Eyepiece Help For a Noob.

[TankBall]

so as the title says im a noob. i've also been into star watching and space but never really though about geting a telescope until now. now heres what made me really get into this, a VN called "A Sky Full Of Stars" but in 2015 in was released in japan. i did play it for a little and i knew at that time i will want to get a telescope. but never went to get one until the VN came to the west and has english subs. so after that i got myself a Vixen A80Mf Telescope (the same one use in the VN) now tonight i went out for my very time and really loved it. i just feel like i dont understand how to really look though the eyepiece i have. it come with a 20mm and a 10mm eyepiece. im using he 20mm cuz i can see more but it feel like im having to look down on the eyepiece and it doesnt feel like im looking at it in the middle. i also tryed the 10mm but that i do not understand how to use it. u cant see anything so i went back to the 20mm after that. now im looking at one of Vixens 40mm eyepiece to upgrade to. im wunding if that would be a good move to see more of the sky or what. im also wanting to see the Winter Albieo (also shown in the VN) now idk if i can see it using the 20mm or a 40mm eyepieace. 

 

Thx for your help and sorry about my spelling an grammar skills. i tend to do videos when asking something like this. i think once i get some sleep im make a video. also heres my telescope. 

[michaelmorris]

Excuse my ignorance, but what is a VN?

[Mak the Night]

Virtual Novel.

[Sunshine]

Your telescope has a focal length of 910mm, you say it came with 10 and 20mm eyepieces, the 10mm eyepiece will give you 91x magnification and the 20mm will give you 45x magnification.

divide the focal length of the telescope by the focal length of the eyepiece to find out what magnification an eyepiece will give you on your scope

910mm divided by 10mm equals 91x there are many types of eyepieces and each have their own qualities, i have no idea what your eyepieces are like but i can say that telescope manufacturers usually don't exactly provide their scopes with great 

quality eyepieces, especially beginner scopes. you mentioned you can't see anything through your 10mm eyepiece and this could be due to a number of things from the eyepiece field of view to the nature of the object you chose, the 40mm eyepiece you are thinking of will give you 22x magnification, this will give you a wider field of view and objects will be brighter, but it is a very low power and useful mostly for the moon really.

Eyepieces are the type of accessory that are very personal, everyones eyes are different and even if you and i were to look through your scope with the same eyepiece we may have totally different opinions, in the end you'll want a low, medium, and higher power eyepiece, you will have to experiment with eyepieces to find the ones you like most. 

 

[Mak the Night]

I have the same mount but with the heavy duty Hal130 tripod. Your scope has a slow focal ratio (f/11.2) so I'd consider a wider angle eyepiece such as a 25mm BST StarGuider which would give about a 36x magnification. 

Depending on where you are geographically, Herschel 3945 aka 145 Canis Majoris I think, is not far from Sirius, the brightest star.

 

 

[MarsG76]

I have the LV 40mm eyepiece. I imagine that it is similar to the Vixen 40mm.. they are good quality eye pieces and you will surely see some nice clusters and nebulae with it...

The eyepieces that come with scopes are generally low quality eyepieces, uncomfortable to use and as you discovered, you need to have you eye right on it... if you get a Vixen or LV or even better a Televue eyepiece, you will find looking through it much more comfortable and not only that the glass will be much better quality so you will see more through it.

Aim for a 20-40mm eyepiece with a field of view that is something not less than 60 but preferably 82 degrees....

 

[Stu]

4 hours ago, MarsG76 said:

Aim for a 20-40mm eyepiece with a field of view that is something not less than 60 but preferably 82 degrees....

The Vixen 80mf has a 1.25" focuser so best options for widest field would be either be a 24mm 68 degree afov such as the ES or a 32mm 50 degree afov Plossl. Anything wider will be a 2" fitting.

[MarsG76]

4 minutes ago, Stu said:

The Vixen 80mf has a 1.25" focuser so best options for widest field would be either be a 24mm 68 degree afov such as the ES or a 32mm 50 degree afov Plossl. Anything wider will be a 2" fitting.

Yup true... I had my 11mm Nagler 6 in mind when I was talking about 82 degrees FOV.

I stand by the 40mm LV.. it is only 42 deg FOV but crisp quality, sharp views and doesn't magnify much so that compensates for the low FOV.

[Stu]

51 minutes ago, MarsG76 said:

I stand by the 40mm LV.. it is only 42 deg FOV but crisp quality, sharp views and doesn't magnify much so that compensates for the low FOV.

40mm 1.25" eyepieces have their place. Keeping as large an exit pupil as possible in small maks which only have a 1.25" visual back is one significant place.

[Ricochet]

8 hours ago, TankBall said:

i just feel like i dont understand how to really look though the eyepiece i have. it come with a 20mm and a 10mm eyepiece. im using he 20mm cuz i can see more but it feel like im having to look down on the eyepiece and it doesnt feel like im looking at it in the middle. i also tryed the 10mm but that i do not understand how to use it. u cant see anything so i went back to the 20mm after that.

I don't know that I've seen someone have this sort of issue before. All I can really suggest is practice to get your eye positioning right. Using the telescope on distant objects during the day or using the moon once it is illuminated to a reasonable level will probably make things easier for you. The brighter image will make the exit pupil that you have to look through in the centre of the eyepiece easier to see. When you look into the eyepiece the field of view that you see should be inside a perfect circle. If the boundary isn't a circle you've probably got your eye in the wrong place so try moving your head slightly in each direction until you find the correct spot. It is also important to have your eye the correct distance from the top of the eyepiece lens. I see you have a 20mm Plossl so your eye will need to be about 14mm above the lens. If your 10mm is also a Plossl then your eye will have to be about 7mm above the lens. If you wear glasses then they will prevent you from getting close enough and so you will have to remove them to use this eyepiece.

This image shows the exit pupil on a binocular quite nicely. This central region is what you need to align your pupil with in order to see through the telescope.

With your telescope and eyepieces the exit pupils will be quite small. With the 20mm eyepiece it will have a diameter of 1.75mm and with the 10mm eyepiece a diameter of 0.88mm.

 

The other possibility is that your 10mm and 20mm do not focus at the same point. If the 10mm is a long way out of focus when switching from the 20mm it is possible you won't be able to see anything. In this case pointing the telescope at a bright object and adjusting the focus will be a good test.

[Mak the Night]

https://oneminuteastronomer.com/840/ngc2362/

More info on the 'Winter Albireo', I've been observing it for years without realising it was so well known. Its similarity to Albireo hadn't escaped me either. 

Sky & Telescope's Pocket Sky Atlas it's pretty easily found on page 27 (h3945).

[Mr niall]

Eyepieces can take a bit of practice to start with - when you say you couldn’t see anything through the 10mm do you mean you couldn’t see anything at all or you could just see black sky?

 

[Mak the Night]

And on Stellarium:

 

I was actually observing it earlier. Until clouds

[TankBall]

thx for all the replys. i never though so meany ppl with reply to help me out. im still a little lost so i made a video talking about where im lost and what not. 

 

[TankBall]

so a got to see Jupiter tonight, now it showed up white and idk if thats normal. i also tried to use the 6.5mm eyepiece that my telescope came with. now just like i said in the last video it was to dark with that eyepiece to see anything, so i have to go back to the 20mm and see any thing. now from what i saw i can get a eyepiece add on that can do good zoom ins even when your using a low power eyepiece but i forget what its called. im wonding if i could us that with my 20mm to get the same type of zoom like i would with the 6.5mm. but using the 20mm eyepiece.

 

[laowhoo]

Well I'm only one minute in but I see your first problem--you're left-eyed. Are those left-eyed eyepieces? (Sorry. Our daughter hates me for this. Going back.) Well first off, you nailed it. They're Plossls, wh/ means maybe 42 degrees field of view and difficult to use. With this comes eye relief issues, meaning you gotta suck your eye right up to it, and perfectly aligned, to use. And the higher the magnification (lower mm), the harder it gets. Worse still, using eyeglasses has everything to do with the eye relief difficulties. EPs with wider AFOV (apparent field of view) will solve most (or all) of this for you. NOW, what you want is somebody who splits doubles to recommend a WFOV EP for those targets, and one which also offers longer eye relief for your glasses. Good video.

[Mak the Night]

This little wheel is the focuser knob, you are using this right? It focuses on the target. Sorry if this seems like a silly question. Mars will just be a red blob until opposition later in the year when it gets much closer. Jupiter is notoriously difficult to see detail, mainly because of atmospheric conditions. I wouldn't go higher than about 150x. The four dots of light around it were the Galilean moons. Jupiter will also improve later in the year. 

[laowhoo]

Video #2 The planets are pretty far away right now and will look less than spectacular. Remember, your initial targets were doubles, then to grow upon...don't go spending big bucks on EPs til someone says what's best for your interests and with your glasses in mind. Bottom line--you want long-ish eye relief for your glasses, and for field of view you probably want something better than a Plossl design, but don't go out and spend $150 on one EP just yet. Others will recommend the better EPs for your scope/glasses/interests (types of objects--I've been viewing 5 years and still haven't split a double, well not deliberately anyway). So check out the different EP designs and see where they excel, how they've developed over time, etc. The Plossl actually isn't bad, but it works better in the hands of somebody more experienced.

[brantuk]

Have a look at some of the main stars in the plough (Uma) - some of those are doubles and are easily split with binoculars.

[Ricochet]

8 hours ago, TankBall said:

thx for all the replys. i never though so meany ppl with reply to help me out. im still a little lost so i made a video talking about where im lost and what not. 

 

Looking at this first video it looks like you've got all the general ideas right. It looks to me like the main problem you've got is with the specific eyepieces supplied with your telescope. With the 20mm I notice that the eye relief (distance between your eye and the lens) is so great that you're making a "tube" with your hand to position yourself.

With the 6.3mm the eye relief is really short (4mm) and the dim image that you're seeing is what you would expect. As you increase magnification you're spreading the light your telescope takes on over a larger area and so it appears dimmer. Generally the magnification limit for any telescope is given as 2x the aperture in mm, or when the exit pupil equals 0.5mm. To find the exit pupil you divide the focal length of the eyepiece by the focal ratio of your telescope (11.375) so your 6.3mm eyepiece produces an exit pupil of 0.55mm which as you can see is right on the limit for your scope. 

Personally, I think that in this case some different eyepieces might be a help to you. I also struggle with eyepieces that require you to "hover" over the eyepiece and find eyepieces with an adjustable height eyecup much more comfortable to use. I'm guessing you're from the US so the eyepiece ranges I would suggest the you look at are the Agena Astro Starguider/Astrotech Paradigm and the Celestron X-cel LX ranges. I can use the Starguider/Paradigms both with and without glasses but I believe the X-cel LXs have a couple more mm eye relief and so might be a safer bet for use with glasses. A 12mm and 25mm in either range would probably be a good start. 

If you can find any local astronomy groups it would be worthwhile seeing if they have an observing night that you could attend. This would give you a chance to try some other eyepieces for ease of use without the need to buy. 

As for an eye patch it is a good idea. Many of us use one to block out the light from the non observing eye. 

[domstar]

I suggest sitting on a chair. When the scope is pointing up at more of an angle it will fit your eye better especially if you are sitting comfortably at the right height. I had the same problem of not looking directly through the eyepiece mostly when I was standing up and my neck was bent. 

Beautiful scope by the way.

[LukeSkywatcher]

On 1/15/2018 at 12:16, Stu said:

40mm 1.25" eyepieces have their place. Keeping as large an exit pupil as possible in small maks which only have a 1.25" visual back is one significant place.

Yes they do.....in the bin.

LOL.

I bought a Celestron 40mm E-lux secondhand from a fellow SGL user a few yrs back to try to replace my 32mm GSO ( I know........what was i thinking?. You can only replace a 32mm GSO with another 32mm GSO).

Terrible experience altogether. It was like looking through a tube of smarties. I quickly moved it on. 

P.S.~ IMHO Vixen make quality products at afforable prices. If i had a Vixen scope, i'd compliment it with Vixen EP's. I have 4 Vixen EP's and love them.

When i was researching scopes online with the intent of buying an 8" scope i was seriously considering a Vixen VMC200L

 

[Mak the Night]

On a slow scope like the Vixen A80MF getting a wide enough exit pupil can be problematical. It's not unlike a 90mm Maksutov telescope as it has a relatively small aperture width in relation to its focal length.

https://en.wikipedia.org/wiki/Exit_pupil

https://en.wikipedia.org/wiki/F-number#Focal_ratio

If you want to sweep star fields and look at most stars and deep sky objects you will want lower power magnifications. This may be why you aren't having much success seeing anything. Your scope is a bit on the powerful side, ideal for high powered planetary viewing, but probably not so hot at low power. Low magnifications = wider exit pupils. 

Wide angle eyepieces can be expensive, but a good 30mm Plossl should give 30x on your scope.

I find 40mm Plossls can be very useful on slower scopes, they may have slightly less fields of view but they will allow you to get down to around 23x on your scope. Don't underestimate the 40mm Plossl. They don't have to be expensive either.

Another way of getting low power is to thread a focal reducer onto an eyepiece to double its focal length. 

An 0.5x reducer threaded onto a 25mm Kellner (shown above) can turn it into a 50mm eyepiece. This gives around 18x magnification on the Vixen A80M. There may be some vignetting around the edge of the eyepiece, but in the main it can be a practical solution to get low power (wider exit pupil) on an f/11 scope. I have similar problems on 90mm, 102mm and 127mm Maksutov Cassegrain scopes, which also have slow focal ratios.

[TankBall]

Thanks again for everyone's help im trying to understand eyepieces but everyone it more or less going over my head since im so new to this. since i have Autism (im in the high end) im more of a hands on learner. sadly here in north west arkansas there r like no astronomy clubs/groups i can go to. the closest one in 3 hours away in little rock. i think i'll want to do this to make it easier for me to understand what i should get. would u guys be willing to give me a list of the type of eye pieces i should get to see the stars i want. right now i want to see Winter Albireo since its a part of the VN i was playing and then i want to go on from there. also what pieces should i get to see the plantes. i also did some looking around and i fond out what i was also talking about. would geting something like a SVBONY Barlow Lens 5x 1.25" be a good idea for what i want to see? like i said i really like how im going so meany ppl on here to help me out but it just goes over my head and i have look at some videos on youtube to for help. 

[Mak the Night]

OK, sorry, it can get a bit technical.

1/ Your telescope is better suited to magnifications of around 80x to 160x. In other words it will be great for the Moon and planets. It has a narrower field of view than my Orion 80mm refractor shown below. It's the same size aperture as yours but my telescope is half as long. Because of this it has a wider field of view and is better at lower magnifications. It's sort of opposite to yours. It's better suited to looking at stars and nebulae. 

 

2/ You will be able to view anything with your scope, you just have to take this into consideration.

3/ I'd recommend three basic eyepieces. Ideally you want:

A/ A low power eyepiece for stars, star clusters and things like the Winter Albireo. Something that will give about 30x. You can't go wrong with a decent 32mm Plossl.

https://agenaastro.com/gso-32mm-plossl-eyepiece.html

I've got one of these, it is pleasant to use and will give you about 28x in your scope. I can see the Winter Albireo at this magnification (I actually saw it tonight lol).

B/ A medium power of around 60x. This will be good for star clusters and the Milky Way. 

https://agenaastro.com/gso-15mm-superview-eyepiece.html

I'd recommend a GSO 15mm SuperView. It has a 68 degree field of view and is quite nice to use.

3/ I'd hold off buying a Barlow for a while. Your scope is quite powerful as it is and you certainly won't need a 5x Barlow. The maximum magnification for your scope is about 160x anyway. 

4/ Finally you could get a 6mm GSO Plossl. This will give you about 150x for looking at planets and the Moon.

https://agenaastro.com/gso-6mm-plossl-eyepiece.html

None of these eyepieces are that expensive. That's my choice of three eyepieces for your scope. A low power 32mm for stars and the Milky Way, medium power 15mm for stars, clusters and nebulae, and high power 6mm for the Moon and planets. 

I hope this is of some help.