Diameter 114 mm Focal Length 900mm Newtonian Reflector Mirror for Astronomical

Perfect for a fun project telescope. I bought 3 of these sets, one for my Dad, one for my youngest son, and one for myself. We used them in 114mm Hadley telescopes that we 3D printed the majority of the parts for. We have really enjoyed the views that these inexpensive mirrors have provided of the moon, and our planetary neighbors.

I had a bad experience with a different amazon seller- the ronchi test showed severe zones in the sphere, some of the worst I've ever seen. This mirror is great, with only slight undercorrection and some TDE at the edge- this is time consuming to remove and largely doesn't affect the view, and can easily be masked. In some cases, like this one, it may even be beneficial to have a slight bit of TDE (but it gets complicated). Overall this is a great buy for 30 dollars. Attached is my outside ROC ronchi test of this mirror, Blue, and a perfect ronchi test, black and white. You can be confident in this purchase.

The mirrors showed up perfect and worked great on my diy telescope, I even ordered a second set!

Used for a Hadley Telescope, worked very nicely. Very nicely packed and inexpensive.

I bought this after getting a very unsatisfactory mirror set from a different seller. This mirror, however, is excellent! The mirror has no visual abnormalities, and provides very clear images at all magnification levels tried. I highly recommend it of you're looking to build your first telescope, especially one of the Hadley design. The attached photo, taken on a cellphone through a 15mm eyepiece, doesn't do the live view justice but gives you a vague idea of what to expect. You won't be disappointed.

Both mirrors are in good shape.

The mirrors were clean and well made. Great for when replacing the old mirrors in my 114mm Newtonian.

I rebuilt an almost free goodwill reflector telescope using these mirrors. They were a perfect fit and an inexpensive way to bring a telescope back into service.