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The Hadley is the perfect gateway to telescope building. A 6" packs a lot more punch in a not too much bigger package, and 6" f/5 consumer mirror kits that we
by chantepierre 1y ago
The Hadley is the perfect gateway to telescope building.
A 6" packs a lot more punch in a not too much bigger package, and 6" f/5 consumer mirror kits that we test often range from okay (0.77+ strehl) to actually quite good (around 0.92).
You'd get quite an improvement on planets !
- cchance 1y agoI've wanted to build one for a while, but seems theres not much info on the actual optics and which ones are worth getting do you have a list anywhere of where you had good results from?
- chantepierre 1y agoHey, I missed your comment. Nowadays the best source for optics is often a secondhand instrument where you scavenge the optics. If we specifically talk about a 6"f/5, most recent industrial tubes have really decent optics. Buying new optics online, avoid any ad where the price seems surprisingly low. For example you can find 6"f/5 mirrors advertised as lambda/8 precision. There's a lot of abuse with this denomination : some sellers use surface precision, whereas we usually talk about reflected wavefront, so lambda/8 becomes lambda/4. Then, there are a lot of ads for optics at great prices that aren't specified as parabolic (in the case of newtonian mirrors). Most often those are spherical, which is totally unsuitable except for longer focal ratios (and that quickly becomes impossible as diameter grows). On the other hand, I recently ordered a 40$ "lambda/8" spherical mirror, and it was a great sphere, so a great starting point to polish it to a parabola.