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Refractor considerations


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Now that I went and sold my SCT, it is time to consider the details of the next step, acquiring a proper refractor.

The primary function of the scope will be imaging, however it will also be my main visual scope. At least for the foreseeable future.... From an imaging standpoint, I'm thinking of focal lengths of around 1000mm. I think that would be a great combo with the WO SpaceCat, and would give me a good flexibility to frame different targets with different sized sensors. Now I have an APS-C DSLR, and will probably get a dedicated astro camera with a smaller sensor in the future. A refractor in the 1m focal length would probably mean an APO in the 120-140mm range. The obvious question is, which model? There is a number of potential options in the new market, and with any luck other options might become available from the used market. I would love to have a, say, TEC140 but I don't think I can afford even a used one.

The scopes that I have recognized as contenders so far:

- Skywatcher Esprit 120

- TS Photoline 130 f7

- APM SD Doublet 140

All of the scopes will require correctors/reducers, and the prices are not exactly the same. The APM represents the upper end of my budget spectrum. It is a doublet, while the other two are triplets. I'm not exactly sure how much that would affect image quality. For the same price one could also get the APM 152 doublet, which uses FPL-51 instead of FPL-53. Again, not sure if the trade-off in terms of aperture/image quality is worth it. My mount is the CEM60, which I think shouldn't struggle with these scopes. 

Any advice or suggestions? Stay safe everyone!

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33 minutes ago, Adam J said:

If your imaging anything at all then you will want a triplet so I would discard the 140mm doublet.

Thanks Adam, that was my impression, too. But how does this quality difference manifest itself? More bloated stars? Are there any photo comparisons of targets photographed with both a doublet and a triplet that could be used as reference?

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24 minutes ago, Nikodemuzz said:

Thanks Adam, that was my impression, too. But how does this quality difference manifest itself? More bloated stars? Are there any photo comparisons of targets photographed with both a doublet and a triplet that could be used as reference?

Yes more bloated stars in lum. Blue / Purple halos if you don't refocus between filters and sometime even if you do. If its mostly imaging and some observation go with the esprit. If its the other way around then the TS due to greater aperture.

 

Edited by Adam J
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4 hours ago, Adam J said:

Yes more bloated stars in lum. Blue / Purple halos if you don't refocus between filters and sometime even if you do. If its mostly imaging and some observation go with the esprit. If its the other way around then the TS due to greater aperture.

 

Thanks for the advice! The Esprit optics are that good, huh? I'm wondering if the winning strategy would be to hold off and save money for the Esprit 150... 😃

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The Esprit 120 is a wonderful telescope - I was sooo tempted to save £2000.00 and buy that instead of the Esprit 150 that I lusted after but for me the purchase was for my 'forever' telescope so I finally went for the the 150 and have no regrets. If this isn't your forever telescope and the 150 is a stretch too far then I don't think that you will regret buying the 120 instead.

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49 minutes ago, steppenwolf said:

The Esprit 120 is a wonderful telescope - I was sooo tempted to save £2000.00 and buy that instead of the Esprit 150 that I lusted after but for me the purchase was for my 'forever' telescope so I finally went for the the 150 and have no regrets. If this isn't your forever telescope and the 150 is a stretch too far then I don't think that you will regret buying the 120 instead.

I can definitely relate to your reasoning. The possibility to mitigate the symptoms of "upgraditis" already now would be worth some extra wait, me thinks. Although, I do believe many members here have a beautiful collection of "ultimate, last scopes", so I'm not sure if that will work long term. 😅

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By the way, are there any reducers that work with the Esprit 150? Or 120 for that matter. I know the flatteners designed for the scopes don't alter focal length, and I might not need to reduce focal length anyway. But is it possible, should the need arise?

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Hi there I’m selling my Meade LX90 12” ACF for maybe an APO myself however I’ve found thay are a little bit like car badges if you get my drift not always more you spend is always the best and many budget scopes have been tested against the big boys of this world like Takiashi if your looking for a Big Bang for your buck I would also consider the Skywatcher EVO ED 150 has focal length of 1200mm which also will be a good contender for visual also however will be a little slower in Asto imaging terms it will not over stress your mounting as weighs in at less than 9kg it was only a dream a few years back an 6”APO for £1550 nothing on the market comes close at that price !?

 

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  • 2 weeks later...

I have been thinking about my future refractor choice a lot, although I am trying to hold off on any impulses and stick to the original plan: save up funds and invest for next season. I'm sure you can relate to the troubles. 😃 The route I think I will be taking is to try and save enough €€ to get a telescope from which there is no reasonable upgrade path. 

I did some preliminary price comparisons for the aperture-wise comparable models from a few manufacturers. I have taken into account the import duties and taxes associated with the US models, and necessary accessories needed to make the telescope a complete package (flattener, adapters etc). I'm sure I have missed something, but at least we're in the ballpark, I think.

- TEC140  10150€

- Astro Physics 140   9050€

- Takahashi TOA 130NS 9380€

- AMP LZOS 152 9570€

- Skywatcher Esprit 150 4980€

Except for the Esprit 150, the models are quite similarly priced. I dropped the 150mm Takahashi, the price is simply out of bounds. Honestly, so are basically all of the models listed above, except the Esprit. If the quality of the Esprit is anywhere near the premium models, it is an absolute no contest in terms of value. Given what I've read in this thread and many others, it sure seems to give the premium scopes a proper run for their money. In other words, if I'm buying new, there isn't much thinking to be done.

However, a used premium scope might be in the same neighborhood as the Esprit 150. However, as a value proposition, would I rather choose a used TEC/Tak/AP or a new Esprit with potentially more aperture? How often do these really come up, from a seller who is willing to ship it internationally? How comfortable am I buying such an instrument from abroad without having a chance to collect it let alone see it before purchase?

This is a documentation of my thought process, more than anything else. Hopefully it is useful to someone who is considering similar topics! 😃

Edited by Nikodemuzz
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If your after a Big Bang for your buck surly the skywatcher Evostar 150ED  is an contender I’m no expert in the imaging department however read the reviews for yourself has some secret glass recipe not the same schott glass in there sibling range weights in around the 9kg mark and will not need a paramount to hold it also has a focal length of around 1200mm lol I think the way I look at it I rather go for the BMW M3 then the Bentley as always seem to pay more for the name unless you can afford one of course.no expert again in the Takashi  APO,s  however read the reviews even tho the skywatcher 150ED pro came very close for £1550 

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I had a TS 130 Photoline here for a fair while a couple of years back, decent scope though not as good as the Lzos of the the same size I also had here, but then it is about 3 times the price, The TS is very good value for money. As for you next list, the TEC would be my choice, stunning quality I am told by Olly and he know a thing or two about astronomy.

Alan

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On 16/04/2020 at 00:28, Supernova74 said:

If your after a Big Bang for your buck surly the skywatcher Evostar 150ED  is an contender I’m no expert in the imaging department however read the reviews for yourself has some secret glass recipe not the same schott glass in there sibling range weights in around the 9kg mark and will not need a paramount to hold it also has a focal length of around 1200mm lol I think the way I look at it I rather go for the BMW M3 then the Bentley as always seem to pay more for the name unless you can afford one of course.no expert again in the Takashi  APO,s  however read the reviews even tho the skywatcher 150ED pro came very close for £1550 

This is an interesting idea, and could very well be true. One user in Astrobin has posted several deep-sky images taken with the Evostar 150, and they are quite good indeed. The fact that it is only one user, is a bit worrying to me, though.

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22 hours ago, alan potts said:

I had a TS 130 Photoline here for a fair while a couple of years back, decent scope though not as good as the Lzos of the the same size I also had here, but then it is about 3 times the price, The TS is very good value for money. As for you next list, the TEC would be my choice, stunning quality I am told by Olly and he know a thing or two about astronomy.

Alan

Thanks for the feedback on the TS scope! I could certainly save a pretty penny by taking that route. 

I have read some of Olly's sermons on the TEC, and to say his results are impressive would be an understatement. However, as new a TEC140 is out of my reach. Used, perhaps not? How often do these pop up?

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3 hours ago, Nikodemuzz said:

Thanks for the feedback on the TS scope! I could certainly save a pretty penny by taking that route. 

I have read some of Olly's sermons on the TEC, and to say his results are impressive would be an understatement. However, as new a TEC140 is out of my reach. Used, perhaps not? How often do these pop up?

They do pop up. There are two of them working at my place at the moment, one of them mine and both bought on the used market.

Given my worldview I'm a little alarmed to be described as having delivered sermons!  Please just look at the pictures, for which I have to thank TEC, Atik, Lucas Mesu and the software engineers on whom, like most of us, I depend.

Olly

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19 hours ago, Nikodemuzz said:

Thanks for the feedback on the TS scope! I could certainly save a pretty penny by taking that route. 

I have read some of Olly's sermons on the TEC, and to say his results are impressive would be an understatement. However, as new a TEC140 is out of my reach. Used, perhaps not? How often do these pop up?

How often do they pop up, I believe Olly bough his secondhand and I have seen two for sale in the last couple of years. So not often but then at that price point there are not going to be so many about. The last one I saw was 4000e, which for the size of scope is not bad, I do think they are expensive new though.

Alan

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15 hours ago, ollypenrice said:

Given my worldview I'm a little alarmed to be described as having delivered sermons!  Please just look at the pictures, for which I have to thank TEC, Atik, Lucas Mesu and the software engineers on whom, like most of us, I depend.

That was a poor choice of words on my part, and was meant very much as a tongue-in-cheek comment. I sometimes forget how careful one has to be with jokes, sarcasm etc in the written form, especially when people don't know each other and their backgrounds. I'm truly sorry if I caused any offense to anyone.

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5 minutes ago, alan potts said:

How often do they pop up, I believe Olly bough his secondhand and I have seen two for sale in the last couple of years. So not often but then at that price point there are not going to be so many about. The last one I saw was 4000e, which for the size of scope is not bad, I do think they are expensive new though.

Alan

In that price range I would certainly be interested. Here's hoping that one comes up! I am not in a hurry now, but I can imagine that when the nights get dark again in the autumn the itch will grow stronger. 😃 Besides SGL and Astrobuyandsell, are there marketplaces that should be on my radar?

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  • 9 months later...

I'm resurrecting this thread, as the process is still underway for me. Hopefully reading how my thought process has evolved will be of interest and perhaps even helpful to some!

I haven't been active on the market since posting last time. I let the matter boil on the back burner of my mind during the summer and the earlier half of this season, and have come to a couple of conclusions:

- First, I'm going to be buying only once. This means that I'll consider only models with proven track record, meaning Takahashi, AP, TEC, etc. Also the Esprits are very highly rated, so they make the cut as well.

- Second, usability is key. This season I can count the clear nights in my neck of the woods with fingers of one hand. I don't want to lose any observing or imaging time because the setup is too tedious or tricky. Also, I have to be able to set up and dismantle alone in the snowy/icy backyard when its -30C without hurting myself or the equipment. On this note, I have ruled out the Esprit 150 and others in its weight class as too cumbersome.

 I have started to gravitate towards the Takahashi TSA-120 as the sweet spot for me, given its compact nature and optical quality. The TEC140 is also lighter than many others in its size bracket, but buying new it is out of bounds for me price-wise. I placed a wanted ad for these scopes, maybe something will pop up! I'm not in a particular rush, but would like to have a new refractor for next season.

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