So I am about 99% of the way toward getting an Explore Scientific FirstLight 500/114 Newtonian, and I just wanted to know if there might be any issues with this?
I already have a 1000/114 Bird-Jones Newtonian, but the Bird-Jones design doesn't work well for high magnifications, and it is clamshelled onto a terrible mount that makes it very difficult to use (an altazimuth GOTO mount without a motor and no manual adjustment knobs). I have been considering all sorts of setups and telescopes to replace it, but I think what is going to work out best for me is something cheap, lightweight, and easy to use for afocal astrophotography with a smartphone or a point-and-shoot camera. Once I have more experience with afocal short-exposure imaging, then I can decide if I really want to get a DSLR and a tracking or GOTO mount to be able to do longer exposures.
Pretty much the biggest things going for this telescope are it's low cost and it's really wide field of view. I checked every telescope from Altair, Astro-Tech, Celestron, Explore Scientific, GPO, High Point, Meade, Omegon, Orion, Stellarvue, TPO, Vixen, and Zhumell, and apparently this is the cheapest telescope in the world (?!) with a 2-inch focuser. I could really care less about that (I only want to use 1.25" accessories), but I do need a telescope with a focuser lock to put up to 2 pounds of weight on the focuser with an afocal camera adapter and an afocal camera. Even with a 1.25" eyepiece though, the true field of view could be almost as good as my 7X50 binoculars, which is pretty impressive, so it should make a nice rich-field telescope in addition to being pretty good for planetary observing and afocal planetary/Lunar/Solar imaging.
As long as the telescope can see Comet Wirtanen (assuming the telescope arrives soon enough), ISS and Mercury transits, Solar/Lunar eclipses, and all 8 planets, I will be happy. I think a 60-mm refractor fits that bill. My primary interest is in Solar-System observing, so not really too interested in hunting down DSOs, but being able to see M31, M33, and some globular clusters would be pretty cool too. I think a 60-mm refractor fits that bill as well.
Especially for Solar/Lunar observing though (and Solar observing is one of my favorite activities), that big 51-mm focuser needs a big secondary mirror, which will reduce contrast. Just looking at the photos between a 500/114 with a 32-mm focuser and a 500/114 with a 51-mm focuser, you can definitely see the difference in size between the secondary obstructions. The 650/130 version would have a smaller relative obstruction size for improved contrast, as well as more clear aperture, and a slightly slower focal ratio for reduced coma. But the 650/130 Explore Scientific actually costs more than the 762/152 astrographic imaging Newtonian from High Point Scientific. So it doesn't seem smart to pay more money for less aperture (and the High Point would have enough backfocus for a DSLR, if I ever did want to remount to a GOTO for long exposures). And there is the rabbit hole that there will always be a better telescope for more money, so my philosophy is usually to get the cheapest one that works for what I want.
So should I be concerned about the loss in contrast with the 51-mm focuser on the 114-mm Newtonian specifically for afocal planetary, Lunar, and Solar imaging? Or should it be tolerable? The Orion 500/114 with a 32-mm focuser has a 30-mm secondary mirror, and I would imagine my 1000/114 Bird-Jones probably has something similar (even a 127-mm Orion Maksutov-Cassegrain has a central obstruction of only 39 mm). I get pretty sharp contrast in the 1000/114 at low magnifications, particularly for Solar and Lunar observing (which is pretty much all that telescope is good for).
My only other concern is the mount, and how difficult it is to polar-align without a polarscope (though I don't think that would matter in the daytime for Solar observing). But I am buying more for the OTA than the mount, and it comes with a Vixen-style dovetail, so I can easily remount it. But if I did have to buy a better EQ mount, then I might as well get the 6-inch High Point reflector maybe. Also not sure if I would need an extra counterweight if I am putting two pounds of accessories on the OTA? I read that extra ES Exos Nano counterweights are basically nonexistent.
I would also need a carry case. One of the biggest advantages of the 114-mm aperture is that I am hoping I can use my 114-mm Solar filter and my Meade StarNavigator 114/130 carry case for the Explore Scientific 114, without needing to buy a new Solar filter or a new carry case. Any idea whether I would need a new case for the GEM or if the case designed for the fork mount would work? I have to be able to carry the telescope up and down stairs and to and from the car to drive to an observing site, so having a good carry case for the telescope is extremely important.
Or could I be better off with a refractor instead?
Edited by Nicole Sharp, 06 December 2018 - 09:51 PM.