849 replies to this topic

[Fiske]

I've been wrestling with something for over a year and finally realized how to articulate it. I need to find the right telescope to support my binoculars.   

 

It's an ironic problem to have because the common scenario is the reverse -- a binocular used as a finding aid to support telescopes. We are occasionally reminded of this by helpful telescope aficionados.  Binocular enthusiasts may ask, do we really need telescopes? Why? Well, certainly not as a finding aid, given how much easier navigation is with binoculars. But telescopes do have possible edge case uses. 

 

Here I was last night with the Oberwerk 100XL-SD and my trusty friend of decades, the TV-101, enjoying its first ride on my iOptron Tri-pier.

 

 

I was comparing views of 6 Trianguli between the 100XL configured with the left OTA at 112x and the right at 40x as a finder considering a question posed by binofrac about using one side of a BT for higher magnification views (thus removing the difficulty of attempting to align dual tiny exit pupils).

 

STF 227 / 6 Trianguli
02h12m +30*18'
5.162/6.613 sep 3.88" pa 67.2*

 

 

 

I was able to resolve the double with both the 100XL and the TV-101, though the view with the latter was slightly cleaner and more refined (as expected). While using a BT in dual mode like this for double stars is workable it's not ideal for a reason that might be overlooked without doing actual side by side comparisons. Using the helical focusers on BTs at high magnification is a pain in the kizitz, and even more so in cold weather when the darn things stiffen up. Swapping eyepieces and focusing with a telescope on the other hand is simplicity itself.

 

So this is my personal use case. Is it possible to resolve closer (under 4-second) double stars with binocular telescopes? Certainly. But it is difficult to manage by mere mortals (particularly the bespectacled) who do not possess high magnification BT super powers (ahem), and more easily accomplished with a telescope. There. I said it. And yes, I know other use-cases exist, like chasing down fuzzy bits of galactic lint with larger aperture telescopes, but that's not on the celestial menu for urban astronomy.

 

What telescope to choose?

 

I added an Orion CC8 Classical Cassegrain last year, thinking it would be an ideal option for double stars beyond the relaxed BT range, not to mention the occasional planetary nebula and etc. But I have rarely used it. Why? It's a lot of work to set it up. It's much easier to plonk the TV-101 on the iOptron Bino-Bracket (a recent happy discovery), and I'm not going to lie, that configuration is a lot of fun, but still nowhere near as easy as setting up a BT or p-gram (a minute or two for either). I've decided to try a StellarVue M002C head on the 161MK2B mount as a quicker setup option for the TV-101, but that will involve manual finding and tracking so we'll see.

 

This morning I thought of an ideal quick set-up, easy-to-use option for double-star peeks -- a Celestron NexStar 6SE. It's light, can be set up in a few minutes, and has goto for easy finding and tracking at high magnification. Plus thrifty -- sort of the telescope equivalent of a value-priced binocular, which has a certain cachet to it.

 

So how about it binocular enthusiasts? What is your ideal support telescope? Or do you need one?

 

Edited by Fiske, 24 November 2023 - 07:47 AM.

[TOMDEY]

Excellent philosophy and point! I enjoy the 90^o APM 100mm ED APO Bino but also have my trusty very old TV Genesis 100mm F/5. With that I can crank up the mag and scrutinize the target both ways... binoscopically at lower mags and monoscopic at higher mag and good wavefront. Good combination.    Tom

[MT4]

My ideal support telescope is a Tak FC-100DZ.   It's the right size for my poor local seeing.   It's for when I can go higher in mag.   I use it with a Leica ASP zoom eyepiece for 45-90x and with a Tele Vue Powermate 2x for 90-180x.   In theory, that could be the only eyepiece I'd need for it, though in practice I have a few super-wide (80-92 degrees wide) eyepieces that I occasionally use the Tak FC with.

 

Like you, my Tak FC scope is there to support my binoculars.   

 

[areyoukiddingme]

I'm not sure I have anything approaching a solution, but do have a couple of observations.

 

I also have a Televue 101, and it mounts well on the Stellarview m2, which can incidentally be fitted with encoders and DSCs.

 

My thinking on the 'support' role is that a ~4 refractor seems like a nice pairing, but personally I like to go for more aperture. I'd think the Televue is overlapping a lot with those 100mm binos, for example. 

 

I also have a C6, which in terms of punch is probably equivalent to about 110-115mm of refractor, so it's not going to give a slam-dunk view over the Televue either. They are nice inexpensive little scopes that put a good aperture in a small space. The optics on them seem to be surprisingly good.  But you will be dealing with fields of 1.5 degrees at the biggest end.

 

From my balcony, with my largest binos being handheld 15x50s, I'm finding that both my 92mm refractor and either 8" reflector or 12.5" make for interesting comparisons.

 

For example, on Auriga, there's a host of open clusters with interesting appearances in binoculars. The 92mm steps up and spits those open while losing the bigger structures. The M36-38 objects then get blown up into views that take up the entire eyepiece field of view.

 

Three steps seems good to me--a binocular view at low power that gives good context. A zoomed-in refractor view that gives a bit of context and some detail, and a really zoomed-in reflector view that brings the object much closer to show its structure.

[mogur]

Something in the 2000mm focal length range for the high-power views of smaller objects that binos are not particularly suited for.

[therealdmt]

My ideal support telescope is a Tak FC-100DZ.   It's the right size for my poor local seeing.   It's for when I can go higher in mag.   I use it with a Leica ASP zoom eyepiece for 45-90x and with a Tele Vue Powermate 2x for 90-180x.   In theory, that could be the only eyepiece I'd need for it, though in practice I have a few super-wide (80-92 degrees wide) eyepieces that I occasionally use the Tak FC with.

 

Like you, my Tak FC scope is there to support my binoculars.   

 

Very nice setup. What’s your finderscope (and eyepiece on it) there?

[Echolight]

I think for double stars, my best option would be the yard cannon.

 

I have a C6. And an SE mount. But I don't really love using goto. And I can't imagine it'd be as good.

[MT4]

Very nice setup. What’s your finderscope (and eyepiece on it) there?

 

The finder scope is as follows:

   1.  Askar FRA180.                                         <-- Note:  It's the original, non-PRO one.

   2.  M42 Female -> M48 Male adapter

   3.  M48 Female -> M48 Female adapter

   4.  M48 Male - M56 Female adapter

   5.  WilliamOptics 1.25" amici prism for RedCat51

   6.  Morpheus 12.5mm eyepiece giving 5.4 degrees at 14.4x.   Or Morpheus 17.5mm giving 7.2 degrees at 10.3x. 

[MT4]

By the way, Fiske, I love this thread.

[jrazz]

I like this topic and I have a different idea!

 

Why not an 8" dob?

 

Stay with me. A ƒ/6 200mm dob with 1200mm focal length is dead simple to set up and use. Light and surprisingly good. I know I knock my dob all the time and yes, for me it doesn't best the BT. However, it's even easier to set up and is sometimes just pure fun as a change. You already have a killer refractor and a Cassegrain. I know you have a dob but that thing is a huge beast! A simple, small mass-market dob will do wonders. I also think the slower ƒ ratio of the 8" will be sharper for doubles than the ƒ/4.7 of the 10".

 

For me the TOA requires much forethought. I need to go and put the AZMP on the pier, lug around the 30lb beast and wait at least 90 minutes for it to acclimate. It's awesome but a lot of work. 

The BT is far easier to use but I especially for looking at things close to the zenith it's not the most comfortable.

The dob can be wheeled out, left for an hour to acclimate. It takes me all of 2 minutes to get a 3-star alignment on my push-to system and I'm off to observing! 

 

Edit:

BTW, one of the reasons the dob is fun is that it DOESN'T have a goto but rather a push to. GOTO's are fun and all but can be annoying and slow. Sometimes going pure manual with a computer looking over your shoulder is much more fun and rewarding.

Edited by jrazz, 23 November 2023 - 09:23 PM.

[norvegicus]

I've said it before.  I'll say it again.  Everyone should have an FC-100.

[MT4]

I've said it before.  I'll say it again.  Everyone should have an FC-100.

 

Agreed 100%.

[Echolight]

I like this topic and I have a different idea!

 

Why not an 8" dob?

 

Stay with me. A ƒ/6 200mm dob with 1200mm focal length is dead simple to set up and use. Light and surprisingly good. I know I knock my dob all the time and yes, for me it doesn't best the BT. However, it's even easier to set up and is sometimes just pure fun as a change. You already have a killer refractor and a Cassegrain. I know you have a dob but that thing is a huge beast! A simple, small mass-market dob will do wonders. I also think the slower ƒ ratio of the 8" will be sharper for doubles than the ƒ/4.7 of the 10".

 

For me the TOA requires much forethought. I need to go and put the AZMP on the pier, lug around the 30lb beast and wait at least 90 minutes for it to acclimate. It's awesome but a lot of work. 

The BT is far easier to use but I especially for looking at things close to the zenith it's not the most comfortable.

The dob can be wheeled out, left for an hour to acclimate. It takes me all of 2 minutes to get a 3-star alignment on my push-to system and I'm off to observing! 

I'm sure Fiske has an XT8 just outside the frame of his picture 

[gwlee]

My XT8 and 90mm Stowaway went to new homes this year, so just have my AT72EDII now, and it’s my emotional support telescope .

Attached Thumbnails

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Edited by gwlee, 23 November 2023 - 10:02 PM.

[Fiske]

I'm sure Fiske has an XT8 just outside the frame of his picture 

Well I do.   

 

Just inside the garage. But I've been pretty much ruined on the XT-8 because of all the time I've spent with the APO BTs. The XT-8 view just looks soft. (And yes, it's collimated.) I get why APO fans are less than impressed with mass-market Dobs. Yes, fainter objects can be seen but the views just aren't crisp compared with a premium refractor. I do have a Royce 10-inch f5 conical primary mirror to build a premium Dob, and the views with that would not be soft.  The thing is, I'm not sure how much I would use it. 

 

The iOptron is the only go-to mount I've owned. Most of my observing is done manually navigating star fields, which is a lot of the fun for me. The purpose of go-to is to minimize fuss with narrow field, high magnification views.

Edited by Fiske, 23 November 2023 - 11:31 PM.

[Echolight]

Well I do.   

 

Just inside the garage. But I've been pretty much ruined on the XT-8 because of all the time I've spent with the APO BTs. The XT-8 view just looks soft. (And yes, it's collimated.) I get why APO fans are less than impressed with mass-market Dobs. Yes, fainter objects can be seen but the views just aren't crisp compared with a premium refractor. I do have a Royce 10-inch f5 conical primary mirror to build a premium Dob, and the views with that would not be soft.  The thing is, I'm not sure how much I would use it. 

 

The iOptron is the only go-to mount I've owned. Most of my observing is done manually navigating star fields, which is a lot of the fun for me. The purpose of go-to is to minimize fuss with narrow field, high magnification views.

I wonder if you would be happy with the C6 then. 

 

I also have an XT8. Got it used for cheap. Although I rarely use it. Not because the view is terrible. But because the eyepiece doesn't seem like it's at the right angle. And the motions aren't super slick.

 

Anyhow, today, I thought I'd give a dob one more try, and I bought a brand new Explore Scientific Firstlight 10. Because the rings let you rotate the tube to put the eyepiece/diagonal where I want,.. I hope.

......And Black Friday.  $499.95 to my front door.

 

Hey,.... maybe a good test bed for a Royce 10 inch f5?

 

I still think I'll like my big achro better for pinpoint stars.

But I'm hoping I'll like the ES Firstlight 10 experience better than the XT8. Still, even if it's a planet killer and awesome deep sky scope, it might just be a special occasion scope for me.

 

But I do have a little C5 that I really like. It throws up a perfect star test. Holds tight on the Moon to 275x. And that's with a reducer and a 2 inch diagonal., with 105mm backspace, roughly. (I use a 20 Hyperwide for a finder)

Just so so easy. One hand out the door on the mount. And it can go on a real little mount.

I should really give it a shot on double stars.

Edited by Echolight, 24 November 2023 - 12:29 AM.

[Dale Smith]

Thought-provoking and fun post, Fiske. Telescopic support for binocular astronomy—I did that tonight. Had my Skywatcher 130mm Newtonian out providing closeups of the Moon, especially Mare Humorum, while observing Luna in various binoculars, especially the 20x60 Pentax, mounted.

 

Also used for close ups on M31, the Double Cluster, Jupiter, Albireo and so on. Basically, whenever I wanted to zoom in for a closer look. 

 

My 90mm Skywatcher Mak is more a dedicated Moon and planetary scope, though I’ve used it on open clusters and a few double stars.

[therealdmt]

Well, not much of a picture, but, it’s what I could do in a quickie attempt in a cramped apartment.

 

I wouldn’t say this 72mm ED doublet is a "support telescope" as much as that the binoculars and telescope support each other, and that this year, this binocular-heavy group has comprised my "everyday carries":

 

Nevertheless, for the mentioned double stars, I enjoy using my 4" f/9 ED refractor much more. Brighter, better (richer) colors and more separation. I can’t say I use my Dob much for double stars, though of course that is completely possible. It’s just that I’m usually thinking about DSOs when I have the Dob out.

 

Fiske, maybe a 5" refractor would be the ticket for you. Would probably take you to your seeing limit more often than not (but I don’t know — that’s just a casual suggestion off the top of my head)

[Fiske]

...

 

Hey,.... maybe a good test bed for a Royce 10 inch f5?

 

...

[dmorrow]

https://www.stellarv...et-apo-svx127d/
 

Killer optics, binoviewer compatible, 55% more light grasp than a 4”, good pairing with your mount . . . And a Black Friday special price too

Edited by dmorrow, 24 November 2023 - 08:44 AM.

[Fiske]

...

 

I also have a C6, which in terms of punch is probably equivalent to about 110-115mm of refractor, so it's not going to give a slam-dunk view over the Televue either. They are nice inexpensive little scopes that put a good aperture in a small space. The optics on them seem to be surprisingly good.  But you will be dealing with fields of 1.5 degrees at the biggest end.

 

From my balcony, with my largest binos being handheld 15x50s, I'm finding that both my 92mm refractor and either 8" reflector or 12.5" make for interesting comparisons.

 

For example, on Auriga, there's a host of open clusters with interesting appearances in binoculars. The 92mm steps up and spits those open while losing the bigger structures. The M36-38 objects then get blown up into views that take up the entire eyepiece field of view.

 

Three steps seems good to me--a binocular view at low power that gives good context. A zoomed-in refractor view that gives a bit of context and some detail, and a really zoomed-in reflector view that brings the object much closer to show its structure.

Exactly. I'm not expecting a big step up on doubles from the 101, though I expect the resolution and brightness will be a slight improvement. The main thing is getting equivalent or slightly better functionality in an easier to deploy/use package.

 

...

 

But I do have a little C5 that I really like. It throws up a perfect star test. Holds tight on the Moon to 275x. And that's with a reducer and a 2 inch diagonal., with 105mm backspace, roughly. (I use a 20 Hyperwide for a finder)

Just so so easy. One hand out the door on the mount. And it can go on a real little mount.

I should really give it a shot on double stars.

 

...

 

Nevertheless, for the mentioned double stars, I enjoy using my 4" f/9 ED refractor much more. Brighter, better (richer) colors and more separation. I can’t say I use my Dob much for double stars, though of course that is completely possible. It’s just that I’m usually thinking about DSOs when I have the Dob out.

 

Fiske, maybe a 5" refractor would be the ticket for you. Would probably take you to your seeing limit more often than not (but I don’t know — that’s just a casual suggestion off the top of my head)

I was pondering a 4" / 100mm f/9 ED refractor, but how much better would that be than the TV-101 I already own. Maybe a tad due to the longer focal length? Plus, for the EvoStar I was considering, the OTA alone costs as much as the NexStar 6SE with goto mount. A 5-inch refractor is too big. And too much money for good quality optics.

 

Just like any binocular or BT choice, it's not a one size fits all thing. Depending on your viewing context and interests, another option like a premium Dob or a larger SCT, or a longer f-ratio refractor (which I'll confess I have a yearning for ) might be a more suitable choice.

 

Larger BTs (I own both the 120XL and 127XL) at low to moderate magnification cover so much of what might be viewed with telescopes that switching back to monovision doesn't seem worth it to me. Yes, a bit more detail can be seen with the CC8 in open clusters like M 37 and M 38, for example, but the overall viewing experience with one eye instead of binocular vision is not nearly so enjoyable to me. YMMV, of course.

Edited by Fiske, 24 November 2023 - 08:51 AM.

[Fiske]

https://www.stellarv...et-apo-svx127d/
 

Killer optics, binoviewer compatible, 55% more light grasp than a 4”, good pairing with your mount . . . And a Black Friday special price too 

 

The NexStar 6SE is due here on Monday. 

 

The StellarVue does look like a beautiful refractor. 

[dmorrow]

If I hadn’t optimized my mounts for its smaller sibling, I would move in this direction.  
 

I’ve previously had the C6 and liked it a lot, but the 4” frac is essentially the same resolution (taking into account central obstructions and other aberrations inherent in the SCT) while providing a more esthetically pleasing view without the hassles of collimating.  
 

As a companion scope for your edge case, it’s about high power for tiny targets that can be set up quickly (and, therefore, can acclimate quickly).  As you know well,  that’s apo territory.  And as a 2 eyed viewer, pairing this with a top notch binoviewer would be perfect for you dude! 

Edited by dmorrow, 24 November 2023 - 09:01 AM.

[Fiske]

If I hadn’t optimized my mounts for its smaller sibling, I would move in this direction.  
 

I’ve previously had the C6 and liked it a lot, but the 4” frac is essentially the same resolution (taking into account central obstructions and other aberrations inherent in the SCT) while providing a more esthetically pleasing view without the hassles of collimating.  
 

As a companion scope for your edge case, it’s about high power for tiny targets that can be set up quickly (and, therefore, can acclimate quickly).  As you know well,  that’s apo territory.  And as a 2 eyed viewer, pairing this with a top notch binoviewer would be perfect for you dude! 

We'll see how the 6SE works out. It will be easy to sell to a local club member if I decide to go in some other direction. 

[therealdmt]

Exactly. I'm not expecting a big step up on doubles from the 101, though I expect the resolution and brightness will be a slight improvement. The main thing is getting equivalent or slightly better functionality in an easier to deploy/use package.

 

 

I was pondering a 4" / 100mm f/9 ED refractor, but how much better would that be than the TV-101 I already own. Maybe a tad due to the longer focal length? Plus, for the EvoStar I was considering, the OTA alone costs as much as the NexStar 6SE with goto mount. A 5-inch refractor is too big. And too much money for good quality optics.

I’d think the Evostar 100ED (what I have) would be basically the same as the 101. I think you’d have to go up to the 120ED to see a difference (the 120 is still a pretty nice weight, 13.9 lbs, and the same length tube as the 100ED. Nevertheless, definitely heavier than the 8.4 lb 100ED). Cost has gone pretty crazy on those 120EDs though, but maybe a used one will come up.

 

Regardless, good luck with and enjoy that incoming 6SE! Hopefully that scratches the itch just right