New Binoculars or a Telescope

[Radium]

I have recently been enjoying the night sky through a pair of 10x50 binoculars. I was wondering if purchasing a pair of 20x80 binoculars would show a marked improvement in what I am able to see. They come with a tripod mount, and I already own a sturdy camera tripod on which I could mount them. They are used binoculars, manufactured by Celestron, and I have already been able to confirm that they work, and are properly collimated. 

I am not sure how to judge binoculars though, I read somewhere that the aperture divided by the magnification shows the resulting size of the exit pupil and that ideally this is around 6 or 7mm. My current binoculars produce a 5mm exit pupil and the 20x80's will produce a 4mm exit pupil. Will this make them worse for observing the night sky despite the larger aperture?

These are fairly inexpensive binoculars, and my hope is that they will allow me to get much better visuals than the 10x50's I'm currently using without breaking the bank while I save up for my first telescope. Would I be better off just waiting and purchasing the telescope though?

[baggywrinkle]

You would get more magnifying power plus the larger size of the objectives would mean they would also grab more light allowing you to view dimmer objects.

Also have a look at http://binocularsky.com/ a very good website for binos, good advice and tips.

[NGC 1502]

Hi from the UK. Always tough to give advice because what suits me may not suit yourself.

Your current 10x50s will have a wider field of view, probably 5 or 6 degrees, 10-12 moon diameters, will be easier to hand hold, compared to 20x80s.

The 20x80s will probably have a field of view of around 3 degrees, 6 moon diameters, enough to encompass most large deep sky objects like the Pleiades, Beehive cluster,

Coathanger and many more. They will show most objects to better effect than 10x50s, as long as the tripod you have is a solid one. Hand holding them is a non starter.

Personally, I don't like too much large exit pupils, the background sky is too bright. I prefer exit pupils a bit smaller than 6 or 7mm, the background sky is darker giving more contrast between object and sky. Partly that's because I do most of my observing from a light polluted town.

If you have better skies, that's less of an issue, but even from a dark site, I don't like very large exit pupils because it shows up the minor astigmatism in my eyes.

That's because the exit pupil is using more of my eye's dilated pupil outer regions. YMMV on that.

But I think it's best to see what others say, not just me. There are many factors that govern choice of kit.

If you can mount the 20x80s solidly, they will give fine views.

All the best in your choice, Ed.

[Radium]

Thanks for the replies guys. I think I will pull the trigger on the 20x80's. Even though they're quite large for binoculars, I feel like they will always be much easier to carry/set up than a medium size telescope, and I will probably continue to get use from them even after I get my first telescope. I have been loving my 10x50's and was really surprised by just how much more I could see with them than with the naked eye. I was mostly just afraid that the smaller exit pupil of the 20x80's would have an adverse effect on what I was able to view through them.

Hi from the UK. Always tough to give advice because what suits me may not suit yourself.

Your current 10x50s will have a wider field of view, probably 5 or 6 degrees, 10-12 moon diameters, will be easier to hand hold, compared to 20x80s.

The 20x80s will probably have a field of view of around 3 degrees, 6 moon diameters, enough to encompass most large deep sky objects like the Pleiades, Beehive cluster,
Coathanger and many more. They will show most objects to better effect than 10x50s, as long as the tripod you have is a solid one. Hand holding them is a non starter.

Personally, I don't like too much large exit pupils, the background sky is too bright. I prefer exit pupils a bit smaller than 6 or 7mm, the background sky is darker giving more contrast between object and sky. Partly that's because I do most of my observing from a light polluted town.

If you have better skies, that's less of an issue, but even from a dark site, I don't like very large exit pupils because it shows up the minor astigmatism in my eyes.
That's because the exit pupil is using more of my eye's dilated pupil outer regions. YMMV on that.

But I think it's best to see what others say, not just me. There are many factors that govern choice of kit.

If you can mount the 20x80s solidly, they will give fine views.

All the best in your choice, Ed.

[Charic]

I'm in preference to wide angle views, and my 8x40s provide that result.

Younger healthy eyes are quite capable of achieving a 7mm dilation when properly adapted to nighttime conditions, so a 7x50  (50/7=7.14mm) will be of some benefit to those users. They will give wide and generally brighter views. You can have too much exit pupil, which although the image wont be any darker, its just wasted because you cant capture all the light in your pupils.  As you increase the magnification, your images will get closer, compared to naked eye observation, but this increase in magnification  magnifies any  handshake movement, therefore requiring the tripod or similar mount. Its often recommended that a good all round 10x50 pair of binoculars, depending on brand, are comfortable and light enough to hand hold for some time, Even just resting the binoculars on a pillow, on a wall, keeps them steady. Also  any magnification increase  ,reduces your field of view, but enhances contrast  with the background, and the more aperture you have allows you to see fainter objects, at the expense  of the manufacturing  costs incurred  with  such larger optics.

There is no real win-win situation with binoculars, except that they work very well during the Day and at Night. Each pair has its own special attributes, like a tool in a tool box. You just have to try and borrow or test instore to see what feels comfortable, and what's affordable.

I have the cheapish 15x70 Revelations, but I don't see any Planetary details on the surface of jupiter with them. But I do remember seeing the shape of Saturn many Years ago with some 20x80s, but those 20x80's were  oh so heavy, and I wasn't able to see  whole constellations, only single stars due to the limited field of view. You won't get telescope quality magnifications, often required for planetary work, but every telescope user should have some binoculars. Which ones................? back to you!

[Peter Drew]

Although I'm a binocular enthusiast I would recommend upgrading to a telescope. The 20x80's would give you some benefits over your 10x50's but you would stll need a similar mounting setup  for the 20x80's as you would a 80mm-100mm short focus refractor. The refractor would make it possible to use similar low powers with even wider fields with suitable eyepieces and would also show far greater detail on almost everything.  Keep the 10x50's though.     

[Digger1895]

I'm going against the grain of what's been said above.

You already a decent pair of binos and upgrading to a better pair will not give you anywhere near the same "wow factor" that you will get from a smallish telescope. Keep the binos you have and save a bit more and get an 8" inch Dob, this will really open up the skies for you.

[Chris]

I'm with Peter, keep the 10x50 bins and get a scope as your next purchase, this will give you the best of both worlds. There are numerous scopes that are very quick to setup and light to carry, often refered to as 'grab and go' scopes, as said there are lots of little short tube refractors about some come with integrated tripod mounting shoes so you can plonk them on your camera tripod. others scopes that are plonk and go include small dobsonians, FLO have a 6" f8 Dobsonian in there clearence section that would do anybody proud and its only 170 pounds, they also have a noice little 130mm Celestron on a light weight EQ mount for around 120 pounds and its motor driven to track with the Earths rotation. 

As for exit pupil 5mm is optimal across the board age wise, and as long as you don't go below 1mm you will be fine

[LukeSkywatcher]

I agree about keeping the bins you have and getting a scope. Sure 20x80 are a marked difference from 10x50, but they cant compete against a scope.

[Astro Imp]

I'm with the majority, keep the 10 x 50 bins you already have and then decide what scope you want to add.

[Radium]

Thanks for all the additional replies guys. It seems like the consensus is to hold on to my current binoculars and save up a little more for a telescope.

Funny enough, I'm torn between a smaller refractor for better portability, or an 8 inch dob. I really want to get something that I will be able to do some DSO viewing with, so I will probably go for the dob. 

Thanks again for all the replies.

[ollypenrice]

A dob is perfectly car portable and, with it's small vertical footprint and stability when just plonked in a corner, can be less bother to store than anything on a tripod, which needs to be 'kept under control' when stored.

Olly

[Hootsitabernacle]

def a scope!

[RT65CB-SWL]

Whilst I agree with all comments mentioned, one thing 'we', (ie the more experianced SGL members), tend to forget, the amatuer astronomer who has to reply on public transport.

Therefore the 20x80 binoculars, or maybe a 'small' but sensible short tube refractor, eg the TeleVue TV85 or catodioptric (ie Mak or SCT) upto 105mm objective, as these can be stored in a flight case and if not bulky, maybe part of your carry on/hand luggage/cabin allowance if you do a lot of air travel, and save on storage space in the home too.

Another useful piece of advice too. Visit a star party and your local astronomy society/club and get feedback from members too. Also visit some local dealerships too rather than relying on Internet, unless you know they are well established dealers for your final purchase. That way you can see and 'try before you buy' and get the sizes into perspective.

BTW, welcome to SGL 'Radium'

[happy-kat]

Keep the bins you have.

You might find a small 80mm refractor could work with the tripod you already have.

Mine in light polluted garden showed me the main bands on jupiter and oh so light to use. Can't wait to see what orion looks like.

[Radium]

I'm pretty set on either an 8 or 10 inch dob for my first scope. Probably the Orion XT8 or XT10. Not the intelliscope versions. After I get my first scope, the next purchase will be a solid equatorial mount. My end goal is astrophotography, but I have a lot of learning to do in between.

A dob is perfectly car portable and, with it's small vertical footprint and stability when just plonked in a corner, can be less bother to store than anything on a tripod, which needs to be 'kept under control' when stored.

Olly