APO Refractor for visual use

[GazofCorra]

Having only recently come more involved in astronomy and deciding to purchase some equipment, i have relied on books and you guys for guidance.

I have a 8" dob and a 5" mak, but want something else that i can just grab and go at any break in the clouds or take with me on our caravan holidays, the reason i have a refractor in mind is it requires little maintenance, is fairly rugged, easy to transport, requires hardly any cool down time (on a doublet anyway), easy to setup especially on a alt-az mount and offers very good planetary, lunar, double star and some good DSO views, and some of them have there own cases for storage and transport, whereas my dob and mak stay fully setup as they have no easily available means of storing them.

I have been reading loads and have came up with a few scopes that may be ideal without going OTT, as after all it is meant to be a quick and easy grab and go style way of viewing and a couple of hours max, but it has to offer great views and i have no idea how a refractor will compare to my 8" dob or my 5" Mak, but hopefully you guys will be able to tell me what i can expect.

1. Skywatcher Evostar 80ED DS-Pro Outfit @ £475 ( a complete package)

2. William Optics Megrez 72 FD DDG APO @ £387 (maybe to small)

3. Skywatcher Equinox 80 APO PRO OTA @ £577 (do not know if this scope offers any advantage over the Evostar 80ED for visual observing only)

4. William Optics Megrez 90 APO @ £870 with diagonal (maybe OTT for what i am after)

From another post here on SGL i will be using the scope of choice on a Skywatcher AZ4 steel legged mount.

Thanks

[russ]

All the scopes you have listed have great reputations, there's not a bad one in the list.

The M72 stands out for its price, compact size and capable optics. Just what you want from a holiday scope. Having owned all in the list except the 90, the scope i would most want as a visual scope however would be the Skywatcher Evostar 80ED with it's F7.5 focal ratio and superior optics to the Megrez 72. Sit beautifully on the AZ4 as well. Just a shame it's bulky by comparison and the dew shield doesn't slide to reduce the size.

Just as an idea, as it's the holiday setup i had. You could marry the Megrez 72 with the Tele-Optic Giro III Mini and a proper sturdy photo tripod. Works like a charm and is truly portable to the extreme.

[GazOC]

I don't know if it fits in with your definition of "grab and go" but you could get a ED100 to sit on top of the AZ4. For visual it'd be a much better combo than the smaller scopes IMHO.

[John]

I don't know if it fits in with your definition of "grab and go" but you could get a ED100 to sit on top of the AZ4. For visual it'd be a much better combo than the smaller scopes IMHO.

I agree. Having owned a few ED80's and a Megrez 90, I decided that 100mm was the minimum aperture that I wanted. My Vixen ED102SS is held extremely well by my AZ-4 and is a pleasure to use on that mount

[GazofCorra]

The scope i would most want as a visual scope would be the Skywatcher Evostar 80ED with it's F7.5 focal ratio and superior optics to the Megrez 72. Sit beautifully on the AZ4 as well. Just a shame it's bulky by comparison and the dew shield doesn't slide to reduce the size.

Thanks Russ and taking your advice as well as the others i am sure the Skywatcher Evostar ED series is the way to go.

I don't know if it fits in with your definition of "grab and go" but you could get a ED100 to sit on top of the AZ4. For visual it'd be a much better combo than the smaller scopes IMHO.

Thanks Gaz and even though i state grab N go, it is more aimed at quick setup and use as well as taking away on our travels, but it has to be visually very good compared to the scopes i already own.

I agree. Having owned a few ED80's and a Megrez 90, I decided that 100mm was the minimum aperture that I wanted. My Vixen ED102SS is held extremely well by my AZ-4 and is a pleasure to use on that mount

Thanks John as you and Russ have owned a few refractors from the one's i suggested i think i have came to the decision of purchasing the Skywatcher Evostar 100ED DS-Pro Outfit i was going to go for the 80ED like Russ suggested but after reading yours and Gaz's posts the jump from the 80mm to the 100mm in the same Evostar ED range sounds as though it will give me brighter views, as i do not want a huge gap in performance from my 200mm dob and 127mm mak, which would possibly stop me using the refractor.

Thanks again all.

[brianb]

Having owned a few ED80's and a Megrez 90, I decided that 100mm was the minimum aperture that I wanted.

But the OP has a 5" Mak ... given that, there's a lot to be said for a high quality short focus 70-80mm scope for rich field views ... the difference in bulk / weight / field of view between a 80mm f/6 scope and a 100mm f/7 scope is considerable.

If it was my money - and given the rest of the kit that the OP lists - my first choice OTA would be the Equinox 80 PRO FPL-83 or the Meade series 5000 ED 80mm APO triplet. (If I had the idea of doing imaging as well then I'd definitely prefer the triplet.) The AZ4 will have plenty of reserve to handle it; loading a mount up to its limit is in my experience a good way to build frustration when the breeze makes the tube vibrate too much to get a good view.

[russ]

But the OP has a 5" Mak ... given that, there's a lot to be said for a high quality short focus 70-80mm scope for rich field views ... the difference in bulk / weight / field of view between a 80mm f/6 scope and a 100mm f/7 scope is considerable.

That crossed my mind too. I was going to suggest the ED100 because in my mind it's the best value visual use 'Apo' on the market. The right balance of aperture, focal ratio (F9), size (AZ4 and EQ5 take it without breaking sweat) and price. But then saw the 5" Mak and thought better not to mention it. Plus my wife would give me definite no to taking the ED100 on holiday.

[GazofCorra]

Brian and Russ can you tell me what my 5" Mak has to do with buying an 80mm or 100mm refractor

Now as i have not seen any of these scopes in the flesh, i have no idea on there size or weight as i can find no info on this, but are the views through the 100mm significantly better than the 80mm?

The AZ4 is the mount i am looking at buying due to ease of use and faster setup compared to the EQ5 so i believe.

I did consider the Meade 5000 ED80 triplet at the beginning of my quest, but i have read that the cool down time of a triplet can take an hour for good viewing to be possible, compared to a doublet whose cool down time is quite short and as i am unlikely to go into astrophotography a doublet seemed a better option.

It would be great if i could see the Evostar 80mm and 100mm next to each other on a AZ4 mount and take a peek through both before i made my final decision, this is the problem not having many actual astronomy stores here in the UK where you can visit, they are nearly all internet based and most do not carry stock due to drop shipping.

What a nightmare

[F15Rules]

Have a look at UK Astro buy sell today...a nice Evostar DS Pro 100mm Apo, same optics as ED100, with own flight case and accessories. £499, worth a look?

I've owned 2 ED100's and agree with Russ that it offers the best apo value for visual use on the market. The slightly longer focal length gives benefits on ease of focus on planets, clusters, Moon etc which IMO outweigh the longer length of the tube (it's approx one metre long end to end.

HTH

Dave

[Mark at Beaufort]

You can guarantee that you will receive a number of suggestions which will make your decision that more difficult. I have a 4" Astro Tech APO refracor which is f7 and I use it for grab and go. I get great views of the moon, planets, doubles, brighter DSOs etc. I support it on an SkyTee mount but it would go very well on an AZ4. I have pasted a link to the 4" Ikharus ED APO which is sold my Ian King for £575. It has been bought by a few on the forum and I think it was well reviewed. Just another scope to think about but it would be my choice above the 80mm varieties. Hope this helps and not confuse you more.

http://www.iankingimaging.com/show_products.php?category=7

Mark

[russ]

Buying anything new is always a nightmare with too many options.

The reason we mentioned the Mak is because visually the ED100 and a 5" Mak will give roughly the same results. The Mak takes a little while longer to cool but is already very compact and rugged for a grab'n'go. And would sit nicely on the AZ4 (that was my son's setup for SGL6).

The ED100 is in another league to the 80's (any of them) visually. Given the choice of a world class 80mm Apo and a £200 secondhand ED100, I would take the ED100 without giving it a second thought. We had one of the Lomo 80 Triplets at our dark sky meet recently. Optically perfect but it's 80mm. The owner of that scope sold it and 'made do' with an FLT98.

If you just want something quick to setup and cool in the backgarden, not too fussed about ultimate space saving for holidays, get the ED100/AZ4 combo. You'll love it. But remember you already have that Mak, so don't be too disappointed if the two perform roughly the same.

[shaunster]

Too be honest your 5" mak is allready a great grab and go scope and takes up very little room anyway

[F15Rules]

Ref that Ed100 I mentioned before at £499, you can actually buy in new for £628 delivered, with a free 25mm additional eyepiece, here : Sky-Watcher Evostar 100ED DS-PRO telescope.

just to make things even more difficult, he he..

cheers

Dave

[brianb]

can you tell me what my 5" Mak has to do with buying an 80mm or 100mm refractor

The 5" Mak is a better planetary scope than any 4" refractor will be. Which makes the smaller refractor more useful for what the Mak does badly: low power wide field work ...

If you're happy to get rid of the Mak, then a good quality 4" f/7 apo would be a good instrument to have. But it will be less "grab and go" than either Mak or f/6 80mm frac.

[John]

If you're happy to get rid of the Mak, then a good quality 4" f/7 apo would be a good instrument to have. But it will be less "grab and go" than either Mak or f/6 80mm frac.

Mak cooling times get in the way of their being classed as "grab and go" for me. "grab, put outside, and wait for 45 mins" is perhaps more accurate

Unless they are kept more or less at outside temperature.....

My 4" ED refractor was putting up views of Saturn comparable to 5" maks at the SGL6 star party over the past few nights.

Still the OP has had plenty of feedback so more to help make a choice, which is good

[MjrTom]

I can vouch for the quality of the quality of the Skywatcher Equinox 80 Pro.

I use it for both visual and astro imaging and find its a perfect size for "grab & go". The scope, 3 eyepieces and the diagonal fit in a case no bigger than the airline carry on limits so its relatively compact and is great for casual viewing.

I use it with a variety of eyepieces ranging from a 36mm 2" eyepiece (14x mag) all the way upto 3mm (167x mag) using the TV Nagler 3-6mm zoom.

Planetary and lunar viewing is awesome and widefield is just as good.

Splitting double stars like Mizar in Ursa Major is a charm.

I compared the performance of this scope against a variety of much larger reflectors (including a 16 inch lightbridge dob) and it held its weight admirably when viewing saturn. The contrast and detail was far greater, admittedly 80mm is not the best light grasping capability but them you have much bigger scopes for that sort of work.

[LMC]

The Equinox has somewhat better mechanicals than the Evostar. Really quite good actually. I believe the optics are the same.

Given your price ranges you might try hunting for a LOMO lensed 80/480. They were (are) sold in various tubes: Stellarvue, WO, APM, Apogee. Its a Russian triplet APO that is widely regarded (rabidly polemicised ) to be the best 80mm scope around.

Its ceratinly miles better than my ED80 and they can be had second hand from the US for around 400-500 GBP. New, they run about 1100 euros.

[MjrTom]

The Equinox has somewhat better mechanicals than the Evostar. Really quite good actually. I believe the optics are the same.

That is correct, they both use FPL-53/shott glass for the objective lens obviously taking into account the Evostar is 600mm focal length versus the shorter (and therefore faster) Equinox which is 500mm.

Build quality between the two is the main difference.

OK, the Equinox cant compete with the William Optics scopes for build quality but its not far off.

The Retractable dew shield of the Equinox scopes is a nice touch compared to others with fixed dew shields. The megrez also has a retractable dew shield.

This can make a huge difference to the compactness of the scope for grab and go.

After using the Megrez 72 at the local astronomy club its a far more compact scope compared to any of the 80mm scopes.

[GazofCorra]

WOW loads of info to digest and after all this i am sure i can make a wise well judged decision.

@ Brian & Russ - Now i see why you compared the 100ED to the Mak.

@ Mark - Thanks for the link i will take a look.

@ Dave - Now i see why they say the 100ED is not so much grab n go, 1 metre long

@ MjrTom & LMC - Interesting about the Equinox Vs Evostar.

@ John - True about the Mak's cooling down time and i believe that it is more susceptible to DEW.

It seems i will be better off selling my Mak if i do purchase a refractor as they are roughly in the same ball park visually.

The Mak to me is not as grab and go as you may think, it has a longer cool down time, i think it is more susceptible to dew than a refractor and it has to be left setup on it's tripod with the legs spread wide for stability, i do not know of a case for storage or transport for the mak and i assume it is more vulnerable to knocks and jolts during transport than a refractor, which can lead to the optics being out and i have no idea if you can collimate a mak or if it needs special attention, plus with mine being the SupaTrak i have to have batteries or a power pack handy.

I am sure i will end up with a refractor, but 80, 90 or 100mm still needs some serious thought, as i like the sound of the ED100 for it's viewing being similar to that of my Mak, but it is huge at 1m long, then the 80mm Equinox sounds a good performer possibly more so for imaging over the Evostar, then i come back to the WO Megrez 90 maybe it is a good compromise between the other two, but i know jahmanson had one of these and got rid of it for a 100mm, ARGH

Thanks for all of your advice, hopefully i make the right choice i might travel to a store/shop if i can find one and take a look at the scopes i am interested as long as they are stocked, doubtful.

Gaz

[GazofCorra]

I have pasted a link to the 4" Ikharus ED APO which is sold my Ian King for £575. It has been bought by a few on the forum and I think it was well reviewed. Just another scope to think about but it would be my choice above the 80mm varieties. Hope this helps and not confuse you more.

Refractors from Ian King Imaging

Mark

UMMM another possibility i must admit i am leaning towards selling my Mak and buying a 100mm ED APO, but now i need to do some further research on the Ikharus ED102 compared to the SW Evostar ED100.

[shaunster]

For visual I doubt you will find much difference, speed aside..

[GazOC]

I'd expect the ED100 to be better coloured corrected than the Ikarus to one degree or another.

[GazofCorra]

Gaz can you explain that to me, thanks.

[GazOC]

Gaz can you explain that to me, thanks.

Its got a longer focal ratio than the Ikarus which, all other things being equal, usually means the scope will be better colour corrected.

Also the ED100 uses FPL-53 glass whereas I'd be surprised if the Ikarus does at that price point.

A longer focal ratio and using better glass doesn't automatically mean a better colour corrected scope, there are other considerations, but they are 2 very important aspects of it.

[russ]

The ED100 should have an advantage over the Ikharus but in reality, thinking back to my days of the Skywatcher ED80 and Revelation 80ED, i doubt very much it will make hardly any difference at all in practice. It's an identical comparison to the one we are making here. The Skywatcher ED80 had an F7.5 FR with FPL53, which in theory should have given the Revelation 80ED, with it's F5.9 FR and FPL51, a good beating. But it didn't really.