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ST120 or EVOSTAR 120


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Hi guys, after much research and reading (about two months) I narrowed down my options to these two refractors, I am a visual astronomer. what i want is a portable setup (I don't drive and I live in apartment block in the city center) I have to walk with my setup to a darker site (about 7 mins away) I decided to go with alt/AZ mount for portability. Another criteria is that I need to look at the portability of my setup in public transport, I visit friends and relatives in Manchester, Wigan and Liverpool almost every week and i am thinking of taking the scope along with me.

Since the scope is moving for long distances I decided to rule out the reflectors all together. I know that alt/AZ mounts are good for low to mid magnifications so not much visual planetary work can be done. However, I am faced with the beast that is called Chromatic Aberration, never looked through a refactor before and I don't understand how can that affect viewing in low to mid powers.

So my questions are (for now!):):

Is the evostar120 + AZ4 portable for things i just explained above (I am 5'6" BTW?

Is the the evostar120 on AZ4 mount considered a good starter scope for DSO using wide angle eyepieces?

Can the evostar120 with suitable wide eyepiece match the performance of the ST120 in low to mid powers on DSO?

Or I should just buy the ST120 on AZ3 and be more restrictive in the kind of eyepieces that i can use? It actually needs more things like modding the AZ3 mount and replacing the erect image diagonal.

Can you adjust the lens cell on the Black diamond evostar120? I am asking this in case i decided to buy one second hand.

I have tried binoculars before (15x70 Strathspey and I can not recommend them enough:) ), but i returned them for they needed a tripod and in my opnion if they are mounted then i might as well get something bigger.

Thanks:)

Hasanain

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I have the ST120 and enjoy the using it. The major problem, which I can live with is the CA, it is noticable on any bright object away from the centre of the field of veiw. I got the Baader fringe killer filter from FLO and it does improve things. I kept the erecting diagonal, but bought a mirror diagonal.

The ST120 is not bad with a low mag ep for sweeping the heavens.

I have used it with a 2x Barlow and 6mm ep on Jupiter, and under good atmospheric condition and was pleased with the views. It came with the AZ3, but I replaced that with an EQ5 and things were better. I wouldn't reccomend the EQ5 for your planned use.

Some one will be along soon with thier thoughts and experience with the Evostar.

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think you will find that although either of these scopes are portable the kind of mount required to keep them stable isn't,an eq5 is ok when your just taking it into the garden from the house,but not if your having to walk 7 or 8 mins to a site for observing(unless your a weightlifter)

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Thanks Naz, your comments are helpful :), is it true that with the ST120 you have to stick with 1.25" eyepieces because of vignetting in 2" ones? Have you tried field stopping it to improve planetary views, say down to 100 or 90mm, in theory it does make a difference in the CA ratio index.

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An AZ4 with the steel pipe tripod weighs around 8 kg. An ST120 would sit nicely on one but I think the Evo 120 would be too long to reach the eyepiece comfortably if viewing things high in the sky.

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Thanks RicMcRae and lw24:)

@RicMcRae I would assume so, but how is this situation any different with the eq3-2 that comes as an option with the evostar120? or with any mount on a tripod for what it matters?

@I am sure the AZ4 is way better than the AZ3 but if I decided to with the ST120 I will start with the AZ3 and mod it.

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how is this situation any different with the eq3-2 that comes as an option with the evostar120?

No real difference at all except you don't have to align an AZ mount so I find them better suited for visual astronomy than an EQ.

or with any mount on a tripod for what it matters?

To use a long FL refractor comfortably you need a taller tripod or a pillar extension.

If you have to carry your kit, get lighter weight stuff. If it is too heavy, you may get fed up carting it about and then it won't get used.

The ST120 / AZ3 would be a good choice if you can live with the colour fringing on bright objects.

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Thanks Naz, your comments are helpful :), is it true that with the ST120 you have to stick with 1.25" eyepieces because of vignetting in 2" ones? Have you tried field stopping it to improve planetary views, say down to 100 or 90mm, in theory it does make a difference in the CA ratio index.

I have not tried the 2" eps, and yes, I have on occasions left the cover on, just removing the central cover. I have done this mainly for the Moon and brighter planets. Yes it does improve the CA, also the fringe killer does add a colour cast, but your eyes / brain adjusts to it :)

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Some one will be along soon with thier thoughts and experience with the Evostar.

The Phenix 127 I have is quite similar to the Evo 120 and it is too much scope for the AZ4 or EQ3. It came on an EQ5 clone and that is a bit more stable but you couldn't carry it any great distance.

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I use a TAL 100RS, which is a fairly long and heavy scope, on an AZ 4 mount, not a bother. The AZ 4 is a great mount, and very under rated, there are a lot of AZ 4 fans on here. The AZ 4 also comes in two flavour, one with stainless steel legs, the other made of aliminium. The Steel version is quite a bit heavier than the Ali legged version but if were you I would go for the steel legged version if I was going to put a long tube on one!!!

The ST is a wide field refractor which will give you "space walk" view of large open clusters like M45 and the Double Cluster. It will also be good for other large objects such as M31 and CA will not be an issue with such objects, Jupiter however will turn into a rainbow with CA. The Evostar 120 has a longer fl and higher mags and much less CA, it also however has a much tighter field of veiw and so finding objects will be a little harder and not so good on DSO, it will however be much better at planetary/lunar work as it will be at spliting doubles. While I love ST refractors the Evostar is more of an all rounder. The ST will be much more portable of course.

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If this helps, I actually bought the ST120 on the EQ3-2 MOUNT THE OTHER DAY, i MANAGED TO GET A FEW HOURS VIEWING IN BEFORE THE CLOUDS CAME AND THE VIEW i GOT OF jUPITER AND 3 OF HER MOONS WAS STUNNING, AS WAS THE 7 SISTERS ETC, i DID NOT GET ENOUGH TIME TO VIEW A CLUSTER ETC. aNYWAYS HERE GOES.

sorry I typed the above in caps, i wont type that again so apologies.

The Scope, has a great feel to it, quite light for its size and the metal casing, however, because it is a long tube be prepared to do some bending to see through the eyepieces when it is moved about on the mount. I hate the diaganol, it is very large and clumsy to be honest, I dont know what the mod change was with this but id love to know. The focuser when new is very very tight, I have had to remove it, remove the thick horrid gunk the chinese put on and used my own silicone based grease, much better.

As I mentioned, viewing so far is great, and i will be able to give a better idea on that before long i hope when the clouds go.

The EQ3-2 Mount, mmmmm, she is a great starter mount and very light indeed, one of the reasons I had to have it due to health issues, however, when the scope is placed on the mount it does tend to allow a lot of vibration, especially when focusing the scope, the mount itself feels great, however, the tripod legs are more akin to a cheap tripod from a camera shop, it does its jobs but it is far too flimsy. If I could Id now go for the heavier steel legged versions just for stability. But all said, it does its job and I have to put up with the wobble every now and again. I am waiting for a dec motor, so i will have more of an idea if this wobble is constant when i start using it. All in all, a good view, a lovely scope, but the mount i would give 6 out of 10, and thats just due to the tripods awful legs.

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I just bought an Evostar 120 last week. I got it with the EQ5 mount and steel legged tripod, which makes it a sturdy setup for observing. I have only had it out in the (light poluted) back garden twice, but the views of Jupiter were excellent, I could see the 2 bands and also 4 moons very clearly with both of the supplied eyepieces (10mm & 25mm) The Orion Nebula looked impressive with the 25mm eyepiece, as did the pliades. All images were sharp, with good contrast. I didn't notice any CA but have yet to look at the moon with the scope. The focuser is probably the least impressive part of the scope, perhaps due to the thick grease mentioned above by proflight, I will have to have a go at cleaning it off, I would have preferred a Crayford, but hey... The finder scope is easier to use than I was expecting, which is a plus. Overall it is a very nice scope and I am really pleased with it. I can't comment on the ST 120 however. Hope that helps. :)

One other thing worth mentioning is that with the EQ5 the scope is not exactly the most portable option you could choose. It's OK for the back garden, but if I was lugging it across a field for any more than a couple of minutes it would be fairly cumbersome.

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If this helps, I actually bought the ST120 on the EQ3-2 MOUNT THE OTHER DAY, i MANAGED TO GET A FEW HOURS VIEWING IN BEFORE THE CLOUDS CAME AND THE VIEW i GOT OF jUPITER AND 3 OF HER MOONS WAS STUNNING, AS WAS THE 7 SISTERS ETC, i DID NOT GET ENOUGH TIME TO VIEW A CLUSTER ETC. aNYWAYS HERE GOES.

sorry I typed the above in caps, i wont type that again so apologies.

The Scope, has a great feel to it, quite light for its size and the metal casing, however, because it is a long tube be prepared to do some bending to see through the eyepieces when it is moved about on the mount. I hate the diaganol, it is very large and clumsy to be honest, I dont know what the mod change was with this but id love to know. The focuser when new is very very tight, I have had to remove it, remove the thick horrid gunk the chinese put on and used my own silicone based grease, much better.

As I mentioned, viewing so far is great, and i will be able to give a better idea on that before long i hope when the clouds go.

The EQ3-2 Mount, mmmmm, she is a great starter mount and very light indeed, one of the reasons I had to have it due to health issues, however, when the scope is placed on the mount it does tend to allow a lot of vibration, especially when focusing the scope, the mount itself feels great, however, the tripod legs are more akin to a cheap tripod from a camera shop, it does its jobs but it is far too flimsy. If I could Id now go for the heavier steel legged versions just for stability. But all said, it does its job and I have to put up with the wobble every now and again. I am waiting for a dec motor, so i will have more of an idea if this wobble is constant when i start using it. All in all, a good view, a lovely scope, but the mount i would give 6 out of 10, and thats just due to the tripods awful legs.

The EQ3-2 ali tripod is fairly wobbly with the legs fully extended but much more stable with the legs right down short. With a short fat Newt it is a very nice package but not such a good match for a long refractor.

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OK guys, wow:) First, I am so lucky to be here among some very helpful and kind people so thank you all for your feedback:), second, My apologies for the late response because I attend a meeting for the first time my at local astronomical society :)(I was bouncing of the floor like basket ball for at least 3hours+:D but that is a different story:))

Mixed basket on both the evostar and the Star travel, however I am leaning towards the evostar more but clearance issues with the long tube is not helping me towards this decision.

Can people with the evostar120 (Black Diamond Edition) comment on the ability to adjust the objective lens cell?

Thanks

Hasanain

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Can people with the evostar120 (Black Diamond Edition) comment on the ability to adjust the objective lens cell?

Thanks

Hasanain

The Black Diamond versions that I have seen do not have a collomatable objective lens cell. The earlier blue tube versions did have this.

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Your in an awkward situation with your location, i had a 120 evostar, good for planets and lunar work, if you could work from say, a balcony at your apartment, i would go with the evostar, but if you have no choice but to set up away from home then go with the star travel, as its much shorter, the lens cell in the evostars is not ajustable.

If you go with st120 you will be limited to mainly dso work, as the false colour on lunar and planets will be very noticable, if you want to do lunar and planets maybe consider a maksutov, as these are even more portable and lighter than the other options

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Thanks John and nightfisher, @nightfisher, your suggestion is logical but aside from issues of size with the long tube, why I can not use the evostar to view DSO as well? if I used it with say wide view long focal 2" eyepiece? a Maksutov was my first option but the cool down times didn't help much beside it is very difficult (I assume) to use for DSO work without a combination of focal reducers and long focal wide eyepiece.

Hasanain

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Please correct me if I am wrong:o, the ST120 will "by the same logic" reveal the same "brighter dso`s" because of the similar aperture only using the non wide eyepiece options and will give extra magnification. In other words, the ST120 is more suitable for DSO mainly because it will allow higher magnification wide views that you can not achieve in the evostar120 even with proper investment in wide field eyepieces (for the same level of magnification).

The question is to what end? I mean if the ST120 can pump more magnification at DSO, I think they will always be a grey smudge no matter how many times you magnify it using the same 120mm aperture.

So my humble confused brain is telling me to stick with the evostar mainly because it can perform well on both planets and DSO (with suitable eyepieces investment).

What do you think guys? I am really confused :)

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I think you are a little confused. The 2 120mm scopes will capture the same amount of light. The ST scope will show wider field of view than the Evostar because of it's shorter focal length. High magnification is not really needed for DSO's - low to medium power is whats mostly used and occasionally it's nice to have a wide angle of view for the larger DSO's like the Andromeda galaxy, Veil nebula etc.

The ST120 will show a lot of false colour on bright stars, planets and the moon, to the extent where it's not a very effective scope for viewing these objects at high power. It is designed as a low to medium power wide field scope.

The Evostar can use higher power on the planets and the moon more effectively and will show DSO's just as well. You can still get a field of view of 2.8 true degrees from an Evostar using a 2" 40mm eyepiece, which is pretty wide. I'd go for the Evostar - it's a more versatile scope.

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Hi again Hasanian, If it's any help, I got great views of the Orion Nebula with my 25mm eypiece, I also bought a 32mm GSO Plossl eyepiece, and tried the Pliades, and although they didn't all fit in to the FOV the view was V sharp and well contrasted. As John says, a 40mm eyepiece would give you over 2 degree fov, which would be enough to fit the Pliades, for example, in to you scope. Also, as already stated, you won't need huge magnification for many DSO's.

Weighing it all up, I would also say the Evostar would be the more versatile of the 2 scopes.

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Hi Hasanain,

You've asked a lot of questions, i'll try & give a few pointers.

I own an st120,& have owned an evostar120.

You're talking of portability & without a car- i'm in the same boat.

I'm happy to use the back yard, but like the odd jaunt into the country which means everything has to fit in a large rucksack on my motorbike :D

Without a car you're quite limited as to the bulk & weight you can carry. If you must have portability, i'd forget the evostar.

The st120 doesn't sit that well on an az3, i think the az4's a bit heavier & bukier option.

If your willing to forgo the portability the evostar's a better allrounder.

max mag for planets with the st120 about 120x in my book, Jupiter has a very strong purple halo with this scope,& i haven't dared look at Venus! not so bad on the moon, otherwise the chromatic abberation isn't much to get worked up about for visual IMO.

As regards car free portability, i'd give an st102 on az3 some thought, or as an alternative a skymax 102 or maybe even a 130mmf5 reflector on the az3. Each has merits & weaknesses.

It's difficult sorting a truly portable setup out without the aid of a car.

I'm currently using a st102 on az3 as my go anywhere rig, can be carried about with one hand.:)

The az3 isn't the last word in mountings but it's light, & that sounds like what you may need.

Hope that helps.

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