Hello :-)
You need three eyepieces or so to get the most out of your telescope.
Telescope aperture: 102mm Focal-length: 1000mm (Aperture ratio F/9.8)
Kit eyepiece: 25mm eyepiece
1000/25=40x magnification
You would need:
Overview
Planets
In-between
Field of view simulation;
Closest eyepieces to the above suggestions
A bit more flexible, warning from too much magnification and such, more pre-sets, https://www.sternfreunde-muenster.de/ocalc.php
Clear skies! :-)
That's sufficient, thanks! :-)
Nice telescope. As mentioned you can see a lot with it, but a good guide like "Turn left at Orion" helps to find things and how to use the telescope.
Speaking of, do you have the mount figured out?
> Not sure what most of this info means, will send pictures of the label and such if needed!
I've seen this telescope, and it should have a 1.25" diameter focuser (eyepiece barrel of 1.25") so it can use regular eyepieces unlike some very old telescopes.
> 130
130mm (5") is the aperture, the size of the mirror (or lens in other cases). The larger the aperture, the more detail & faint structures you can see. 130mm beats any entry level telescope with 60mm, 70mm or such.
> 900
900mm is the focal length. Other then cameras, the eyepiece defines the magnification. Focal length divided by eyepiece = focal length.
> 7
F/7, the aperture ratio, is better known in the camera world, where it's important regarding brightness & exposure times. It's just 900 divided by 130 in this case. For visual astronomy, it has nothing to do with image brightness, as the eyepieces are more important. But it tells a lot about the telescope, how cheap eyepieces will perform.
> EQ
EQ stands for equatorial, the type of mount it's on. In theory, these mounts are great, as they counter field-rotation and allow for easy tracking by just turning one axis... But in reality, all sets come with a pretty weak EQ mount. In order to make things more stable, don't extend the tripod fully, possibly add some weight to the center plate.
For planets, you would require the mentioned eyepiece.
Eyepieces & Magnification
900 / 25 = 36x magnification
(900 / 15 = 60x magnification )
900 / 6 = 150x magnification
More is possible, e.g. 4.5mm (1, 2), but while things get larger, they also get dim!)
Cheaper eyepieces like PLössl under 10mm have short eye-relief. This makes it difficult to view through them. Same with common eyepiece sets (that are also almost always overpriced, and you don't need a dozen eyepieces and filters anyway).
> observed a handful of them.
Great :-)
> Yes, my budget is 100 dollars for one good eye piece that i can use with every scope I own.
What other telescopes do you have?
> one good eye
You will need three good eyepieces or so to cover the bases, and depending on the other telescope that might not be as ideal for DSO in the other. Some smaller clusters, doubles, planetary nebulae will also benefit from more magnification than a 25-32mm would provide.
1.
> another 25mm eyepiece because my current one shows stars with tails at the edges.
Coma in the outer field will be an issue even in expensive eyepieces. A coma corrector is a bit overkill in F/5 though :-)
Get a 32mm Plössl (52°) instead, it will perform a bit better and shows a larger field too! (http://blog.pixelgiraffe.com/wp-content/uploads/2014/06/fieldcompare.jpg)
2.
> planets
For planets, consider the 4mm 58°. The 58° HR Planetary clones perform quite well in F/5 telescope for their price! :-)
3.
> dso's
A 15mm might fill the gap, though coma, degrading sharpness will be apparent in the 15mm gold-line or Plössl. (Only the 6mm and 9mm gold-line have a barlow-like element built-in)
Do not get Plössl under 10mm due to poor eye-relief. https://imgur.com/FkEaOBG
Hello :-)
Great advice already! Here some of my thoughts:
> 1
Check for old binoculars where you can just take the eyepiece, small magnifying glasses such as jeweler loupes, you can use them as make-shift eyepieces.
> 2
If you aren't in a hurry, you can get eyepieces cheap from Aliexpress. Otherwise Amazon. But many good budget eyepieces are currently out of stock.
Overview: 25mm, ideally 32mm Plössl ($26 via Amazon, $19 or less via Aliexpress)
Planets: 6mm 66° (not a cheaper short Plössl) for planets, already pushing it but it's relatively cheap and will work in most future telescopes. Usually these are $[29] via Amazon but sold out right now, you can find them for $35 or order them for $17 in China via Amazon Marketplace or Aliexpress.
ideally one in-between. (15mm Plössl or 66°, $20-$35)
Even with just two, you're already at $50-60 if you order them locally. A cheaper way can be to skip a short decent planetary eyepiece and just get a ~20mm for an overview and a cheap barlow (doubles or tripples the magnification, but reduces the contrast).
At $79.99 you can get a refurbished (Telescope.com) Skyscanner 100 with basic eyepiece, which has a larger aperture (shows more) and at least has two simple eyepieces (but also lacks a planetary eyepiece to really observe the planets, and it's not as good as a 5" table-top).
> 3
> unscrew
Usually you don't have to unscrew anything but pull off the front cap.
As it has been an issue several times, and people went to disassemble the bottom or even scratch things off to "look through properly":
Don't take off the back, this is how a reflector works: https://images.app.goo.gl/v2vSzsj3vcNRkVAL8
Remove the full cap https://imgur.com/kShN887
> 4
Yes, it's not overly intuitive :-)
Videos:
How to use an equatorial mount
And look at Orion's website for a manual (or Celestron's, the 76eq telescopes are identical).
> 5
No, color filters have very limited effect and make things very dim.
Light pollution filter are not needed for planets and are very limited.
A Moon filter isn't required as more magnification also makes things dim.
Solar filters: The sun's not that interesting in white light. Solar eyepiece filters are dangerous, throw away.
Nebula filters... I wouldn't get one for this aperture size IMHO.
> galaxy
Do you have binoculars? And a dark location? Andromeda is even visible to the naked eye if it's truly dark.
> 6
"Turn left at Orion"- the missing manual :-)
> kit
No, for $175 you can (almost) get a better telescope (even for $79.99 even...). So do not over-invest in accessories!
> dobsonian
You can get good dobsonians for $200-$280 that already show more.
Links on what to expect in different telescope aperture sizes.
> 7
Yes, they are interchangeable, but of course different telescopes have different focal-lengths and such, so not all eyepieces are useful in every telescope (e.g. a 3mm eyepiece might be useful in a very short table-top telescope, but not in a long focal-length dobsonian or cassegrain telescope as it results in too much magnification).
> Celestron eyepieces
Avoid ANY of their kits. Not worth it. Overpriced, mediocre, redundant.
> literature
> pinpoint exactly what I'm looking at
"Turn left at Orion" - the missing manual :-) :-)
https://stellarium-web.org/ or an app.
Clear skies!
I'd suggest a 32mm plossl as a must have for wide fields. Then it'd be nice to have an mid-high magnification eyepiece, between 8 and 15mm focal length. 8mm would be nice for planetary observations (which it isn't the season of yet, expect good views of the planets in the fall). Here's a pretty decent8mm eyepiece . 15mm is more for mid sized deep space objects, it can be a plossl as well.
​
The thing sticking up is your finder, a red dot finder to be specific. Learn how to align, it'll come very handy when looking for stuff
​
Since you're seem to have little knowledge I suggest you watch these videos to get a better grasp on telescope basics: https://www.youtube.com/playlist?list=PLqIRvigAC-kC\_DEdpp8cWx7NRLziZt0UH
Hello :-)
Great advice so far! :-)
Field of view simulation(!), 130/650 and magnification
http://blog.pixelgiraffe.com/wp-content/uploads/2016/03/130-650-high_3.png
http://blog.pixelgiraffe.com/wp-content/uploads/2015/11/awb_Heritage_Magnifications_small.png
As it was said, a 4mm will be plenty (~163x). 260x is often stated as maximum, but it's pushing things too much (dim, dull image, not really gaining detail despite the desire to "enlarge and enhance" ;-) ).
4mm HR Planetary clone (Random link; Check seller/item reviews. Aliexpress is sometimes cheaper)
Do not get a 4mm Plössl or set (horrible eye-relief makes it hard to observe at all) or 4mm "copper brim" 62° eyepiece (contrast and eye-relief aren't great, even though you can get them for under $10).
A barlow will work, but reduces the contrast a bit. For a decent one, you can afford a dedicated planetary eyepiece. There's a "5x Apo" chinese barlow that's more like 3x, for $8-$12, so it is a valid budget option (better than a short Plössl IMHO).
There are also the "gold-line" eyepieces, with a nice 66° apparent field of view eyepieces. It's only available as 6/9/15/20mm though. The 6 and 9mm can be modified though (adding a piece of tube as spacer between the barrel-element and eyepiece) to reach 3-4mm.
> able to get focused
It doesn't get easier with more magnification, the telescope needs to be collimated, cooled to ambient, and atmospheric seeing has to cooperate :-) Sometimes it just works better than at other times. Observing longer can help spotting more and more detail.
The telescope really shines for wide-field, so upgrading the kit eyepieces is also nice. If you enjoy wide fields, a 32mm Plössl would show a lot more field. 25mm are a bit cheaper. 40mm aren't worth it (too large exit pupil, narrower apparent field of view than the 32mm, resulting in the same field).
If you're happy with the kit eyepieces, a 4mm and 32mm would complete the set for now.
A 4mm HR Planetary, 6mm gold-line as moon eyepiece, 9mm gold-line as replacement, 15mm gold-line as replacement, and a 32mm for an overview would be a pretty ideal set- But even from Aliexpress and eBay, they cost over $100. So it would be quite the investment relative to the telescope.
Clear skies! :-)
Measure the eyepiece diameter. Or try - If they fit, they will work. :-)
The barlow and erecting eyepiece of such sets are usually garbage, they reduce the contrast and have very limited use. They work for bright stuff like the moon and during the day, but otherwise should be avoided.
Older telescopes have 0.965" focusers, modern ones 1.25". Smaller eyepieces in larger focusers isn't a problem with a simple adapter. The other way around is a problem due to the lack of back-focus on reflectors, as adapters put the eyepiece further out.
What eyepieces are those? Not the tubes, but the smaller ones, the one in the middle you're holding, and there's still one in the focuser.
They often have plastic imprints or markings such as H6 or SR12.5.
> code
> 114mm
Awesome! What marking exactly?
> mount is useless
Without seeing more images, and if you can't find the controller, I'd say so. A replacement part would probably cost more or will be hard to find.
Check the mirror (make a image). Dust doesn't matter really (don't clean unless it's gunk), corrosion or other damage will.
> try out making a rockerbox
As you have seen with the simpler ones, I used the cheapest wood (roof battens), simple materials (laminate flooring, chair felt gliders, pipe covers from the hardware stores... heck, we even tried using old cans for one of those mounts :-) ).
> an eyepiece
Focuser diameter? Can it fit 1.25" eyepiece barrels?
How much time do you have? If you're not in a hurry (or order it to the location you visit) you can get amazing eyepieces via Aliexpress or eBay from China.
How much do you want to spend on those?
Overview: 25mm-32mm overview eyepiece, Plössl type
Planets: 4.5mm-6mm eyepiece, HR Planetary or "gold-line" 66° type. More magnification isn't necessarily better, things get dim/dull!
One or two in-between, e.g. 15mm gold-line or Plössl. Medium magnification is ideal for a bunch deep-sky objects (faint, medium apparent size).
If you are only interested in moon and planets, you could skip the medium magnification or even the overview (but then "aiming" the telescope is pretty hard if the finder is not aligned 100%).
Field of view Simulation for a 114/900mm telescope
Apparent field of view of different eyepieces
If it's a 76/700 telescope though, more than 6-9mm will be way too much magnification.
> trying to justify
Have you observed with a telescope like this before? What would you like to observe?
Clear skies! :-)