When I reviewed the Celestron Landscout 12-36×50, I thought it was the smallest 50mm spotting scope available. Technically that’s still true. But about 10 years ago there was a smaller scope: the collapsing Bushnell Spacemaster.
The Spacemaster has a telescoping design (no pun intended) where the tube body collapses inside itself when stored. This reduces the overall length of the scope almost in half. This makes the spotting scope very convenient for travel where packing space is a premium. The scope comes in an old-school hard travel case with a compact folding tripod.
The optical quality of the scope is as good or better than any 50mm scope I’ve reviewed. I could see little or no chromatic aberration with good sharpness from center to outer edge of the field of view. Sharpness was among the best 50mm scopes.
Unfortunately, the scope was discontinued by Bushnell a few years ago. And as far as I can tell, no scope currently sold has the same telescoping design. I purchased mine used on Ebay for just under $100.
USAF-51 Resolution Test
Group 0: Element 1
SPECS
15-45X zoom plus 25x fixed power Eyepiece
Fully coated optics
Long Eye relief (14mm)
Collapsible spotting scope with 15 to 45x magnification
Telescoping design packs down ultra-small for travel
Fully coated optics produce bright, crisp views
Long eye relief; integrated window mount
Measures 8 inches long; weighs 22.8 ounces