LP 110mm Refractor

[Max Vondel (Peter)]

Saw the LP, ED APO 110mm f/6 QUADRUPLET refractor with ED FPL-51+NBM51 lens and new heavy duty bearing type 2.7" 11:1 microfocuser! listed and Andrews comms..... Has anyone tried one of these refractors?

[brian nordstrom (As avatar)]

Not me , but going by its spec's it would be a nice scope , as good as any WO , SV or others at a better price .

Brian.

[MortonH]

Originally Posted by Max Vondel

Saw the LP, ED APO 110mm f/6 QUADRUPLET refractor with ED FPL-51+NBM51 lens and new heavy duty bearing type 2.7" 11:1 microfocuser! listed and Andrews comms..... Has anyone tried one of these refractors?

That scope has been on the Andrews for quite some time (years) so it's not new. I seem to remember reading some negative comment somewhere, but it may simply have been questioning the 'risk' of keeping four elements aligned properly.

Of course, now we have six-element scopes but their robustness in maintaining alignment over time remains to be seen.

[Nikolas (Nik)]

http://www.iceinspace.com.au/forum/s...d.php?t=117848
https://stargazerslounge.com/topic/1...apo-refractor/
Hope that helps

[ab1963 (Andrew)]

It seems from what I've gathered about the LP scopes is the weak link seems to be in the quality control department so what Morton is saying is probably right

[Max Vondel (Peter)]

Thanks for your feedback
Might try another WO

[Wavytone]

Morton more elements don't necessarily mean better optically, often they're not.

Frankly a Thomas Cooke 4.25" f/15 achro doublet made in the 1880's (my school had this work of art) craps all over the modem fast refractors when it comes to resolution and chromatic aberration at high power. The only downside was its size, and the size of the massive mount it has, together with tripod or pier.

The modern refractors are short primarily because of the size of the mount needed to hold a long OTA rigidly; it's a lot cheaper to make it f/6 or 7, on a small cheap mount, and stick a few more lenses inside than to use an f/15 OTA and the much bigger heavier mount and tripod.