4" Apo and mount choices

[Druid]

Considering the following possibilities.

Altair-Astro 102/7

APM 107/6.5

Vixen ED103S

Williams Optics FLT98

Idea is a simple, idiot-proof, alt-az based visual observation set-up with no flaky stuff to go wrong.

Knowing though that if I get further into astronomy, I'll probably a) want to buy some sort of monster dob at some point and I'll probably also eventually want to try imaging, so I'd like a scope that can cope on e.g. HEQ5.

Meanwhile though, some questions. Please also feel free to share any experiences, comparative or otherwise of these instruments and any in the same class that I've failed to consider here.

Altair-Astro 102/7 is notably the cheaper option, what are the drawbacks of going that route? Are there significant improvements to be had by spending the extra for one of the other three?

80mm scopes of equivalent quality are cheaper and lighter, so am I right to think that 100mm ish is the sweet spot if I want an easily manageable set-up that can see a lot of interesting stuff from a mag 4.something suburb.

With the sort of telescope I'm considering, what are some suitable mounts? I must admit I fancy the lovely looking Televue Panoramic and such, but perhaps there's a more practical solution for my intended use?

Thanks in advance.

[Tim]

Are you sure you don't want to get a GEM from the outset? Especially as you are planning for photography in the future?

[Druid]

Yes. I'm quite sure of that. Idea is to make astronomy accessible, for both myself and the wife. Hence I want to minimise the amount of fiddling, potentially flaky systems and gear humping involved from the start.

[Stargazer_00]

Can't go wrong with an AZ4 then but it does put the eyepiece end of refractors quite low. You might need to get a HEQ5 16" extension pillar (£90) if you dont intend to view zenith seated.

[John]

My "grab and go" scope is a Vixen ED102SS F/6.5 on an AZ-4 mount. It would fit your criteria I think. The Vixen ED 103S replaced my model I believe but is slightly slower in focal ratio. 4" scopes of this type can see quite a lot of lunar and planetary detail and are pretty portable but obviously it's not a lot of aperture for the fainter deep sky objects. The wide field of views possible with the right eyepieces do give some lovely views of the more expansive DSO's on a dark night though.

I've not tried the others on your list and I'm not an imager so can't really comment on those aspects.

[Druid]

Yeah, I'm sort of wishing I hadn't mentioned imaging at all.

What I'm really looking for here is a high quality visual instrument and mount that's fast to set up, has as few things to go wrong as possible and will handle high magnification without fuss.

[Mr Fiery Jack]

The AZ4 is a fantastic mount for 4 inch refractors.

[John]

Yeah, I'm sort of wishing I hadn't mentioned imaging at all.

What I'm really looking for here is a high quality visual instrument and mount that's fast to set up, has as few things to go wrong as possible and will handle high magnification without fuss.

200x is quite feasible with the sort of instruments you have listed when the seeing conditions are decent. You do need short focal length eyepieces or a good barlow lens / telextender to achieve this though.

[JG777]

Have to agree with Mr Jack, I have used my 4 inch SW F9 on the AZ4 and it works very well, even the aluminium leg version is OK if there is no breeze. I already had the steel legs from the HEQ5 but I imagine that would make it even sturdier. Very easy set up and not back breaking either.

[ollypenrice]

The more expensive apos come into their own in imaging. In visual use you'd be hard put to tell the difference between the scopes you list and, indeed, some more expensive ones which you don't list.

Build quality comes into it, the mechanical quality of the focuser, the lens cell, ets etc. You don't get something for nothing. However, I'm lucky enough, through work, to have the best there is and honest enough to say that it is hard to tell the best there is from the considerably cheaper if all you are doing is looking through the eyepiece - not that there's anything wrong with looking through the eyepiece.

Olly

http://ollypenrice.s...39556&k=FGgG233

[E621Keith]

My grab and go set up is a 3" apo with an AZ mount, either a Borg SWII or SW Skytee. I use them much more often then my GEM in the current weather. No need to accurately level, no need to polar align, and no need to carry out GOTO alignment. Just plonk it down and go.

The Borg is very light and probably can't handle any 4" except Borg's own 101ed. The Skytee on the other hand can handle a much heavier load, each side is rated for 15kg.

[htj]

Hi

I agree with the AZ4 as mount for this class of scope. I use a 100ED with an AZ mount myself (a more substantial one than the AZ4 though), and I am quite happy with it, though aperture feber has struck.

The scopes you list are somewhat different. Two of them are triplets (the APM & FLT). There are two Altair 102 f/7 scopes, one is a doublet, and one is a triplet, so I don't which one you a referring to. The Vixen is a doublet though. Triplets will usually have tighter stars and less CA, but I doubt you will see much difference for the scopes you have listed. The triplets will take longer time to cool down, which may or may not be an issue for you.

The FLT98 has great optics, but it is expensive and is largely considered an imaging scope. It will also have the most field curvature of the three scopes (shortest focal length). You could get an Equinox 120ED for less than what the FLT98 costs. Have you considered the Skywatcher Pro/Equinox 120ED?

The APM should have a very nice focuser and has the biggest aperture, which is in its favor (but it comes at a price), but I am not sure I'd go for a triplet here.

[Druid]

Yep, I was looking at an Equinox 120 yesterday. Seemed a bit bigger than I was happy with, especially in terms being likely to need a bigger mount.

[E621Keith]

Don't be so sure about triplet vs doublet. A well made doublet can out perform an average triplet, especially when cooling speed is taken into account.

Yep, I was looking at an Equinox 120 yesterday. Seemed a bit bigger than I was happy with, especially in terms being likely to need a bigger mount.

Have you considered a Skytee II instead of an AZ4. A Skytee will give you more room for upgrade.

[John]

Yep, I was looking at an Equinox 120 yesterday. Seemed a bit bigger than I was happy with, especially in terms being likely to need a bigger mount.

I have a Skywatcher ED120 and it is a noticeable step up in all departments (including weight and length) to the Vixen ED102 I mentioned earlier. While I have used the ED120 on an AZ-4 mount occasionally, it's not an ideal solution and usually I mount the larger refractor on a sturdier alt-azimuth mount for real stability. It becomes more of a "grunt and go" set up then !

[Druid]

I guess what I mean is, by the time you've put the 120 on a suitable mount, you're moving away from 'quick and easy' and into 'might as well get a 8" dob' or 'just put the tube on a GEM already' territory.

[allen g]

can someone fill me in on what is the Az-4 or AZ mounts. Is there an alt-az grab/go and go-to mount that would work real well with a 4" apo. thanks in advance..

[John]

FLO carry a range of alt-azimuth mounts:

http://www.firstlightoptics.com/alt-azimuth.html

Of those shown in the above link, the AZ-4 and the Vixen Porta II would be able to carry a 4" F/7-ish refractor of the sort being discussed here. The SkyTee 2 mount has a greater capacity but, in my opinion, is moving away from the "grab and go" concept.

The Vixen and SkyTee 2 have slow motion controls on the two axis of movement. With the AZ-4 you track by gently pushing it but it's motions are smooth and the tension adjustable.

[Brian Nordstrom]

I use my Takahashi SKY90 on a GSO/Astrotec Alt/Az mount when I cant be bothered setting up its usual Vixen SP eq mount and it is a nice mount , similar to the VixenPorta but much cheeper and slightly bigger in size , but no heavier .

It has nice slo mo controls like the Vixen .

I have put my ( now sold ) 150mm f5 SW refractor on it and it held that well , so a 100mm scope wont be a problem .

Oh yes they have a 14 inch extension that you can buy if your scope is in the f9-10 range to raise the eyepiece when viewing the zenith , have a google , these are a really good mount .

Brian.

[vlebo]

I use to have a Equinox 120 on a William Optics EZ Touch mount and Tripod ( which I believe is no longer available ) and used that as a grab n go setup . I found it very easy to set up and was up and viewing in less than 5 minutes ( kept the scope at ambient temperature in the garage ) plus had some fantastic views as the Equinox 120 is a very accomplished scope. If I was to go down a similar route today I would go down the same road but get the Sky Tee 2 and possibly the Evostar 120ED package http://www.firstlightoptics.com/pro-series/skywatcher-evostar-120ed-ds-pro-outfit.html as you get the same optics as the Equinox in a cheaper package and some handy extras thrown in and should be an excellent scope for grab n go

[Brian Nordstrom]

Yes a nice 'Grab and Go' set up really cant be beat , here's my Tak FS60C on GSO mount .

Brian.

[Druid]

The more expensive apos come into their own in imaging. In visual use you'd be hard put to tell the difference between the scopes you list and, indeed, some more expensive ones which you don't list.

Build quality comes into it, the mechanical quality of the focuser, the lens cell, ets etc. You don't get something for nothing. However, I'm lucky enough, through work, to have the best there is and honest enough to say that it is hard to tell the best there is from the considerably cheaper if all you are doing is looking through the eyepiece - not that there's anything wrong with looking through the eyepiece.

Olly

http://ollypenrice.s...39556&k=FGgG233

I take your point about 'little difference through the eyepiece' but build quality is also a factor in my mind (and imaging might be one day) Having seen a fair bit of fuss in the past about bargain-priced Chinese clones of high-end photographic gear (ball-heads etc) developing severe issues after a while due to component quality and workmanship, I'm a little bit suspicious about how well the equivalent astronomy gear is going to hold up. The impression I get is that going from "cheap" APOs to mid-range ones like those I named in the first post, is mostly a matter of quality assurance, ie a reduced chance of getting a lemon with e.g. APM's quality control being applied to mostly Chinese components.

I could be mistaken though, so I'm very interested in views on build quality with any scopes in that sort of range. I'm pretty sure the quality on e.g. Tele Vue is going to be good, but I'm not sure where the sweet-spot is for price, given that vendors are unlikely to let me dismantle scopes in their shop to poke around in their innards and try to determine the hardness of the focussing rack or whatever. So I'd be interested in views from people who've owned and used instruments in this class for a while.

[ollypenrice]

Well, the budget Chinese apos haven't been around all that long. I've had a WO ZS66 for about five years. It's been OK. You need to adjust the focuser tension from time to time but it is faring well, though it doesn't get a lot of use. I had a Meade 127 for a few years also. The focuser, again, needed attention to the adjustment and the optics, though good at the time and superb in visual, have been roundly surpassed by the latest Chinese apos. In imaging the Meade did get fair old bloat in the blue which the new designs don't.

Quality control very obviously isn't the same in the Chinese budget apos as it is from TeleVue, Takahashi or TEC, all of which we have here and use. The three posh ones have been superb and show every sign of aiming to last forever. On the other hand I have a Chinese 102 F7 which is optically right up there with them and, indeed, ahead of the TeleVue doublet.

I would always, always, prefer a rack and pinion to a Crayford, any Crayford. And when Crayfords are bad they are very bad.

The sweet spot on price, for me, is offered by second hand premium scopes. I paid £2,300 for a Tak FSQ106 in case, about £250 (!!!) for a TV Pronto in soft case and £3,800 for a TEC140 with rings and scopeguard case. You can find TV85s for less than a thousand. routinely. Seriously sweet and probably done with depreciating altogether. As the the Pronto... what can one say?

Olly

[swag72]

Ive had the cheaper Chinese offerings from Skywatcher and I have to say that the build quality was average. I say average as this was my first scope and I had no comparisons. However, the focuser was poor there was no doubt and so that got replaced.

I have since bought a secondhand Pentax 75SDHF and while has been a scope of utter class. The build quality is superb, the R&P focuser is a joy to use and the optics aren't half bad either!! Given a choice I'd recommend a quality brand over the Chinese offerings, although I accept that there is a place for them. Not everyone can or wants to blow close to £1000 on a small 500mm scope.

Now whether that extra ££'s spent equates itself in an equal increase in quality either at the eyepiece or the camera is open to debate. I think probably not. If my scope is double the price of a Skywatcher, will it give me double the visual or imaging quality? No. But what it does give me is confident in my equipment and I have learnt that is priceless.

[E621Keith]

I agree if you are after build quality there are a few other non Chinese brands to consider, TMB/APM, the rare Pentax and the ultra rare Astro-Physics. However, If you equipped those Chinese scopes with Feather touch focuser, it eliminates most of the build quality issues. In that original list of 4 scopes, the FLT98 isn't strictly a Chinese scope. The optics is Russian (Astreya) and the 3" Feathertouch is American. The CNC tube is Chinese, but that's just a tube. I'd be very surprise if a Televue doublet can offer anything more than that scope optically and mechanically.