop (tape the fixture to the countertop so it won’t move), and targeted the wall 6 meters away. The diameter of the circle traced on the wall as I rotated the laser on the fixture was 2 cm. Not bad but not perfect. This alignment (right out of the box) was +- 0.2% (equivalently +- 0.1 degree). For my 1200mm focal length scope, the targeting of the center of the primary would be +- 2mm; as reflected back onto the target on the laser (2x focal length): +- 4mm. (It could be adjusted better than that if I wanted to, but see below.)While googling to see if that alignment would be sufficient, I came across the Barlowed laser method. I tried it, and it works GREAT! I was very happy. Super easy and convenient!(Assuming your telescope collimation is pretty close, secondary ok, and you just need to fine-tune the primary, which is typically the case with a frequently-used and unabused Newtonian....)1. Put the laser in a 2x Barlow.2. Put the Barlow in your focuser.3. Turn on the laser, using a fairly bright setting.4. Observe the shadow of the primary mirror’s center marker “donut” in the target area of the laser.5. If the donut is already centered on the target, you’re done. Mine was about 1/4” off.6. Loosen the lock screws on the primary.7. Adjust the primary, turning one screw at a time to see where the donut shadow moves on the target. (You can see the target while at the primary end, so you don’t have to move back and forth between the primary end and the focuser like you would with a Cheshire or collimator cap.)7. When the donut shadow is centered on the target, tighten the lock screws, and you’re done.Quick and easy. Love the Barlowed laser method. Note: unlike with the direct laser method, the Barlowed laser method is insensitive to small laser collimation and positioning errors. So this works even with the laser alignment a little off.

I have had telescopes for years and always used a home made Cheshire Eyepiece for initial collimation and then an out of focus star to "tweak" that last tiny adjustments. When I saw the price of this laser collimation tool I decided to give it a try after reading a few reviews. The one I received was spot on collimated and required no fiddling with correcting the aim of the thing. It worked as expected and the variable brightness of the laser was a useful feature. As far as the "Collimate in Minutes" goes, yes, you can complete the process if your scope is not too far out of adjustment, but if you have had the mirrors out and replaced them it will take a little longer time. A center dot on the primary mirror is needed and easy to do. Several YouTube videos on adding the dot and using this Collimator. The only issue I have with it is the switch is sketchy. As you turn it the laser will come on at the brightness I desire but then it goes off. If I wiggle the switch it will come back on and stay on. I thought I may return it as defective but since it was shipped collimated correctly I do not want to take a chance of exchanging it for another one. I will just wiggle the switch. I will still use a star for the final tweaking but this Collimator is an excellent starting point. 4 Stars Overall

Well made, excellent tool and good value for the price

Works great was finally able to focus the telescope I got it for, used it once and it was like using a new telescope, sadly I have misplaced it and can't find it but I hope I do before I have to buy another one