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Meade standard coatings

Started by Phil Barker, 02/11/2003 08:40AM
Posted 02/11/2003 08:40AM Opening Post
Are these the same as the emc multi-coatings. I see an add with the seller saying they aren't.

Whats the story in a reference to the mirrors in my lx200 manuel it states the reflectence is around 94% which would mean more thruput than the standard coatings shown in the ads or its wrong?

Interested in opinions
Posted 02/11/2003 03:45PM #1
The trouble is that they tout so many numbers, and statistics in their advertising that nobody can figure out exactly what they are saying.

It would appear that the once 'great' standard coatings are now just terribly hopeless judging by the graphs printed in their advertising. It just depends on what they are trying to prove at the time.

I read somewhere that MEADE optics incorprate a thick layer of balonium as standard on all their scopes smile
Posted 02/11/2003 04:33PM #2
Hi Phil.

My understanding of the new UHTC vs. "standard" coatings is this:

Prior to UHTC, *ALL* Meade cats were supplied with EMC (i.e. none had "lesser" coatings).

Now, with UHTC being Meade's best, they also offer a "standard" coatings group. Meade's new "standard" coatings are not the same as their prior EMC. The standard coatings are less reflective/transmissive.

That's my understanding, anyhow.

Best wishes.
-Dan
Posted 02/11/2003 09:57PM #3
Mirror reflectence and throughput are different things. Reflectence (of say 94% for example) is totally dependent on the mirror coatings; i.e., of all the light hitting the mirror, 94% gets reflected. Now this light has to go through the corrector plate first; 94% of the light coming through the corrector plate gets reflected. If only (for expample, not an actual figure) 90% of the light is getting to the mirror (10% reflected back into space by the corrector plate), 94% of 94% (some light loss at each the primary and secondary mirror) of 90% would yield 79% of the total photons hitting the corrector plate actually making it 'through' to the eyepiece. These numbers are purely made up, just used to illustrate the surfaces involved. That's how you can have a reflectence of 94%, but a much smaller throughput. Please anybody correct me if my theories are in error.
Posted 02/12/2003 02:24AM #4