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6-7x vs 8x Magnification (1 Viewer)

fotbg

Member
Lately I have been using my kowa bd II 6.5x32 quite a bit and I am enjoying its easy eye placement with 5mm exit pupil, great depth of field, bright view and wide field, etc. When ever I compare it to an 8x32, I struggle to see any benefit from the extra magnification ie. I don't find I am able to see that much more detail. Of course, these are only hand held comparisons and not mounted on a tri-pod. A good example was just yesterday when I observed a merlin perched high up on a tree from approximately 150 feet away. If I compare to a 12x binocular then I am able to see more detail, although it becomes more challenging hand holding a 12.

I'm just wondering if anyone else has compared a 6-7x binocular against an 8 and feel the same way? If so, my next question is why do so many people gravitate to an 8 power binocular? Is it simply because there is so much selection out there in this power in the marketplace?
 

Pinewood

New York correspondent
United States
Hello Fotbg,

A rule of thumb is you have to increase the magnification by 50% to notice a difference or benefit from the difference. From a 6.5x you would have to go to 9.75x to get a truly noticeable difference or benefit. Rules of thumb are not certainties, so a 9x might give you some benefit. For sure, the 12x is a big jump.

As it happens, when I carry two binoculars, one is a 6.5x or a 7x, and the other is a 10x.

Stay safe,
Arthur Pinewood :hi:
 
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chill6x6

Well-known member
Hello Fotbg,

A rule of thumb is you have to increase the magnification by 50% to notice a difference or benefit from the difference. From a 6.5x you would have to go to 9.75x to get a truly noticeable difference or benefit. Rule of thumb are not certainties, so a 9x might give you some benefit. For sure, the 12x is a big jump.

As it happens, when I carry two binoculars, one is a 6.5x or a 7x, and the other is a 10x.

Stay safe,
Arthur Pinewood :hi:

Perfect explanation....

When I carry two binoculars it is a 7/8X and a 12X
 

Ries

Well-known member
I recently compared a 7x with a 8x, different brands/models and same model, and the mag difference was just barely noticeable and absolutely no argument to pick the bigger over the smaller. Have the same 6,5 as you (which seems to actually be a 6x)and an 8, took with me one each day and really didn't miss the 8x when using the 6,5x a day later. Differences might be there, but marginal. Seems Pinewood's rule of thumb here is very valid.
 

fotbg

Member
Thank you Arthur and Chuck - this completely makes sense. I never thought there was a formula but it seems I have been practicing it all along. I usually carry the 6.5 and the 12, ideally with a tripod.
 

pbjosh

missing the neotropics
Switzerland
I do quite notice the difference between 6/6,5x (the same Kowa) and my 8x bins. The change from 8 to 10 is harder to notice. At least for me, the 33% jump from 6x-8x is a good bit more noticeable than the 25% jump from 8x-10x, and I it certainly seems that increased effect of shake at 10x plays a part of that as well. If I just handhold my 12x without IS turned on, without bracing elbows, etc, I really cannot see more detail than with my 10x, and dislike the experience - prefer the 10x until the 12x get braced or IS switched on.
 

Patudo

Well-known member
I have two 7x binoculars and although both are great, I'm one of those who uses 8x for a lot of my birding. I've found that the slight extra mag just better suits what I'm trying to do. For instance: once I found that merlin (and I do agree that if it was at 150 ft you could find and identify it just as efficiently with a 6.5x as you would with an 8x or greater mag), I'd have sat down, maybe backed off a bit, and waited for it to do something - hopefully dash off after prey. Once it does, I've found that 8x, especially if I can get my elbows braced, allows me to follow the bird further out, and I can see detail better at distance. If she, or he (and the jack merlin is only about a six ounce bird) is off after a group of starlings 500m away - a distance that a merlin can cover in less than ten seconds - I know I'll see the action better, and more satisfyingly, with an 8x.

I've used my 7x42 a fair bit (my 7x35 extra wide much less so, as the short eye relief means I can't wear glasses, which greatly reduces my situational awareness). It's a great binocular, but there is a range at which it performs best, and if the birds I'm observing are likely to go beyond it, I do prefer 8x. There are some locations for which the distances, to me, better suit 10x and for the most demanding spot I've come to prefer 12x. But for those situations where 7x is a great fit, it's fantastic - giving you less shake and often a wide field of view. I had a spot once, sadly now lost to "development", where a 6.5x with the field of view of your Kowa would have been great.
 

WJC

Well-known member
Hello Fotbg,

A rule of thumb is you have to increase the magnification by 50% to notice a difference or benefit from the difference. From a 6.5x you would have to go to 9.75x to get a truly noticeable difference or benefit. Rules of thumb are not certainties, so a 9x might give you some benefit. For sure, the 12x is a big jump.

As it happens, when I carry two binoculars, one is a 6.5x or a 7x, and the other is a 10x.

Stay safe,
Arthur Pinewood

Perception is reality? The image on the left is from a binocular with a 7-degree field of view. The image on the right shows that object—at the same magnification—but with a 9-degree field. Quite often, the observer sees a larger field of view and equates it to more magnification. The difference, in better binoculars, lies in the unsung field stop. :cat:

Just a thought,

Bill

PS Arthur, did you know any of the Murrow boys, personally?
 

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Pinewood

New York correspondent
United States
Thank you Arthur and Chuck - this completely makes sense. I never thought there was a formula but it seems I have been practicing it all along. I usually carry the 6.5 and the 12, ideally with a tripod.
Hello fotbg,

You are quite welcome. I came across that nugget of wisdom, on Cloudy Night where it was applied to astronomical observations with a binocular.

Stay safe,
Arthur :hi:
 

Pinewood

New York correspondent
United States
...
Bill

PS Arthur, did you know any of the Murrow boys, personally?

Hello Bill,

No, but Charles Collingwood, Winston Burdet, Richard Hottelet, and others were familiar only from TV.

Stay safe,
Arthur
 

[email protected]

Well-known member
Supporter
I recently picked up a like new Leica Trinovid BA 7x42 and have been birding with it and I like it a lot. The 7x magnification has the advantage of better DOF which means less focusing and a steadier view and the big 6 mm exit pupil of the 7x42 makes for easy eye placement with no black outs and a nice bright image under low light conditions. It is just a very easy relaxing binocular to use. I understand why a lot of birders like the 7x42 format. The older Leica Trinovids have exceptional build quality although they are heavy, and they have the rich saturated colors Leicas are known for. The older Trinovid BA 7x42 are actually as good as the newer Ultravid HD + 7x42 because Leica has not changed them much over the years and the older Trinovid BA has better build quality. Here is a review of 7x42 binoculars. The Leica Ultravid HD + 7x42 is the preferred binocular.

http://www.greatestbinoculars.com/a...hootoutpremier7x42s/shootoutpremier7x42s.html

"In the end, I liked the Ultravid 7x42 HD Plus most, due to ease of view, sparkle (microcontrast), colour, ergonomy, industrial design. It is a totally great and very underrated glass. My new master binocular."

"Why am I writing about it? On our website you can find tests of all 10x42 models, from the Trinovid BN to the Ultravid HD-Plus. It is easy to check what the customers gained throughout all these years. Firstly the results show unanimously that, within the margin of measurement error, the HD-Plus model is practically the same as the HD model. Maybe the transmission level varies a bit but even if you compare the measurements taken with a spectrophotometer the differences remain very slight; it is really difficult to say whether they are an effect of measurement errors, natural differences between two specimens or the actual influence of Schott HT glass. If the spectrophotometer doesn’t show any distinct difference, it won’t be visible to the naked eye either. So we have a situation where the Ultravid HD doesn’t differ markedly from the Ultravid BR and the Ultravid BR is an almost identical copy of the Trinovid but closed in a lighter casing. It seems that for almost 25 years Leica haven’t introduced any innovative optical solutions to its key series of binoculars. Of course the weight reduction and hydrophobic coatings are appreciated, along with a slight transmission increase or a tad wider field of view. Still such a reputable company should have done better, especially if you take into account the length of the period of time we are talking about. As a result of such stagnation Leica devices started to compete with each other: you can still buy second-hand specimen of Trinovids in mint condition for half the price of the new Ultravids HD-Plus."
 
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Kammerdiner

Well-known member
I have two 7x a bunch of 8x and one 8.5x. No tens as of now. Having used them all for years I can tell the difference in mag. The 8.5 SV has a narrower FOV than the 8x32 SV, but the difference in magnification is in fact noticable, and I like it.

Maybe it's just my aging eyes, but I want more than 7x these days. In fact I may end up trying the 10x NL. Yikes, I haven't used a 10x in years.
 

[email protected]

Well-known member
Supporter
I have two 7x a bunch of 8x and one 8.5x. No tens as of now. Having used them all for years I can tell the difference in mag. The 8.5 SV has a narrower FOV than the 8x32 SV, but the difference in magnification is in fact noticable, and I like it.

Maybe it's just my aging eyes, but I want more than 7x these days. In fact I may end up trying the 10x NL. Yikes, I haven't used a 10x in years.
I think a 10x is just harder to hold steady and because of that shaking you lose the resolution you gain with the extra magnification. Maybe the head rest on the new NL will help though. Once the NL is out on the market awhile we will see.
 

eitanaltman

Well-known member
I have two 7x binoculars and although both are great, I'm one of those who uses 8x for a lot of my birding. I've found that the slight extra mag just better suits what I'm trying to do. For instance: once I found that merlin (and I do agree that if it was at 150 ft you could find and identify it just as efficiently with a 6.5x as you would with an 8x or greater mag), I'd have sat down, maybe backed off a bit, and waited for it to do something - hopefully dash off after prey. Once it does, I've found that 8x, especially if I can get my elbows braced, allows me to follow the bird further out, and I can see detail better at distance. If she, or he (and the jack merlin is only about a six ounce bird) is off after a group of starlings 500m away - a distance that a merlin can cover in less than ten seconds - I know I'll see the action better, and more satisfyingly, with an 8x.

This is exactly how I feel -- there aren't many situations where I couldn't make the ID with a 6-7x that I could make with an 8x, but I do notice the higher magnification when enjoying the detail, being able to observe from a bit farther away, etc.

That said I've never used an alpha 7x, only lesser mid level options like Vortex Viper 6x32, Vortex Fury 6.5x32, and Kowa BDII 6.5x32.... but not the Ultravid HD or Zeiss FL which I admit may make my observation moot. I've been using 10x a lot lately, and really enjoying the extra magnification, but whenever I use my wife's Ultravid HD 8x32 it makes me slightly question whether I'm getting that much benefit. The little UVHD are crazy sharp with incredible contrast, and resolve details at distance nearly as well as (and in some cases equal to) my good 10x options. This has made me a believer that optical quality is more important than slight differences in magnification, i.e. a super sharp alpha 8x will be better than a pretty good 10x, and by extension I imagine a 7x42 UVHD or Zeiss FL would give up nothing in detail/resolution to a non-alpha 8x in real world usage.
 

Pinewood

New York correspondent
United States
...

Maybe it's just my aging eyes, but I want more than 7x these days. In fact I may end up trying the 10x NL. Yikes, I haven't used a 10x in years.

Hello Kammerdiner,

Other parts of your body, besides your eyes, are aging. Getting the most from a 10x it has to be held steady or steadied by a monopod or image stabilised. I can use my 10x but not for extended periods.

Stay safe,
Arthur :hi:
 

Kammerdiner

Well-known member
Good point Arthur. The 10x binoculars I've used didn't seem to give me much benefit. My eyes aren't great but my body is thankfully robust. I might give it another try.

Mark
 

fotbg

Member
Great comments and feedback, thank you to everyone!

So yesterday I did a little experiment. I taped up a $20 bill on my fence in the backyard and tried to read the serial numbers (which are about 3mm high) from 40ft away. It was a bright day and the sun was shining on the bill with no shadows. I did this completely unsupported with a 6.5, 8 and 12x binoculars.

6.5 - I could determine that there were indeed serial numbers present and maybe make out a few of them if I was steady enough but I could not read them all off by any means.

8 - it was more apparent numbers were present and I could make out a few individual numbers, more so than with the 6.5. However, I could not read them all sequentially due to movement.

12 - this was interesting. Even with such a high power, I could easily make out the numbers and read them all off. So in this case magnification was sufficient enough to overcome any shakes I had to get the detail I needed.

The binoculars I used were the Kowa 6.5, Leupold Bx-4 8x32 and Viper HD 12x50, all mid to lower tier and by no means close to an alpha. It would be interesting to try a 10x but I don't have one at the moment.

Granted we (luckily) don't have to read serial numbers on a bird, but I feel I would still prefer the 6.5 when birding over closer distances when free holding a binocular. I would trade off the slightly higher magnification of the 8 for the easier view of the 6.5 which I am noticing more and more.

In my yard I have a feeder and view it from inside the house about 40 ft way with the 12x on a tripod. Even with such a terrible depth of field at that distance, while supported it gives better detailed views then my 6.5 or 8. As well, I'm usually looking at a fixed object so the need to move it around and refocus rarely presents itself.
 

CMB

Well-known member
Try different combinations of objective lens size and magnification and use whatever combination you like and find comfortable.

I’ve often wondered if people mistake “shake” for difficulty keeping a smaller exit pupil properly aligned with their eye, and the ability of one to keep their eyeball steady as opposed to the eyeball moving left and right excessively.

We regularly see the comment posted about 10x having more “shake” than 8x, so 10x is bad. Yet people also regularly say 8x magnification is fine because there is such a small difference in the detail seen between 8x and 10x that the difference in magnification is basically moot.

Said another way... On the one hand the change in the level of detail is so insignificant that the difference in magnification doesn’t matter, but on the other hand the change in the level of detail is so great that the smallest amount of shake makes 10x unstable or even not useable.

Doesn’t that seem like a contradiction?

Could the reason 6x and 7x appear streadier to some people be that with a larger exit pupil it is easier to keep the image inline with the eye? And maybe a larger exit pupil is more forgiving if someone’s eye is moving around a lot?

People regularly comment that they no longer need a bin with a large exit pupil because they are older and their eyes no longer dilate to the size of the large exit pupil. But is it possible that the decrease in pupil dilation, combined with a bin with a smaller exit pupil, is making “shake” worse because it is more difficult to line up the image to the eye? Could the right approach to reducing shake be not to focus just on magnification but rather to focus on getting a bin with a larger exit pupil?

If that is true then an 8x50 would appear steadier than an 8x32, or a 6.5x32.

There is a lot of professional optical knowledge on this forum. If I am wrong I hope that someone would explain why.

Chris
 
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Patudo

Well-known member
Eitan, fotbg, CMB - my experience agrees with fotbg's in that the larger image provided by brute magnification sometimes just shows you more (especially if you can brace your elbows). I've tried following distant targets with my 7x42 Dialyt, P model, which if not truly an alpha by the superb standards of today, is at least within shouting distance, and - although I very much agree with Eitan that an excellent 7x (or 8x) can deliver a remarkable image in terms of sharpness, clarity and definition - it is still a smaller image than say a 10x, and a peregrine facing the wrong way at close to 1.5km is a really small target even in 8x; the slightly larger target 10x gives me is that much easier to follow. Exit pupil does count for a lot to me - something I've recently reminded myself of once again when using two 4mm exit pupil binoculars (8x32 and 10x40). 5mm exit pupil (8x42) is very definitely "easier on the eye" - more effortless, less fatiguing, giving the impression of greater steadiness - than 4mm; 6mm (7x42) is wonderful, but not IMO necessary for the jobs I need my binoculars to do.

The older Trinovid BA 7x42 are actually as good as the newer Ultravid HD + 7x42 because Leica has not changed them much over the years

If that was really the case secondhand prices of the two would be much closer than they are. The Ultravids have dielectric prisms and probably better coatings. I'm not a LEICAMAN but I know which I'd take, classics though the BA series are.
 

[email protected]

Well-known member
Supporter
"If that was really the case secondhand prices of the two would be much closer than they are. The Ultravids have dielectric prisms and probably better coatings. I'm not a LEICAMAN but I know which I'd take, classics though the BA series are."

There is really not a lot of difference between the Leica Trinovid BR or BA and the Ultravid HD + if you look at the tests on Allbinos. Also, I have had all the Leicas from the Trinovid BR to the Ultravid HD + and compared them and if you didn't know which model you were looking through I will bet you couldn't tell them apart. You mention Leica changed to dielectric prisms and better coatings. If they have it hasn't increased their transmission at all. The Trinovid BN 10x42 has 88% transmission and the Ultravid HD + 10x42 has 87%. Leica has not made any significant changes over the last 20 years in their optics. So my point is buy a Trinovid BA and save your self a lot of money over the Ultravid HD+ and you get better build quality!

"Why am I writing about it? On our website you can find tests of all 10x42 models, from the Trinovid BN to the Ultravid HD-Plus. It is easy to check what the customers gained throughout all these years. Firstly the results show unanimously that, within the margin of measurement error, the HD-Plus model is practically the same as the HD model. Maybe the transmission level varies a bit but even if you compare the measurements taken with a spectrophotometer the differences remain very slight; it is really difficult to say whether they are an effect of measurement errors, natural differences between two specimens or the actual influence of Schott HT glass. If the spectrophotometer doesn’t show any distinct difference, it won’t be visible to the naked eye either. So we have a situation where the Ultravid HD doesn’t differ markedly from the Ultravid BR and the Ultravid BR is an almost identical copy of the Trinovid but closed in a lighter casing. It seems that for almost 25 years Leica haven’t introduced any innovative optical solutions to its key series of binoculars. Of course the weight reduction and hydrophobic coatings are appreciated, along with a slight transmission increase or a tad wider field of view. Still such a reputable company should have done better, especially if you take into account the length of the period of time we are talking about. As a result of such stagnation Leica devices started to compete with each other: you can still buy second-hand specimen of Trinovids in mint condition for half the price of the new Ultravids HD-Plus."

https://www.allbinos.com/allbinos_ranking-binoculars_ranking-10x42.html
 
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