Easy to use refractor suggestions?

[Mr Brownstone]

I'm looking for an easy to use refractor scope with viewfinder and tripod. I live in a bortle 4 area. I'm not interested in astrophotography. I just want it to view planets, brighter deep sky objects, and any comets that might pass through. I don't want to be bothered collimating anything and hope to transport to a darker site on occasion. Budget about $300-$800. Any suggestions? Thanks

Edited March 1 by Mr Brownstone
Misspelling

[DirkSteele]

That might be tougher than you realise.  How objectionable is chromatic aberration to you?  Given the planets are one of your key targets, Jupiter and Venus in particular will cause achromatic refractors some issues with false colour.  I would argue that you really need at least a 4" scope to give satisfactory views of the planets and DSOs but that budget for refractor, mount and tripod likely excludes apo refractors of that aperture class.

If you do not worry too much about false colour (and some astronomers really are not that bothered by it) then we can certainly make some recommendations that meet budget.

 

You mention transport and no collimation.  Have you considered a 5" Maksutov?  Will perform well on the planets and has the aperture for DSOs, but the limiting factor will be the 1500mm focal length and ability to really only use 1.25" eyepieces meaning max field of 1-degree.  Now that is enough for all but the largest DSOs so that is not too bad.  The other disadvantage would be a longer cool down time that refractor before it performs at its best.

Something like this:  https://www.firstlightoptics.com/slt-series/celestron-nexstar-127-slt.html

Decent optics and computer controlled which means easier to locate objects and will track them for you and in budget.

[vlaiv]

https://www.firstlightoptics.com/evostar/sky-watcher-evostar-102-ota.html

+

https://www.firstlightoptics.com/alt-azimuth-astronomy-mounts/skywatcher-skytee-2-alt-azimuth-mount.html

or

https://www.firstlightoptics.com/equatorial-astronomy-mounts/skywatcher-eq5-deluxe.html

depending on whether you prefer EQ or AZ type mount

With rest of the budget - get some additional eyepieces ...

[GTom]

Give reflectors/other optical systems a bit of thinking. $3-800 goes very long way in the Dobsonian world but a second hand C8 also comes in this range. Visually aperture is really the king, a 200mm mirror shows you things that are completely invisible to an ~80-100mm APO/semiapo refractor.

[Elp]

I think they want simplicity and portability over aperture, refractor will likely get used more as a result. I'd also second a 4 inch refractor but with mount and tripod your budget will quickly disappear. Do not skimp on the mount and especially the tripod, these are the most important pieces over the optics as the slightest vibration either from your movements or a slight breeze will ruin the experience.

I've mentioned 4 inch, personally I find I tend to use my 60mm more due to the wider field, even on planets they're sharp though small. The 4 inch however does reveal more dso (which will greatly depend on the local LP levels) and this is where increased aperture will provide a benefit. 

Edited March 1 by Elp

[bosun21]

I would choose a Maksutov over an achromatic refractor especially for the planets. You will also have the added benefit of tracking and go to. I am one who hates CA while observing and a Maksutov will provide near apo performance.

[GTom]

16 minutes ago, Elp said:

I think they want simplicity and portability over aperture, refractor will likely get used more as a result. I'd also second a 4 inch refractor but with mount and tripod your budget will quickly disappear. Do not skimp on the mount and especially the tripod, these are the most important pieces over the optics as the slightest vibration either from your movements or a slight breeze will ruin the experience.

I've mentioned 4 inch, personally I find I tend to use my 60mm more due to the wider field, even on planets they're sharp though small. The 4 inch however does reveal more dso (which will greatly depend on the local LP levels) and this is where increased aperture will provide a benefit. 

A cat (mak or sct) will be just as easy to move around and the same weight+budget will give you more aperture (=light and resolution) in a shorter package.

Also wouldn't call a Heritage 150 or 150pds difficult to handle, they weigh the same as my 90mm refractor and not really bigger, same length.

[Elp]

I had a 130PDS, I didn't use it much. It's small, but no where near as user friendly as a refractor, the volume is the issue as well as eyepiece position, you don't want to keep rotating the OTA around within it's rings, and they are also wind sails and vibrate at the slight catch of a breeze so the tripod needs to be even more sturdy. The dob would be a good one, stable mount so tripod stability is out of the equation.

[Gonariu]

I think that a 100/1000 refractor is of almost universal use because it allows both good views of the Moon, planets and double stars and of deep sky objects, even large ones like the Pleiades (with a 40 mm eyepiece that gives ). For residual chromaticity, a light yellow W8 filter can be used. The Maksutovs are very beautiful but they are very specialized optics for the planetarium, double stars and DSO objects such as planetary nebulae, for more extensive deep-sky objects they are not good. As a mount, I prefer the equatorial one as it allows you to better follow the object observed at magnifications over X200. Furthermore, setting it up for visual use is not difficult if you can see the Polaris. For high magnifications an azimuthal mount is less comfortable although more intuitive to use.

Edited March 1 by Gonariu

[GTom]

1 hour ago, Elp said:

I had a 130PDS, I didn't use it much. It's small, but no where near as user friendly as a refractor, the volume is the issue as well as eyepiece position, you don't want to keep rotating the OTA around within it's rings, and they are also wind sails and vibrate at the slight catch of a breeze so the tripod needs to be even more sturdy. The dob would be a good one, stable mount so tripod stability is out of the equation.

I have a C5: I even mounted it on a mini tabletop photo tripod to show the Moon to the kids in the neighborhood. Perfect eyepiece position for the 3-4yr olds 😂 Also fits in a carry-on baggage on any airlines I flew with. Wouldn't try that with a 4" refractor, not to mention 5... As I recall I paid around £300 new, CA is as good as any triplets (zero). The only drawback is the slower cooldown, but again, a C5 is not a c14 in terms of thermals.

Edited March 1 by GTom

[Elp]

I replaced the 130pds with a C6. It's decent, but I still prefer the 4 inch refractor (Starfield 102), the views of DSO are much better because they're sharper and higher contrast, I managed to see Andromeda with the SF, with the C6 it's far more difficult due to the lack of clarity (and my bortle 7), very faint DSO benefit from the clarity in order to discern whether you're actually looking at a target or not in such a LP situation.

[dweller25]

11 hours ago, vlaiv said:

https://www.firstlightoptics.com/evostar/sky-watcher-evostar-102-ota.html

+

https://www.firstlightoptics.com/alt-azimuth-astronomy-mounts/skywatcher-skytee-2-alt-azimuth-mount.html

or

https://www.firstlightoptics.com/equatorial-astronomy-mounts/skywatcher-eq5-deluxe.html

depending on whether you prefer EQ or AZ type mount

With rest of the budget - get some additional eyepieces ...

Hello @Mr Brownstone and welcome to SGL……
What vlaiv said 👍
 

.

Edited March 1 by dweller25

[vlaiv]

For Mak to win over refractor on planets, it really needs a bit more aperture. That is, if both instruments are fairly decent in optical quality.

I have both 4" F/10 achromat and 4" F/13 Maksutov, and to my surprise - I could tell the difference. In one head to head comparison on planets, frac gave slightly better views. I don't know the cause of that - was it down to thermals (although there was enough time to cool down for both instruments) - or if diagonal was to blame - I used different diagonals - both GSO 99% dielectric ones - but 2" version with frac and 1.25" version with Mak.

Since then - refractor gave me even better views, but although Mak gave me nice views - I was never really impressed with what I saw (unlike refractor on one particular night).

I guess that above is sample of one and that conditions were not controlled, so should only be viewed as anecdotal evidence, however, physics also slightly favors refractor for visual, even if it has some residual CA (and F/10 4" has some obviously, but it was not really that obtrusive to my eyes - I even preferred unfiltered view versus Baader Contrast booster).

To match (or even surpass)  4" frac in planetary view - 5" Mak is needed. Then it comes down to other things - like this one:

4" F/10 refractor is capable of showing x3 wider field of view over 5" Maksutov.

 

 

[Louis D]

Or, if you get the American-spec Skymax with the 2" visual back or make the mods yourself as I did for my Orion 127 Mak:

The difference isn't quite so drastic.  Sure, there's about a 40% falloff in illumination, but I find it works quite well visually.  This is a comparison image through the 127 Synta Mak:

You can see how the 2" Meade SWA (ES-68) 40mm gets darker due to vignetting center to edge thanks to the 27mm diameter rear port throttling the 46mm field stop.

 

[Beardy30]

On 01/03/2024 at 00:50, Mr Brownstone said:

I'm looking for an easy to use refractor scope with viewfinder and tripod. I live in a bortle 4 area. I'm not interested in astrophotography. I just want it to view planets, brighter deep sky objects, and any comets that might pass through. I don't want to be bothered collimating anything and hope to transport to a darker site on occasion. Budget about $300-$800. Any suggestions? Thanks

Hi - I would highly recommend the Sky-Watcher Star Travel 102, yes you will get some chromatic aberration at that price point but it’s not as bad as you may think, it is however a superb scope that is hassle free and gives great wide field views of stars etc I have one and recently sold my 127 as it could t get a look in on the 102 by comparison- just my personal perception of course.

I had some impressive views of Jupiter which blew me away to be honest which gave a lasting impression.
 

Mount wise you’ll struggle so I’d recommend looking at this separately personally- I went for the AZI GTI - and I’ve not regretted it 

[Beardy30]

10 hours ago, Elp said:

I think they want simplicity and portability over aperture, refractor will likely get used more as a result. I'd also second a 4 inch refractor but with mount and tripod your budget will quickly disappear. Do not skimp on the mount and especially the tripod, these are the most important pieces over the optics as the slightest vibration either from your movements or a slight breeze will ruin the experience.

I've mentioned 4 inch, personally I find I tend to use my 60mm more due to the wider field, even on planets they're sharp though small. The 4 inch however does reveal more dso (which will greatly depend on the local LP levels) and this is where increased aperture will provide a benefit. 

Good advice here and I agree 

[Moonlit Night]

I take it you live over the pond? I would save and buy an Astro Tech scope. Honestly you don’t want to buy a Star Travel, you will absolutely want to upgrade and then you would lose money. Be patient and buy a ED scope. 800 dollars would easily buy one second hand and if you are lucky a mount too. Check out Cloudy Nights forum or whatever Astro Buy and Sell sites you have over there.

[Moonlit Night]

3 hours ago, Beardy30 said:

Hi - I would highly recommend the Sky-Watcher Star Travel 102, yes you will get some chromatic aberration

Some? At that focal length you would be buying pretty much the most CA you can buy. I am sorry if this comes over as mean, I am absolutely not trolling, but on planets or bright stars you are going end up with a large purple hallo all over the object. Even at fl10 you are going to get plenty of CA

[vlaiv]

29 minutes ago, Moonlit Night said:

Some? At that focal length you would be buying pretty much the most CA you can buy. I am sorry if this comes over as mean, I am absolutely not trolling, but on planets or bright stars you are going end up with a large purple hallo all over the object. Even at fl10 you are going to get plenty of CA

I agree about ST / short versions.

It's not only CA - there is quite a bit of spherical aberration (spherochromatism).  My ST102 showed fuzzy blob on planets when used as is.

However - I would not say that F/10 version has plenty of CA. CA index of F/10 4" achromat is about 2.5 - which is in "filterable" range, and close to Sidgwick criteria of CA index being >=3.

Interesting thing about F/10 4" achromat is that you can easily turn it into CA index 5 instrument that is virtually color free - by simply putting aperture mask on it.

I actually managed to get rather good (color free) image of Saturn with ST102 - by placing 50mm aperture mask in front of objective cell - that created 50mm F/10 achromat that has CA index of ~5. Of course - resolution suffers because of decreased aperture but you can see where you have sweet spot - the least level of CA versus the best level of detail with aperture size

(I use my 4" F/10 unfiltered and without mask because level of detail is best that way even if there is some level of CA present).

 

[Moonlit Night]

I think it has enough for most folks these days not to buy one. Obviously f10 is going to much better than fl5, but still too colourful many. Now if you’re getting in fl15, well that’s another matter, especially a 3 inch frac.

But as they say, CA is in the eye of the beholder.

fpl 51 glass even is a massive step forward. 

[Moonlit Night]

I take your point about masking btw, but I don’t think many people would accept it as a long term solution.

[vlaiv]

11 minutes ago, Moonlit Night said:

I think it has enough for most folks these days not to buy one.

I think that it is still very good buy in it's price range.

FLO currently sells it for £194 - together with 2" diagonal, x2 eyepieces and 30mm finder.

4" F/7 ED doublet like StarField goes for £899 - that is more than x4 as expensive.

If one has the budget - then sure, ED doublet is the way to go, but I really don't think anyone can complain at 4" F/10 achromat at current price.

[mikeDnight]

Here's one that caught my eye. At F11 it is still not long by classical standards. And easy to use too! Just point fat end skyward and look through thin end. Simple!!

[woldsman]

There’s a guy in Swansea on U.K. astronomy buy & sell offering a Vixen 102mm aperture refractor on a Vixen Polaris mount for £500. I don’t think you will do better than this unless you are very lucky. https://www.astrobuysell.com/uk/propview.php?view=211604. Reasons: superior optics, long focal length (mitigates chromatic aberration) & a mount that is very pleasant and easy to use. Scope is also very light for its size. Lastly, if you look after it the resale value is good. However, you may not be U.K. based!

Edited March 2 by woldsman

[vlaiv]

If we are talking that sort of money (and that is over OP stated budget for setup) - I would personally choose this scope:

https://www.firstlightoptics.com/stellamira-telescopes/stellamira-110mm-ed-f6-refractor-telescope.html

over both F/7 4" Starfield and F/11 4" ED

- It is easier to mount than ED

- has more light grasp than 4" F/7

- will offer widest field of view than both

- has very good CA correction (not as good as either of those scopes - but scope has potential to go all the way up to 0.997 Strehl in green part of spectrum)