Bahtinov Mask, FP410H - fits Celestron 8" SCT with Hyperstar/Fastar. | Fast Easy focus for your astrophotos a lifesaving tool for focusing your astro camera or dslr.

I have had several of these and they work as expected. the best one i have has a thumb tab that makes it easy to remove, otherwise you have to pry up with your finders to get it off the lens.

I actually ordered this twice, by accident. The first time, I didn't notice the bit in the description about newer C8's needing the FP410H model. It arrived and I realized it didn't fit, then noticed this wasn't the correct model. My mistake. So, I searched Amazon for "FP410H" and this was the first result and flagged as "Amazon's Choice". In a hurry, I ordered again...guess I didn't notice the banner at the top indicating I'd ordered it once before. I realized what I'd done a day or two later and tried to cancel but Amazon was unable to cancel the order. When it arrived, to my surprise, it was the FP410H model...which is what I actually needed.Glad it worked out, just not sure how it worked out :)

I am another buyer where this piece did _not_ fit. Period. By the time I realized what had happened and managed to pry the thing off of the secondary mirror housing, my collimation was ruined and so was my evening. Wasted a lot of time re-acquiring collimation so I'm not that pleased. But since I did manage to get the mask off without further damage, I modified it based on other Bahtinov mask I have.Once I fixed that, the mask works great and so I am keeping it.Suggestion: Do NOT try to force this down onto the glass of the SCT, if it contacts or rubs against your secondary mirror housing, re-evaluate before proceeding.1. I opened the center with a round file to reduce contact to the secondary mirror housing.2. I rigged some soft stops to prevent the piece from dropping down again and wedging against the glass and housing. The stops sit on the glass surface and the mask is flush and square to the mirror, and _just_ _touching_ the secondary mirror housing at the edges.3. Also wrapped a few pieces of electrician's tape so I can pull it off with equal pressure, as this thing has a tendency to dive down onto the glass when you pull from only one end.Once you get past any fitment issues, the mask works flawlessly and it's part of the kit now.

Glad to have finally gotten this

The mask is great except one thing. The center hole is not large enough to fit around the HyperStar so you can use it if you are using HyperStar. 🫤

Works as advertised makes easy work of focusing

I had to sand out the center whole slightly to get it to fit around the secondary mirror housing as the scope I have is Fastar capable, other than that it works great and is made of study plastic.

Perfect fit! With the terrible weather here, I have not had a chance to try it out.

I read reiws that this model would fit Celestron 8 SE and that's why I bought it. This model does not fit around the secondary mirror well. I should not have to force it on the plate.