11 replies to this topic

[Sir James]

I'm thinking of purchasing both. Would that be redundant or would they compliment each other? If redundant, which one should I get for overall astronomy viewing?

[JoeFaz]

You're going to get a very different set of responses having posted here as opposed to anywhere else on CN...

 

Some thoughts:

• Aperture being effectively equal, the BT should show brighter views with more contrast due to binocular summation.
• The BT excels as a low mag instrument, but the reality is that the 4" f7 can get just as wide a FOV because it can use 2" eyepieces. It may not be an equal view given the last point, but on paper it can go wider.
• The refractor should blow the BT out of the water at high mags - the BT may not even get you there if you aren't willing to do some collimation yourself. You might get responses claiming otherwise... I don't really know what to tell you or those responders in that case except "I strongly disagree"...
• Color correction will be better on the refractor, depending on how important that is to you.
• The BT lets you use two eyes... to some of us that's a big deal.
• The prices are similar, but the BT is a bit more expensive. As much as I love mine, I'm still convinced that BTs are grossly overpriced. They're not easy to make well, I get it, but as far as astronomy gear goes, the value/dollar is quite low IMO. Unless there's a reason you know the BT is the right choice for you, most likely it isn't. For those without a strong penchant for two-eyed viewing, BTs really aren't necessarily great options, IMO.

 

To your actual question... "is it redundant"...

I don't know if I can answer that for you. I have a BT-82, along with 80mm and 100mm refractors and 6" and 10" dobs, besides standard binos, and I don't consider it "redundant" even though there's really nothing that it can do that one of my other telescopes can't (and at least one of them will probably do it better). The combination of factors (two-eyes, not straight-through, interchangeable EPs) is why I decided it was worth having for me. If those things aren't uniquely important to you, then it may very well be redundant.

Edited by JoeFaz, 19 March 2025 - 02:43 PM.

[K-night]

As Mr. Fazio said, you're going to get biased responses in this section of the forum. Mine is, if you can afford both then get two Stellarvues and combine them to make a double telescope.

[sevenofnine]

Welcome to C/N! 

 

I recommend starting off with a good astronomy guide book before you buy equipment. "The Backyard Astronomer's Guide 4th ed." will help you make better choices that are right for you. The authors explain all of the latest equipment and accessories. They also cover basic astronomy so you won't feel lost under the stars. Best of luck to you! 

 

https://www.amazon.c...,aps,256&sr=8-1.

Edited by sevenofnine, 19 March 2025 - 06:01 PM.

[Sir James]

Welcome to C/N! 

 

I recommend starting off with a good astronomy guide book before you buy equipment. "The Backyard Astronomer's Guide 4th ed." will help you make better choices that are right for you. The authors explain all of the latest equipment and accessories. They also cover basic astronomy so you won't feel lost under the stars. Best of luck to you! 

 

https://www.amazon.c...,aps,256&sr=8-1.

Thank you. I'm happy to be here. I've read many comments from you and several other prominent members in the bino threads. 25 years ago I had an old edition of Nightwatch by Dickinson & Hewitt-White. Great book. I want the BT's for astronomical & terrestrial viewing. I want the telescope for higher magnification. I'm just worried that being basically the same aperture it would be redundant to have both. I'm hoping they'd complement each other because they'd be the only scope and bt I'd purchase. I will get 2 more binoculars in the future, widefield and a pair of 2x54

[sevenofnine]

I don't think the BT and refractor are redundant at all. The BT is basically a low power wide view instrument that has a little higher power capability than a standard bino. Usually up to 60x is about it although some go higher in a well tuned instrument. The 102mm refractor is just getting warmed at at 60x so no concern there. However, you still only have 4" of aperture and will run out of light (objects get dim) on some DSO's. In future time, you may want to consider a larger Dob or SCT for those objects. Best of luck to you! 

[Rich V.]

I'm most comfortable with a 100mm BT at around 75x maximum, though I can go higher but with diminishing gains in detail; not the best for reaching the highest mags an aperture is capable of, nor the lowest. 

 

I can compliment the BT with both an 80mm f6 triplet and a 130mm f/7 triplet, both of which have a wider range of useful mags.  The 80mm can range from 12x to 160x+ and the 130mm from 22x to 300x+.  Both can make use of 2" eyepieces.  A 102mm f/7 refractor would also be a fine compliment to a BT with it's range from 17x to 200x+.

[Sir James]

I don't think the BT and refractor are redundant at all. The BT is basically a low power wide view instrument that has a little higher power capability than a standard bino. Usually up to 60x is about it although some go higher in a well tuned instrument. The 102mm refractor is just getting warmed at at 60x so no concern there. However, you still only have 4" of aperture and will run out of light (objects get dim) on some DSO's. In future time, you may want to consider a larger Dob or SCT for those objects. Best of luck to you! 

Weight is a concern and I'm not hip on collimating

[Sir James]

You're going to get a very different set of responses having posted here as opposed to anywhere else on CN...

 

Some thoughts:

• Aperture being effectively equal, the BT should show brighter views with more contrast due to binocular summation.
• The BT excels as a low mag instrument, but the reality is that the 4" f7 can get just as wide a FOV because it can use 2" eyepieces. It may not be an equal view given the last point, but on paper it can go wider.
• The refractor should blow the BT out of the water at high mags - the BT may not even get you there if you aren't willing to do some collimation yourself. You might get responses claiming otherwise... I don't really know what to tell you or those responders in that case except "I strongly disagree"...
• Color correction will be better on the refractor, depending on how important that is to you.
• The BT lets you use two eyes... to some of us that's a big deal.
• The prices are similar, but the BT is a bit more expensive. As much as I love mine, I'm still convinced that BTs are grossly overpriced. They're not easy to make well, I get it, but as far as astronomy gear goes, the value/dollar is quite low IMO. Unless there's a reason you know the BT is the right choice for you, most likely it isn't. For those without a strong penchant for two-eyed viewing, BTs really aren't necessarily great options, IMO.

 

To your actual question... "is it redundant"...

I don't know if I can answer that for you. I have a BT-82, along with 80mm and 100mm refractors and 6" and 10" dobs, besides standard binos, and I don't consider it "redundant" even though there's really nothing that it can do that one of my other telescopes can't (and at least one of them will probably do it better). The combination of factors (two-eyes, not straight-through, interchangeable EPs) is why I decided it was worth having for me. If those things aren't uniquely important to you, then it may very well be redundant.

Thanks 

[Sir James]

I'm most comfortable with a 100mm BT at around 75x maximum, though I can go higher but with diminishing gains in detail; not the best for reaching the highest mags an aperture is capable of, nor the lowest. 

 

I can compliment the BT with both an 80mm f6 triplet and a 130mm f/7 triplet, both of which have a wider range of useful mags.  The 80mm can range from 12x to 160x+ and the 130mm from 22x to 300x+.  Both can make use of 2" eyepieces.  A 102mm f/7 refractor would also be a fine compliment to a BT with it's range from 17x to 200x+.

What size eyepiece do you use to get 75x in the BT?

[Rich V.]

What size eyepiece do you use to get 75x in the BT?

I use a 10mm eps, but my 100mm Miyauchis are f/7.5, not f/5.6.  With a 560mm BT, you'd have to choose an eyepiece somewhere between 6.5mm and perhaps 9mm.

[Dr Arnheim]

If you don't want to go super wide field I would rather go with a bigger refractor + binoviewer.