Telescope opinions/recommendations

[Razz]

I'm currently looking to get my first real telescope...I'd like to be able to look at planets but my main interest is in DSOs...I've been looking at the Celestron Nexstar 6SE  and the Evolution 6 scopes, but I'm open to suggestions...Also, I'm sure that eventually I'm going to want to take pictures and I have no idea if either of these scopes are good for that...I'm basically asking for suggestions on a good telescope that I can use for a long time and can add things to that will enhance the experience...

[Nightspore]

I'm not into AP but most scopes used for that are 'fast' (focal ratio f/5 or lower). SCT's are usually f/10. I'd suggest something like a 150mm Newtonian or a 102mm refractor ED doublet. Unless you want to spend a lot of spondoolies on a triplet refractor.

 

 

150mm f/6 TS (Guan Sheng Optical) Newtonian.

 

 

102mm Altair Starwave. The above scopes are on manual mounts. The Newtonian is shown on a Sky-Watcher EQ5 Deluxe and the refractor is shown with a Vixen Porta II alt-az with a HAL-130 tripod and half-pillar.

[Razz]

Thanks for the info. I'm looking at them now. 

[Nightspore]

55 minutes ago, Razz said:

Thanks for the info. I'm looking at them now. 

 

Obviously you'll need a mount. I tend to prefer manual mounts as they are easier to set-up usually. Although GOTO and Push-to mounts are popular. GOTO mounts will need a power source. As a rule of thumb the mount/tripod should be approximately twice the weight of the telescope, predominantly for stability. If this can be achieved. This can limit the weight of the telescope somewhat. My 102mm Starwave is just over four kilo, but with a diagonal, finder and eyepiece it can push five kilo. I can just about get away with a Vixen Porta with a sturdy tripod.

 

 

Altitude-azimuth mounts are pretty intuitive to use, unlike Equatorial mounts which were designed to track in Right Ascension often with a single motor drive (compensating for the Earth's rotation). 

 

 

EQ mounts have to be polar aligned and balanced (they have counterweights), basically this part of the mount (arrow points to Polaris) has to be aimed at the Pole star. A small telescope is contained within some of the larger mounts to achieve this more accurately.

 

 

Often requiring a 90 degree eyepiece/reticule attachment. Unless you can align it while lying on the ground lol.

 

Edited December 18, 2021 by Nightspore

[Razz]

I appreciate the info. It'll definitely help me when I'm looking at different telescopes and equipment. I have a question, tho. Which is better for tracking, the Altitude-azimuth or the Equatorial mount? I understand that will partly be influenced by the quality of the mount. Wouldn't they both basically track in Right Ascension? I mean the Earth doesn't rotate differently just because of the mount I use...lol...maybe I just need to research how the tracking works on each of those type mounts. 

[Nightspore]

10 hours ago, Razz said:

I appreciate the info. It'll definitely help me when I'm looking at different telescopes and equipment. I have a question, tho. Which is better for tracking, the Altitude-azimuth or the Equatorial mount? I understand that will partly be influenced by the quality of the mount. Wouldn't they both basically track in Right Ascension? I mean the Earth doesn't rotate differently just because of the mount I use...lol...maybe I just need to research how the tracking works on each of those type mounts. 

 

The predominant difference is that tracking with an EQ basically only needs the OTA to travel or be driven in RA. The declination will move with the mount itself. Depending on how well polar aligned the mount is in the first place.

 

 

Or whether the tripod/mount has shifted slightly of course. Alt-az mounts have to travel in two planes: altitude and azimuth (up and down and in a circle). Both mounts travel in two planes, but achieve it differently. The EQ mimics the Earth's rotation.

 

 

Due to the rotation of the Earth objects in the sky appear to rise in the east, reach transit (highest point) in the south, then start to set in the west. 

 

 

If you followed an object in the sky with your finger as it rose in the east it would appear to make a large arc in the sky with its apex due south until eventually setting in the west.  This 'apex' at due south is referred to as the transit.  

 

 

The Moon and planets more or less follow this 'plane of the ecliptic'. My Newtonian is set up for lunar/planetary observing and at the extreme north of my garden for this purpose. This way I get the best view of the plane of the ecliptic. Although looking north isn't easy with it set right next to the fence in the picture (ignore the metal cats and ultrasonic motion detector, they're to convince the neighbourhood cats to stop using my lawn as a toilet lol).

 

 

At high magnifications (150x~300x) any object in the sky will appear to move incredibly fast in the field of view. Keeping it in field in the eyepiece will be a serious problem. With a manual mount the RA and declination can also be controlled very precisely with fine 'slow motion' controls. This is the only way to track at high magnification. Otherwise you will lose the object as it speeds out of view. The idea with an EQ is that you don't have to adjust the declination but can just move the OTA (optical tube assembly) in RA. Also, the first clock (mechanical motor) drives only had to operate in RA. Today modern computer controlled powered (GOTO) drives can move accurately in both altitude and azimuth at the same time. Like the mount to my 235mm Celestron Evolution (below).

 

 

 

At high magnifications with an alt-az manual mount you have to adjust both fine movement 'slow motion' controls more or less at the same time. This can be difficult and your arms can be moving like 'a fiddler's elbow' as Sir Patrick Moore once described it. If you are seated directly behind the OTA/mount this isn't always a huge problem.

 

 

I tend to do this with my Mak's and SCT. Although the tripod needs to be set low. However this then makes comfortably viewing near the zenith impractical without raising the tripod height. 

 

 

Furthermore any Newtonian telescope tracking in RA will have to be periodically rotated in the tube rings to keep the focuser in a position to be used. 

 

 

Hence my original recommendation to start off with a small refractor on an alt-az.

 

Edited December 19, 2021 by Nightspore

[Cumbrianwolf]

A good tip is to not think in the terms of magnification as you would with terrestrial viewing, this game is all about light (photons) collection that is the key to seeing DSO at their very best and larger apertures allow more light, therefore a brighter more detailed image, the caveat of this is that the weight, size, and cost of the telescopes / mount(s) increases as well which makes grab and go viewing more of a time and effort consideration.

 

Not to burst your bubble, but you will not see all that much detail in most DSO as most will be fuzzy blobs which are improved upon under very dark sky areas, some DSO show a little detail, this is not a fault of the optical instrument but rather the limitation of the human eye, it is still very enjoyable as your eyes adapt, and the images slowly improve, averted vision is another tip that improves things even more. Cost wise, the Newtonian telescope on a Dobsonian mount is one of the very best options for value for money, you can get tracked ones with motors so that there is no need to push them onto objects.

 

Keep asking questions, and we will help as much as we collectively can.

[Razz]

So, most of the telescopes I'm interested in are on backorder...lol...I did manage to find these two...any thoughts?

 

 https://octelescope.com/products/startravel-80-az-gte-s21150?currency=USD&utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping                                                                                                                                                                                                                                                                    https://agenaastro.com/catalog/product/view/id/6761/s/sky-watcher-102mm-startravel-alt-azimuth-refractor-telescope-s10100/

[Nightspore]

4 hours ago, Razz said:

So, most of the telescopes I'm interested in are on backorder...lol...I did manage to find these two...any thoughts?

 

 https://octelescope.com/products/startravel-80-az-gte-s21150?currency=USD&utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping                                                                                                                                                                                                                                                                    https://agenaastro.com/catalog/product/view/id/6761/s/sky-watcher-102mm-startravel-alt-azimuth-refractor-telescope-s10100/

 

 

The first is an ST80 on an AZ5 tripod and pillar combined with a GOTO. Achromatic doublets like these can show some chromatic aberration (false colour) although it isn't that noticeable on the ST80. A simple #8 yellow filter can ameliorate any cyan fringing. I often use a stacked yellow filter with a 'light pollution' filter. The light pollution takes out a couple of the sodium lines and naturalises the colour a bit I find. If you feel like splashing some cash Baader have specialist fringe killing filters for a bit more dosh. I don't know much about the AZ-GTe as I'm a bit old school and prefer a manual mount.

 

 

Bear in mind it will need a power source.

 

 

The second link shows the ST102, also an achromatic doublet.

 

 

I bought one of these several years ago, although I never used it with the stock focuser and replaced it with a GSO rotating Crayford. It's basically a bigger ST80. See this review. It's an excellent rich field scope, although it shows some CA on the Moon and planets. Unfortunately your second link shows it bundled with the infamous AZ3 mount and tripod which should be avoided at all costs as it is total pants.

 

 

The altitude has serious drift problems and couldn't even cope with my ST80. The AZ5 mount/tripod was eventually thrown into a skip. I couldn't in all conscience sell it to anyone else. The lock washer probably caused the problem as it wasn't up to the job. Although the centre of gravity of the pivot point being so far below the OTA is a factor too.

 

 

The ST102 is a pretty impressive and portable 102mm scope though. It's one of my favourites and weighs in at around three kilo. Mine's had a few aftermarket focusers and now sports a MoonLite. These are about 360 quid here and hand made in the US. Unfortunately they aren't being produced at the moment. People have questioned the sanity of putting a £360 focuser on a £170 OTA. But it transforms a good 102mm achromat into a very good 102mm achromat. Plus it looks great.

 

Edited December 19, 2021 by Nightspore

[Nightspore]

 

ST102 with TS Optics (GSO) Crayford-rail focuser.

 

 

Below with Sky-Watcher (Long Perng) rotating Crayford.

 

Edited December 19, 2021 by Nightspore

[Nightspore]

 

ST80 on an EQ2 mount. Eventually I gave up on the EQ and decided to go with a Vixen Porta II alt-az. Later still I used the AZ5.

 

 

My SW ST80 still gets used. It's been out eighteen times this year.

 

 

The aftermarket rotating Crayford enables 2" accessories to be used as well as providing a fine focus.

 

 

Dion from Astronomy Shed with some ST80 mod's and tweaks:

 

 

Edited December 19, 2021 by Nightspore

[Razz]

Thanks for the info. I'm leaning towards getting the ST80. I'll check out the Baader lenses that you suggested, Nightspore...on a side note, I wandered onto the observatory section of this forum...this could be an expensive hobby! LOL

Edited December 21, 2021 by Razz

[Razz]

I bought the ST80telescope...I'll either like it or I won't but I have to start somewhere....based on what I've been told, I think it'll make a great starter telescope...

Edited December 21, 2021 by Razz

[Nightspore]

7 hours ago, Razz said:

Thanks for the info. I'm leaning towards getting the ST80. I'll check out the Baader lenses that you suggested, Nightspore...on a side note, I wandered onto the observatory section of this forum...this could be an expensive hobby! LOL

 

Oh, there's no could be about it! I probably have over £5000 worth of eyepieces alone lol! 

 

 

A Baader Neodymium filter is basically a sine qua non for me. It's often been referred to as the Swiss Army Knife of filters as it is so useful, particularly for defining detail on Jupiter and Mars when used on its own and not in a stack. Baader stuff is pricey Stateside though, compared to here, so there can be slightly more economical alternatives. An inexpensive Moon & Skyglow filter stacked with a GSO #8 is basically the same and makes a good fringe killing stack for a fraction of the price.

 

 

You could stack a Lumicon #8 Wratten with a Baader Neodymium. I actually prefer the Lumicon #8 with a TS Optics UCF (universal contrast filter) for anti-cyan fringing as I find it more natural than the Baader Fringe Killer, which is a bit too 'yellow' for an 80mm aperture IMO. I also liked the BC&F cyan reduction filter, these were made in the UK but seemed to have mysteriously disappeared. They're all basically just light yellow filters though.

 

 

TBH you won't need a yellow filter for low magnifications anyway. CA just isn't a real problem with the ST80. For rich field (sweeping starfields/open clusters) and virtually all deep sky objects like nebulae you won't notice CA and so won't need yellow filters. Although as the ST80 is f/5 you could use broadband and narrowband ultra high contrast filters and also OIII filters. These are often good for certain nebulae. It's only at high magnifications that you may notice some cyan fringing around planetary limbs or lunar features. This is a known problem with achromats and only alleviated with more expensive ED glass doublets or triplets. My 72ED DS Pro can display some CA on a bright Venus. Although I've not seen it on my other ED doublets which have better quality Ohara FPL-53 glass. ED doublets and triplets are much better colour corrected than basic achromats. Although achromats themselves are somewhat corrected though. 

 

72ED DS Pro

 

And now for some slightly *anorak info:

 

A Wratten #8 or fringe killer/minus-cyan filter is a longpass filter blocking visible wavelengths below 465 nm. Blue light is between 450-495 nm and cyan light is between 490-520 nm. 

 

Yellow light is between 570-590 nm and light produced from old low pressure sodium (streetlight) lamps is around 589 nm  (589.0 ~ 589.3 nm) on average. 

 

Light pollution, Moon & Skyglow and basic contrast filters are designed to attenuate sodium light 'skyglow' produced by older type streetlights. 

 

A Wratten #8 will attenuate or block blue/cyan light below 465 nm and a contrast filter stacked behind it will further attenuate the 589 nm length of sodium light.

 

The effect the stacked contrast filter has is to reintroduce a very slight blue tint to the image effectively slightly naturalising it. 

 

 

*Anorak is British English slang roughly approximating otaku, nerd or geek.

[Nightspore]

8 hours ago, Razz said:

I bought the ST80telescope...I'll either like it or I won't but I have to start somewhere....based on what I've been told, I think it'll make a great starter telescope...

 

Yeah, they're great little scopes for what they cost. The mount looks good as well. The AZ5 tripod is pretty stable.

 

 

My AZ5 was actually bundled with my 127mm SkyMax although I mostly use it on a Porta II/TL-130. The tripod can handle the 3kg Mak' OTA and binoviewers.

 

 

FWIW on the 4th of November (very early in the morning to avoid the fireworks) I got my modified ST80 out to look at the Orion Nebula (M42). I can use a 2" diagonal with the rotating Crayford and with the 31mm Baader Aspheric got 12.9x magnification. I had found my 2" Orion UltraBlock narrowband filter out. I bought it years ago but don't recall using it before as I always intended to use it with bigger refractors. I often use the 1.25" UltraBlock version with my 72ED. I had a superb view of M42 with the 2" UltraBlock proving that the ST80 can be used with narrowband filters pretty effectively at low magnifications. I live in the greenbelt so LP isn't a huge problem but a narrowband can still be useful for faint nebulae. M42 isn't exactly faint, it's a naked eye object for me. It still looked great with the UltraBlock though lol!

[Nightspore]

 

The ST80 solved a problem for me a few years back. I wanted a portable short tube achromat as a grab and go. It took me a while to sort out a suitable alt-az mount and tripod. I'd originally bought it with a bundled EQ1.

 

 

When everything was more or less sorted I discovered that the dew shield was stuck fast on the SW ST80. Not only that the focuser appeared to have a screw loose lol. So I just bought an Orion ST80 as I could get it as an OTA with absolutely no accessories. 

 

 

I was so impressed with it I decided to replace the stock focuser with the GSO Crayford. Although it does shift a lot of weight to the rear of the OTA it has the advantage of being able to rotate and has a dual-speed for fine focus. This modification has become a standard upgrade for many ST80 users.

 

 

Eventually I fixed the stuck dew shield on the SW (elbow grease and a butter knife) and also added a Crayford.

 

 

So I was double happy!

 

 

With the AZ5 it has become a light grab and go easily deployed. I have better small refractors now but the SW ST80 still gets out. 

 

Edited December 21, 2021 by Nightspore

[Razz]

Thanks for all the info, Nightspore. Up until a week ago, my mindset was just get the highest magnification telescope you can, point and look...I've learned a lot here since last week...lol...I mean, I know a lot about space. Nebulae, pulsars, quasars, things like that. Apparently, my telescope knowledge is severely lacking! Keep the "anorak" moments coming...I like to know how things work. One of my mottos is : Don't just tell me what to do, tell me why I'm doing it...Thanks again...

[Nightspore]

9 hours ago, Razz said:

Thanks for all the info, Nightspore. Up until a week ago, my mindset was just get the highest magnification telescope you can, point and look...I've learned a lot here since last week...lol...I mean, I know a lot about space. Nebulae, pulsars, quasars, things like that. Apparently, my telescope knowledge is severely lacking! Keep the "anorak" moments coming...I like to know how things work. One of my mottos is : Don't just tell me what to do, tell me why I'm doing it...Thanks again...

 

You're welcome. Amateur backyard astronomy isn't always about the highest magnification or the biggest aperture. It can be though. Size can matter. Astronomy and 'telescopy' (lol) are different animals.

 

You have to take into consideration certain practicalities. Windows of opportunity to observe and weather (seeing and transparency) conditions will dictate a lot. Setting up a little refractor will be much faster than setting up a huge scope. If you take an hour to set up a large SCT, and then the weather changes for the worse, you aren't probably going to get a session in.

 

One single telescope type won't have the versatility and can't do everything. Although a short tube refractor is the closest you will probably get to it. This is why I recommend them if you're just beginning. For a start they are eminently practical. Portable, easy to manipulate on the mount, no real collimation issues, and have virtually no cool-down time.

 

My 150mm Newtonian can take 45 mins for the air temperature inside the tube to equalise the outside air temperature. To witness this you only have to de-focus on an object to actually see the thermals swirling in the tube. Before this 'thermal equilibrium' happens you will not get a sharp image due to swirling hot air currents inside the OTA itself.

 

 

Catadioptrics are even worse as they are enclosed systems. It can take over an hour before my 127mm Mak' cools down enough to get a sharp 200x ~ 250x on the Moon. My 235mm SCT can take up to two hours. A short tube refractor is basically thermally stable by the time you get it into the mount.

 

 

Scopes with focal ratios greater than f/8 have limited fields of view and are best for high magnifications. However, slow scopes are poor at observing at the low magnifications often required for open clusters and many nebulae. A fast scope OTOH will have a wide angle field and good light gathering. Fast scopes are not good for high magnifications. An old trick to remedy this is to use a Barlow lens. You'll need one with the ST80. It's usually placed in the diagonal and then the eyepiece is placed into it.

 

 

There are 'long' and 'short' Barlows. The short ones are more easily used in diagonals. Basically they double (or more depending on the specific Barlow) the magnification of the eyepiece placed in them. The Takahashi 2x Barlow below was specifically designed to be used between the diagonal and the focuser. It's particularly useful used conventionally with a 2" diagonal as it won't make contact with the mirror or prism in the diagonal. Used as such it gives a 1.6x magnification.

 

 

Essentially they increase the focal ratio of the scope. A 2x Barlow will turn your ST80 from an f/5 into an f/10 focal ratio!

 

 

Furthermore the element can be threaded off from many Barlows and then threaded into the eyepiece itself for about a 1.5x magnification increase. The GSO and Barsta 'shorties' below are relatively inexpensive but very effective.

 

 

Also a refractor will always be sharper and have more contrast than a reflector. Principally as the light is refracted rather than reflected and there is no obstruction by a secondary mirror. As a consequence an 80mm refractor often seems to equal a 130mm refelector. Even though the 130mm reflector has a light grasp of 2.64x the 80mm refractor, the refractor will show a better contrasted and sharper image. 

 

 

I have a 60mm short tube refractor (Altair 60EDF).

 

 

It only has a 11.59 magnitude resolution limit. By contrast a 150mm aperture has a 13.58 magnitude limit. There's an awful lot of stars around 12 magnitude though. I can see M57 (Ring Nebula) with the 60EDF. It looks like a tiny smoke ring, but I can see it. I've seen Galilean moon transits on Jupiter and the Cassini Division in Saturn's rings with the 60EDF. Size matters, but not as much as you think. It's what you do with it that matters. So they say lol.

 

 

 

 

 

 

Edited December 22, 2021 by Nightspore

[len2376]

.Also, I'm sure that eventually I'm going to want to take pictures and I have no idea if either of these scopes are good for that..

 

A whole different ball game!

[Razz]

Well, turns out that the telescope I ordered was actually out of stock and hey cancelled my order...the search is back on!

[Nightspore]

1 hour ago, Razz said:

Well, turns out that the telescope I ordered was actually out of stock and hey cancelled my order...the search is back on!

 

There seems to be a lot out of stock Stateside. FLO export to the US.

 

There's this: ST102 Gte

 

Amazon UK are selling Orion ST80 OTA's, so you should be able to get one from Amazon US. Get the one without the dovetail.  Or the Orion site. 

 

Some bloke from Orion talking about the ST80.

 

All you need then is the mount. Dovetail. Tube rings you should be able to get locally, probably from Agena. 

 

These should fit the ST80. They're 90mm but will hold the OTA which is slightly larger than the 80mm objective. Orion tube rings for ST80.

 

The only thing you'll need then is a reflex sight (probably cheaper from Amazon) and some eyepieces.. 

 

 

Edited December 24, 2021 by Nightspore

[Nightspore]

Altair also export to the US. 

 

Omegon also market the ST80.

 

Astroshop (Omegon)

Edited December 24, 2021 by Nightspore

[Razz]

Thanks for the suggestions. I checked out the links you posted and actually learned quite a bit this morning. (Mostly because I tend to check out other things on the websites just to see what they are for) I've started a list of things I'll need to get as well as things I may want in the future. Of course, since I got interested in doing this I've been checking out the sky at night and it's always cloudy...lol...I haven't even bought anything yet...

[Nightspore]

40 minutes ago, Razz said:

Thanks for the suggestions. I checked out the links you posted and actually learned quite a bit this morning. (Mostly because I tend to check out other things on the websites just to see what they are for) I've started a list of things I'll need to get as well as things I may want in the future. Of course, since I got interested in doing this I've been checking out the sky at night and it's always cloudy...lol...I haven't even bought anything yet...

 

I got lucky last night and got three and a half hours with my 72ED and a cloudless night sky. Then the clouds came ... lol. I doubt I'll get out for a bit the way it's looking. Mounting the ST80 was a bit of a process for me. After abandoning the EQ mounts it took quite a while to find a suitable AZ mount and tripod combination (Vixen Porta II & HAL-130). The HAL tripod was a bit heavy for a small scope but very stable. A retailer in the UK advertised a 127mm Mak OTA with the finder shoe in the right position to use in a Vixen style mount.

 

 

If it's not in the right position it ends up like this (above). I had to add a Rigel sight to my 102mm Mak. I contacted the retailer three times to check that the 127mm they were selling had the dovetail position I wanted. As they are usually sold only with Vixen type mounts. Three times they told me it was in the correct position. When it was delivered it looked like this below!

 

 

 

So I returned it and bought a 127mm SkyMax bundled with an AZ5 mount. I usually use the 127mm on a Vixen. But the SW AZ5 has become invaluable as a grab and go tripod for smaller scopes. All's well that ends well right? Good luck with obtaining a suitable scope.

 

 

Edited December 24, 2021 by Nightspore

[Razz]

What's up with that? Did you talk to the same person 3 times? I've been a mechanic for 36 years and I've run into the same kind of "lack of knowledge" at auto parts retailers. The kids behind the counter only know what the computer tells them. They have no idea what the parts are or what they do. That's why when I go to an auto parts store, I just walk in and tell them I want this part and here's the part number. And EVERY time they tell me that they need to know the vehicle info to look it up. And every time I say that if you can tell me what that part does then I'll give you the vehicle info otherwise just get me what I asked for...lol...

Anyway, I ordered the ST80 OTA, tube rings, eye pieces and reflex sight from the Orion website. I may have to get the mount and dovetail from the UK, most likely FLO. I'm still looking...

Edited December 24, 2021 by Razz