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"The Nightlight" by Eyes on the Sky is all about how to see things in the night sky, things you can build to improve your amateur astronomy experience, and general thoughts on astronomy and light pollution.
By Dave Fuller on 5/19/2020 3:35 PM
Something I see regularly on astronomy forums and on social media - and a question I get in person a lot - is the question: "What telescope should I get?" I often begin by pointing out that there is NO PERFECT TELESCOPE. Yes, the Hubble Space Telescope is amazing, but 1) you can't use it and 2) it's expensive. So unless you can afford to put your own space telescope up in space, it's not a perfect option, because cost is a factor. 

Also, it's in space. Breathing there is difficult, because lack of air. So how would you even use it? But I digress.

In this post, I am actually NOT going to recommend a telescope, because often what we need to do is think about some important things so that you can get the best success with whatever telescope you decide to purchase. And this will help you think about the things that are more important to you, and which ones you may be alright compromising on. 

The first, as I mentioned above, is price. Think about what you want to spend. Many people start out thinking...
By Dave Fuller on 5/19/2020 12:09 PM
Can I vent a frustration? This is a long semi-rant, and truly, I'm really not trying to start an argument (though it might, truly that's not the intention). Rather, I hope I can get people to think a little about how to better encourage people with minimal astronomy budgets, especially when it comes to discouraging comments I've read about the very low end budget telescopes.
I see lots of newcomers to amateur astronomy ask what telescope they can purchase for X amount of money. And invariably, one - or sometimes several - "more experienced" amateurs jump in and say, "You can't buy ANY decent telescope for under X amount!"
This is objectively *not* true anymore.
Perhaps that was the case for telescopes made 20 or 30 years ago (never mind decades before that). But today? Not the case. Oh, for sure, there ARE still crappy telescope options under $200 (heck, even under $400 for some things out there). But there are decent options too.
For one thing, the people who do that "jumping in" like that were the same type of person who complained for years that telescope manufacturers - making telescopes to a price point - made crappy telescopes that were on shaky tripods, had miniscule mounts, included bad 0.965" eyepieces, came with terrible finderscopes, and claimed "575 POWER!" with too-small optics - with, at least, a decent achromatic lens of f/8 mirror (often the telescope's only saving grace).
They had some valid points then. Heck, I was making those arguments too!
So telescope manufacturers responded. And they came up with telescope options that are not only LESS expensive, but addressed the criticisms: They have a solid mount, come with 1.25" eyepieces, have useful finders (if red dot in style rather than magnified) and don't try to claim huge magnification as a selling point - AND the optics are at least pretty acceptable.
Isn't that what you wanted? Now keep in mind - people have budgets, so telescope makers are making some telescopes to HIT that price point. But what happens?
The criticizers from before now say, "OMG! The COMA in those little tabletop reflectors is AWFUL! It's a SPHERICAL mirror! You can't see ANYTHING in those! And there's NO COLLIMATION possible! You can't buy ANY good telescope for under X money!"
Again, all of this is objectively untrue. (Okay, the coma *is* severe, but more on that in a moment.)
See, it bothers me that people get jumped on for pointing out these little scopes have some pretty good benefits for low budgets - or dismissing them as "not good" because they are under $200 or $100.
For one thing, they are larger than the 50mm and 60mm refractors (and even 70mm ones). So the newbie gets APERTURE. What do you need to see more in the sky? Aperture! That was a criticism before, right?
Oh, you can't collimate it? So? Many of these tabletops are good *because* they don't require collimation - that's what some touted as being good about refractors before. Collimation is a skill that isn't for everyone - so less fiddling with the optics is perhaps better. Oh, the collimation is off? Okay - usually it's minor, at worst.
The red dot finders are at least useful (unlike the atrocious 5x24's that were often worse than not having anything at all), and while the eyepieces are often Huygens, in some cases, they are at least 3-element Kellners - that was a GOOD eyepiece just a couple decades ago. And remember - price point! You're not going to get a $100 telescope including two eyepieces that are $50 or $60 new.
All of those are IMPROVEMENTS on the criticisms you leveled previously.
And coma? Big. Freaking. Deal. YOUR 10" f/4.5 or 16" f/4 has coma! Where do you observe when looking through the eyepiece? At the edge? No. In the center, where there is what?
No. Coma.
(Yes, you may have a coma corrector for that. How much did that cost?)
And, about that aperture again. I've seen M1 in my 76mm Funscope. I've seen M81 and M82. Faint? Sure. But M13, M92, M11, M6, M7, M22, M27, M57, M31, M42, Double Cluster, ET Cluster - all EASY! Could I see Saturn and Jupiter too? Yes. Are they small? Yes. Did I need a 3x barlow to see those well? Yes. But so what? They're small in any telescope limited to 150x on a given night due to the atmosphere anyway! For $100 or $120 ($60 telescope + good 3x barlow), I can get a telescope that can get me EXCITED about the night sky, because the telescope is at least USEFUL and will show objects in the sky.
How is that bad? Have you *really* used one? I don't mean, "I looked through it and saw the coma sucked." I mean, "Have you used one and tried to get the most out of it to see what OTHERS might be able to get out of it if their budget is small?"
EVERY telescope has trade offs somewhere. Even your best, most awesome, "I love-this-telescope-and-will-never-sell-it-EVER" instrument has trade offs. If it's not aperture, it's price, or the weight, or the coma, or the fact that your telescope is not Hubble and above the atmosphere or doesn't have adaptive optics... your telescope has trade offs too.
For some, especially newbies with small budgets, it's very often three things:
The price.
The price.
The price.
So if you have never used a little tabletop - or even if you have - can we at least appreciate and encourage newbies who have very limited budgets with these? They are FAR better than the crappy 50mm alt-az refractor I got some 30 years ago and somehow managed to find and see things with.
Are the tabletop reflectors perfectly ideal? No. Are they are 6" f/8 or 8" f/6 Dob? No. But they are 1/3 to 1/4 those prices and as such an amazingly budget-friendly entry point into this pasttime/hobby/passion we all share. Some people don't have the budget you do - or aren't sure they want to spend $300 or $400 yet. And learning on a small telescope that is at least useful and affordable will help them learn what those optical aberrations are, and how to choose perhaps a better telescope later.
Let's encourage people with limited budgets, not berate them. Yes, I get that we should try to push budgets up if possible. Let's get newbies excited about what they CAN see and promote the more useful budget options out there.
And maybe buy one yourself for $60 or $70. When we aren't social distancing and can actually do outreach again, they are a GREAT way to let small children use/move a telescope, aim it at the Moon, and not worry about them breaking it. Want to get KIDS excited? Get a Funscope or Firstscope or other tabletop option. Try it. Use it. Push yourself to see what YOU can see with it. Seeing a kids face light up that not only can they look through the telescope but MOVE it and USE it can spark a lifetime of interest. Plant that seed, outreach-person. That's a small investment. And you might come to appreciate how good these little 'toys' are (and are more than a toy) for people on a very limited budget.
Okay, long rant over. And remember, I'm trying to encourage us to think differently about those "lower budget" folks, and to think differently about how we respond to their queries rather than saying there's "nothing" good under $100 or $200. Don't be a snob about optical perfection. Be encouraging about whetting a beginner's appetite for a lifelong passion of exploring the night sky.

By Dave Fuller on 4/20/2020 7:52 AM
One of the things I really try to do well with Eyes on the Sky is share good, factual information about what can be seen well in the night sky, by most amateurs. Are there a lot of faint things that could be seen that I overlook? Yes. Are there are lot of not-so-great things that get hyped by some media sources of people looking to boost their views or clicks or whatever? Yes also. As such, somewhat frustratingly, I have recently seen one making the rounds with a headline saying unequivocally "We will see 100's of meteors per hours!"

This is just plain FALSE. 

So perhaps it goes without saying that nothing annoys me more when I see plainly sensational language used to describe astronomical happenings. This latest one - which I see nearly every year - is the Lyrid meteor shower. We may see that many Lyrids - IF - there is an outburst, which will only happen IF we are very lucky to go through a particularly dense stream of particles which is not likely to happen this year.

Some facts To provide...
By Dave Fuller on 11/21/2018 7:32 PM
PLEASE READ this information carefully as it takes into account a lot of different factors for many differing requests. If you really don't like to read or watch the video and just want an answer RIGHT NOW, skip to the end for the TL;DR info. Also, when asking a telescope question, start a new post so everyone sees it; otherwise it will get lost in the comments here about this particular post.

Beginner telescope options First, I would strongly encourage you to learn about telescope types, accessories like eyepieces and barlow lenses, plus how to calculate magnification, understanding telescopic and apparent field of view, and the types plus how to align a finderscope. So that equatorial mounts are not confusing, you can also learn how to align and how to use an equatorial mount will help make those kinds of mounts more easily understood as well. You'll be better...
By Dave Fuller on 1/30/2016 2:36 PM
The last couple of weeks have a number of articles on the five naked eye visible planets in the morning sky. A lot of them are well meaning, but don't offer much help in the way of assisting the observer in identifying the stars AND planets visible, or specifically when and where to look. 

I created this chart to specifically tackle that issue. You can download the five planet identification guide here. Also, check out the homepage for a video on finding the planets, along with other great "how to find it" videos. 

On January 30, 2016, I took a photo of the sky with these planets in it (see below) Although the Moon was near Spica then, it will move towards Mars, Saturn and eventually Venus and Mercury by February 6th. 

Five naked eye planets in sky, January 30, 2016...
By Dave Fuller on 12/30/2015 10:41 AM
Don't give up! Telescopes seem like they are easy to use - just point it generally where you think the object is you want to see, and it should be visible in the eyepiece, right? I mean, that's what we do with our phones and cameras - just point it, and "Boom!" - there it is!!

So why isn't a telescope so simple? What are you doing wrong? 

There's a few things that beginners may not realize they're doing. Here's how to find things more easily with a telescope your first time out. 

1) Make sure the mount and tripod are steady

This is easy to overlook, but it is VERY important. Your telescope only shows a very narrow slice of the sky, even at low power. Keep in mind, if you drew a line from horizon to horizon, that is 180 degrees. Your telescope only shows 1/180th of that line, at low power. So even very small movements of the tripod or mount will appear to be HUGE changes in the eyepiece! Think about zooming in a camera all the way, without using a steadying feature to smooth out your...
By Dave Fuller on 9/8/2015 8:08 PM

Check out the slim crescent Moon as it first appears above, then in between, the planets of Mars and Venus in the eastern morning sky. This video shows when and how to see the planets and Moon together. 


For more on what you can see, check out the blog's past posts, or the home page for the most recent video(s). There's also info on basic stargazing and how to understand telescopes

By Dave Fuller on 9/8/2015 7:55 PM

Composed of three stars, in three different constellations, the Summer Triangle is really just a convenient way to look for Cygnus, Lyra and Aquila in the summer sky. How to find it at this time of year? Easy? Check out this quick 30 seconds long video:

For more on what you can see, check out the blog's past posts, or the home page for the most recent video(s). There's also info on basic stargazing and how to understand telescopes

By Dave Fuller on 9/3/2015 8:12 PM
Today, I saw this question on the astronomy sub-reddit:

If the Earth is moving at 30 km/s around the Sun, and the Sun is orbiting the center of our galaxy at about 200-250 km/s, and our galaxy is moving relatively to the Local Group where it orbits, and the local group moves around the Virgo Cluster - How do the stars stay so consistent in the sky?

I don't particularly think I'm all that smart when it comes to astronomy. I mean, I know how to find things in the sky. I understand what they are, in a very general sense. I know a lot about telescopes, and a fair amount about how they work. And I understand cosmic scale, which is towards the edge of my understanding. 

So when I see someone struggling with a question, I will do my best to respond to it in a way that I'd like to see it answered - that is, give me something I can relate to in the response. It's the only way I'll grasp the concept fully. 

So here was my answer to the question (lightly edited for clarity):

The mountain...
By Dave Fuller on 9/2/2015 8:43 PM

I point Saturn out to them with a green laser, or say, "It's just to the right of that bright star," and their surprised reactions like, "Really? That's it, right there?" tell me that they didn't know it was so easily seen. I mean, it's a naked eye object, and has been for as long as humans have looked up at the sky.

How to find Saturn, September 2015

So try something: Share this graphic. Let people know how easily they can see Saturn right now, this week. Let's see how many people we can educate about some of the simpler-to-see celestial sights. 

The Nightlight

This blog includes what to see in the night and daytime skies, thoughts on telescopes, binoculars, and other astronomy observing accessories and equipment, plus my own occasional notes on objects I've seen and observed. Oh, and the random theater or other "my take on life" post. In other words, there is always something interesting. Check it out.