ED Megrez? How about it William.
Do you think you could bring out a "ED" glass version of the
Megrez 102 mm Doublet?
I have the 80mm SD now and I am VERY happy with the optical
quality of the objective lens. The optics in my 80 are truly
I really seems a shame for the optical house which provides
your lenses to put so much effort into grinding an accurate
surface figure, and then have the ultimate optical performance
limited by the glass which was used.
I would guess that a 102 Megrez at about $1499, with ED glass,
would get you about 90 percent of Al Nagler's TV 85 market
You could do the scope as a F6.5 to keep the compact profile
of the current Megrez.
Provide a two part double lens cap assemble with a precision
85 mm threaded cutout in the outer lens cap. This cutout
would be covered by a low profile high quality second lens
cap with side release tabs like those on the lens caps
used on a 35mm camera lens. This threaded cutout in the
outer lens cap would also be ideal for an 85mm partial
aperture solar filter.
When "stopped down" to 85 mm the optical system would be
working at F7.8 and would be a true APO by the standards
of scopes such as the TV85. This would only be needed
for objects like venus. In this mode the scope would
still out perform a TV85.
With ED glass, most work could be done at full aperture,
giving the Megrez a significant advantage in both light
grasp and resolution over the TV85. Even at this full
aperture the scope would show false color on close to
the same level as the Takahashi Sky 90 and could be
legitimately called an "APO".
At $1499 retail the scope would be about $500 dollars
more than the SD version which will more than pay for
the cost difference in the materials. (FPL53 blanks are
expensive but not THAT expensive).
Please don't poor mouth about how such a scope would be
much too expensive. Takahashi does a scope in almost
the same aperture (the sky90) using fluorite crystal
which is MUCH more expensive and MUCH harder to work.
Even given these difficulties, and the high labor cost
in Japan, this scope sells for only a little over $2200.
So if you can't do a ED Megrez 102 for $1499, you and your
Russian optical house are just not trying hard enough.
What do you think William? Can we expect to see an APO
"ED" version of the Megrez 102 Doublet in the future?
To everyone else in the group, chime in here and let
William know if you would also be interested in this
version of the scope. They could still offer the
current SD version as an option at a lower price,
but I think the ED version would be a really super