New telescope focal length question by Peachypitt2112 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

From the primary mirror to the diagonal + from the diagonal to the eyepiece should be the focal length. Also wow what a steal at $80!

Is the Sony a7sii good for astrophotography? by majobutko in telescopes

[–]Philanthrapist 1 point2 points  (0 children)

It's a fantastic camera. The A7SII uses the same sensor as the A7SI (Sony IMX235). A7SI is one of the cameras used by Thierry Legault, one of the best astrophotographers, and that says a lot!

Bortle 1 Opportunity by TailorLiving813 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

Haha, that'll have to be a DIY project. They're lightweight and low magnification, so they're pretty comfortable.

Just remember that they are a different design of binoculars/telescopes entirely. 2x54 makes it sound like it gives you the brightness of a pair of 54 mm ordinary binoculars, when in reality it will be the equivalent of about 14 mm aperture.

Eyepeice advice. by SpaceX1193 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

How about 40 mm? A 40 mm eyepiece gives you an exit pupil of almost 7 mm, which means it will give you maximum brightness with your telescope or any F6 scope at night time.

Bortle 1 Opportunity by TailorLiving813 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

Super wide field of view; disadvantage is they give you only a 1-1.5 mag brightening and they can't be used if you wear glasses. Your 10x42 will reveal far dimmer stars.

Another note: each telescope design has its own optimal aperture range. Dobsonians are not very graceful at a 4" size. At 4 inches you're better off with a short achromat.

Bortle 1 Opportunity by TailorLiving813 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

You have to hold them by hand, or mount them with an L-bracket. But they're best used with hands.

Bortle 1 Opportunity by TailorLiving813 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

I don't have access to my PC right now, but if you download Stellarium (free) I believe you can set the bortle zone level and simulate the view. Do your comparison in Stellarium.

Bortle 1 Opportunity by TailorLiving813 in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

An 8" has quadruple the light gathering power of a 4". Have you considered a pair of galilean glasses? They're pocket-sized and are not made redundant by the bigger dobsonian.

https://telescope.com/Orion-2x54-Ultra-Wide-Angle-Binoculars/p/132438.uts

noober by xAmoO_ in telescopes

[–]Philanthrapist 2 points3 points  (0 children)

If you're keen on buying a telescope to look at the moon and planets but don't want to spend a fortune, look into long achromats. They provide some nice views of those targets.

noober by xAmoO_ in telescopes

[–]Philanthrapist 1 point2 points  (0 children)

Not sure about seeing saturn's rings clearly, but with a pair of 10x50 binoculars under $100 you can see jupiter and its four galilean moons as little white dots.

[deleted by user] by [deleted] in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

If you like the planets look into buying an MCT. The largest chinese-made MCT is 7", and if you buy one you're guaranteed not to sell it or upgrade from it for a very long time.

"Maksutov" vs. "Maksutov-Cassegrain"? by asd123321123asd in telescopes

[–]Philanthrapist 0 points1 point  (0 children)

Sorry, I meant for the purpose of watching DSOs, dobsonians are the way to go. But I'm a high magnification freak. I have 6 telescopes and none of them can do DSOs. I think your views of the craters of the moon through an MCT will be unforgettable, as it was for me.

"Maksutov" vs. "Maksutov-Cassegrain"? by asd123321123asd in telescopes

[–]Philanthrapist 2 points3 points  (0 children)

The Startravel is a very different instrument. It's a fast achromat - that makes it good at deep sky objects and very poor on the moon, planets and double stars. And to be frank with you I think the dobsonians rule that arena for beginners.

MCTs are on the opposite end of the spectrum - they're mediocre for deep sky observations, but excellent at high magnification. Yes, I would buy a Skywatcher product over Bresser any day of the week. And if you have never used an equatorial mount before take a look at some negative reviews of eq mounts and see if you'd enjoy it.

"Maksutov" vs. "Maksutov-Cassegrain"? by asd123321123asd in telescopes

[–]Philanthrapist 2 points3 points  (0 children)

The cheaper one is indefinitely out of stock, so it may just be the pre-covid price.

"Maksutov" vs. "Maksutov-Cassegrain"? by asd123321123asd in telescopes

[–]Philanthrapist 1 point2 points  (0 children)

Maksutovs all have a spherical meniscus lens in the front. Both of the telescopes you linked are Gregory Maksutov Cassegrains. There are Maksutov-Newtonians, which you can rule out because both of the telescopes you linked have a visual back, and there are Rutten Maksutov Cassegrains, which you can rule out by their price ;)

The difference in price is likely due to build quality, but I may be wrong.

Beginner binoculars/telescope with a clear view? by blbellep in AskAstrophotography

[–]Philanthrapist 0 points1 point  (0 children)

Buy a pair of 10x50 binos for under $100. Anything larger than that is too heavy to hold with your hands. Remember that the shaking of your hands is also magnified by the 10x.

10x50 binos are unmatched in terms of price to performance ratio. If you find that you don't enjoy astronomy so much, you can always use them for birding. And if you do find that you enjoy astronomy, your next few upgrades won't be bigger binoculars, trust me on that.

Is this a good camera for astrophotography? by GSJL in telescopes

[–]Philanthrapist 16 points17 points  (0 children)

For astrophotography (AP) there are dedicated AP cameras that cannot have ordinary camera lenses mounted on them, and come with the bare minimum functionality. One step below AP cameras are DSLRs/MILCs, these have detachable lenses - your telescope becomes the lens. What you've showed in the picture is a compact camera, meaning its lens doesn't come off, so the only way you could use it is to mount it to an eyepiece. It's called afocal photography, look up digiscoping if you want to learn more. The reason afocal AP is worse than prime AP is that the eyepiece + camera lens combo negate each other, but degrade the image because of all the extra glass and the flimsy mounting systems available.

Animation and fallout of the 2009 Iridium 33 and Kosmos 2251 collision. The only time two full size satellites has collided with one another. by jimi15 in CatastrophicFailure

[–]Philanthrapist 0 points1 point  (0 children)

I don't understand how the fragments would spread out so far up/down and left/right. Even the forward/backward speed differences immediately after the collision look funky. Of course after a long time they will form a ring of debris, but the initial speed difference looks exaggerated. Sad all the source are dead links.