15 replies to this topic

[Lostinspace12]

Hi! First post in the refractor forum after reading a ton last few days.

 

I have an 8” SCT that I’m enjoying as my main scope. I’m looking for a refractor for two new things for me: (1) wide field and (2) solar. Have read a ton of threads here about complementing an 80-120mm with the 8” SCT.

 

Wide field: I am looking for TFOV ~1.5 to 3*, under 100x. Basically just extend where the SCT falls short. I’d like to use same 2” eyepieces on both scopes. E.g 31mm Nagler, 17 and 10 Ethos.

 

Solar: Mainly full disc white light with proper upgrades…Herschel, filters, etc. Maybe zoom in a bit more for spots.

 

I’m leaning towards an AT102ED f/7 or similar. That would give me:

31mm: 23x, 3.4 TFOV, 4.4 EP

17mm: 42x, 2.4 TFOV, 2.4 EP

10mm: 71x, 1.4 TFOV, 1.4 EP

 

I’m in Bortle 6 skies typically; dark sky site is 3-4. Visual only. Will use a simple tripod mount. Budget is flexible, want to pay for quality but not overpay for features I won’t use. Portability is important.

 

Question: Am I on the right path with something like the AT102ED? Will I see any benefit with a more expensive triplet or lanthanum optics in these uses?

 

Thank you in advance for all opinions and advice!

 

Oh, and if anyone is wondering why not just binoculars for low power, I can’t merge images well.

 

Edited by Lostinspace12, 17 February 2025 - 11:42 AM.

[hyiger]

Hi! First post in the refractor forum after reading a ton last few days.

 

I have an 8” SCT that I’m enjoying as my main scope. I’m looking for a refractor for two new things for me: (1) wide field and (2) solar. Have read a ton of threads here about complementing an 80-120mm with the 8” SCT.

 

Wide field: I am looking for TFOV ~1.5 to 3*, under 100x. Basically just extend where the SCT falls short. I’d like to use same 2” eyepieces on both scopes. E.g 31mm Nagler, 17 and 10 Ethos.

 

Solar: Mainly full disc white light with proper upgrades…Herschel, filters, etc. Maybe zoom in a bit more for spots.

 

I’m leaning towards an AT102ED f/7 or similar. That would give me:

31mm: 23x, 3.4 TFOV, 4.4 EP

17mm: 42x, 2.4 TFOV, 2.4 EP

10mm: 71x, 1.4 TFOV, 1.4 EP

 

I’m in Bortle 6 skies typically; dark sky site is 3-4. Visual only. Will use a simple tripod mount. Budget is flexible, want to pay for quality but not overpay for features I won’t use. Portability is important.

 

Question: Am I on the right path with something like the AT102ED? Will I see any benefit with a more expensive triplet or lanthanum optics in these uses?

 

Thank you in advance for all opinions and advice!

 

Oh, and if anyone is wondering why not just binoculars for low power, I can’t merge images well.

Unless you plan to venture into astrophotography at some point you can skip the triplet and get a decent doublet. The AT102ED is a excellent choice. 

Edited by hyiger, 17 February 2025 - 12:05 PM.

[fishhuntmike]

Looks like you are making a wise, cost-effective and very complementary choice to me.

[truckerfromaustin]

I would usually recommend the 102edl. Since you're after a wide angle, fairly low magnification usage scope, the 102ed will be fine. As a bonus it's currently on sale at astronomics for $584.10. It's fine up to around 180-200x magnification before you see any false color depending on the seeing conditions. I can't comment on its solar abilities, but there is a thread on the 102ed in the refractor section that might help with its capabilities.

Clear Skies

Edited by truckerfromaustin, 17 February 2025 - 12:12 PM.

[balcon3]

For your intended use, since you don't intend to go over 100x, I would go smaller than 102. An 80mm scope will get you what you want, will be cheaper, will be easier to mount, and for the same money you can get a better quality scope. You can get a nice AT80mmED scope for under $400.

[NiteGuy]

Well, if it's gotta be a refractor, I too agree with the choice of an AT102ED to fit your intended application. Low-power images should be great, if a bit on the weak side regarding light gathering power. The 102ED is an extremely well-made scope and the doublet objective means that it shouldn't weigh as much and be as nose-heavy as the triplets.

 

As much as I love refractors, for use at 100x or less, I personally would skip the refractor and opt for a 6-inch F4 rich-field Newtonian. Combined with a coma-corrector, you would have refractor-like images, similar weight, and considerably more light gathering power.

 

That said, I have an AT115EDT and can attest to the high quality of the baffling, focuser, dew shield, rings, coatings, etc.

[sevenofnine]

Welcome to C/N! 

 

A lot depends on your sensitivity to CA. If a slight color fringing on the brightest objects like the Moon, Jupiter, Venus and bright stars doesn't bother you then the AT102ED is a fine choice IMO. You pay a lot more for lanthanum and triplets to remove more visible CA. Consider the smaller 80ED if you really want a grab-n-go telescope. The mounting requirements are much less. Good luck with your selection! 

Edited by sevenofnine, 17 February 2025 - 01:46 PM.

[RichA]

Hi! First post in the refractor forum after reading a ton last few days.

 

I have an 8” SCT that I’m enjoying as my main scope. I’m looking for a refractor for two new things for me: (1) wide field and (2) solar. Have read a ton of threads here about complementing an 80-120mm with the 8” SCT.

 

Wide field: I am looking for TFOV ~1.5 to 3*, under 100x. Basically just extend where the SCT falls short. I’d like to use same 2” eyepieces on both scopes. E.g 31mm Nagler, 17 and 10 Ethos.

 

Solar: Mainly full disc white light with proper upgrades…Herschel, filters, etc. Maybe zoom in a bit more for spots.

 

I’m leaning towards an AT102ED f/7 or similar. That would give me:

31mm: 23x, 3.4 TFOV, 4.4 EP

17mm: 42x, 2.4 TFOV, 2.4 EP

10mm: 71x, 1.4 TFOV, 1.4 EP

 

I’m in Bortle 6 skies typically; dark sky site is 3-4. Visual only. Will use a simple tripod mount. Budget is flexible, want to pay for quality but not overpay for features I won’t use. Portability is important.

 

Question: Am I on the right path with something like the AT102ED? Will I see any benefit with a more expensive triplet or lanthanum optics in these uses?

 

Thank you in advance for all opinions and advice!

 

Oh, and if anyone is wondering why not just binoculars for low power, I can’t merge images well.

It's a very good choice, Bortle 6 skies are pretty good for a small scope too.  Don't worry about lanthanum, it's being used because some "regulation happy" countries don't like the composition of traditional glasses.

[Lostinspace12]

Thanks everyone for your opinions and advice.

 

Welcome to C/N! 

 

A lot depends on your sensitivity to CA. If a slight color fringing on the brightest objects like the Moon, Jupiter, Venus and bright stars doesn't bother you then the AT102ED is a fine choice IMO. You pay a lot more for lanthanum and triplets to remove more visible CA. Consider the smaller 80ED if you really want a grab-n-go telescope. The mounting requirements are much less. Good luck with your selection! 

I don’t think I’m overly sensitive to CA, but a few eyepieces I’ve tried have exhibited more CAEP than I cared for. But I don’t figure to use this scope on planets, moon, etc, at higher powers so not overly concerned. I am curious if the full disc sun will have a lot of CA…but I’ll dig into that over in the solar forum.

 

For your intended use, since you don't intend to go over 100x, I would go smaller than 102. An 80mm scope will get you what you want, will be cheaper, will be easier to mount, and for the same money you can get a better quality scope. You can get a nice AT80mmED scope for under $400.

Yes, and the 80 might be better for the solar application too, from what I’m learning there. 

 

I have been worried about aperture fever coming from the 8” SCT. I know many DSOs will be faint fuzzies, I just hope the wider view will give me more context while still showing some detail on the larger nebulas and clusters that I’ve seen with my SCT.

 

So I’ll have to give this some thought too before I pull the trigger. The dual-use for solar has me leaning towards a smaller refractor based on what I’ve been learning over there, too.

 

Well, if it's gotta be a refractor, I too agree with the choice of an AT102ED to fit your intended application. Low-power images should be great, if a bit on the weak side regarding light gathering power. The 102ED is an extremely well-made scope and the doublet objective means that it shouldn't weigh as much and be as nose-heavy as the triplets.

 

As much as I love refractors, for use at 100x or less, I personally would skip the refractor and opt for a 6-inch F4 rich-field Newtonian. Combined with a coma-corrector, you would have refractor-like images, similar weight, and considerably more light gathering power.

 

That said, I have an AT115EDT and can attest to the high quality of the baffling, focuser, dew shield, rings, coatings, etc.

I hadn’t really thought about a newt mostly because of the solar application. But it’s a good suggestion and down the road I could see myself with a fast newt, a slow SCT, a solar refractor, and a big dob…if my wife doesn’t divorce me first! 

Edited by Lostinspace12, 17 February 2025 - 07:30 PM.

[dryfly]

I think the 100ED is a good choice that you'll be happy with.  I used to have a 100mm telescope, now have an 80, and kind of miss the little extra the 100 gives you.

 

Mike

[PKDfan]

Hi Lostinspace12 !

I always help when someone says please !

I'm going to suggest that you've gone too big instead think of a smaller apo for what you want.

My 400mm 62mm Evolux is exceptional on the sun terrestrial lunar birding plane spotting and planetary too.

I've recently gotten back into solar work and i've been gobsmacked at the penumbra and umbral contrasts i've seen with it. It gets to a possible 7.1X view (55Plössl) and with my 40XW does 10X and a 6.75degree true field while 4TOE gets me to 100X.


This line-up has been discontinued and is priced very well so if you can find some in stock go for it.


If you want a more general purpose refractor for other pursuits thats great and i suggest 4inches or 100mm for a good quick GnG scope.

Think 100ED F/9.

I've looked through two Evolux samples and can attest that their figure was excellent and mine which is exceptional.

SW has a drastic sale on now so is a GREAT time to invest in high quality scope for essentially pennies on the dollar.


Good Luck in your search !


CSS
Lance
Edit another typo

Edited by PKDfan, 17 February 2025 - 09:00 PM.

[Lostinspace12]

Thanks for the suggestions.

 

I haven’t had much luck finding many slower f/9 or f/10 80-100mm scopes, except for the cheap beginner scopes which I don’t trust to hold my 2” grenades like the 31mm Nagler.

 

Hi Lostinspace12 !

I always help when someone says please !

I'm going to suggest that you've gone too big instead think of a smaller apo for what you want.

My 400mm 62mm Evolux is exceptional on the sun terrestrial lunar birding plane spotting and planetary too.

I've recently gotten back into solar work and i've been gobsmacked at the penumbra and umbral contrasts i've seen with it. It gets to a possible 7.1X view (55Plössl) and with my 40XW does 10X and a 6.75degree true field while 4TOE gets me to 100X.


This line-up has been discontinued and is priced very well so if you can find some in stock go for it.


If you want a more general purpose refractor for other pursuits thats great and i suggest 4inches or 100mm for a good quick GnG scope.

Think 100ED F/9.

I've looked through two Evolux samples and can attest that their figure was excellent and mine which is exceptional.

SW has a drastic sale on now so is a GREAT time to invest in high quality scope for essentially pennies on the dollar.


Good Luck in your search !


CSS
Lance
Edit another typo

[kmparsons]

In my experience, a 100mm (4") scope hits the sweet spot for most applications. A 100mm objective gathers over 50% more light than an 80mm, A doublet is light, quickly cools down, and is fine for visual. A quality ED doublet like the AT102ED can give you highly satisfying views of all objects (except faint fuzzies) at the magnifications you will normally be using. 

[HDEO]

If your budget is flexible enough, the Takahashi FC100D scopes are superb.  Very light and easy to mount.  Sometimes they come up in the classifieds.  I think your longer term plan for a fast newt, a slow cat, a big dob and a solar frac is a great menagerie.   lots of flexibility in your plan.  

[Lostinspace12]

Thanks for all the helpful opinions and advice! Great community.

 

I ordered a AT102ED from Astronomics!

 

Now I need to figure out the mount…I’m spoiled by the Evo / NexStar Goto on my 8” SCT. So I’m on the hunt for something similar for this guy. I’ll explore that in the mount forum.

 

Clear skies to all!

[Oldfracguy]

Thanks for all the helpful opinions and advice! Great community.

 

I ordered a AT102ED from Astronomics!

 

Now I need to figure out the mount…I’m spoiled by the Evo / NexStar Goto on my 8” SCT. So I’m on the hunt for something similar for this guy. I’ll explore that in the mount forum.

 

Clear skies to all!

That was a great choice.  The regular ED versions of these scopes are excellent, and only fall behind the EDL models when it comes to seeing fine details on the planets, the lunar surface and perhaps splitting close unequal double stars at magnifications over 150 to 200x and higher.  If you look at a bright star like Vega or Sirius you will see a little bluish fringing, but other than that at 100x and below the AT102ED is a great scope.  With a 2" eyepiece having a field stop close to the maximum of about 46 mm you will get a TFOV of 3.7°, enough to frame the showcase spread-out DSO targets like the Veil Nebula using a 2" filter.

 

People have been happy with the Sky-Watcher AZ-GTi GoTo mount for the AT102ED/L scopes, but the stock lightweight "Star Adventure" tripod that comes with the AZ-GTi mount is much too wobbly for that scope.  If you get a SW AZ-GTi, put it on at least a tripod like the one that comes with the Sky-Watcher AZ5 "Heavy Duty" mount.  That tripod has 1.75" tubular stainless steel legs and the necessary 3/8"-16 threaded bolt to attach the AZ-GTi mount head.

Edited by Oldfracguy, 20 February 2025 - 01:16 PM.