ED100-V-TAL100RS

[Caldwell 14]

I may well have not written this review for my latest outfit had it not been for a couple of messages and posts asking me to compare the Skywatcher ED100 DS pro and the TAL100RS.

The review could or should perhaps really be two, three or even four reviews depending how you want to read it.

TAL 100RS & AZ4

SW 150P & AZ4

ED100, AZ4 & extension pier

AZ4 & extension pier

I have written this review after giving my new outfit several nights out and targeted as many different objects as I could mange at this time of year with a 4 inch refractor. I hope this report is as honest and as unbiased as I have intended it to be, here goes...

From the ground up the gear used was Celestron vibration suppression pads, an AZ4 mount with a 16 inch extension pier and of course an ED100. All the ep's used were Celestron X-Cel LX from 5mm to 25mm at 1.25 and the 28mm 2” ep which comes as standard with this scope. Straight off I better tell you that this scope would been out of my league (wife and two kids at university) had it not been a second hand scope, 12 months of age in very good condition indeed for £390

My first impression when I arrived home and opened the case was of mild disappointment, my new toy certainly did not have the TAL factor (perhaps that should be wow factor) and a rather ordinary looking little scope stared up at me. The first thing I noticed was how much lighter and shorter it was than the 100RS. I added the tube rings, finder and 2 inch stock diagonal and the weight naturally rose quite a bit. The finder on the ED100 was noticeably heaver than the stock TAL job, the 2 inch diagonal obviously far heaver than the WO 1.25 carbon number I had in the 100RS.

On my bathroom scales, the same ones I weighed my TAL on, the ED100 weighed in at 10lb, a pound lighter than the 100RS. I was surprised that it weighed this much to be honest as the scope felt almost “poxy” in comparison to the solid soviet style TAL before the rings, diagonal and finder were added. On measuring the ED100 its a fair a bit shorter than the TAL, 4 inches to be exact, from diagonal to the end of the dew shield.

The finish of the TAL has been commented on this forum many times, quirky, a little rough around the edges are some of the comments that have been made. Beautiful, built like a tank, a modern classic are others. The ED100 was certainly better finished than the TAL but lacked the same, oh I don't know what it is, character? Old school charm? What ever it is the TAL has it, the ED100 does not.

It probably best here to mention the pier extension for the AZ4 which continently arrived the same day as my new scope. Including delivery my extension cost a whopping £96 from the Widescreen Centre, a lot of money for a bit of drain pipe. The “Drain Pipe” turns out to be a nicely engineered piece of kit weighing in at a hefty 8lb. Why then you may ask did I not just buy the extension and keep the TAL? Well fear mostly!

My concern was the the extra height would lead to extra OTA wobble, I needn't have worried, on the contrary, the extra weight actually added stability to the pod, pulling the centre of gravity down. Although the extension comes with no instructions its hardly rocket science to work out how to fit one. Three hex bolts unscrew the “lid” after you have fitted the pier onto your pod in the same was you would bolt any head on. The head then fits straight onto the top of the “lid” and is tightened in place with a similar bolt and plastic grip nut as you would find on your pod, pop your lid back on and screw your 3 hex bolts in place and you're done...simples. Both the AZ4 and the extension pier share the same matt black anodised finish and look like they were sold a package. I believe they are made by Orion who also have their own version of the AZ4, this is of course exactly the same as the AZ4 as its made on the same production line with a different stamp printed on it, its the same mount.

To my surprise it was actually clear outside and despite being still light Venus was clearly seen and nice high in the sky. I slipped my new scope onto the mount and was delighted to discover just how well it sat there, and the ep was now at just the right height. I always felt that while the AZ4 the TAL were a good combo that this was absolutely the most weight I wanted to put on one. I have to report that the ED100 is a far better match for the AZ4, its lighter and the shorter length reduces much of the long arm tremors that long refractors suffer from. It also stays where its put and does not appear to need everything tightening all the way up as I approach the zeneth. The 150P with all it weight at the back of the OTA had to be tightened up fully to avoid sudden and dramatic wallops against the pod, I don't rate the 150P and AZ4 combo at all.

The ED100 and the AZ4 were however made for each other, very solid and look quite cool together I think, fantastic...phew.

I started off with a 5mm ep in place and aimed the scope at my target.. Much praise has been heaped on the very fine finder of the 100RS, quite right too, its very good, the ED100s finder is IMHO better. Its far easier to alien for a start only two screws to fiddle with rather than six on the TAL. Aliening the finder is child's play and takes seconds, this is more than I could say about the one on the 100RS. Once its set, it stays there after use, defiantly more than I could say about the TAL. The finder has a wider field of view I think and is optically very good, it does however have to be focused by unscrewing and then re-tightening the objective lens.

The Crawford focuser on the TAL feels very smooth compared to the ED100 but is of course single speed. There is no doubting the advantages to using two speed focuser's, it all to easy to just over steep the mark with a single speed, especially with cold hands and then there's also the wobble factor to consider during those tweaks of focus.

Venus is, as I'm sure you all know quite a thin crescent at the moment, extremely bright but thin. As I focused in on my first target to my relief this first star test revealed a perfectly collimated scope and a perfected framed second rock out from the Sun, perfect, just perfect, no colour, no nasty diffraction spikes nothing, just a sharp perfect image. But wait, its was still quite light told myself, lets see what the view is like later on. Even with the planet heading into the gloom the view held up for ages and ages...and still no colour.

In exactly the same conditions the TAL 100RS would have thrown a mass of purple round the planet, I only used to view Venus in day light for this reason. The view in the ED100 was also perhaps a little sharper. Mars was now also beginning to look like a reasonable proposition as my next target so I swung the ED100 around to sneak a quick butchers.

Mars is past it best now from this earlier on this winter and is now noticeably smaller but I was still able to pick out quite a bit of detail dispute less than perfect seeing (it was quite windy at this point) There was of course no colour whatsoever around Mars with the ED100. The TAL would have shown a very small amount when Mars was at it brightest but certainly not enough to have been intrusive. I would have expected the 100RS to have shown similar views to the ED100 and indeed have some very good views earlier in the year. Anyone out there who thinks Mars is only resolved as an orange disc doesn't own a refractor.

Saturn later on that evening (I went in for a quick coffee) was just wonderful, the wind now having died down. The Cassini division was clearly seen, although these views were fleeting. There was also just about as much detail as you would expect to see on the surface of the planet as you would ever reasonably expect to see. I would have expected to see very similar views with the 100RS which never ever showed any colour when viewing Saturn.

So that was the available solar system objects out of the way. So I set about about splitting the available doubles, all easy ones I'm afraid and there was nothing to separate the ED100 and the TAL 100RS (certainly nothing larger than half an arc second anyway) I just had enough time to view M13 and the Double Cluster before the clouds rolled in again. Caldwell 14 wasn't the best, its was still relatively early, perhaps an hour or so after astronomical twilight and at this time of year that's not very dark. What there was was to be seen was as expected, wonderful exquisite pinpoints of light, perfect to the very edge of field, again I would have expected to to have seen a very same view with the TAL100RS with a 25mm ep, I switched to a slightly wider field of view with the 28mm 2” ep which threw up some very nice wide views of the star fields around Cygnus. I moved back again to 25mm and 18mm X-CEL eps and had a quick gander at M13, which was a rather lovely looking fuzzy blob, before heading indoors and into bed.

The views with this little scope are to die for and its hard to imagine a better planetary scope without paying an awful lot more money. The ED100 sits far better than either the SW 150P or the TAL 100RS did on my new extended version of the AZ4 and is very solid.

The TAL 100RS is a good scope, no its a great scope but for me, for my needs the ED100 wins for its apochromatic-ish views and its greater suitability for use on the AZ4 mount, a mount I enjoy using greatly. The views of open clusters (my favourite targets) and binary systems are very similar, I couldn't split em (geddit?) But the eradication of colour around Venus was nothing short of dramatic, and most welcome around Mars. It was only after selling Comrade scope that I realised how important planetary observation was to me, I just can't wait to see Jupiter in the autumn.

[spaceboy]

A very interesting read and congrats on the new scope.

[John]

Thats a great report of two excellent 4" class refractors. Those 16" pillar extensions are very useful for getting the eyepiece end of refractors up to a comfortable height - and I agree that the additional weight adds to the stability of the mount.

When you consider what you can get them for on the used market, the ED100's are outstanding value I feel. I used to have the original blue tubed version and it's one I wish I still had

Not really a case of "winners and losers" though, all are very nice scopes

[nightfisher]

A superb review, nice to hear the tal was not a million miles behind the 100ED, im pleased that judging from your review, you now have the perfect combination for your own astro needs, well done

[AndyH]

A very good review AND an enjoyable read !

Andy.

[Caldwell 14]

Thank you chaps. glad you enjoyed the read. Just back inside after a few hours out with the ED100 and if anything I like it even more. The seeing here was really very good Mars and Saturn were both excellent. Mars produced the best views from the red planet I have had for sometime and when the seeing was perfect, which it was in short patches Saturn was sharp and Cassini was there to be seen in its usual "Now you see it, Now you don't" fashion. But do you know without that extension pier I wouldn't be having half as much fun, its all so very steady. I don't know how much difference the anti viberation pads make but there is no shake and if I do knock the scope the damping down time is so quick its irrelevant, I highly recommend them.

[nightfisher]

Your review has got me thinking of parting with my beloved 100rs and getting a 100ED myself now and more:eek:

[Caldwell 14]

Your review has got me thinking of parting with my beloved 100rs and getting a 100ED myself now and more:eek:

And more you say...pray do tell.

[nightfisher]

And more you say...pray do tell.

just more exclamations, but i will stick with my russian lovely, might be getting a rather nice little williams otics apo though:D

[Alan_B]

That wouldn't be a Zenithstar 70 would it ?

[nightfisher]

That wouldn't be a Zenithstar 70 would it ?

might be, if its still available:D

[tony4563]

Thanks for taking the time to give us this splendid comparison review.

It was a great read

I love my AZ4 mount (dare I say more than the Skytee2 ?)

Its just so nice and simple to use!

[spaceboy]

The 150P with all it weight at the back of the OTA had to be tightened up fully to avoid sudden and dramatic wallops against the pod, I don't rate the 150P and AZ4 combo at all.

I was under the impression the 150P didn't catch the tripod due to the offset of the mount? Can you just clarify that please. I only ask as I almost went with this combo myself and wondered if I'd had a lucky escape.

[Qualia]

Great review, Caldwell and thank you for taking the time to write this out. It sounds like a cracking scope and I'm almost certain the review will help other readers.

If I've identified the ED100 correctly, in Spain it sells for just under €800 brand new, whilst the Tal 100rs goes for around €250 to €300. That is a significant difference, but would go say such an upgrade was worth it, is there really that much improvement moving on from the Tal 100rs to ED glass?

If I recall correctly, were you not also using a reflector for a wee while? If this is so, it would be very interesting to hear what you have to say between your experiences of the mirror system and that of the lens.

Anyway, thanks for a most informative read.

[Caldwell 14]

IMHO the ED100 is a fantasic scope and work every penny of the £390 I spent on it, but that is all I would spend on one. If I had bought one new I think I would be feeling a little disapointed. For £250 you buy a TAL 100RS, A better looking scope, a more robust scope a scope with a smoother focuser, the same views on 99% of targets...you also get far more CA on Venus and I expect Jupiter too. The CA on Mars and the Moon is so small its not worth talking about in a 100RS.

The CA cut in Venus is dramatic (It will be on Jupiter too!) but it is its lightness and suitabilty for use with my newly extended AZ4 that does it for me, rock solid. I had a straight choice £250 for a TAL 100RS (plus £20 for a dove tail) or pay and extra 140 quid for the ED glass and a flight case, no contest...........simples

[Caldwell 14]

Sorry Qualia you also mentioned reflectors. For DSO (faint fuzzy objects) a large mirror is the job, no doubt about it. For splitting doubles (a pastime I find addictive)observing open clusters and planetary observations a refractor is my scope of choice. For planetary observations IMHO Dobs and Newtonians are un-useable, I just can't use them, the star spikes from the secondary mirror spiders just ruin the views. I had no idea how much good planetary veiws mean't to me till I bought a Newtonian, I sold it 14 days later

[dobbie]

fantastic review caldwell really got me thinking ....my stellavue ed80mm doublet matched the tal views if not bettered them on planets even with the tal,s extra 20mm and its a lot smaller in length thats why my tal went..

[John]

.... For planetary observations IMHO Dobs and Newtonians are un-useable...

Blimey - thats fighting talk ! :)

I'm a huge refractor fan but I'd jump at a 1/10 wave 10" F/6.3 newtonian - if the collimation is on (easy with an F/6.3) it will out perform apo refractors costing £thousands on the planets.

[Caldwell 14]

Blimey - thats fighting talk ! :)

I'm a huge refractor fan but I'd jump at a 1/10 wave 10" F/6.3 newtonian - if the collimation is on (easy with an F/6.3) it will out perform apo refractors costing £thousands on the planets.

Fighting talk? I think you have taken me up wrong here, its just a forum! perhaps its my fault, I'd better explain.

I find differentiation spikes in the middle of a planet I find so annoying I that it ruins the entire experience, for me they are unusable. I'm not mad keen on poor contrast or an inability to cope with less than perfect seeing either to be honest. I only expressing my own fobiles...er...what do I know?

[John]

Fighting talk? I think you have taken me up wrong here, its just a forum! perhaps its my fault, I'd better explain.

I find differentiation spikes in the middle of a planet I find so annoying I that it ruins the entire experience, for me they are unusable. I'm not mad keen on poor contrast or an inability to cope with less than perfect seeing either to be honest. I only expressing my own fobiles...er...what do I know?

I was pulling your leg mate :)

I know what you mean about the diffraction spikes being intrusive. 4 out of my 5 scopes are refractors because I just love their simplicity and the views they give

So I share your foibles

Sorry if my post came across as a challenge in anything other than the most light hearted way - it certainly was not intended that way

[Alan_B]

Never get diffraction spikes when viewing Saturn or Jupiter with my Don - I mean dobsonion - blasted predictive text wont let me type D O B.Kelsey changing it to DON

Now its changed keep to kelsey

Sent from my Nexus One using Tapatalk 2

[Qualia]

Thanks, Caldwell. It's nice to see the Tal holding its own, especially in the 'upper market' of more expensive refractors, but, I guess, in the long term, an ED is worth every penny, although it probably makes better sense to buy one second hand.

Although hottly debated and rather a polemic, to be honest, the mention of differentiation spikes, poor contrast, and sloppy collimation apparent in the majority of beginner's OTAs was one of the reasons I felt the refractor would make the ideal first scope for me. The Tal 100rs being the best in its price range and a scope many have said is for keeps. In the future, I will probably buy a 8" to 10" Newtonian but any smaller than that doesn't make a lot of sense to me when being compared to the Tal.

You also mention light aberration on the Tal and although I have found a hint of this on the brightest of stars (Vega, for example) and sometimes on Venus, I have never seen anything of this on any of the other planets or moon. Maybe it boils down to my poor eyesight, or seeing conditions in the city. I don't know.

Thanks for the kindly response and here's wishing you clear and peaceful skies.

[smeech]

Thanks Caldwell. I have been looking at both these scopes in the last few months mondering whether the ED really was worth the extra money. You've made my mind up. Now I just have to talk the missus round!

[spaceboy]

I agree also there is no better scope for splitting doubles than a refractor. Even my 127 Skymax lost out to both my EVO120 achro and smaller 100ED. I don't even bother with my newts unless they are well spaced doubles.

[Caldwell 14]

I was pulling your leg mate :)

I know what you mean about the diffraction spikes being intrusive. 4 out of my 5 scopes are refractors because I just love their simplicity and the views they give

So I share your foibles

Sorry if my post came across as a challenge in anything other than the most light hearted way - it certainly was not intended that way

Oh its ok, as long as I haven't offended any Newton owners, for DSO there's no contest.

On another subject the seeing round here was just fantasitc last night (11.30pm -1.00am) Saturn was superb and Mars was far better than I would have expected at the minute too, lots of detail considering it diminished size and alt.