MIRROR COATINGS

(ALUMINUM COATING WITH A PROTECTION OVERCOAT)

(SEE NEXT SECTION FOR STRIPPING CHARGES FOR EXISTING ALUMINUM COATING REMOVAL)

DIAMETER

STANDARD ALUMINUM

ENHANCED ALUMINUM

4.25"

SAC425

EAC425

6.00"

SAC600

EAC600

8.00"

SAC800

EAC800

10.00"

SAC1000

EAC1000

12.50"

SAC1250

EAC1250

13.10"

SAC1310

EAC1310

14.50"

SAC1450

EAC1450

16.00"

SAC1600

EAC1600

18.00"

SAC1800

EAC1800

20.00"

SAC2000

EAC2000

Newport Glass Works coats other non-standard mirror sizes. The above chart was provided for standard size mirror blanks. Call for a quotation if you have a size that is not set forth above.

The above codes cover the aluminum coating of both the primary mirror and the secondary mirror used in Newtonian or Cassegrainian systems.

There is a stripping charge to remove the old aluminum coating prior to applying a new aluminum coating to the parts.

There is a protective over coat placed on the aluminum coating to seal from moisture and give it some protection so that it can be "gentle" cleaned from time to time. Just as your mirror’s current coating has become oxidized over time, so will the new coating oxidize over a period of years. The speed of this oxidation will depend to a great extent on how you handle it.

Selection Guide: Standard aluminizing usually results in a reflectivity of 88 percent or higher over the visible transmission range (450 nm to 1000nm). Enhanced aluminum coatings usually results in a reflectivity of 92 percent or higher in a narrow range of the visible light spectrum (the range selected is usually around 550 nm were the human eye is most sensitive). The reflectivity for enhanced aluminum usually forms a bell shaped curve centered at 550nm and then tapers off to less then 88 percent as the curve approaches the ultra-violet and infrared regions. This may affect the intensity of hues in both ends of the visible spectrum where it approaches the ultraviolet and infrared regions. As a result, photographs taken with standard aluminum coating may be better in these regions when compared to photographs taken with a system having mirrors with enhanced aluminum coating. In general, standard aluminum coating is sufficient for most applications.

If the fabricator is concern about energy through put on his/her system and if the his/her wants to maximum his/her funds that he/she has to invest in a telescope, than he/she may be better off selecting the standard coating and spending more money on the eyepieces. Within any given eye piece there could be 5 or more lens. Each lens surface (2 surfaces per lens) could lose up to 5 t0 6 percent of the light energy reaching it if it does not have a good anti-reflective coating on it, e.g., a 5 lens system could lose as much as 50 percent of light energy before the image reaches the viewer's eye.

RECOATING: STRIPPING CHARGES

(REMOVAL OF OLD ALUMINUM COATING)

DIAMETER RANGE

STRIPPING CODE

FROM 3.00" THRU 3.99"

RAC300

FROM 4.00" THRU 4.99"

RAC400

FROM 5.00" THRU 5.99"

RAC500

FROM 6.00" THRU 6.99"

RAC600

FROM 7.00" THRU 7.99"

RAC700

FROM 8.00" THRU 8.99"

RAC800

FROM 9.00" THRU 9.99"

RAC900

FROM 10.00" THRU 10.99"

RAC1000

FROM 11.00" THRU11.99"

RAC1100

FROM 12.00" THRU 12.99"

RAC1200

FROM 13.00" THRU 13.99"

RAC1300

FROM 14.00" THRU 14.99"

RAC1400

FROM 15.00" THRU 15.99"

RAC1500

FROM 16.00" THRU 16.99"

RAC1600

FROM 17.00" THRU 17.99"

RAC1700

FROM 18.00" THRU 18.99"

RAC1800

FROM 19.00" THRU 19.99"

RAC1900

20.00"

RAC2000

 

Other aluminizing services are available upon request.