Small aperature refractors? I don't get it?

I don't want to start a flame here. However, I seriously don't understand the love for small aperature refractors. I honestly want to know. Why would I buy a TV85 for instance instead of a 125/127 MAK at 3X the price?

I'm wanting to purchase a grab and go that I can use to view planets and the brighter dso's. Sometimes the NS11 is just too much to set up for a 1 hr viewing session. With all of the hype about the 80ED's, the TV 85's, etc I honestly don't know what to do. I have a ST102 celestron and quite frankly it's worthless for planetary viewing.

Any constructive advise and insights would be appreciated.

flame suit on
brian

Well for one thing, as a grab and go the Mak will need more cooldown.

A small APO refractor will give you the steadiest
view (least atmospheric impact) while giving
you the brightest, highest contrast image
possible for that aperture. It will be a
nice looking image even if seeing conditions are
bad. If I take out a TV85 and look at Saturn
90% of the time I'll think "what a nice image!"
If I take out an big Dob and look at Jupiter,
90% of the time I'll think "man I wish the
seeing was better. I hauled that monster out
here for that?"

Of course, nothing is going to beat aperture
on those rare nights with great seeing. And
some lucky people get great seeing all
the time (Florida?). They will never fully
understand why other people like small refractors.

Different folks have different perspectives, interests, and needs. I like lunar and planetary viewing, and for planetary viewing I'd be unhappy to be restricted to anything under 8". I do own a 90mm APO, though. It is quick to set up, provides wide field views that are not available through any 8" telescope, doubles as a birding/nature scope, and does a surprising job on some deep sky objects under dark skies. It's just a lot of fun to use, and to push to its limits.

There are a lot of things other folks do that I don't understand, but they are not me, and I am not going to worry about what drives them.

Clear skies, Alan

Hi Brian,

That's the beauty of Astromart. Check the ads, and if a good deal comes up on a scope you want to try, go for it. If it's not your "cup of tea", then you can usually re-sell back on Astomart for close to what you paid.

30" dobs may be the exception here.

Small scopes are especially nice this way, as they are hardy survivors of shipping.

Try a few out then let us know what you think.

Don't forget the "Cloudy Nights" review website. Lots of nice firsthand info there.

Again, the age old advice.. check out a star party if you can. Many scopes will be found there.

The C5 may be for you also. Aperature and very small size.

For me, the Sky 90 seems to hit all the bases. Decent aperature, very small, sharp images, great wide fields, well built but not heavy, and loves power also.

David Simons

Attached Image:

I have just acquired what I consider to be the ultimate scope for me (limited by budget, portability etc), a 12.5-inch Newtonian. However, I'm thinking about purchasing a small refractor as a supplement, probably an 80mm in the f/6 range for low power wide field viewing. When I have the opportunity to observe under dark skies and good seeing conditions, I will always use the Newtonian. Quite often, however, conditions are less than perfect, and why not use the opportunity to pan the star fields with low power, and use the scope on clusters like M44, M45 and M39?
Anyhow I do not intend to spend very much money on the small scope. I will probably select optics that give decent images up to a power of about 40x, and leave high magnification work for the reflector.

I can't offer any logical reasoning for my affection for these things. I just can't stop myself. I always seem to have 2 or 3 on hand at any given time. Here's a list of ones that I've owned:

2 Short Tube 80's (One each Celestron and Orion)
UO 80mm refractor kit
TV 85
TV Ranger
TV Pronto
and currently,
TV 76
Celestron/Vixen 70mm Triplet Semi-Apo

Don W

I don't want to start a flame here. However, I seriously don't understand the love for small aperature refractors. I honestly want to know. Why would I buy a TV85 for instance instead of a 125/127 MAK at 3X the price?

I'm wanting to purchase a grab and go that I can use to view planets and the brighter dso's. Sometimes the NS11 is just too much to set up for a 1 hr viewing session. With all of the hype about the 80ED's, the TV 85's, etc I honestly don't know what to do. I have a ST102 celestron and quite frankly it's worthless for planetary viewing.

Any constructive advise and insights would be appreciated.

flame suit on
brian
**********************************************
I'm a scope lover of all types! But i love the small APO's in the 75mm to 102mm range, nothing beats them for that snap in focus, or that perfect high power star image or contrast. I have a Brandon 94mm thats as sharp as anything out there, it easy to use and move around, makes a great solar scope, as well as using powers up to 400x!

Chas

Everyone has covered most of the pros and cons, but no one
mentioned my problem.

I have a 102f6.6 Vixen/Orion, a TMB 100/f8 and a 108/f15
Jaegers (now that's tradition), among the many reasons,
a primary reason is because...

I can't afford and don't have the space/strength for a
BIG refractor.

With turbulent skies and background city lights, these little guy yield a higher percentage of good viewing.

J
guys

>>>I'm wanting to purchase a grab and go that I can use to view planets and the brighter dso's. Sometimes the NS11 is just too much to set up for a 1 hr viewing session. With all of the hype about the 80ED's, the TV 85's, etc I honestly don't know what to do. I have a ST102 celestron and quite frankly it's worthless for planetary viewing.
----

Small refractors are popular because they make good companions for larger longer focal length scopes such as your NS 11. A 5 inch MAK is more portable than the NS-11 but there is nothing it does that the NS-11 can't do.

A good quality, small refractor on the other hand, can provide widefield views, split double stars, and provide some decent planetary views at the same time. It will also double as a decent scope for terrestial viewing, something a 5 inch MAK will not do.

The old rule of thumb which has some analytical support is that one subtracts the central obstruction from the aperture to get the equivelent unobstructed scope. This says a 125mm Mak with a 35% central obstruction would be comparable to an 81 mm unobstructed scope...


I agree with Alan French, if I want to do some planetary viewing, I want at least 8 inches of aperture to work with. If that Nextstar 11 is too much to haul out and get going, consider a DOB, it will require cool down, probably no longer than the 5 inch MAK and the setup time is minimal and will provide some fine planetary views.

The problem with the ST102 is that it is a 4 inch F5 scope, not too much hope for planetary viewing unless you mask it.

jon