You may not yet know our name, but it is quite possible you've used our product. Chroma has manufactured quality filters for worldwide professional and amateur astronomy markets since 1991. Our full arsenal of equipment from design to coating to analysis allows us to develop some of the highest T% and most durable filters on the market while maintaining reasonable prices.

Keep an eye out for our ever expanding line of catalog amateur and astronomy products.

For the amateur professional grade product at amateur prices 
Modifications can be accommodated, often at no extra charge.
TWF: _ wave/inch, 30arcsec parallel, sputtered (extremely durable) coatings, >93% peak T where it counts
Thickness 2 or 3mm

For Astrophotography or Observation

	FWHM	1.25" in ring	50mm round	50mm square
etOIII/8	8nm			$700
etSII/8	8nm			$700
etHa/8 (not solar)	8nm			$700
etOIII/14	14nm			$530
etH-beta/6	6nm			$850
etContrast/30
etSKYGLOW	Dual band			$935

For the professional: custom product, built to spec at reasonable prices
Contact Mark Kfoury:

 

U, B, V, R, I Filter Recipes (Bessel type)

U-Band UG1(1)/S8612(1)/BK7(3)

B-Band GG385(2)/S8612(2)/BG12(1)

V-Band GG495(2)/S8612(3)

R-Band OG570(2)/KG3(3)

I-Band RG9(3)/BK7(2)

 

Common Specifications

AR: Durable AR coatings on both exterior surfaces over applicable transmission range

Scratch Dig: 60/40 or better (max scratch width 0.006mm, max dig 0.40mm)

Transmitted wavefront @ 633nm: Better than 0.25 wave/inch
Wedge: Better than 30 arcsec

Thickness: 5 +/- 0.05mm, parfocal +/- 0.2mm, (filters start parfocal +/- 0.1mm per recipe)

Ring: These filters are not mounted in rings except by special request. Upon request, we will mount filters in black anodized aluminum rings, in customer-supplied filter mounts, or both typically at no extra charge. Please call for details.

Part Numbers
Single: filter 

Size (square or round) Single Set See size table for typical dimensions	Single		UBVRI Set Pricing
	U or B	V or R or I
24 - </=28mm	$137.00	$110.00	$575.00
>28mm - 32mm	$160.00	$135.00	$685.00
48 - 50.8mm	$275.00	$220.00	$1,150.00

Size	Actual Dimension (no ring)
25	24.95 +/- 0.05mm
25.4	25.35 +/- 0.05mm
28	27.21 +/- 0.05mm

 

Size	Actual Dimension (no ring)
32	31.95 +/- 0.05mm
50	49.85 +/- 0.05mm
50.8	50.75 +/- 0.05mm