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PEGASUS OPTICS Frequently Asked Questions |
Question: Why do you now recommend >95% Enhanced EAL coatings? (You didn't before)
Answer: We feel strongly that our coater's advances in this technology produce a coating that is noticeably superior in all aspects, and produces visibly brighter images than a regular, protected aluminum coating. We feel so strongly about this that we include this coating in the cost of the mirror, although it is more expensive. Recently, our coating provider, Spectrum Coatings, introduced a proprietary enhanced coating process that produces greater than 95% average reflectance across the visual spectrum. This coating has been calibrated, proofed, and used extensively by our customers, with favorable comments about its optical performance. It is produced using a process that insures maximum surface mobility at low-temp/high energy, and is consequently very smooth, dense, highly oxidized, and more durable (not less) than regular coatings. These coatings, in spite of their hard, durable nature, are chemically strippable, although it takes longer to strip because of its integrity. It is important to note that mirrors that are coated by a multilayer dielectric, or have a hard metallic primary layer, may not be chemically strippable, necessitating regrinding, repolishing and refiguring of the mirror. This destroys the figure, and rework costs exceed 1/2 the acquisition cost of the mirror.
Question: What if I'm not convinced and prefer to stick with a standard 91% coating?
Answer: We'll give you a reduction in price of $50 for 16 - 18" mirrors, $75 for 20-22" and $100 for 24" mirrors. The PAL coating with quartz overcoat is still as good as ever, and we'll have it coated with this regular coating if you wish.
Question: Can you make my mirror more accurate than your usual standard for additional payment?
Answer: No. We do not accept additional payment for tighter figuring because the work we do is as tight as any in the industry (and tighter than most. We found through that experience that a 1/10th wave wavefront peak-valley or 1/36 wave RMS is repeatable, however, improvements beyond this point are theoretical and not visible at the eyepiece.
Question: Do you do testing or refiguring?
Answer: Yes. Before we test your mirror, we'll discuss the problem with you and attempt to isolate other factors that may cause the problem besides the mirror, including support and collimation issues. We charge a $75 fee for testing, plus $25 reshipping fee for mirrors up to 16", $50 for 18"-22", and $75 for 24" mirrors. We'll give you a report on the mirror's figure, and an estimate of cost of refiguring/recoating. If you decide to have the mirror refigured after test results are available, we'll credit your refiguring account with the amount of the check for testing and reshipping fees. Only after you give us a go-ahead will we strip the mirror's coating and refigure it. When we refigure your mirror, it is refigured after the current backlog of production is finished, which typically results in a 90-day or shorter turn-around back to you. We complete initial testing within a day or two of receipt of the mirror, and if you decide not to have the mirror refigured, we get it back to you within a day or two, or forward it to the coating lab for recoating as you indicate. (It is not necessary to strip the mirror's present coating in order to complete its testing.) We now recommend the >95% coating for your refigured mirror, at additional cost, although you can opt for a 91% coating.
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PEGASUS OPTICS
16426 Martins Ferry
San Antonio, TX 78247
(210) 267-9937 | | |
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