Showing posts with label Observing equipment. Show all posts
Showing posts with label Observing equipment. Show all posts

Thursday, March 20, 2025

How much does amateur astronomy cost?

Astroboy and stack of Benjamins
tl;dr: It costs whatever you have to spare that you want to invest in it.

I was recently reading a thread on the Cloudy Nights amateur astronomy forum in which the poster was complaining how some people are always claiming how expensive amateur astronomy is, when it "really isn't." These threads pop up periodically, and usually follow the same course. (Above: Andrew Magill from Boulder, USA, CC BY 2.0, via Wikimedia Commons; Astroboy by Astronomerica)

First, let me comment that many of the most frequent posters on Cloudy Nights seem to mostly be retired engineers, white collar skilled workers, or successful retired "boomers" (full disclosure: I am a retired "boomer") who have fairly large disposable incomes. Often someone will state that compared to expensive motorcycles, high end photography, golf memberships and green fees, high end gaming, skiing equipment and lift fees, and the like, amateur astronomy is cheap. Well, if you look at it that way, it is. Until you buy land out in the boonies and build your own observatory to house your 6" refractor imaging rig. But most of us will never have the money, opportunity, or life situation to do that.

Eric observing with his Tasco telescope
But how about those people, and not just kids, who don't have thousands or even hundreds of dollars to spend on a hobby? I remember when I lived in a 24' travel trailer, had a minimum wage job, and thought that buying a 4.5" Tasco 11TR department store reflector for almost $200 was a huge splurge—and it was for me. By the way, I did start out with $20 Tasco binoculars before I could afford the telescope.

I grew up being frugal and I still am as a matter of principle. Even if I can afford something more expensive, I like to see how much enjoyment I can get out of a less expensive option. That extra 300% in price often only buys a 10% improvement in what really counts: enjoyment. Maybe 1000% will buy a 50% improvement, but that often takes the expense well out of a person's budget range. (Above: At Bull Creek Wildlife Management Area in Central Florida, 1993, with myTasco 11TR department store reflector. Some of the happiest nights of observing in my whole life.)

The SV510 solar telescope
Hence, with Astronomerica I attempt to demonstrate that it doesn't take a lot of money—whatever that means to you—to enjoy amateur astronomy. We constantly read about "hobby killer" cheap telescopes. That's probably what my 4.5" Tasco was considered by many at the time, yet it helped me develop a hobby that I have enjoyed for the rest of my life, because if you don't approach it from an elitist perspective, it's not a bad scope. 

No one wants to buy crap, but even now there are some decent telescopes for $250 or even less. I just picked up a Svbony SV510 solar telescope (above) for less than $10 new that actually shows sunspots pretty well, even if it's on a very rickety tripod. If that's what you have to start with, then go for it. Just understand the limitations. "Perfect is the enemy of good" (Voltaire).

Many times I read posts where people say for $500 a particular piece of gear is too good of a deal not to buy, even if it's just to try it out. After all, it's "only" $500! Don't we all wish we had that kind of mad money? Others consistently recommend finding a higher quality piece of gear used. But most people don't want to wait weeks, months, or even years for that particular equipment to come up on the used market, just to see it sold to a retired "boomer" engineer before they can even get home from school or work to check the classifieds.

The Apertura 8" Dobsonian telescope
I know from experience that there are ways to get a lot of enjoyment out of amateur astronomy for very little cost.  But as you get more into the hobby it can cost you more. Want to get away from your Bortle 9 city lights out to the country? Better have a car and gas money, or a friend who has both and is also into astronomy (good luck with that). Want to buy that perfect beginner 8-inch Dobsonian? Better have $600, plus a phone with a charting app or money for a star charting book, plus a suitable observing chair, plus good cold weather gear, etc. 

It does get expensive by many people's standards. But do we really need that 8-inch dob as our perfect starter scope that will "serve us well for a lifetime?" No. You can get good binoculars for a third of that price, and "recommended" cheap binoculars for perhaps half of that. Cheaper if you get them on sale, or the price of club dues if you're lucky enough to have a local astronomy club that has some to borrow. (Above: Apertura 8-inch Dobsonian, the "perfect" starter scope for those with $600 to spare.)

Woman harvesting wheat and dreaming of that high-end Takahashi refractor
While I love forums like Cloudy Nights, Stargazer's Lounge, and Reddit (r/telescopes), there is a strong tendency for the frequent posters to make it sound like if you don't get this or that recommended equipment, then you're making a huge mistake. "Better to buy once and cry once," is the mantra. Easy to say if you have the money on hand to do so. If not, they then suggest you wait and save your money until you can. Depending on your situation, that might take many months, if not years. There really is no reason not to start with whatever modest equipment you have, even if it's a cheap lawn chair, your own eyes, and a bottle of bug spray. (Left: Nikolay Andreyev, Public domain, via Wikimedia Commons, modified for amateur astronomy FOMO)

I recommend you read those forums but don't fall into the trap of thinking you have to have a pile of high quality equipment to enjoy amateur astronomy. Consider the situations of those making the recommendations, and consider your own situation. One user may have 20 telescopes, 50 eyepieces, and a fountain of experience (who is also the one that tells you "Better to buy once and cry once!"). You don't need to be that person. You aren't that person. You can enjoy the night sky the way you can, given your own means and situation. Don't feel like you're missing out. You're seeing the same things everyone else is. Someone will always have a better view. Don't let that keep you from looking up.

Enjoy the journey, wherever you start and wherever you wind up.

Friday, March 7, 2025

Taking an astronomy trip by air

Southwest Boeing 737-700
Whether you're taking a trip purely for astronomy observing, or you'd like to do some observing on the side, having something to magnify your view can really add to the experience. Here I'm not talking about scopes that pack into the car for a drive but ones that you can carry with you on an airplane. That's a big difference. Your standard "grab 'n go" scope may not make a good airline travel scope once you try to put it in your luggage.


When to go

Southern Cross and the Coal Sack
The Southern Cross from Florida in September?
Not gonna happen!
(Naskies at en.wikipedia, CC BY-SA 3.0,
via Wikimedia Commons)
The most obvious consideration for when to go is to plan it around new moon. Consult an app or website to see when it gets dark and when the Moon rises or sets. If you are likely only to observe during the early part of the night, go within the week before new moon, when the Moon rises in the early morning hours. 

Research your destination and find out what months have the best chances for good observing weather.

Consider what objects you would really like to see. For example, going to the Florida Keys to see the Southern Cross, Omega Centauri, and NGC 5128 won't work in September. Use a charting app such as Sky Safari or Stellarium to see what will be up throughout the night.


Choosing a destination 

First and foremost, you'll want dark skies that have frequent clear nights and good seeing. Harder than finding that, though, is finding a place where there are no local lights to ruin an otherwise great sky. Non-astronomy people will often rave about the great sky, with no attention paid to all-night lighting that would be a deal-killer for astronomers. Even a single LED on a nearby outbuilding can be incredibly annoying.

Unless those traveling with you are as excited about astronomy as you are, and even if they are, it's good to have alternate activities available so everyone is happy and you have some variety. If they aren't into nature and the outdoors, you'll probably be limited to a fairly mediocre sky with lots of lights. Most destinations also have a chance of cloudy nights.

I recommend a place that has a kitchen, so you can prepare your own meals. You won't spend as much money, you'll be able to be set up and ready at dusk, and you'll be able to plan the meals and snacks around your observing and sleeping schedule.

Excepting stays in really posh digs, the largest part of the budget will likely be the air travel. You might find dark skies closer than you think unless you're bent upon seeing the opposite hemisphere. After all, the constellations are the same until you change latitude significantly.


Access to a telescope at your destination

Equipment rental list
The most convenient travel solution is to have a telescope waiting for you at your destination. You could ship your equipment, but that could be expensive and any delay could ruin your chances to observe. I have read about some people doing this for very distant trips, and maybe that's a decent solution in that case.

Above: The non-profit Reach for the Stars in Tucson, AZ, rents telescopes. Check for telescope stores or astronomy clubs at your destination that might be able to set you up with a telescope.

Marathon Motel Sky Park telescope presentation
Some astronomy-suitable vacation rentals (dark sky, minimal light pollution) come with telescopes, but while I was doing research I found that most don't. I think trying to maintain them is more of a hassle than it's worth, except for a very few number of places dedicated to astronomy observing. Most places cater to a wider variety of interests because, let's face it, the market for astronomy vacation rentals is pretty miniscule.


Above: The Marathon Motel Sky Park in Marathon, TX, provides nightly observing programs with their 20" and 24" Dobsonians, as well as powered telescope pads if you bring your own.

Still, if I had a rental property where I knew astronomers would be staying, I would probably have an 8 or 10-inch Dob available because there's not much you could do to break one of those. However, then you have to have a chair and eyepieces and a finder and all that kind of stuff that can be broken, lost  stolen, or ruined fairly easily. So I understand the lack of available equipment.

As a renter, you don't know what kind of shape the equipment is in, or what comes with it. So it's good to bring, at the very least, binoculars, and if you can manage it, a small telescope and a small collection of eyepieces.

On my recent trip to Arizona Sky Village, I had arranged several options for on-site telescopes in advance, including observing with somebody who lived in the area and renting a telescope from a place near the airport. In the end we just used what I had brought with me. I couldn't have even rented an 8 or 10-inch Dob because it would not have fit in the rental car with three of us and all of our luggage!


What makes a good air travel scope

I'm not a refractor guy, not because I don't like them, but because refractors have never really fit into my style of observing. Many people use wide field refractors, for example 80mm refractors, as travel scopes. It seems like a good idea because they're small and relatively lightweight, and many people go that route. Little Maksutovs are also a popular choice, and although they have a limited field of view, they can double as a terrestrial scope with an erecting prism.

Using the Bino Body Mount
For me, it makes more sense to bring a good pair of binoculars than a wide field refractor or "Mak" of small aperture. Binoculars can be used for birding and nature watching in addition to astronomy and don't require much else. And what can be better than lying back while you're observing? See my Bino Body Mount post for a great lightweight mount for binoculars, pictured at left, that you can easily break down and pack in a suitcase.

Therefore, If I'm going to bring a telescope, I want something with as large an aperture as possible because I already have the low power/wide field experience covered with the binoculars. But it's problematic when you have to pack a telescope for a plane trip. 

Do-it-yourselfers have built some pretty incredible travel telescopes with larger apertures. But most of us don't have the skills, the time, or the money for that. Commercial versions are pricey. So we look for mass-produced telescopes that are lightweight and small but pack as much aperture as possible. 


Can a 6-inch be a travel scope? 

I can definitively say yes. I took my collapsible Sky-Watcher Virtuoso GTI 150P (6-inch) optical tube assembly (OTA) off its bulky go-to mount and built a travel mount for it. The entire setup weighs about 25 lbs. I took it with me from Virginia to Arizona and back by air and rental car, and was really glad to have that much aperture to appreciate the dark Arizona skies. 

If you want to go with a refractor or Maksutov, fine. You'll need that, a tripod, and some eye pieces, at a minimum. If you want to sit, you'll need some sort of chair you put outside and move around. 

I don't recommend a high-end scope or even a medium-end scope for air travel, because you may never see your luggage again, it may get broken, and even if you carry on the OTA, you still have to pack it well and there's a chance you may end up having to gate check it. 

I packed my OTA in a 22-inch hard shell carry-on suitcase, packing all my warm jackets around it, and it did fine. The mount, tripod table, and associated gear all fit in a 26-inch checked roller suitcase. My wife and I carried on the eyepieces, finderscope, and two pairs of binoculars (15x70 and 10x56) in a case and a small bag that fit under the seats. You can't put lithium batteries in your checked bags, so I carried them in my "personal item" bag that fits under the seat.

For eyepieces, I brought a Celestron Xcel-LX 25mm (30x), an Astro-Tech UWA 10mm (75x), a Svbony 7-21mm zoom, and a Svbony 2x barlow, giving me a range of powers from 30x to 214x, plenty for a 6-inch.

My 6-inch travel scope setup
My Sky-Watcher 150P came with a go-to mount, which I wasn't about to take apart, and it was too big to fit in any kind of suitcase I want to be lugging on a plane. I decided to put together a new mount for it, and chose the Svbony SV225 alt-az mount. It's relatively inexpensive, weighs a bit more than 5 lbs., it's sturdy, and can be compacted into a pretty small form factor. I fit it in a plastic shoebox with foam padding. I also built a tripod table which could be broken down flat, upon which I bolted the mount.

The biggest challenge was finding a chair that I could bring with me that was the right height for the telescope. I do not like observing standing up, especially for many hours at a time. The chair I usually use is a big heavy Denver style adjustable chair, which is too big and heavy for airline travel. 

I looked online and finally found a folding tripod chair where each leg folds in half, making it even more compact. It's called a GCI PackSeat. It weighs just over 1 lb. I stuck tennis balls on the bottoms of each leg to keep it from sinking into soft ground, and that worked great. It was just the right height, about 18", for my telescope once I added a stool cushion, fastening it to the chair seat with sheet stays.

Your rental may not have any outdoor chair suitable for use with the telescope, so if you're planning a trip and planning on sitting at your scope, make sure you know what height chair you need, and what they have at your destination, or bring something the right height to sit on.

Don't forget to inquire about reclining chairs if you plan on doing binocular observing. Some people use tripods or monopods, but for me they are tough on the neck for more than a few quick looks well below the zenith. The place I recently rented had Adirondack chairs that worked well.


Sizing it up 

Suitcase packed with mount, tripod and other gear
The three main rules for traveling by air are keep it light, keep it compact, and make it easy to assemble and disassemble. If you already have some luggage, it may be fine for your scope and mount/table/tripod. Otherwise buy luggage that will fit what you're designing or buying. I found that a 22-inch hard shell carry-on roller suitcase was the perfect size for the 6-inch collapsible 17-inch long OTA with suitable padding, namely my ski pants, a hoodie, a light down jacket, some gloves, and a hat. 

Try to use stuff you're going to bring anyway for padding rather than packing a lot of foam and dedicated padding. Just make sure it's packed well enough that it's not likely to receive damage under normal handling. 

Someone on Cloudy Nights mentioned they packed their OneSky 5-inch tube in their checked baggage in a duffel bag filled with clothes, and it made it fine. It depends on your own risk aversion how you want to handle that. I feel much more comfortable carrying the OTA on.

Watch your baggage weights and sizes and make sure you stay within the airline's limits. My 26-inch roller suitcase (above) that held the scope mount, table, bino mounts, observing stool, tools, windscreen, and other gear was pretty close to the max limit of 50 lbs. 


Disassembly and assembly

My travel mount and table disassembled
You want to make sure you have all the tools and bolts and other things that you'll need to assemble and take apart your gear. I found it was a good idea to go through the whole disassembly and reassembly process once I had collected all my tools and equipment, using just those things that I would be packing. That way I would immediately recognize if I was missing some key tool or item. 

Bring a few extra critical bolts, screws, washers, and other items in case you drop them and lose them. A single bolt could shut you down if you lose it. If you need a wrench, bring a compact 3/8 inch socket wrench and bring sockets in the right sizes that you'll need. Get a cheap stubby screwdriver if you need one.


Plan for the weather at your destination

Snow covered Chiricahua Mountains
Research the environment you're going to be in. For my trip to Arizona Sky Village in late October/early November, I realized based on my research that it was likely to be quite cold at night, possibly going into the mid-30s. Therefore, I made sure I brought plenty of warm layers, wool gloves, headband, hand warmers, and anything else I would normally wear for winter observing. It rained on the last night, and the nearby mountains (left) were covered with snow in the morning. 

I recently got a heated vest that's powered by a pocket power bank. It took up very little space but kept me very warm along with a hoodie and a light down jacket. Use several layers instead of bringing one huge bulky coat. You can add layers as it gets colder.

Even if it's nice and warm during the day, it may get quite cold at night, depending on where you're observing. So do your weather research in advance. 

Wind screen set up at my local observing site
The Arizona high desert can have some pretty strong winds, so when I went there, I brought a privacy screen I found at a Lidl grocery store (similar to this one) and used that. It worked very well, but I had to replace the cheap steel wire shepherd's hook stakes with aluminum gutter spikes. They were lighter and a bit stronger than the shepherd's hook stakes, which bend if you just look at them wrong. I used a local rock to pound in the stakes. I set the screen up at my local observing site first (above), so I knew how to do it and could evaluate the components.

A wind screen can also double as a light screen in case you encounter some unexpected all-night lighting, or a steady stream of car headlights.

If you will be observing in cold weather, your Mukluk or Sorrel boots are great, but they take up a lot of space in your luggage. Instead, bring chemical hand warmers, for example Hot Hands, and slip one under your toes in each shoe. Unless you're observing in sub-freezing weather, they will keep your toes warm all night. If the warmers are still hot and soft when you're done observing, put them into a Ziploc sandwich bag to cut the air off, and you'll be able to reuse them the next night. I used one pair of hand warmers three consecutive nights doing that, wearing them for probably a total of 12 hours.


Observing

Screenshot of Sky Safari Pro observing list
Bring whatever charts you're going to need, whether on an app or if you use paper charts. Don't forget a red light for when you're moving around or reading at night. Pack some spare batteries and a small charger if you think you'll need one, as well as wall chargers and charging cables. Even a non-electric setup probably has some requirements for juice. 

If you're going to be going in and out of a brightly lit house, room, or cabin, you can get a pair of red goggles that are used for laser work to protect your night vision when you go in for a snack or go to the bathroom. The darker the sky, the more important it is to protect your night vision.

What finder scope are you going to use? I packed my RACI finder with my eyepieces in a carry-on bag. I wrapped each one in bubble wrap.

Make a list of those objects that you really want to see. Maybe they're ones that you can't see from your light polluted home or typical observing site, or ones that are perhaps further south than you can ever view from home. Make sure they're reasonably high above the horizon at some point during the night from your destination location.

Above: Sky Safari Pro allows you to make your own observing lists. I made one for my recent trip to Arizona. Easy to load it in the app and cruise around to view your "must see" objects.


Dealing with an "oops"

It's a good idea to bring a small bottle of alcohol or lens cleaner and some q-tips and lens tissues. You might end up dropping an eyepiece in the dirt, as I did, and it's great to be able to just clean it right off and go right back to observing. See Televue's instructions on cleaning optics.

I brought a roll of white duct tape. I flagged the guy lines for the windscreen with them, which allowed us to see them easily at night so we didn't trip over them. I also made a repair to a plastic box that got broken on the outbound flight. 

Thursday, November 7, 2024

Bino Body Mount - build a travel mount for binocular astronomy

Using the Bino Body Mount while reclining
I recently took a dark sky vacation to Arizona. I wanted to bring my 15x70 Garrett Optical binoculars, but they are 5.5 lbs., and I can't hand hold that with any kind of steadiness. I had previously built a zero gravity chair mount, but I wouldn't have access to a zero gravity chair. 

I was pondering compact and, of course, inexpensive solutions, and came upon this post on Stargazers Lounge. The observer uses a mini-tripod with one leg removed, resting the other two legs on his shoulders. This seemed like a great idea, except you still have to keep your elbows raised, which introduces both unsteadiness and fatigue. 

The Bino Body Mount
Taking that idea a step further, I devised a very simple apparatus that I call the Bino Body Mount, which solves the problem of having to raise your arms by adding a 90 degree handle to each side of a basic wood frame. You don't have to buy a mini-tripod, just a cheap 1x2 furring strip (my go-to wood for this kind of thing), a binocular tripod adapter, a 1" 1/4-20 stud knob, two star knobs, two hanger bolts, a flat washer, two fender washers, two neoprene washers, four wood screws, and two tennis balls (well, three really because they come in 3-packs). See parts and tools list at the end.

The mount breaks down flat for packing by removing three knobs. It's very lightweight, and can be used standing or sitting in any type of chair. Your arms stay at your side to provide comfortable support when standing and rest on the arms of your chair when sitting. As you recline further back toward the zenith, the shoulder bars transfer more and more of the weight to your shoulders, resolving the problem of raising your arms and tiring quickly. The Bino Body Mount also improves the view and fatigue factor with any size binoculars because you don't have to hold them in front of your face with your arms raised. 

Using the Bino Body Mount while standing

For Comet C2023/A3 (Tsuchinshan-ATLAS), I sometimes used the mount standing because it was relatively low to the horizon and I really didn't need a chair. It worked great. I wouldn't recommend standing and looking anywhere near the zenith with binoculars, whether handheld, on a Bino Body Mount, or on a tripod. That's just painful and awkward.


Using the Bino Body Mount while sitting

For objects near the horizon, you can sit up and rest your arms on the chair arms. 

Note: That's a Bino Bandit around the eyepieces. It's a neoprene eyepiece light shield that I highly recommend despite it's relatively high cost because it works so well. 



You're not going to get rock steady views with this, but surprisingly close, and your arms and neck won't get tired. My brother and I spent many hours on our Arizona vacation using these, and they worked great with almost no fatigue. You will primarily see a jiggle from your heartbeat. You can look around anywhere in the sky that you could just handholding the binoculars. You can loosen the knobs to tilt the bino bar at whatever angle works best for you. You can adjust focus with one or both hands.

At this point, I am using the Bino Body Mount for all of my binocular astronomy observations, regardless of whether I'm traveling or not. It's simple, it's lightweight, it's compact, it's inexpensive, it's easy to build, and it works very well.


Build it

Thread-to-eye measurement
The critical measurement is the distance from the tripod threads in between the barrels of your binoculars to the end of the eyecups, what I call the "thread-to-eye" measurement. The correct distance places the binocular eyepieces exactly where they would be if you were handholding them. This doesn't need to be super precise- within 1/2 or 1/4" is fine. You can tilt the bino bar when observing to make up for any slight error.

If you have multiple binoculars with different thread-to-eye distances, as is the case with my Meade roof prism binoculars, you just drill a pair of holes in the shoulder bars at the correct distances and you can easily reposition the bino bar as needed. Or you could just make two mounts!

See the parts and tools list at bottom of the post.

Step 1:
Measure and cut

Measure and cut a 1x2 furring strip into five pieces. You can make them whatever lengths that work for you, but I made the two shoulder bars 12" long, which accomodates most porro prism binoculars with an approximately 4" thread-to-eye distance. On a second Bino Body Mount, I cut the bars 13-1/2" long for my Meade roof prisms, since the measurement is about 6" for them. The bino bar (the crosspiece that holds the binoculars) is 11". The two handles are 12". One six or eight foot furring strip will be plenty and leaves some extra in case of "constructor error."

Step 2:
Bino bar

The bino bar
Drill a roughly 11/64" hole in the center of both ends of the bino bar (the 11" piece) and insert a 2" 1/4-20 hanger bolt into each, using the "two-nut" technique (thread two nuts on the end, tighten them together, then screw in by turning the upper nut, screw out by turning the lower nut). The threaded end of the hanger bolt should stick out far enough to accomodate the 5/8" width of a furring strip, another 1/8" for a neoprene washer, 1/16" for a flat washer, leaving about 1/4" for the knob to screw onto. So leave about one screw thread of the wood screw part showing and you should be fine. You can always adjust it.

Drill a 1/4" hole in the middle of the bino bar. This will hold the tripod adapter using the 1" stud knob and flat washer.

Step 3:
Shoulder bars

Various parts labeled
Drill a 1/4" hole in each shoulder bar where the bino bar crosspiece hanger bolts will be inserted. This should be the measurement above plus about 6 inches. So for a 4" thread-to-eye measurement, drill the hole about 10" from the end of the shoulder bar that will rest on your shoulder. Put a neoprene washer between the bino bar and the shoulder bar, then on the outside of the shoulder bar, a 1/4" flat or fender washer and the knob.  

Step 4:

Test the fit. People's bodies vary, so if the above calculation doesn't work, make an adjustment by drilling a hole a little closer or further from the end. This is the important part, so make sure you get it right and it's comfortable for you. Adding tennis balls will give you a little more distance, and putting a thicker pillow behind your head or wearing a hood will give you a little less. It doesn't have to be perfect, just close enough to work for you. 

Remember you can make minor adjustments by loosening the side knobs and changing the bino bar tilt slightly. I like to have the binoculars tilting slightly downward compared to the shoulder bars (see images above), except when observing near the zenith. In that case, I like to have the binoculars pretty much pointing straight out parallel with the shoulder bars, especially when observing in a chair that doesn't recline very far.

Cut an X or hole in two tennis balls and stick them on the ends of the shoulder bars so they fit snugly and won't fall off easily. This is harder than it sounds. Tennis balls are tough! I used a large folding knife to poke an initial hole, then cut the rest until it fit snugly on the end of the 1x2. See this video, or if  you have an electric carving knife, this video. I always wear heavy leather gloves when working with sharp things near my hands that could slip. 

Step 5:
Handle bars

Attach the handle bars on the outside of the shoulder bars about 7" from the ends that rest on your shoulders with two wood screws per side. You can also add tennis balls to the handle bars for the ultimate in opulence.

Step 5:
Finishing touches

With fender washers under the two side knobs, a flat washer under the bino mount knob, and neoprene washers on each end of the bino bar (to help keep it from slipping without having to overtighten the knobs), test it all and if no further adjustments are needed, sand and paint the wood pieces. 

Completed Bino Body Mount with 15x70s mounted



The final assembled Bino Body Mount (with my 15x70s mounted).






Front view of Bino Body Mount



Front view showing placement of the neoprene washers.




The Bino Body Mount disassembled

The pieces disassembled for packing in a suitcase. This mount has longer shoulder bars with two sets of holes to accomodate both my porro and roof prism binoculars. No tools required to assemble and disassemble. Just unscrew three knobs.







Two Bino Body Mounts!
What's better than one Bino Body Mount? Two Bino Body Mounts! One for me and one for my brother. I hope you enjoy yours!








[1/27/2025 update] Some tips on use:

  • Always carry the apparatus by holding the binoculars. That way, if you forgot to tighten something or it got loose, it's the mount that will hit something, not your binoculars.
  • Apropos the above, periodically check that the three knobs are tight.
  • Some tilting of the binoculars from side to side on the tripod adapter is desirable so that if you are looking off to the side a bit it will stay lined up better with your eyes. 
  • When observing near the horizon while sitting, I like to rest my palms on the side knobs with my fingers curled around the ends of the handle bars, tucking my elbows in for support

Parts list

1x2 furring strip (6 ft.)

Binocular tripod adapter (example)

1" 1/4-20 stud knob (most come in multi-packs- good for lots of projects)

Two 1/4-20 2" diameter threaded five-star knobs

Two 1/4-20 2" hanger bolts

Three 1/4" hole flat washers 

two 1/4" neoprene washers

Four 1-1/4" wood screws

Two tennis balls


Tools:

Tape measure or ruler

Power drill with 1/4" and 11/64" (or close) drill bits, and phillips head bit (or screwdriver, or both)

Hand or power saw

Two 1/4" hex nuts and two 7/16" combination wrenches or pliers (to screw in the hanger bolts)

Sturdy pointed knife to make holes/cuts in tennis balls

Sandpaper, tack cloth, paint, and paintbrush

Nice to have but not essential: 

    Mitre box (to make straight cuts)

    Clamps (to hold the wood for sawing and drilling)

Saturday, October 26, 2024

Upgrading from starter eyepieces

Svbony SV135 7-21mm zoom eyepiece
Beginner telescopes come with very basic eyepieces to get you started as soon as you open the box. Sometimes these are pretty decent and will work for you for a long time and sometimes they suck, but most people want to upgrade at some point. Unfortunately, many people now tend to upgrade too much, too soon.

My recommendation is to get an inexpensive zoom eyepiece to go with your new telescope. There are quite a few under $100 that are available. Even though I have a nice Baader Hyperion 8-24x zoom, this year I purchased a Svbony SV135 7-21mm zoom. It's a lot lighter, about six times cheaper, and a decent performer, getting mostly good reviews on Cloudy Nights for its price, and I agree. I got one for my brother, too, and he loves it. [Note: If you wear glasses or want a slightly wider view, you might want to go with the Svbony SV191 7.2-21.6mm zoom, which is a bit more expensive and not quite as sharp.]

Svbony SV135 zoom eyepiece showing the Moon at different focal lengths
With a zoom, you will get a feel for how different objects in the sky look in various eyepiece focal lengths, which determine the power, and what works best in your telescope. (Telescope focal length ÷ eyepiece focal length = power. For example, a telescope with a 750mm focal length with a 10mm eyepiece in it will give you 75x.) If you do eventually upgrade your eyepieces, after you get to know the sky better and know what you like to look at, you can keep the zoom and use it when you want to travel light, for quick sessions, planetary and lunar detail, double stars, and for outreach. That's what I do.

Zoom eyepieces like the SV135 have a narrower field of view than many comparably priced eyepieces and generally aren't quite as sharp or well corrected for aberrations, although this one does tolerably well. By twisting the barrel, you are able to zoom into exactly the desired power, replacing a large set of eyepieces with just one. 

As you progress, you might want wider or sharper views, which come at a cost. Televue eyepieces, the premier example of consistently high end eyepieces, are expensive because they give you well-corrected wide views, which don't come cheap. But a relatively cheap zoom allows you to experiment with different powers on different objects so you can find what works best in your telescope for you. Then you have a better idea of what you want if you decide to upgrade. This also allows you to take full advantage of your new telescope immediately. 

Screenshot from the Sky Safari Pro app.
Well, maybe not immediately. More critical than upgrading eyepieces is learning the sky and how to find things in it with your telescope. See the Space Walk Among the Stars sound guides, which will help you find some wonderful deep space objects, as well as posts on determining directions in your telescope, how to set up your telescope for starhopping, the Astrohopper app, and others. 

The internet is full of observing guides. I would start by visiting the Sky & Telescope site, with their Interactive Sky Chart and lots of information for beginners. You'll find tons of information there. Also visit Cloudy Nights, the premier amateur astronomy forum. The Beginners Forum will keep you occupied for many cloudy nights to come and provide a place to ask questions.

Left: Screenshot from Sky Safari Pro. Apps like this help you locate objects in the night sky and can even control your telescope if it is go-to equipped.

Sunday, September 1, 2024

Mounting a RACI finderscope on a collapsible tabletop telescope


I recently bought a Sky-Watcher Virtuoso GTi 150P tabletop 150mm (6-inch) telescope. This is a slightly larger variation, with a go-to mount, of a popular design sold by Astronomers Without Borders as the OneSky, a 130mm (5-inch) altitude-azimuth mounted collapsible tabletop telescope, shown at left.

These telescopes have a Vixen-style dovetail bar attached to the solid part of the tube—the green thing in the pictures of my telescope below. This is how the tube attaches to the mount, which has a Dobsonian style groundboard for the azimuth (side to side) axis and a half-fork with dovetail saddle for the altitude (up and down) axis. The tube can be removed from the saddle and clamped back on with a single threaded knob, the knob sticking up from the blue tube in the picture of the OneSky, making this portable design even more portable.


The problem

For finding objects, or in the case of the go-to model, aligning the mount or finding objects when the go-to isn't cutting it, the scopes are equipped with a straight-through red dot finder that projects a red dot on a window in front of the stars. A clever design with many variations, but like some people, I have trouble—no, make that pain—bending my neck enough to comfortably look through one, especially at objects high in the sky. 

On my other two scopes I have added azimuth circles and a digital angle gauge to find objects by looking up their alt-az coordinates in an app like Sky Safari Pro, moving the scope so that the coordinates are set on the azimuth circle and the gauge, and then using a right angle correct image (RACI) finderscope to zero in on the target. A RACI finder doesn’t require neck contortions and shows a correctly oriented view like you would see in binoculars.

I wanted to add a RACI finder to the Sky-Watcher tabletop telescope, but the problem is that the front ring that holds the secondary mirror and focuser is extended out on two truss tubes so that the whole front half can collapse into the solid rear half that holds the primary mirror, making it quite compact. There is no good place to add a finder on the front ring and it would make the scope quite front-heavy, requiring some sort of counterweight for manual operation. Others have added reinforcement to the front plastic ring or have drilled holes in the tube to add a finderscope, but I didn’t want to do either of these things. 


The solution

Finished finderscope mount on the telescope.
I added a universal dovetail shoe (base) to a block of wood attached to the scope's dovetail bar (the green thing) and swap my RACI finder between my 4.5-inch and this telescope. Looking at the design, the long dovetail bar attached to the telescope tube has two channels that run its length and a single 1/4-20 threaded hole close to the front end of the bar. The hole is presumably for mounting on a tripod, but it’s at a very poor location for balance. I had seen others mount a laser pointer and finder on that part of the dovetail bar, so I experimented with mounting a Svbony SV182 6x30 RACI finder that I have on my 4.5-inch reflector. I zip tied it in place to see how it worked. The problem was that, sticking out straight from the dovetail bar, the finder was too far from the observer’s position and I had to get up and either lean over or walk around the back of the scope to the other side to use it.

If I were to fasten a block of wood to the end of the dovetail bar at a 90 degree angle, then I could mount the RACI finder on the end of it, bringing the eyepiece to a much better position, even better than if I had drilled a couple of holes in the solid tube to mount it. After doing just that, I noted a post on the OneSky megathread on Cloudy Nights that did something similar, but by drilling and tapping a dovetail clamp instead of using a block of wood. Same end result.

Finderscope with updated forward mount extension
10-19-2024 Update: I wasn't happy with how far I had to scrunch down to look through the finder at or near the zenith, so I added an 8-1/2" extension bar made out of a piece of 1x2 furring strip where the dovetail shoe was and put the dovetail shoe on the end of the new bar, moving the finderscope forward and closer to the eyepiece. Wood screws all around. Shifts the balance slightly, but I just move the scope down the dovetail bar a small amount to compensate.


Here’s how to do it

[Note: See 10-19-204 updates below for an improved version that puts the finder closer to the eyepiece.] I cut all the pieces using a basic mitre box and a hand saw.

Finished finderscope mount off the telescope with finder mounted.
I cut a 5” piece of 2x2 baluster (vertical railing piece) that I had left over from making the legs for the telescope’s table mount. I cut a 45 degree corner on one end so I wouldn’t have a sharp corner sticking out. These balusters tend to vary slightly in cross section width, so I checked a few pieces before I found one where the dovetail finder shoe, or base, fits tightly in one direction—one more way to make it even more solid. Note: I used balusters rather than the 8’ lengths of 2x2 that they have because the balusters tend not to be as warped as the long pieces and they were actually cheaper per foot.

I glued and screwed two small pieces of wood to the block to sit in the bar channels and keep the block from rotating on the single bolt. I cut the two little pieces from a large size paint stirring stick (1/4” thick). The pieces are 7/16” wide and 2-1/4” long. I sanded them so they fit tightly into the bar channels.


This side will face the observer sitting at the telescope.

Close up of the end of the dovetail rail on the telescope.
I dry fit the block and the two channel pieces to make sure they fit tightly in the dovetail bar. There are two screws in the dovetail bar at the bottom of each channel 1/8” from the front end of the bar. The block would need to sit behind these screws with the channel pieces butting up against them to add stability. I marked where the bolt would go through the block into the dovetail bar and also where I would need to glue the small channel pieces that would fit snugly into the two channels in the bar. I had cut them a little long just to give a bit more twist resistance in the channel.

Unpainted finderscope mount with dovetail base attached- back view.
Where the bolt would go through the block and screw into the dovetail bar, I countersank a 3/4” diameter hole about 3/16” deep, enough so the bolt head, with a 5/8” outer diameter - 1/4” inner diameter washer, would be flush or nearly flush with the surface, using a 3/4” Forstner bit. (3/4” because my wrench socket would fit in it so I could tighten the bolt.) You must do this before drilling the hole for the bolt so that the bit can center properly. It’s not essential to countersink the bolt head, but I thought it would be better than having it sticking out, and I recently got the Forstner bit set, so I’m eager to find reasons to use it! I then drilled a 1/4” hole all the way through the block, centered in the 3/4” countersunk hole.

I inserted the two little channel pieces into the channels and pushed them tight up against the screws in the bar channels. I inserted the bolt and tightened it to make sure the fit was good. Then I removed the bolt, put wood glue on the two channel pieces where they would join the block and bolted the block into place. Once the glue had dried for about 45 minutes, I removed the assembly and cleaned off some glue that got on the dovetail bar. It removes easily.

Top view of mount showing dovetail base screwed into top.
The dovetail shoe for the finder has four slots for screws. I screwed it into the top of the block with four 1-1/4” #6 wood screws. Everything looked good, so I took the shoe off the block assembly, painted the block assembly black, reattached the shoe, and attached the whole assembly to the dovetail bar. The shoe stays on the bar and the finderscope is removed for transport. This modification is also entirely reversible with no alteration to the telescope. [Note: With the updated extension, you'll screw the extension bar in here and screw the dovetail shoe to the forward end of the extension bar.]


The finished mount. Note the four screws added to the channel bars. I found glue alone did not hold. Make sure you recess the screw heads into the wood with a countersink bit so they don't scrape the dovetail bar. 








View of telescope with finderscope in place.
The finder is at a more comfortable, although still not optimum, location. I can also fit my head in there to use the red dot if necessary. The scope can rotate through the entire range of altitude motion without anything bumping or binding, but be careful when pointing above 50 degrees, as the additional weight of the finder will want to flip the tube backwards.


Telescope collapsed with mount attached.
Packed up, the finder mount is out of the way and adds very little weight or volume to the overall package. Just loosen the two thumbscrews, slide the finderscope on, and tighten the thumbscrews. 








View from above of telescope collapsed with mount attached.
View from above when collapsed. The finderscope mount does not stick out beyond the round baseboard of the telescope mount. The dovetail shoe is mounted so that the thumbscrews point inward and are less likely to catch on a cover or other item.





Now I can use the RACI finder more easily and swap it between the two telescopes. It's still not an optimum viewing position especially at higher altitudes, although being able to rotate the diagonal on the finderscope helps. But for these collapsible telescopes, this makes a useful addition or alternative to the red dot finder.

Extended mount on the telescope
10-19-2024 Update: The scope with the new extended mount for the finder. Because it sticks out further when the scope is collapsed, I plan on getting a 1-1/2" knob to replace the bolt holding the bracket to the dovetail bar, making it easy to remove for transportation.