4" refracter - a good all rounder?

[johngccfc]

obviously it has the advantage of being used for AP too

would it be a smart move for an only scope ?

thx

[Naemeth]

It depends - a 4" APO is much more expensive to manufacture than a 3" APO, but visually the extra inch in aperture would help.

I don't think it's a matter of finding an all-rounder, because you'll end up with a compromise whichever way you do it (for example, a Tak 85 FSQ is an amazing widefield AP scope, but is blown away by a C11 for planetary work and for small DSOs visually - and it's also cheaper). This is why many of us end up with more than one scope - one scope doesn't do everything.

[fondofchips]

It depends - a 4" APO is much more expensive to manufacture than a 3" APO, but visually the extra inch in aperture would help.

I don't think it's a matter of finding an all-rounder, because you'll end up with a compromise whichever way you do it (for example, a Tak 85 FSQ is an amazing widefield AP scope, but is blown away by a C11 for planetary work and for small DSOs visually - and it's also cheaper). This is why many of us end up with more than one scope - one scope doesn't do everything.

I would agree with this, I own a 4" Lyra refractor telescope but will have to use another scope probably a reflector for DSO work, one telescope will not do everything.

[John]

For a few years a 4" refractor was my only scope, firstly a Vixen 102 F/9.8 and then a TAL 100. I didn't image with them and enjoyed their performance on the moon, planets and binary stars but, as soon as I tried a larger aperture newtonian I realised that 4 inches aperture does restrict what you can see of deep sky objects.

If I had to have just one scope now it would either be a 6" or 8" dobsonian I think. No good for imaging but good all rounders for visual, especially the 8".

[rowan46]

If it was the only scope you will ever own and you intend doing ap as well as visual yes it will do it. but as qualia has pointed out it will not do everything well. it will not be great on planets for visual or imaging as I think you need 6" for decent resolution of planets and to get a half way decent chance of seeing most dso's you need 6-8" apparture but you will certainly be able to image with it. smaller apparture scopes are not the best for viewing but they are not hopeless. I have an 80mm and derive a lot of pleasure from my scope but I would prefer more apparture

[Moonshane]

bear in mind that some 4" scopes have a long focal length and therefore a slow focal ratio - not good for most imaging, a 4" scope is a good scope but personally I find it's not worth observing with less than 6". each to their own and many will totally disagree with this viewpoint. unlike many refractors the average newtonian (of 6" aperture anyway) has a fast focal ratio of f5 so would be good for imaging too.

[Ags]

Not all 4" refractors are good for imaging. Yes, an APO might be (but it would need a heavy equatorial mount), but an achromat would not be. Even though you can use an achro for narrowband imaging, you will still have the problem that achros don't have field flatteners, so you lose half the field.

[dick_dangerous]

I use a 3'' refractor and love it - having said that I will be wanting more apeture at some point. Because it's a short tube (f5) it's rubbish on planets but, you know what? It's good enough for me right now! It kicks bottom on big widefield stuff though - I can't wait to point it at M31 or the Pleiades later in the year.

The reason I have the ST80 and not a great big dobsonian is because I need something that can be transported on foot to a park, about five minutes from my first floor flat. The ST80 is a perfect model for this, although I'm pretty sure I could handle the ST102 on an Alt-Az mount, or even the ST120... Will consider an upgrade soon...

DD

[nightfisher]

Armed with what i now know, if i were buying just one scope for all uses i would get an 8" dob, if this was just for observing

[Stu]

I have a 4" apo triplet, and if pushed, could live with it as my only scope (it would probably be the one i hung onto until the bitter end!) Bear in mind though that I do visual only. It is wonderful on widefield targets (particularly at dark sites) and open clusters, great on doubles and pretty good on planets too. I generally use it on a Giro mount. It is fairly portable and quick to set up.

That said, it would not be ideal for AP, probably too heavy and tricky to guide, I guess an ED80 would be better for this, and it would be blown away by an 8 or 10" dob on DSO's so is far from being an all rounder, I just love the views through it.

Stu

[m37]

Totally sound advice as always from these guys. As far as a general purpose scope, I have just bought a relatively cheap 4" skywatcher achro. Totally agree with what the guys are saying but I've managed to keep my expectations in line with my budget and the portability issue. I used to have a larger rig but used it less frequently due to set up hassles. Hey, I have a 40 hour a week job, two bands, a burgeoning cyclocross habit and a six year old competing for my time!

I've managed to see the moon in detail, Saturn (albeit very tiny!), groups of stars and lots more. I've only just started imaging but I've got M15 captured in sufficient quality for me and my meagre budget, some lovely moon pictures, and a a passable Saturn. These images can only get better as I learn from the excellent supportive community here.

They're not the greatest pictures but the ease of setup and portability, and the lack of maintenance means I get out more often than I used to. I would totally recommend it for the bit-more-than-just-casual observers. And I can use it for wildlife photography apparently.

My aim was to see what I could with my restrictions, get our as often as possible, and see a variety of stuff. It's also fun trying to squeeze every last drop out of a smaller rig! Everyone has different expectations, cash, free time, spouses etc. I guess.

Check out http://www.amazon.co.uk/Astronomy-Small-Telescopes-Patrick-Practical/dp/1852336293 but probably from the library as it seems to be £35.99 now!

I would love and apo though!

[Schorhr]

For an only telescope I would not go lower then 5" anymore ;-)

But it really depends on what you want. I did put my h130p on an eq mount but it's not exactly a telescope for astro photography. For visual it's great, for pure ap I suppose 4" will be lots of fun, not that I have much experience with ap...

[michael.h.f.wilkinson]

For an all-round scope I find my C8 to excel on planets and DSOs visually, it is great for planetary imaging, but not so much for DSO imaging. I did get some half-decent results (on film) using an F/6.3 reducer, however. I will try to see what I can get out of it in that arena, but My 80mm F/6 will probably be better for many DSOs

[Qualia]

Not really going to help much but just wanted to say that I've had some lovely evening's with my 4" Achromatic Tal 100rs. It really is a gorgeous telescope and within that small 4" packs a tidy, sharp, almost free CA punch. Jupiter, Saturn, the Moon, doubles and clusters are wonderful to behold and on a price to quality ratio must surely be one of the best achros on the market. It also doubles as a fantastic white light scope and offers visual images as sharp and detailed than the best white-light images you'll find here at SGL.

There's really no need to fork out a lot of dosh to discover what kind of thing a 4" can do. It'll be able to show you Jupiter, Saturn with a fair amount of detail, all the Messier objects albeit many will be underwhelming, pick out many NGCs, all the open clusters you can stomach, and you'll have fun picking out and splitting hundreds of doubles.

Obviously, my 10" can do all that and more and to be honest if I'm heading out the city or have cooled down the mirror sufficiently, the 4" doesn't get a look in. The image is brighter, you'll be able to tweak out more detail, trickier doubles can be split, Messier objects take on otherworldly, significant, awe-inspiring shape and so on.

As can be seen, I love both my scopes. Each has a function, a beauty, an aesthetic appeal of their own and neither would or are ever going to be sold on. I figure whatever choice is made, you'll learn by it and hopefully will come to love this curious hobby more and more.

On a side note, if I were thinking of getting into APO I don't think I'd be looking at the scope at first, but more on the type of mounts available and of their price.

[planet15]

I can only tell from my experience as well. If I were allowed to have one telescope only, it has to be 8" Dobs - for capability and portability, ease of set up, cost and storage.

Having said that, smaller scopes such as 4", 3" and even 2" can be a great fun to use. Last night I was watching Saturn with 60mm Celestron Refractor on CG4, and it was such a fun, as it looked different - smaller image but sharp, contrasty and dark, and the OTA being so light and small, it was easy to track.

12" Reflector was also set up beside, but it could not contain the Saturn in the FOV, due to the planet being far too low on horizon just about 5 degrees above fence line.

[Moonshane]

I think the low balance point of dobs is one area not often appreciated and even I concede that it's a weakness. I have 5 foot fences too and some objects are out of range (albeit in the mirk anyway).

[LukeSkywatcher]

I have a 90mm refractor. It has a focal length of 1000mm (f11). Its brilliant for observing planets and the moon, but not so good on DSO's. I also have a 70mm refractor (Celestron travelscope) which i LOVE for the widefield views it gives in general. Its not great at anything else really apart from nice views of the moon.

So basically all scopes are designed to do different jobs.

I dont think i'd want to be tied down to a 4" refrac as an only scope. Even a small 5" Dob would deliver better views on most objects (moon,planets,DSO). Why buy a small 5" Dob when you can buy an 8" Dob for not a hell of a lot more cash?

Dobs really are cheap per inch of aperture and give you the best bang for buck.

[johngccfc]

I dont think i'd want to be tied down to a 4" refrac as an only scope. Even a small 5" Dob would deliver better views on most objects (moon,planets,DSO). Why buy a small 5" Dob when you can buy an 8" Dob for not a hell of a lot more cash?

Yeah yeah, thats how it starts. lol

Before you know it you're measuring the inside of your car to see how big a dob would squeeze in.

;o)

[johngccfc]

the reason for my original question was that there was a nice 4" APO triplet wih an EQ6 mount for sale, but its not anymore.

an 8" Dob appears to be the general concensus for an all rounder (not that one appears to exist)

[AlexB67]

I think the low balance point of dobs is one area not often appreciated and even I concede that it's a weakness. I have 5 foot fences too and some objects are out of range (albeit in the mirk anyway).

One benefit of the tiny 130p is I can put in on a table, or a chair. My misses is too short to use it on a table, the chair works better for her. The table is perfect for me and clears the fence nicely. It is an easy to carry wooden table I can pick up in one hand, fold it out, setup and go in most places in the garden really, it is surprisingly robust ( for visual anyway, I don't imagine doing any photography with it ) . Keeping out the nearby street light is the bigger issue that determines where I position myself. 200+ mag on Saturn very doable with my cheap table setup.

Perhaps for you get something like this for a bigger DOB or a larger version of it

[planet15]

I think the low balance point of dobs is one area not often appreciated and even I concede that it's a weakness. I have 5 foot fences too and some objects are out of range (albeit in the mirk anyway).

The 12" DX300 was on GP-DX EQ mount on a pillar stand, and it could be actually lower than Dobs.

[Chris]

I enjoy both imaging and visual and if I could only choose one scope to own for the rest of time I would perhaps buy the very best 6" f/5 Newt I could affored, maybe one of the those Orion 1/10 wave mirror jobbies then drop a Moonlite focuser on it, flock it, Bobs Knobs, Telrad and maybe a RACI. Either that or the very best carbon fibre tube f/4 Newt I could affored with a decent coma corrector and collimation kit, plus decent EP's.

I would much rather have the choice of 2 or 3 scopes for the rest of time though

Chris

[LukeSkywatcher]

Yeah yeah, thats how it starts. lol

Before you know it you're measuring the inside of your car to see how big a dob would squeeze in.

;o)

I think i'd be able to squeeze a 14-16" in mine but i wouldnt be able to use it.