Free USPS First Class shipping has been taking as long as 3 weeks to arrive, for the reasons you are probably already aware of.
Please be aware of this when you order.
I have added the option to choose Priority Mail shipping for an additional fee at checkout, which does seem to move quicker through the USPS system.
A TriBahtinov mask operates under the same principle as the Bahtinov mask
for focusing and adds the ability to collimate scopes with collimatable
The design is based on Cytan's idea, documented on his Github site here, and the sketch was made using Satoru Takagi's Mask Generator.
I added a few minor tweaks. The 90deg angles have been rounded off which helps keep spurious star spikes down, and I beveled the edges of the slots for a sharper cutoff yielding better defined star spikes.
The mask has a raised center for an easy grip and comes in three sections that snap fit together and can be taken apart for easier storage.
A TriBahtinov mask can be used for SCT's, Ritchey Chrétien, and Newtonian telescopes. If you don't see your scope listed below I will be happy to design a mask to meet your needs.
2-3 day Priority shipping available also.
International shipping calculated at checkout.
Ships in 2-4 days.
Printed in durable, temperature tolerant PETG filament.
Please see Cytan's wiki page.
**For Hyperstar versions, the center hole accommodates the Hyperstar, and will not go around cameras that are wider than the Hyperstar body. In such cases the camera must be removed for installation and removal of the mask.