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Nearly forgot.
Collimation - no more difficult than any other Newt I use. But I have modified the secondary assembly of the solid tube OTA as what comes out of the factory is poor in design and materials & the primary mirror cell is also my own build, and the other dob is totally my own construct. I check the collimation of all my dobs/Newts every time I use them, & find I need to do minimal tweaking of the collimation. No scope any more tweaking than any other.
f/4 any more difficult than say f/5? No. I find no difference.
f/4 any more critical than f/5? Again no. Initial collimation is always tricky with all Newts, but from then on no problem.
The BIGGEST problem is as I said earlier the design and materials used in mass production scopes is poor, and it leaves the secondary mirror poorly supported in the spider assembly and liable to shift as the scope moves about, and the primary cell is a compromise too. THIS is where I would say the problem lies, and not because the scope is f/4 or f/5. These movements can be small, but that's enough to cause problems, and if not resolved will prove a constant pain in the neck, and even people to say that these scopes are problematic. They are not problematic, just poorly built (mass production scopes) - there are thousands of pages written on "fixes" for these mass production scopes for a reason. This is a shame as the optics can be mighty fine.
Alex.
Last edited by mental4astro; 09-03-2020 at 01:13 PM.
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