Age old debate - 10s vs 8s

[Matt Cashell]

In other words an 8x32 porro prism with 98% light transmission will be brighter than a 7x32 roof prism with 91% light transmission, and potentially some 8x42s that have fallen behind.

I have not seen this statistic published by many binocular manufacturers, so we have to dig for it. It would be like publishing horse power and not miles per gallon for a car manufacturer.

First off, RTS,

Great thread. I love getting geeky about optics!

You porro/roof comparison above may or may not be true. Larry is right that biggest factor affecting apparent brightness is exit pupil. A bigger exit pupil providing more light to the rods and cones of your eye SHOULD make for a brighter image than a smaller exit pupil with a higher transmission level - to a point.

As far as measuring transmission, it gets sketchy since the tester may be only measuring at certain wavelengths, and total transmission across the visible light spectrum would be the most beneficial.

Bottom line,

trust your eyes on brightness, and it may not be the same for everyone.

 

[larryschwartz]

This is due to the image being magnified, not brightened, however.

Actually, I think that it has more to do with the focusing of the light into a smaller image when it comes out of the binoculars into your eye (which is what I was trying to say) than it does with magnification. Just like when you try to use a magnifying glass to burn some paper, the smaller the image gets the more concentrated the light is and the brighter it gets; in the same way your binoculars take all the light coming in through the objective lense and concentrates it (minus what is lost by bouncing around in the binoculars and going through the lenses) into the exit pupil which intensifies the image for you.

It really doesn't matter to most people why it works, what matters is that you can see better in low light and dark conditions with binoculars than you can with the naked eye.

Larry

 

[Matt Cashell]

It really doesn't matter to most people why it works, what matters is that you can see better in low light and dark conditions with binoculars than you can with the naked eye.

Agreed.

But this isn't limited to low light, as you can see more/better with a magnified image in good light too.

 

[shaun]

I like Luke have been all over the place. 8/32 slcs 10/42 slcs 12/50 meoptas now I am back to the 10/42els I am a believer to each there own. Everyones eyes are different and for mine I perfer a swaro 10 power

 

[luke moffat]

I like Luke have been all over the place. 8/32 slcs 10/42 slcs 12/50 meoptas now I am back to the 10/42els I am a believer to each there own. Everyones eyes are different and for mine I perfer a swaro 10 power

Nice Shaun, glad I'm not the only one out there. I don't test out a lot of binos, more like just pick a set and use the heck out of them and try to remember how they compared to the ones I used before....not exactly ideal. But being in on over 20 animals and 6+ difference species every year the past 3 years seems to show that the binos aren't my limiting factor. Now that i think about it, roughly half the animals killed were spotted while hiking with the naked eye.

I don't do math about my optics and likely should understand it all better, but I just try to buy some top tier glass at a bargain and use 'em. I look to guys like BB to breakdown my glass to show where it shines and fails cause he knows what he's talking about obviously and uses words I never even knew existed like CA (nope not gonna try to spell it out for ya ) and what not that actually convey what I see sometimes when using different glass. Keep up the good work guys I like reading the optics geek stuff as much as I understand anyways, though I would probably be just as successful/happy with some Nikon Monarchs

 

[Racethesunset]

Bitterroot, thanks for dropping some knowledge on us.

Less technical question for you - when you wear 10s around the neck, do you also bring the 12s or 15s for open country?

On a tripod, with the stability and resolution you can pull from a quality pair of 10s, sometimes I find it a bit redundant to pack another 2x or 5x (I use both btw) at a cost of 2-4 lbs except for the most expansive of geographies.

 

[Matt Cashell]

RTS,

I only take one binocular when I hunt.

If I hunted desert country for Coues or something, I would consider taking a 8x (with a super wide FOV), a 15x on a tripod, and a spotter.

I fully agree on the 10s on the tripod. If you have never used your 10s on a tripod, you haven't used them to their full potential.

 

[peddler]

As Matt would tell you I have every item that Kowa makes, so it's 10.5 X44 for me and 8.5 X44 for my better half. Seriously though it would always be 10 over 8 for me. I'm an old guy and I need lots of help. Should I have said Genesis?

Peddler

 

[Racethesunset]

As Matt would tell you I have every item that Kowa makes, so it's 10.5 X44 for me and 8.5 X44 for my better half. Seriously though it would always be 10 over 8 for me. I'm an old guy and I need lots of help. Should I have said Genesis?

Peddler

Thanks... Do Kowa Genesis models have the 1/4x20 tripod input? Where can I get a loaner to try these out?

 

[Matt Cashell]

As Matt would tell you I have every item that Kowa makes, so it's 10.5 X44 for me and 8.5 X44 for my better half. Seriously though it would always be 10 over 8 for me. I'm an old guy and I need lots of help. Should I have said Genesis?

Peddler

Yeah Peddler has all the fancy Kowa stuff. Of course that is easy when he works for Kowa!

RTS,

The Genesis does NOT have a tripod socket that I can find, unfortunately.

 

[Stinky Coyote]

Moved to 10x from 8 years ago, love the 10's, and I window or tripod mount them whenever possible and they still make do around the neck on foot, and when I made switch to 10x I went down to 32mm same time, dropped weight, gained fov, love this configuration and may be the most versatile going...IMO.

 

[peddler]

Yeah Peddler has all the fancy Kowa stuff. Of course that is easy when he works for Kowa!

RTS,

The Genesis does NOT have a tripod socket that I can find, unfortunately.

Matt, the Genesis can be mounted on a tripod. We just cqame out with an adapter for bins and I believe most bins use the same thread size

Peddler

 

[peddler]

I need to make a clarification on the new bin mount, it only fits the following series:Genesis 33, BD25 and YF30. The model # of the adapter is
KB1-MT. I'm not sure of the thread size but I can tell you it's large. I'll try to find out on Monday.

Peddler

 

[Racethesunset]

Has anyone here actually measured their pupil size in low light conditions? How can I verify this to see if I'm missing out on light because of younger, more active pupil dilation? I am pretty sure that my pupil can exceed 6mm at night, dusk even.

 

[Racethesunset]

I need to make a clarification on the new bin mount, it only fits the following series:Genesis 33, BD25 and YF30. The model # of the adapter is
KB1-MT. I'm not sure of the thread size but I can tell you it's large. I'll try to find out on Monday.

Peddler

Peddler, let us know. I'm interested in the EL SV 8x32, but if these Genesis 33's are excellent for less money, I'd reconsider.

 

[blb078]

I went from 10s to 8s cause I got a good deal on the 8s I bought and I don't think there is a huge difference for me, I highly doubt I'll be missing any animals w/the 8s over the 10s, which is all I'm really worried about.

 

[Stinky Coyote]

note, both swarovski and leica make bino mounts that will fit pretty much all bino's, they sit on a base and a rubber deal pulls over top of them and hooks back to the base, the leica one is pretty lightweight, fits my 32's fine and would be able to throw pretty much any other roof prism on there at any given time. just an FYI, the swaro one a bit too big/heavy for my leica 32's when i test fit in the shop...the leica one would be good deal for guys with multi-pairs of bino's and use different ones for each hunt etc. plus pretty much only way to fly to mount 32's imo...i've used traditional bino mounts on other bins and like this leica strap style one alot

 

[peddler]

Has anyone here actually measured their pupil size in low light conditions? How can I verify this to see if I'm missing out on light because of younger, more active pupil dilation? I am pretty sure that my pupil can exceed 6mm at night, dusk even.

I sent an email today requesting the size. I have a feeling it's a standard size. But you know what's said about assuming. So I decided to ask.
Skip

 

[peddler]

Thanks... Do Kowa Genesis models have the 1/4x20 tripod input? Where can I get a loaner to try these out?

Yup it's 1/4" just got a reply.

Peddler