A Zeiss Conquest HD on steroids. (1 Viewer)

[Swedpat]

You will see better in low light with an 8x56 than you can with your own eyes, which is not so with an 8x42. That huge 56 mm aperture makes a big difference in low light. That is why hunters that hunt in low light use an 8x56 like hog hunters.

I want to comment about this. Providing you can make use of the entire exit pupil 8x56 is indeed brighter than 8x42. But already above 40 years age many have not still 7mm eye pupil.
Even if you have max 5,25mm eye pupil, the same as exit pupil of 8x42, 8x56 can still have an advantage because you don't use the edges of exit pupil. This is explained in some article, I don't have a link just now, though. How noticeable the difference is may be debateable.

And the reason you in any case see better in low light with a binocular than naked eye is because of the magnification. An optical system can never provide a brighter image than the naked eye. At most 96% of naked eye with the brightest prism binocular. A galilei binocular should be able to reach even higher transmission.
So if you have max dilated eye pupil of 7mm and use a 8x56 you of course see better than naked eye. But you see even better with naked eye at 1m than with 8x56 at 8m, because the observed object has the same apparant size but is slightly brighter because of the lack of light loss through the optical system.

BUT: there is a reason you in some cases can get the impression the view in the binocular is brighter. With naked eye there is often stray light reaching your eye from the sides from light sources, worsening the low light vision. And when you put the binocular to your eyes these become usually, more or less, blocked.

 

[henry link]

Henry. Here is one of your old posts where you photographed the difference in a Habicht 8x30 and Zeiss 8x56 FL, stopped down to 22 mm to simulate bright daylight. It really shows what a difference a bigger aperture can make, even in daylight. The Zeiss 8x56 FL is obviously better. A lot of your posts like this are what made me try an 8x56, and I have come to agree with you. I have not photographed the difference, but subjectively I can easily see a difference in an 8x42 and an 8x56....

The photos from that post were designed to show the visible difference in image quality between a low aberration 8x30 and a high aberration 8x30, not a difference that can be expected between any 8x56 and any 8x30.

I picked the Swarovski Habicht because I had star-tested it and knew it had relatively high spherical and longitudinal chromatic aberrations. I picked the Zeiss just because it was handy and I knew it had relatively low SA and longitudinal CA when stopped down to 30mm. If I had picked a high aberration 8x56-ish binocular, like the Zeiss 8x54 HT, and a very low aberration 8x30, like the Nikon 8x32 SE at 30mm, the results would have been different.

 

[Paultricounty]

The photos from that post were designed to show the visible difference in image quality between a low aberration 8x30 and a high aberration 8x30, not a difference that can be expected between any 8x56 and any 8x30.

I picked the Swarovski Habicht because I had star-tested it and knew it had relatively high spherical and longitudinal chromatic aberrations. I picked the Zeiss just because it was handy and I knew it had relatively low SA and longitudinal CA when stopped down to 30mm. If I had picked a high aberration 8x56-ish binocular, like the Zeiss 8x54 HT, and a very low aberration 8x30, like the Nikon 8x32 SE at 30mm, the results would have been different.

So then it was completely taken out of context by the OP and twisted to support a position that is false. Thank you for clearing that up. I’m good.

 

[[email protected]]

I want to comment about this. Providing you can make use of the entire exit pupil 8x56 is indeed brighter than 8x42. But already above 40 years age many have not still 7mm eye pupil.
Even if you have max 5,25mm eye pupil, the same as exit pupil of 8x42, 8x56 can still have an advantage because you don't use the edges of exit pupil. This is explained in some article, I don't have a link just now, though. How noticeable the difference is may be debateable.

And the reason you in any case see better in low light with a binocular than naked eye is because of the magnification. An optical system can never provide a brighter image than the naked eye. At most 96% of naked eye with the brightest prism binocular. A galilei binocular should be able to reach even higher transmission.
So if you have max dilated eye pupil of 7mm and use a 8x56 you of course see better than naked eye. But you see even better with naked eye at 1m than with 8x56 at 8m, because the observed object has the same apparant size but is slightly brighter because of the lack of light loss through the optical system.

BUT: there is a reason you in some cases can get the impression the view in the binocular is brighter. With naked eye there is often stray light reaching your eye from the sides from light sources, worsening the low light vision. And when you put the binocular to your eyes these become usually, more or less, blocked.

I agree. Magnification brings you closer to the object and the result is you can see more detail. It is almost like the dark areas are illuminated.

 

[[email protected]]

The photos from that post were designed to show the visible difference in image quality between a low aberration 8x30 and a high aberration 8x30, not a difference that can be expected between any 8x56 and any 8x30.

I picked the Swarovski Habicht because I had star-tested it and knew it had relatively high spherical and longitudinal chromatic aberrations. I picked the Zeiss just because it was handy and I knew it had relatively low SA and longitudinal CA when stopped down to 30mm. If I had picked a high aberration 8x56-ish binocular, like the Zeiss 8x54 HT, and a very low aberration 8x30, like the Nikon 8x32 SE at 30mm, the results would have been different.

Yes, but the Habicht 8x30 is at full aperture and the Zeiss FL 8x56 is stopped down to 30 mm so wouldn't that be the same as in your Zeiss 8x56 FL thread The World's Best 8x42 in that now the Zeiss has a slower f ratio, and you are also eliminating aberrations caused by the edge of the objective or essentially using the sweet spot of the objective.

I would think that would give the Zeiss an advantage, even though, as you say, it initially has lower spherical and longitudinal chromatic aberrations than the Habicht 8x30. Since your daylight EP on both of them is the same, it would still seem to indicate the advantage of a larger aperture because your eyes are only using the 3.75 mm EP.

World's Best 8X42: The Zeiss 8X56FL

The image provided by the best current binoculars looks so good that it’s easy to fall into the assumption that binoculars are now so close to optical perfection that further improvement wouldn’t accomplish anything as it would be invisible to the eye. Every now and then I disabuse myself of...

www.birdforum.net

 

[[email protected]]

When somebody doesn't pay attention to what others are saying, they waste everyone's time.

Oh, I believed it; I got an SLC 10x56. The problem is that you keep corrupting whatever Henry said by exaggeration, ignoring distinctions or subtleties, and worst of all, combining it indiscriminately with false and misleading claims from other sources.

The point you seem unwilling to grasp is that the differences are less obvious when not using a tripod, as hardly anyone here does.

I didn't say puff is a bot; I said the author of BBR reviews "sounds like a bot, or at least uses cut and paste heavily". You seem unable to distinguish the quality of sources, just scrounging for anything at all that seems to support your view of the moment (or perhaps that's your definition of quality?) and dismissing anything that doesn't -- including, until very recently, most anything Henry said (one wonders what changed there).

Such a peculiar combination of confidence and ignorance. (Bots constantly join Birdforum and post garbage, usually in Chinese. It turns up in the new posts list but the mods clean it up quickly.)

When somebody doesn't pay attention to what others are saying, they waste everyone's time.

I pay attention, but when I know they are incorrect, or I disagree, to continue arguing is pointless. It is like pounding your head against a wall.

Oh, I believed it; I got an SLC 10x56. The problem is that you keep corrupting whatever Henry said by exaggeration, ignoring distinctions or subtleties, and worst of all, combining it indiscriminately with false and misleading claims from other sources.

I confirmed Henry's tests and the Size Matters article with my own subjective tests, and If you think I am spreading false and misleading claims, that is because you don't agree with me. Show me your proof that Henry's results are false or that The Size Matters article is misleading. You are saying they are misleading because you don't agree them.

The point you seem unwilling to grasp is that the differences are less obvious when not using a tripod, as hardly anyone here does.

The differences are still there, and I can easily see them without a tripod when comparing an 8x42 to an 8x56 binocular.

I didn't say puff is a bot; I said the author of BBR reviews "sounds like a bot, or at least uses cut and paste heavily". You seem unable to distinguish the quality of sources, just scrounging for anything at all that seems to support your view of the moment (or perhaps that's your definition of quality?) and dismissing anything that doesn't -- including, until very recently, most anything Henry said (one wonders what changed there).

BBR for your information is written by a very knowledgeable author who I have discussed binoculars with from time to time, and he does an excellent job on BBR Reviews, and it is a very helpful source of information for binoculars especially beginners starting out in birding. He doesn't sound like a bot at all, and he doesn't cut and paste. I am sure he would not appreciate your comment if he read it.

Such a peculiar combination of confidence and ignorance. (Bots constantly join Birdforum and post garbage, usually in Chinese. It turns up in the new posts list, but the mods clean it up quickly.)

That is the point. They are screened by the mods, so as I said they will never show up on Bird Forum.

 

[Swedpat]

I agree. Magnification brings you closer to the object and the result is you can see more detail. It is almost like the dark areas are illuminated.

Dennis,

Nobody disagrees with that magnification brings you visibly closer to the object so you can see more details.
Because it's a fact. That is the very function and purpose with the binocular.
And "It is almost like the dark areas are illuminated" means nothing else than they are not (more) illuminated.
It's like with saying "almost better", "almost bigger" etc. These are kind of nonsense expressions. They simply mean they are the same.
Sorry if I am picky, but you still seem to put the meaning that binoculars can be ever so slightly brighter than naked eye. While it's the opposite.
I would not describe it like objects become ever so slightly brighter by approching them. I see more details because there was enough light in the first place.

 

[[email protected]]

Dennis,

Nobody disagrees with that magnification brings you visibly closer to the object so you can see more details.
Because it's a fact. That is the very function and purpose with the binocular.
And "It is almost like the dark areas are illuminated" means nothing else than they are not (more) illuminated.
It's like with saying "almost better", "almost bigger" etc. These are kind of nonsense expressions. They simply mean they are the same.
Sorry if I am picky, but you still seem to put the meaning that binoculars can be ever so slightly brighter than naked eye. While it's the opposite.
I would not describe it like objects become ever so slightly brighter by approching them. I see more details because there was enough light in the first place.

Good explanation of magnification and how it works in low light. Do you think bigger aperture binoculars like an 8x56 are better than an 8x42 in other ways besides being brighter in low light and having easier eye placement because of the bigger exit pupil?

 

[Swedpat]

Good explanation of magnification and how it works in low light. Do you think bigger aperture binoculars like an 8x56 are better than an 8x42 in other ways besides being brighter in low light and having easier eye placement because of the bigger exit pupil?

According to a report I read there is an advantage by not using the edges of exit pupil.
There may be other advantage as well.
But I don't think there are some overwhelmingly significant improvements. No detecteable sharpness improvement at such low magnification. At least not according to my experience of binoculars from 20 to 110mm aperture.

 

[tenex]

I pay attention, but when I know they are incorrect, or I disagree, to continue arguing is pointless.

Consider for a moment(!) what you're missing here... the possibility of genuine conversation, and actually learning something.

It is like pounding your head against a wall.

It certainly is. I've had enough of it.

[to Henry] Maybe if you didn't stay out of it until now, and corrected or had little input to what Dennis was saying and misquoting you ( I believe out of context) then we wouldn't have had to tolerate 132 posts on it

No, clearly we would have anyway, just as in other threads on glare etc. Dennis just does his thing, and even Henry can have no impact because there's no real thought occurring, just reflex action. It's not worth my own time to keep doing this either; the essential points have been made for the record.

 

[[email protected]]

According to a report I read there is an advantage by not using the edges of exit pupil.
There may be other advantage as well.
But I don't think there are some overwhelmingly significant improvements. No detecteable sharpness improvement at such low magnification. At least not according to my experience of binoculars from 20 to 110mm aperture.

By not using the edges of the exit pupil, do you mean that would eliminate optical aberrations?

 

[Swedpat]

By not using the edges of the exit pupil, do you mean that would eliminate optical aberrations?

I don't remember the exact explanation. I think I read it at Cloudy nights forum

 

[Steve222]

I have slight astigmatism in both eyes.
I don't wear glasses to observe and when I stop the 7x42 FL down to a 21mm aperture I find a much sharper image during the day.
This really comes into play at night on the stars and moon where the image is much sharper/tighter.
Obviously on deep sky objects you need the aperture.

This is the reason why very small refractors of about 60mm aperture { with long focal lengths } are so good on double star observing.
Many a time I've been unable to resolve an airy disc with a 3" aperture only to see an airy disc when I place a cardboard stop in the dew shield.
Seeing conditions and the observers own eye play such a crucial part.

For some reason this trick also works when looking through glass windows.

 

[[email protected]]

I have slight astigmatism in both eyes.
I don't wear glasses to observe and when I stop the 7x42 FL down to a 21mm aperture I find a much sharper image during the day.
This really comes into play at night on the stars and moon where the image is much sharper/tighter.
Obviously on deep sky objects you need the aperture.

This is the reason why very small refractors of about 60mm aperture { with long focal lengths } are so good on double star observing.
Many a time I've been unable to resolve an airy disc with a 3" aperture only to see an airy disc when I place a cardboard stop in the dew shield.
Seeing conditions and the observers own eye play such a crucial part.

For some reason this trick also works when looking through glass windows.

When you increase the f ratio or slow it down it eliminates a lot of aberrations, especially CA, and that is what you are doing when you stop down your binoculars or use an 8x56 in the daytime which is essentially stopping them down because your eye can only take in about 2 to 3 mm of the exit pupil.

That is why before ED glass refractors were so long. Once I had a cheap 60 mm refractor telescope next to my C8 Celestron cadioptic and the little refractor was actually sharper. The C8 was brighter, but the 60 mm was sharper.

Birders don't understand f ratio, but astronomers do. That is why a birder has a hard time understanding why an 8x56 is better in the daytime than an 8x42. All they know is exit pupil and brightness.

 

[CharleyBird]

Birders don't understand f ratio, but astronomers do. That is why a birder has a hard time understanding why an 8x56 is better in the daytime than an 8x42. All they know is exit pupil and brightness.

Rather condescending🙄

Birders understand that the weight of an 8x56 at 1350g is far too heavy to carry, and that an 8x42 is therefore better in daytime.

 

[Steve222]

Perhaps it's case of astronomers experiment more with apertures as it's easier with a static instrument like a telescope.
Much easier to place a stop in a dew shield as opposed to walk about with two cardboard stops on your binoculars.

We have some heavy rain forecast this week in the UK so it might give some people an opportunity to stay indoors and experiment.

All you need is a ruler, compass and scissors and a bit cellotape or masking tape for sticking.

Here's one I made earlier.
I knew all those years of watching Blue Peter would eventually payoff.

 

[[email protected]]

Rather condescending🙄

Birders understand that the weight of an 8x56 at 1350g is far too heavy to carry, and that an 8x42 is therefore better in daytime.

Maybe, but true. An 8x56 is not too heavy at all as long as you're not hiking for miles, and even then with a harness it is easily manageable. The only thing better about an 8x42 is the lighter weight. An 8x56 is brighter, has better transparency, easier eye placement, less optical aberrations because of the slower f ratio, and it handles glare better.

An 8x56 takes in almost 2x the light of an 8x42. I understand about weight. I use a Zeiss SFL 8x40 when I am hiking but when I am not, and I want the best view I use my Swarovski SLC 8x56's.

 

[[email protected]]

Rather condescending🙄

Birders understand that the weight of an 8x56 at 1350g is far too heavy to carry, and that an 8x42 is therefore better in daytime.

Charley. You should try stopping down your 8x42 as shown in post 156. It is easy to do, and it would open your eyes to what difference a slower F ratio makes and avoiding the aberrations at the edge of the objective. You will be surprised how much sharper your 8x42 is. That is why an 8x56 is better than an 8x42 in the daytime. It is essentially a stopped down 8x42 because your eyes can't take in the 7 mm exit pupil in bright daylight.

 

[Steve222]

It's not just the f/ratio it's also the fact that a smaller exit pupil means you are using the best part of your eye.
Of course there are trade offs here in the form of floaters but, two eyes show far less floaters than one eye.

I regularly use an exit pupil of 0.5mm when I binoview with a telescope.
A 0.5mm exit pupil in mono telescope mode would be full of floaters { for me }.
This obviously varies with each observer.

 

[tenex]

That is why an 8x56 is better than an 8x42 in the daytime. It is essentially a stopped down 8x42 because your eyes can't take in the 7 mm exit pupil in bright daylight.

No, it's effectively stopped down to around 8x20, but you don't care about accuracy, do you? (This is why pocket bins are 8x20.)

Oddly enough, any 8x binocular is stopped down to about 20mm by a ~2.5mm daylight pupil, even that 8x42. Or an 8x32 or 30, or even 8x25. (Do I see smoke rising from your ears?) Whereas a 10x is stopped down only to 25mm, so your 8x56 will be even sharper than my 10x56, right? But at least mine will still show better color? No, wait, why bother lugging a 56 at all if...