Apochromatic queries

[Dieselwheasel]

Hello everybody,

I have very tight space constraints in my small house andI had been thinking about an Apochromatic telescope as I thought they were smaller than others but the price is very high. Why are they so pricey and what else could I use that's small enough to store away when not in use and be able to transport to the countryside. I might add that I would very much like to see as much as possible in the sky from the moon to deep space and later on take photos?

Cheers,

[Starhoparfa]

Hello everybody,

I have very tight space constraints in my small house andI had been thinking about an Apochromatic telescope as I thought they were smaller than others but the price is very high. Why are they so pricey and what else could I use that's small enough to store away when not in use and be able to transport to the countryside. I might add that I would very much like to see as much as possible in the sky from the moon to deep space and later on take photos?

Cheers,

Sky-Watcher Heritage 130P Dobsonian.

A great 'grab and go scope' that you just take outside and point- it has no set up requirements. Ours will transport upright (still on its base) in the corner of the boot of our Vectra.

Edit: sorry it's a reflector, not a refractor but I'm very pleased with the views I get of Jupiter as well as DSOs.

[rowan46]

the reason apo's are so expensive is mainly because they are more expensive to make and partly because people will pay more for that extra perfornance. other portable designs besides the heritage dob

First Light Optics - Celestron NexStar 6SE

First Light Optics - Skywatcher Skymax 127 SupaTrak

the celestron c5 spotting scope can be picked up for about 200-300 used and with a good alt az tripod makes a good portable scope as a nexstar 5 however it is a little overpriced

[hunterknox]

They're pricey because they're made of fancy glass and use short focal lengths, which makes it hard to get the lenses 'just so'. If you want to get into photography then the mount is going to have to take up far more space than the scope.

Also consider some of the small Maksutov-Cassegrain type telescopes. Very neat, very useable and a better choice for planetary photography or visual deep sky stuff (and conversely pretty useless for deep sky/wide field stuff).

[Peter Drew]

Apochromatic refractors, ones that exhibit little or no false colour contain two or three elements of exotic glass which is very expensive and difficult to produce to the necessary high quality. The most compact telescopes are the Maksutovs and Schmidt-Cassegrains, they give pretty good all round performance, are sensibly apochromatic and less expensive than the refractors. When it comes to photography you will probably have to have a complete rethink and most likely an alternative or additional instrument.

[Dieselwheasel]

Thanks so much for the replies very helpful. I am just starting out and I think I may have to rethink the APO. I was going by what I was told by someone at an astronomy talk I visited recently who said that cassagrains are not very good in scotland due to the atmosphere here or something. To be honest i was kind of lost and it disheartened me a little to find out that i would have to spend over £1500 to get e decent view of anything.

[AndyH]

Oooh. You were given bad info.

Whilst we don't get brilliant steady skies, in Scotland or the UK, one of the cassegrain types WILL work very well and let you have a compact scope.

Andy

[Chris H]

If it's for observational use you don't need an Apochromatic refractor, don't know what the person meant about Cassegrains (SCT) unless they were referring to dew. The front lens on an SCT needs a dew shield and maybe a small heater strip that stops dew forming on it. You certainly don't need to spend £1500 the Skywatcher Heritage mentioned by Starhoparfa is a very good scope for £135 compact too hardly takes up any room but it is a bit small and can be awkward to use if you don't have something solid like a picnic table to put it on.

If your tight on storage space a Skywatcher Skyliner 150 Dob (£197) really doesn't take up that much room just stand it in the corner of a room and there you go, much easier than having to find room for a tripod, apo telescope and tube rings.

[Dieselwheasel]

Once again thanks for all of your help. To further help me I have £500 to spend what would your recommendations be for someone who is starting out but is reluctant to change telescopes every few years. I would like something that may last a while with the aim to maybe upgrade or add to the collection?

Cheers,

[E621Keith]

In addition to exotic glass, APO also have more glass to polish. In a newtonian, there is one surface that needed to be polished to a high precision plus one small optical flat for the secondary. An triplet APO on the other hand has six precision surface, hence six times the work. Even a doublet has 4 precision surface.

If you want compactness, a Celestron C6 is hard to beat, but when you add the mount, it will be similar to the size of a dob. You can use the C6SE as a table top scope. In which case it will probably be the smallest 150mm you can get. You can pick up a used C6SE for around £500.

[rwilkey]

As suggested above, you only have to look at the spec of the 150P Dobsonian to see how much you get for £197, that's unbeatable, and it will store nicely in more-or-less upright position in the corner of a room. My vote is for this scope, you cannot do better!

[MikeWilson]

Hi there,

I might add that I would very much like to see as much as possible in the sky from the moon to deep space and later on take photos?

Cheers,

To further help me I have £500 to spend what would your recommendations be for someone who is starting out but is reluctant to change telescopes every few years. I would like something that may last a while with the aim to maybe upgrade or add to the collection

The "what should I buy" question has been answered quite a bit on the forum over the years but in short:

1. There's absolutely nothing wrong with a Cassegrain design and there are many happy Cassegrain scope owners in the UK

2. There's no one scope that does everything well - it's all about compromises

3. The eyepieces that come in the box with scopes are usually poor quality and there's a big contrast between these and the higher quality glass eyepieces.

4a. Deep sky astrophotography requires a tracking mount (ideally a HEQ5 or EQ6) which are above this budget.

4b. Planetary/solar system astrophotography can be done with a special webcam or even holding a camera up to an eyepiece and snapping away.

Now, telescope designs:

More aperture = Better deep sky views and higher resolution views of solar system objects.

Focal length = Longer = more zoom (and generally dimmer) so better for solar system objects but worse for deep sky objects. The opposite is also true, many deep sky objects are quite wide and benefit from a shorter focal length but this in turn reduces their effectiveness on solar system objects.

So considering your budget:

- Cut out any GOTO/Tracking to put the funds towards better optics.

- Cut out any lower end EQ mount (because you said that you want to avoid upgrading/replacing later)

[Dieselwheasel]

many thanks, this has been most helpful. Do any of you rate the Meade ETX range as they look fairly compact too?

[John]

... Do any of you rate the Meade ETX range as they look fairly compact too?

Optically they are fine but I've seen lots of issues posted regarding the reliability of their mounts, enough to make me wary of them.

[MikeWilson]

many thanks, this has been most helpful. Do any of you rate the Meade ETX range as they look fairly compact too?

As John says - issues with mounts. Plus, I think they're a tad on the expensive side for what you get.

Back to your original question, you want to observe things? Then you'll need eyepieces.

Revelation Photo-Visual set (http://www.firstlightoptics.com/eyepiece-sets/revelation-photo-visual-eyepiece-kit.html): £125

or (better..)

Baader ClickZoom: (http://www.firstlightoptics.com/baader-planetarium/baader-hyperion-zoom-eyepiece.html): £169

Those are good to get going with.

Next, a scope..

Portable grab'n'go: Heritage 130P: (http://www.firstlightoptics.com/dobsonians/skywatcher-heritage-130p-flextube.html): £135

or much better: 200P Dob: (http://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html): £270

Then you'll need a basic tool to collimate with: £15-20 ish

These are Apochromatic telescopes, the first is 5 inches and the second is 8 inches. The focal length of the 200P is 1200 and at 8mm on the Click Zoom eyepiece, that'll give you 150x zoom. With a 2x barlow you'll get 300x zoom which is about the useful limit of the scope during average seeing.

Second hand saves money too. SGL used to have an excellent For Sale & Wanted section which I think is coming back but in the meantime you've also got Astro Buy & Sell.

Both of the above two scopes are Dobsonian-mounted Newtonian Reflectors. That means that the mount is rugged and as cheap and simple as possible.

The Cassegrain scopes will limit your potential for deep sky observing, but they're proportionally better on planets and the moon and also more portable.

So it's up to you

All the best,

Mike

[MikeWilson]

As space seems to be an issue for you - I'd go for the Heritage 130P. That looks to be a terrific small scope with substantial aperture for the money.

[Darrent]

Also looking for something smaller that can offer a little of everyrhing with astrophotography alongside. Considering the Startravel 102 or 120 although not sure about the mount. Will by better EPs at the same time. As purchasing a scope. Do I need EQ or AZ?

[LukeSkywatcher]

The Heritage takes up less storage space then a small vacuum cleaner. It is also a damn sight better for observing with then a vacuum cleaner.

[rowan46]

The Heritage takes up less storage space then a small vacuum cleaner. It is also a damn sight better for observing with then a vacuum cleaner.

it's not as good as a vacuum cleaner for cleaning your carpets though

[Byz1453]

Don't forget that there are plenty of astro societies that you can go along to and see examples of scopes in practice.

From your earlier post it sounded like you are in Scotland. There are many good societies up here as well as a small band who get together informally whenever the clouds allow - the central Scotland observers group

Feel free to get in touch with any of them and hopefully you will get the chance to see some of these scopes in anger

A word of warning however, aperture fever can take hold at any stage, specially when you see some people's pride and joys. Happened to me the other night with Tom's (Albireo380) 14" Dob...

But don't worry there's all sorts of us out there with all kinds of scopes...

[E621Keith]

Also looking for something smaller that can offer a little of everyrhing with astrophotography alongside. Considering the Startravel 102 or 120 although not sure about the mount. Will by better EPs at the same time. As purchasing a scope. Do I need EQ or AZ?

If you want a small astrophotography platform, you will need an Astrotrac, it is the only lightweight that can handle a small scope and still be accurate enough for long exposure astrophotography.

The HEQ5, normally considered the minimum requirement for astrophotography, is big. Long exposure astrophotography requires big mounts. EQ5 and other smaller EQ mount just won't do.

[Dieselwheasel]

God it all gets so confusing and here was me thinking it was going to be easy. Rock up buy a telescope and away we go. I guess my real problem is that I want to be able to pack the telescope away when I am not using it and that will be first and foremost. What size is the Skywatcher Explorer 200p Eq5 as it seems to get good reviews?

[John]

Here is one of our members beside her 8" and 5.1" Skywatcher newtonians:

http://stargazerslounge.com/1674991-post1.html

[Dieselwheasel]

I have to agree, that is too big for me to lug around. So it looks like I may go for the Celestron SLT 127 or something similar.

[AndyH]

A 5"/127mm SCT or Maksutov will provide lovely views in a nice compact package. I don't think you'd be dissapointed.

Edit: Plus, you could sit down to view. Something that I prefer these days. I don't use a fancy schmancy astro seat, but an old creosote drum and scabby cushion. As these styles of scopes are what we call 'slow', you don't need expensive eyepieces to get the best out the scope.

Andy.