Finally!

[Nexus 6]

sorry to read you have not been able to use it yet Nick, didn't realize you were an engineer! looks like a decent work shop you have there.

[spaceboy]

LOL an engineer I wish. More like 'all the gear and no idea' mate.

[Nexus 6]

LOL an engineer I wish. More like 'all the gear and no idea' mate.

think that title is more apt for myself!

[spaceboy]

A quick update for those of you who were interested in comparisons:

I had promised my son that I would get out under the stars with him last night so I felt it a good opportunity to give the C100ED a quick hose down while I got to spend some quality time with my boy. The refractor was purchased to compliment my larger newts and was really only intended as a lunar and double star scope but as the moon was not up last night I perused the targets I would have usually looked at with my EVO 120 and grab and go 127 Skymax.

Going off my first ever experience of using a refractor I knew a warm scope would not perform as well as a cooled one, bright stars like Sirius or Vega were going to be shrouded in a purple halo and any thing low in the sky was going to give a colorful display. With this in mind I was going to put the C100 through an unforgiving test. The mercury was sitting at around 16' Celsius when I started observing so there was never going to be any big impact regards the OTA's ambient temperature so this will have to be considered in the winter months if any adverse effects are noticed.

1) Had to be Jupiter. Sat 14' in the sky it only just broke the tree line in the back garden. In went the 3-6 zoom and at x150 Jupiter was a good size clearly revealing the equatorial bands and Io Just to it's edge. Both polar regions were visible but it was not easy to define the temperate belts. Some darker areas could be picked out with direct vision but a slightly averted vision was required to pick out two fainter bands in the one pole. (As the GRS was not in view I'm unsure of the orientation) Now the big test for me was going to be what most distracted me when using the EVO "CA". If I was to be uber critical I would say it reminded me of when I have to RGB align in Registax. There appeared to be a slight red fringe to one side and a faint blue fringe to the other. With lower magnification it was invisible and with more magnification it became no worse. It was in truth only a hint and I was purposely looking for it and was in no way distracting to the image any more so than the poor seeing experienced at the high magnifications.

2) After seeing a hint of colour I wanted to see how it would perform on some thing notorious for colour fringing. As Sirius was still way below the horizon I settled on Vega which was now sitting at 61' in the sky. Again I went with using the nag zoom. This for me was to be the most surreal experience of using the C100ED. While the EVO120 coped reasonably well with Jupiter and the moon the brighter pin point stars really did highlight in a purple way the shortcomings of the achromatic design. Almost as if it were a bright purple bonfire night sparkler sitting in the sky. A bright white core with radiating purple glow was my only real disappointment when using the EVO120. This was not to become a similar disappointment with the C100ED as there was no obvious fringe visible. I was almost wishing a fringe around Vega to convince myself I was looking through a refractor. I tried really hard to pick up any coloration and if I had to say maybe there was but I certainly couldn't see it even when zooming to a ridiculous x300 nothing to my eye was evident.

3) While in the vicinity of Vega the next obvious target was going to be the double double. This was a target that I felt the 127 Skymax let me down. The MAK would split the 4 stars but I never felt it did it as cleanly as the EVO. This may be due to the central obstruction or not? this may be due to the long cool down times of MAK's and my impatience to get observing? but either way I feel on splitting close doubles for me the MAK didn't cut the mustard. It goes with out saying the C100ED did a superb job. I don't know if it was the seeing, position in the sky or what but I felt the smaller 4" did a better job of cleanly splitting the Doubles than the larger 4.75" did ?? The stars were more apparent and the airy disk more contrasted than it ever was in the EVO and certainly a vast improvement over the again larger 127mm MAK.

4) Need I say where I went next.... M57 I felt was going to be a deal breaker for the C100ED due to the smaller aperture. The ring high in the sky was always going to be in it's favor but to say I was impressed would be an understatement. This really was a big shock for me. The ring was a reasonable size and the contrast simply made it pop. The ring is good in both the EVO and Skymax but the C100 performed equally as good despited the loss of aperture.

5) M13 again was to prove a real shock. At 36' I was not expecting too much as it was sitting in some of my local urban LP. While the mighty gas giant Jupiter can shine through I didn't have high hopes for the speckled globular cluster. I would say the view was equal to the EVO120 with averted vision allowing many of the core stars to be distinguished from the central glow. This is the one target I would have really insisted on a side by side comparison with the EVO as I find it difficult to accept the smaller refractor could do as good a job given aperture is king. Maybe the image might be slightly dimmer ???? but it sure wasn't any less impressive. The MAK again struggled IMO with M13 only allowing for a fuzzy ball with little if any Central star to be clearly obvious from the crowd.

6) I was now getting in the mood for a nights DSO hunting so I was drawing to an end the session with the refractor in the favor of my larger flek. As I had previously gone in favor of the higher magnifications I figured I would give the 7 & 9 mm Nags ( x128 & x100) a quick look in on M31. LP makes these sorts of targets less than idea and usually reserved for dark sky observing or better seeing I though I'd have a look anyway. As you would expect all that appeared is the fuzzy white blob of the central core neatly centered in the 9mm 1.0' FOV. M32 clearly to sat all by itself with no hint of what should be the edge of M31. M110 was it's usual hint of existence only just visible with averted vision. Although not spectacular it served it's purpose of showing what wide FOV the C100ED would offer over the 127 Skymax's 0.84' @ x93.8.

Before heading off to the obsy I felt it only right to pay another visit to Jupiter now it sat move favorably of the horizon. Now around 24' the views were significantly improved. The slight hint of colour previously experience was still visible but much fainter and practically invisible when the focus was bang on. For this reason I really do feel the C100ED would benefit from a duel speed crayford focuser.

Overall I couldn't be happier with the Celestron C100ED. The celestron was only purchased for the improved contrast of refractors on the moon and the brighter wider clusters on those moon lit nights but it has proved to be capable of so much more. Sure on the outside it is a cheap and cheerful scope but where it counts it is a down to job, do as it says on the tin, shockingly impressive performing ED refractor. While it would benefit from a focuser upgrade I think this would distract from what the C100ED was intended to be... an affordable CA free refractor. If I can at a later date upgrade the focuser within a reasonable budget I feel this would make a good refractor a great refractor while still being a bargain.

I did not want to write this review flying the flag and in so try to justify the sale of two other perfectly good scopes. I have tried to be as picky as I could but found very little to critique. This is my first ED experience so I'm no authority on how well it performs against other scopes in it's class. My experiences are purely based on the scopes I have owned and what I demand from my observing.

In the attempt to restore the balance I wanted to include some of the C100ED's weaker points. 1) The most obvious being the focuser. This can be improved on but it will never be as good as a crayford. It can be upgraded but will no doubt end up costing more than the S/H equivalents out there. 2) Celestron clamshell ?????? whats that all about ???????? while it serves it's purpose and would no doubt be great on a shorter grab and go frak it's not best suited to the C100ED IMO. 3) I think the C100ED came out the factory with a lens cap of a tub of Pringles. Ill fitting and the lack of a stopper means any solar observing will require a filter to back made as apposed to taping some solar film to the objective cover. 4) The only real bad critique against the performance of the scope is that there is not much room either side of focus. It behaves very similar to a reflector in that the focus although sharp when gained dose not have much room for error compared to the EVO 120 which seemed to snap sharp with relative ease. 5) For some unknown reason re-focusing is required between EP's changes even though Naglers are parfocal ???? 6) Although very nice... the gloss black shows up every little paw print.

The Results:-

Sky-Watcher Evostar 120 (Blue version) 'vs Celestron C100ED (Finger print version)

The Evo was much loved and my first serious refractor (the other being my son's Celestron 70AZ.) I feel the views were just as good through the C100ED on DSO's despite the smaller aperture. I would hazard a guess and say the EVO would have offered slightly brighter views but was let down by CA on the brighter targets. The C100 no doubt offered better contrast and viewing Jupiter was a pleasure as there was not as so noticeable colour fringing. Aperture is king but given the views were no lesser impressive in the C100 and the more manageable tube both on the mount and in the hand means that the Celestron for me turned out to be a good choice. The advantage the EVO blue version no doubt had over the C100 is that it had a collimateable lens. While some choose refractors due to the low maintenance and no need for collimation I like to know I have the choice to tweak it if the need was to ever arise. Regards fittings and fixtures the EVO and C100 are almost on level playing fields. Both have 2" R&P focuser's and both mount the finder so you can bash your head every now and again (EQ users only). The EVO has a much better dust cap but lacks the ED coatings on the 9x50 finder. They are two different kettles of fish optically so they are both good scopes at what they do and I was very happy with the EVO when I had it but the C100 is just for me more enjoyable to use.

Sky-Watcher 127 Skymax supatrak blue tube Schott glass version 'vs'

I have now owned two Skymax as they are a really good compact scope that packs a punch way above it's size. If I am honest there really wasn't any comparison to be had between the C100 and MAK. The MAK was purchased with the intension of being a compact grab and go scope and for this purpose there is not really much else out there that could offer the same performance in such a small scope at that price range. The MAK obviously doesn't suffer with CA when properly cooled. It is incredibly sharp, free of diffraction spikes and has a smooth focuser. Again the MAK and C100 are different beasts and both serve up some superb views. Both have good contrast but I feel the views in the MAK were not only tighter but smaller even at similar magnifications. Tighter objects like globular clusters lacked any real definition in the MAK compared to the two refractors even with the larger 127mm aperture. While the MAK is good on double stars but the airy disk was not as well contrasted and make it more difficult to cleanly separate the tighter doubles.

In an ideal world the scopes in mention would be lined up side by side under the same conditions and a much better comparison could be carried out. All of the scopes are good in there own rights and I have enjoyed having each one of them. The rules at play mean I cannot afford to keep all of them and I had to make a decision based on both my own other peoples experiences. This is why I joined SGL and why I appreciate everyones comments and input on my other threads. "Particularly this time as it took hours to type this lot out :icon_eek:" I just hope my review may help someone else who is in a similar boat that is if anyone can spare the time to sift through this larger than life post.

[todd8137]

my 90mm frac gives a better view than the reflector

[SiriusB]

Glad it's worked out for you spaceboy! thanks for the report.... i'd better start saving

[spaceboy]

Your welcome Sirius.

[bish]

Looks like a good report but I am sat with my credit card next to me at the moment. Better put it away first, just incase.

[spaceboy]

I have to admit I took the lens cap off keeping an open mind. The C100ED is cheap as chips compared to the more glitzy SW models and I kind of expected it to perform poor both because of the loss in aperture (this is the smallest scope I have ever owned other than my bins) and also because you often get what you pay for. I was pleased to find it far exceeded my expectations and it will do the job perfectly for what I'd intended it to do. Only problem is I now want a 120ED more than ever

[Moonshane]

really excellent write up Nick.

I have an achro 90mm f5.5 and this is not really any good at higher powers but lovely (for a 90mm aperture anyway) at wide field lower powers and this is what I bought it for.

If I can fit in my 6" f11 for PSP I'll be bringing it too make comparisons (I hope) directly with an ED of about 100mm aperture as this would be the only scope I'd feel is in competition with it. if not then it would be interesting to compare my masked off 16" f4 with the same competition.

I hope for my financial sake that my scopes are at least as good!

I have to say though that despite the nice wide fields, having looked at targets with good aperture, there's really no comparison and I really only use my frac for those quick impromptu sessions when time is short.

[spaceboy]

I agree Shane. There simply is no substitute for aperture and this is why I felt it pointless going to any major expense. This said I really don't think there is any beating a refractor at the views it gives. For the best part the views are sharp and clean looking. There is very little shimmer of the image due to the closed tube design and the contrast is unbeatable.

While I'm sure the 6" f11 gives some amazing lunar and planetary views some might argue the added size, subsequent cool down due it's size and need for collimation already puts it out of the running. There is then the issue of thermals and turbulence unavoidable in the newt design. I myself would be on the fence as I know you have already had a OMNI 120 and so have experience of a fair sized refractor but still went in favor of the 6" newt.

They are at the end of the day totally different telescope designs and there for the one will always have pros and cons over the other. The observer is the common denominator in this case and ultimately it's what we demand from our scope that decides which design works best for you on which target. Unfortunately this often entails having more than one scope

[Moonshane]

totally agree mate. In the end the main factor for me ignoring aperture is comfort. I tend to get more neck ache looking through a refractor for some reason and find the newt focuser position (at least on an altaz mount) much more comfy. vive la difference!

[bish]

I would like an ED frac for planets, doubles etc -although I have always been pleased with my reflectors in general. Buying from new, I wonder whether the more compact skymax 150 pro would be a more suitable grab n go / doubles/ planets scope than the 100ED. I've looked through a 100ED at a dark site and was very impressed with it's overall performance. It certainly seemed to punch above it's weight.

While the 150 has a lot more aperture I still like the idea of a good quality refractor. need to get my eyepiece case properly inorder first though.

[spaceboy]

I wouldn't know what to best advise you there Bish. A 100mm refractor is reasonably light although some what longer than a 150mm MAK. Both ideally need to be sat on a good mount be it EQ5 or similarly sturdy AZ. When you start lugging this kind of equipment around your going to loose the idea of grab and go. I think Shane has got himself a really good G&G setup http://stargazerslounge.com/members-equipment-gallery/155816-heres-why-i-sold-my-bgos.html. OK you might think 90mm is going to leave you wanting more aperture but the idea of a grab and go is to do just that. While my 127 MAK is compact and would just about work on my sons Celestron AZ mount there was the matter of long cool down times. Now sold I'm now on the look out for a G&G scope again myself but I think my mind is already made up on the SW Heritage 130. I had chance to look one over the other week and while it's not the most robust of things for me it is ticking all the boxes. The scope and mount can easily be carried in one hand, the tube can be collapsed for transporting, 5" is a respectable size, the AZ base will offer a sturdy base and is easy enough to use, cool downs should be reasonable short and it's not hugely expensive new. I doubt this would work for you as I gather its a different telescope design you are looking for as well as a grab and go scope? but though I'd put the idea out there

I'm not 100% sure but I think Celestron did a short tube 100mm ED which would probably suit you well. Again it would require a fair sized mount.

[bish]

You're right there. The 150 mak is nice and small but an EQ5 is not exactly grab n go. the grab n go would be mainly for trips to my parents where the skies are very dark (I often just take the bins) - so 90mm would be useful. Of course if I'm not taking the girlfriend and dogs then I can just throw the 10" dob in the car!

[spaceboy]

The counter weights alone rule out EQ mounts for practical grab and go's IMO and heavy duty AZ mounts capable of high power observing in larger instruments seem to cost a fortune.

[Moonshane]

you can pick up a used Giro 2 for maybe £150. well worth it in my relatively short experience. in all honesty, I am considering changing my short frac for a short 150mm or even 130mm newt as I feel this will give better all round views. plus it will still be pretty much grab and go for wide fields and I can create a mini suitcase dob from it for traveling and retain the solid tube for home use.

I am finding the switching between the reversed left right but corrected view of the frac and the upside down only view of the newts annoying. Perhaps if I had all newts I may be better.

I'll try it a bit longer though and see how I get on.

[spaceboy]

I have never found the difference in orientation a problem to be honest as I still get confused by the view in the newts

How about a 10" suitcase dob

[Moonshane]

that's a super scope. I find the newt view easier as I can just turn the map upside down - not possible with fracs.

[spaceboy]

Just been thinking while browsing sky at night magazine. What defines and apo over an ED ? Is there more to it than colour correction ? I can't say that the images were that bad in any other sense so why is an apo an apo ?

[Moonshane]

the only true apo is a reflector. (runs for cover).

[Ags]

A newt without a coma corrector is merely half a catadiatropic! (Joins shane in bunker)

[Damo636]

I have never found the difference in orientation a problem to be honest as I still get confused by the view in the newts

How about a 10" suitcase dob ;

Now that's what i call the ultimate grab and go

Great write up by the way and sounds like a cracking scope.

[spaceboy]

Now that's what i call the ultimate grab and go

.

Tell me about it. It's a fellow SGL members