Hey all,

A few months ago I mentioned to some of you about a focusing mask I made to assist my CCD camera focusing. And I must say this mask is amazing! I can achieve perfect focus (perfect in my eyes) in 30-45 seconds with no guess work…

The inventor of this wonderful tool is a respected Russian Astrophotographer Pavel Bahtinov (any one speak Russian?) and he deserves all the credit.

It is easy to make, mine was made from foam board material and then spray painted flat black. I think I have around $6.00 invested. Looking at the attached picture you will see that it does take a little effort with a knife, but it is well worth it. And if you think it would be too much work or don’t have the time… search the web and you will find vendors ready to take your order.

How does it work? Like most other masks. I simply place the mask in front of my secondary using cut pieces of weather striping so that it fits snug in the OTA, just like the dust cover. I slew to a star, if I haven’t already and use the zoom tool on my capturing software, adjust focuser and in seconds I’m done and ready to snap some DSO’s. This can be used for visual as well, but one needs to find a nice bright star.

If anyone is interested in making their own, I still have foam board left and will gladly let you have some at no charge.

You can also download a Mask Generator it will calculate the slot widths according to aperture size and enable you to print your own template.

I’ve attached some images of what exactly you’ll see on your monitor, laptop or EP

Intrafocal

Focus

Extrafocal

Cool tool, Larry! That sure looks like it would make focusing easy.

Larry,
Great article - thanks.
I can't print the mask overlay 'cause my printer can only handle 8X11, which isn't large enough for my 8", probably stuck with doing the "commercial" thing - shucks!
Warm regards,
Mike

We could make them out of cast iron and sell them as "Manhole Covers"

He...............He...............

Are you implying that my newt is a sewer pipe? LOL Good one Leonard!

Hello there.Nice to meet you again guys.It is easy to make, mine was made from foam board material and then spray painted flat black. I think I have around $6.00 invested. Looking at the attached picture you will see that it does take a little effort with a knife, but it is well worth it. Please try it at home!!!!!!!!!
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