Astrozap Focusing cap w/ built-in Bahtinov focusing mask | Meade 10" LXD-75 Schmidt-Newtonian


Availability: More on the way

This Astrozap Bahtinov mask focusing cap fits the Meade 10" LXD-75 Schmidt-Newtonian, or any scope with an optical tube outer diameter between 280mm and 304mm . . .
Our Product #: FC10LXAZ
Astrozap Product #: AZ-411

Product Description

This Astrozap focusing cap with built-in Bahtinov focusing mask will fit the Meade 10" LXD-75 Schmidt-Newtonian, or any scope with an optical tube or lens shade measuring between approximately 280mm (11") and 304mm (12") in outer diameter. Check your optical tube diameter for certain before ordering.

The inside of the focusing cap is lined with soft foam to protect the finish on your scope or lens shade. Three nylon thumbscrews tighten onto your scope's front cell or lens shade to hold the focusing cap in place and allow the cap to fit the above range of scope diameters. When not used for focusing, the Bahtinov wheel can be closed as shown below allowing the focusing cap to be used as a dust cap for your scope.

The feature image below will show you a star's appearance in a Takahashi Epsilon 180 reflector as seen through the Bahtinov Mask. The difference in the focuser position between the almost-in-focus images and the sharply focused image shown below is very small, only a few tenths of a millimeter, showing the sensitivity of the Bahtinov focusing method.

Tech Details

Warranty 1 year


Review by:
As a guy who's making a serious attempt at astrophotography in the modern CMOS age, over the last two years of trying to understand it all in order to take great pics I've come to understand just how many differing things have to be exactly right to get a good image. Some of those things are difficult like mount tracking, telescope collimation, auto guiding etc.

Wouldn't it be great if there was an easy, inexpensive way to knock one of these critical path things off the list and get right EVERY time? Well there is and the Bahtinov mask is a godsend!

After all the setup is all done ultimately you have to take the picture(s) and all your efforts don't mean squat if you can't get your image in focus! Yeah you can buy a fancy focuser and a computer controlled motor focuser but now you're in for $1000; $60 seems much more appealing doesn't it?

The mask thing is simple, get all set up and balanced and find a bright star in the neighborhood of what you're trying to shoot. Put the mask over the scope and increase the gain on your camera until you see 3 diffraction spikes on opposite sides of the star. The middle spike will probably not be centered between the outer two; adjust your focus until it's as perfectly equidistant from the outer spikes as you can get it, lock the focuser and you can image in confidence that at least this one thing is taken care of.

Since I got the mask I can honestly say that I have never had a blown shot because of focusing issues.

Bill the Sky Guy (Posted on 11/22/2018)
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