Solomark Bahtinov Focus Mask for Telescopes 80mm-suitable for 80mm Diameter Telescope

Used this and it led to a "perfect" focus. Amazed at how easy it is to get a precise focus. Recommend you use with a camera having live view so you can adjust the focus while watching the diffraction pattern. The attached photo was from my first time use. Star = Altair and the telescope was an AstroTech 80mm EDT. The camera was a Nikon full frame DSLR (D750). I'm very pleased with the effectiveness of this product.

Still had drawing marks on it so they could make the cutouts. It didn't fit the OD of my dew shield which I had measured and ordered to fit. It did fit the ID, so I can make it work. One of the slots for the screws is not regular, the screw won't slip through the whole length of the slot. I would think with automation being what it is, it wouldn't be that hard to mass produce these with perfect dimensions. I recently used it and it does help achieve near perfect focus. Notice in the bahtinov star image that the diffraction spikes are not perfectly centered, I could have done better.

A very nicely made product...fragile, like all Bahtinov Masks, but not cheap plastic construction. Most importantly, it is adjustable to fit perfectly on my Orion ED 80 T CF...so, it should easily fit any 80mm scope. Makes focusing very easy. Good product...highly recommend it.

Excellent product. I use it with my Meade Series 6000 80mm scope and this is the second one I've ordered after I stepped on my first in the dark.

Not sure about other scopes, but this is too small for my orion ed80. Wish solomark was more specific about which common telescopes this mask fits.