ADJUSTABLE SUNGAZING GOGGLES
1: Some sort of set of goggle frames to hold the iris diaphragms.
I used a pair of ‘I Glasses’ with lenses that simulate an insect’s compound eye. I remove the lenses and use the frames and lens cups.
Edmund Scientifics Catalog #L31091-00 price: $7.95
Anther cheap possibility $3.95 MIT Eye Guard Goggles or
or check these welding goggles for usable frames
2: Two adjustable optical iris diaphragms
expensive on Edmund Scientifics ($50 approx)
I purchased on e-bay, 2 for $27.50 - 34mm outside diameter. Another source (also not cheap):
iris diaphragms from Rolyn Optics
On ebay.com, the cheapest currently (3-22-09) with the maximum opening 25 mm, minimum opening 1 mm
is $29 plus shipping from India,
This source has small-size (19 mm) for $19. Best price I’ve seen. but you may have to adapt to the diameter of the goggles' opening somehow
(these are about two-thirds of the overall diameter of the ones I used.)
Someone put together a very elegant set of variable-aperture antique-looking steamfitters goggles here
This site describes how to make a cheap set of costume goggles (without the diaphragms)