Confusing Amazon (1 Viewer)

[Swedpat]

Is it 15 or 20x?



And 23mm eyelens? Not likely for the short focal length required to get 15 or 20x with such a short focallength objective lens.
And larger lens than ANOTHER 15x25mm. Is it 25 or 32mm objective?
A qualified guess is that it's actually a 5x25 or similar.

 

[Mono]

Who knows? These numbers are just being used for marketing. I doubt the people putting them even know what they mean.

 

[Swedpat]

Who knows? These numbers are just being used for marketing. I doubt the people putting them even know what they mean.

Yes, that's right. Higher number sounds better and sell better to ignorant people.
I remember several years ago, I commented(I think it was at Cloudy nights) to a person who had been fooled. He had bought a claimed 30x50 binocular of very low quality, and it turned out that it was only 7-8x magnification.
I wrote he shall be happy it was not 30x, because if so the binocular had been pretty much unuseable. Dim unstable image, really bad sharpness and contrast, a lot of CA, and possibly collimation issue.
But with 7-8x it was actually useful even with low quality and bad coating.

 

[Binastro]

Firstly, the binoculars shown in this post are fraudulent.

Secondly, My 30x50 Yukon folded refractor binocular splits 6.5 arcseconds double stars and is fully usable braced against a window.
Coatings, as with other Yukon products are rather poor.
Blanket statements that 30x50 binoculars don't work are just not true.

Thirdly, blanket statements that zoom binoculars are awful are also not true, although this might be the case for most bird watchers.

Regards,
B.

 

[Swedpat]

There might be decent 30x50 binoculars but often the image sharpness worsens with low quality optics. At least CA starts to be prominent.
12x binoculars can have a noticeable sharpness loss compared to 8x.
I have not tried any high quality zoom binoculars.
But those I tried, for example 7-21x50, were all sharp and good contrast at 7x, but then a noticeable degradation above ~12x followed by really bad contrast and not sharp at all at 21x.

 

[Maljunulo]

From what I have read, there are no high-quality zoom binoculars.

 

[Swedpat]

Nikon had a 8-16x40. I think it was decent quality.

 

[Binastro]

Come off it.

There are many sharp 12x binoculars.
The sharpness loss is due to hand tremor not optics.

The Pentax 8-20x24 zoom binocular, in a good example, is very sharp at 16x to 20x, say looking at the Moon.

My 25x-135x80 Japanese binocular is good at 60x and usable at 80x when empty magnification sets in.

Regarding empty magnification in telescopes, this is not, as suggested on this forum, an absolute optical consequence.
It depends on how fine the optics are.
With really high quality telescopes empty magnification does not occur at 100x per inch of aperture.

With low quality optics, empty magnification can occur at 5x per inch of aperture.

In my opinion too much emphasis on this forum is on £2,000 plus binoculars, when lower price binoculars can be good but not as durable for bird watching.
I suppose though as a Bird forum the quest for expensive optics is justified.

Regards,
B.

 

[Swedpat]

Come off it.

There are many sharp 12x binoculars.
The sharpness loss is due to hand tremor not optics.

The Pentax 8-20x24 zoom binocular, in a good example, is very sharp at 16x to 20x, say looking at the Moon.

My 25x-135x80 Japanese binocular is good at 60x and usable at 80x when empty magnification sets in.

Regarding empty magnification in telescopes, this is not, as suggested on this forum, an absolute optical consequence.
It depends on how fine the optics are.
With really high quality telescopes empty magnification does not occur at 100x per inch of aperture.

With low quality optics, empty magnification can occur at 5x per inch of aperture.

In my opinion too much emphasis on this forum is on £2,000 plus binoculars, when lower price binoculars can be good but not as durable for bird watching.
I suppose though as a Bird forum the quest for expensive optics is justified.

Regards,
B.

I have not said there are no good 12x binoculars.
Of course the performance depends on the optical quality. There are many examples when a low optical quality is noticeable when comparing between different magnifications. The higher the magnification the higher quality is required to maintain sharpness. And not to forget CA, which very soon becomes a problem at high magnification combined with short focal length achromatic objective.

 

[Maljunulo]

I don’t see a problem with “focusing on” the best.

Whether or not you believe the best is “worth it” or you are willing or able to spend that much money is an individual decision.

You can always find a less expensive version of anything.

 

[Binastro]

You can always find a more expensive version of anything.

It does not mean it is better, although it might be.

Rolexes and Ferraris are expensive.
It does not mean they are better.
As to BMWs the AA men say they are the most popular make on the back of their trailers.

Regards,
B.

 

[Elpha8888]

15x, it says so in the description.

 

[yarrellii]

Not to mention the supposed 7,2° in a 20x binocular Or else the 114 m at 1000 m (around 6,5°) in the 15x. I really wouldn't mind a 6,5° 15x for 40 $. Now that would be something!

 

[Swedpat]

Not to mention the supposed 7,2° in a 20x binocular Or else the 114 m at 1000 m (around 6,5°) in the 15x. I really wouldn't mind a 6,5° 15x for 40 $. Now that would be something!

I actually did not notice that! Great with such a wide angle. I guess they are eyeglasses friendly too! 😃