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Updated 11/19/24
 

 
Dobsonian Goodies

Apertura/GSO motion/stability fix.
Apertura setting circles prototype
EZ adjust setting circles.
Height adjustment stands
 


Image Sharpening Masks
 
Visual: Fix turned down edge.     
Imaging: Remove mirror clip flare.
  

Premium Mirror Cells
for 6" to 13.1" mirrors.

Optimized support points.
Removes mirror-clip flarirng.

Imaging back-focus extender
Cell removes mirror-clip flaring.
 

Clamshell & Rotating Rings

For Dobsonian mounts.
For Equatorial mounts.
 
 
Favorite Links

Adventures In Deep Space
Golden State Star Party
Equatorial Platforms
 

Mirror Masks

12" and 6" masks shown.

Detail of flat black and gloss sides.

Fix Turned Down Edge (what is TDE?)

Standard sizes: for 6", 153mm, 200mm, 8", 250mm, 10", 304mm 12" and 12.5" O.D. mirrors.
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Custom/nonstandard size: select custom size masks entering the outside diameter (O.D.) and inside diameter (I.D.) required (up to 12.5" diameter and 1.5" wide) in the measurements box.

Imaging - removing diffraction spikes: see imaging masks.

TDE masks cover the mirror outer 1/8 inch, where TDE usually occurs. Construction: 1/8" thick black acrylic, stiff, light weight with a non-reflective matte side. Three 0.25" holes spaced at 120 degrees allow you to precisely center the mask at the mirror edge. Use double sided sticky tape or small Velcro adhesive dots to attach on top of mirror clips.

Standard sizes:
Mirror size:
Custom size:
Enter custom size:.

Prototype masked mirror clip intrusion.

Current design example 10" mask.
More on Turned Down Edge
See #2 How to improve image quality on masking mirrors .

"Turned down edge (TDE) Outside of proper parabolization, edge problems are the most common maladies afflicting mirrors. A turned down edge, or TDE, is a narrow zone, no more than 1/8 inch [3mm], at the extreme edge that turns downward, focusing long. If the zone is wider then it is called a rolled edge. Rarely the extreme edge will turn upward, focusing short. This is called a turned up edge." - Mel Bartels