20x80 v's 25x100 Binoculars - Pros and Cons?

[bond19]

I have a set of 20x80 straight though binoculars (mounted) but my goal is to own a pair of 25x100. I'm fairly new to big binoculars but already love their ability to sweep the Milkyway. When comparing a 80mm frac v's a 100mm frac the larger glass obviously opens up more possibilities especially for higher powers.

Does anyone have experience with the two different sets. I realise bins are meant for low power, wide field views. So does lugging around a slightly bigger, heavier set of bins outweigh the extra 20mm gain in aperture?

Thanks everyone

 

 

[Tomatobro]

I have both. The 80's are mounted on a parallelogram and the 100's are fork mounted. Both have provision for precise Alt/Az positioning which when used with a laptop makes finding objects easy. I would say that neither are usable without some kind of support.

The 100's that I have say that they can be used with standard 1.25" eyepieces but all the ones that I have will not achieve focus. There is not enough    " in" movement.

Mine came with x20 and x40 eyepieces. The x20's get used the most.

The 100's give brighter views but a smaller field of view

Edited September 22, 2020 by Tomatobro
more info

[BinocularSky]

I love my 100 mm binocular (probably my most-used bit of astro kit) but, looking at your kit list, I wonder if a bog standard 25x100 is what you need. Your TV 102 + 41mm Panoptic  will give you far better wide-field views. Something like the Helios LQ-HR  might suit you (my review is here ), but the cheaper ones tend not to have anywhere near as sharp a field. The common 100mm binocular lenses tend to be around f/4, so aberrations tend to be quite pronounced.

In view of the duplication in aperture with your TV, have you considered something bigger? APM and Vixen both do bigger binos - but they are pricey, mind!

But, to directly answer your question, in my opinion it is worth lugging around the bigger bino (+ sturdy parallelogram and tripod), but I wouldn't do it if they didn't have angled eyepieces.

I've just noticed @Tomatobro's post - mine has x20 and x37 eyepieces; I've not used the x20 for more than a decade - the wonderful variety of human experience... 🙂

 

Edited September 22, 2020 by BinocularSky

[bond19]

13 minutes ago, Tomatobro said:

I have both. The 80's are mounted on a parallelogram and the 100's are fork mounted. Both have provision for precise Alt/Az positioning which when used with a laptop makes finding objects easy. I would say that neither are usable without some kind of support.

The 100's that I have say that they can be used with standard 1.25" eyepieces but all the ones that I have will not achieve focus. There is not enough    " in" movement.

Mine came with x20 and x40 eyepieces. The x20's get used the most.

The 100's give brighter views but a smaller field of view

Thanks Tomatobro, I was considering buying a BT with interchangeable eyepieces. Do you have any recommendations on which make to go for?

Edited September 22, 2020 by bond19

[Tomatobro]

Actually I fibbed a bit. I mentioned that 1.25" standard eyepieces don't fit so I machined up a matched pair of eyepieces to fit and they do give very flat and sharp views and I know they give slightly smaller field of view than the 20's so I am guessing they are higher magnification. But before I had them the 20's got used the most.

That's not to say I don't use the 40's though

[Tomatobro]

Helios Quantum-5.2 20/40x100 Semi-Apo Binoculars

I posted some sketch's on SGL of the views through these on SGL somewhere

Edited September 22, 2020 by Tomatobro
update

[bond19]

17 minutes ago, BinocularSky said:

I love my 100 mm binocular (probably my most-used bit of astro kit) but, looking at your kit list, I wonder if a bog standard 25x100 is what you need. Your TV 102 + 41mm Panoptic  will give you far better wide-field views. Something like the Helios LQ-HR  might suit you (my review is here ), but the cheaper ones tend not to have anywhere near as sharp a field. The common 100mm binocular lenses tend to be around f/4, so aberrations tend to be quite pronounced.

In view of the duplication in aperture with your TV, have you considered something bigger? APM and Vixen both do bigger binos - but they are pricey, mind!

But, to directly answer your question, in my opinion it is worth lugging around the bigger bino (+ sturdy parallelogram and tripod), but I wouldn't do it if they didn't have angled eyepieces.

I've just noticed @Tomatobro's post - mine has x20 and x37 eyepieces; I've not used the x20 for more than a decade - the wonderful variety of human experience... 🙂

 

Thanks Steve,

I've only recently gotten into serious binocular astronomy and it has proved a revelation. I feel so much more comfortable seeing with two eyes and my BT has given me the kind of space walk experience I has been yearning for. When comparing looking thought my 20x80 over my Tele Vue / 41mm pano I simply prefer the binos. So much so I'm now seriously considering selling my TV (something I though I would never consider) and purchasing a BT with changeable eyepieces. Then somewhere done the line getting a 127 Mak to fill the high power gap for moon and planets.

Edited September 22, 2020 by bond19

[bond19]

2 minutes ago, Tomatobro said:

Helios Quantum-5.2 20/40x100 Semi-Apo Binoculars

Thanks, they are ones I've been considering. Seem a good price too.

[Tomatobro]

Sample drawings

[bond19]

Lovely sketches. Thanks for sharing. I bet they looked even better through the eyepieces.

[BinocularSky]

17 hours ago, bond19 said:

and purchasing a BT with changeable eyepieces.

Mine is a Miyauchi BJ100 - no longer made, but I have compared it to others that are available. Quality-wise I prefer it to the Helios offerings, but a friend had the APM ED version, which was noticeably better. He mated it with some TV eyepiece pairs and it was, frankly, stunning. I was tempted to consider selling the Miya and getting one.

One caveat about eyepiece pairs: make sure you get them from the same batch. A bloke in our club has the 125mm Vixen and bought two used eyepieces separately; although nominally the same, they were slightly different.

 

[bond19]

Good points Steve. I will be mindful to source eyepieces from the same batch. Although more expensive, overall the APM's do seem a step up from the Helios but cost might mean I opt for the Helios eventually.