Astrozap focusing caps with integrated Bahtinov focusing mask.

[FLO]

Unlike a simple Hartman or Bahtinov mask, the Astrozap Bahtinov Focusing Cap is a multi-purpose tool which allows for quick 'shutter-like' operation. Just turn the wheel to the open position for focusing, and then turn it again to the closed position to keep the dust out, or to image dark frames with your CCD or DSLR camera.

The focusing wheel can be easily removed and replaced with an off-axis wheel for regular observing or an off-axis solar filter wheel for solar viewing on larger telescopes.

• Simply turn the thumbscrew to the open position, and turn to close.
  
• No tools or plastic plugs required.
  
• Additional wheels are available (coming soon) for regular off-axis viewing and off-axis solar viewing.
  
• Available for a wide range of telescope apertures, up to 14-inches.
  
• Manufactured from from lightweight aluminum and black-texture powder-coated.
  

Our first delivery is due in approx two weeks.

Please see our website for up-to-date prices.

[Psychobilly]

Very Neat,

Good luck with them ...

Billy...

[FLO]

Thank-you Billy

[centroid]

So what's the principle of operation Steve?

Its a Hartmann Mask, with three areas of Bhatinov Mask pattern showing through the holes.

So, are we going to see the standard out of focus, three star image of the Hartmann, but with stripes?

Or, are we going to see a full Bhatinov pattern displayed?

Dave

[Kai]

Dave there are some images here

http://www.astrozap.com/pages/astro-caps.htm

[FLO]

Yes, when it is very out of focus it looks like a Hartman but as you approach focus you see the characteristic Bhatinov patterns.

[Dangerous-Dave]

Great idea that. A lot more marketable than Bahtinovs which are matched to individual OTAs.

[Psychobilly]

I Wonder why there was so much discussion on other forums about the need to accurately match slot widths etc to the focal lenght of the scope ... must have been a load of codswallop...

At least I wont have to spend anymore time on the CAD in the evenings...

The US prices represent very good VFM...

Billy.....

[FLO]

The US prices represent very good VFM...

Yes, and if you factor in Duty, VAT, shipping, then convert to UK pounds, they are within a £ or two of FLO's prices

[Psychobilly]

Indeed they are...

Those little extras that people tend to forget about when comparing prices both sides of the pond.... Thats one thing you can rely on from FLO great value as well as superb service...

Billy...

[centroid]

Thanks Steve and Steve

It certainly seems like an interesting/innovative approach to the focus mask scene.

I'll be very interested to see how one one these 'stacks up' against a Bhatinov mask that is 'custom cut' for the scope.

Having now made two 'custom cut' Bhatinov masks, one for the 80mm APO, and another for the 12" LX200R, I reckon it would be worth buying one for the smaller scope, to compare it.

If its as 'good as', then perhaps one for the 12" too, as these masks would be a lot more durable than my homemade ones.

Dave

[Reggie]

I thought the point of a bahtinov mask was to give back some of the light grasp and better accuracy than a hartmann mask? so with those holes and the bahtinov slits its got even less light grasp than a hartmann?

[FLO]

I think we'll find there is enough light grasp for the mask to work its magic, even on the smaller apertures