Dusk/dawn and 32 vs 42 vs quality? (1 Viewer)

Hello, I've been going through binocular comparisons, and after first buying some 10X42 Viper Diamondbacks, a few months later I ended up with Leupold 8X42 Mojaves that I'm quite pleased with (noticeably brighter and crisper).

I don't have access to the higher-end binos to compare but I have been considering going to a pair of golden rings. The weight of the standard golden rings worry me and I have been looking into the switch-powers.

I prefer 7X or 8X power, and I like the light gathering of the 42mm for dusk/dawn, but I am wondering if the higher quality lenses of the switch-power 7-12 X 32 (at the low setting) would be as bright as my 8X42s?

I know they have 10-17X42s, but I prefer the lower end magnification.

Perhaps my post is overly complicated, I'm just wondering;

...would the Switch-Power Golden Ring 7-12X32s at 7x power be as bright as my Mojave 8X42s?

343150 said:

Perhaps my post is overly complicated, I'm just wondering;

...would the Switch-Power Golden Ring 7-12X32s at 7x power be as bright as my Mojave 8X42s?

Click to expand...

Welcome to the Bird Forum.

Brightness, in my humble opinion, is a combination of glass quality, coatings, prism quality, existing lighting conditions, and exit pupil size. There is not much you can do to abstractly measure the effect of glass quality, coatings, and prism quality. However, you can measure exit pupil size, which is aperture divided by magnification.

Thus, your Mojave 8x42 has an exit pupil size of 42mm / 8x = 5.25mm. Zooms sometime do not figure exactly, however, you can estimate exit pupil size by calculating 32mm / 7x = 4.6mm. Therefore, the Mojave will have a larger exit pupil size. Which probably will not matter much in full sunlight, but may influence brightness if viewing in shade or twilight.

Still, the unknowns come into play. The transference quality of the Gold Ring may allow more light to pass through than the Mojave. Sometimes you will read transference expressed as 95%, 90%, etc. Leupold puts the Gold Ring brand on their top-of-the-line optics. My guess is--and it is purely a guess--that the Gold Ring zooms have higher transference than the Mojaves.

The only way to know for sure will be to have both binoculars in hand at the same time.

. . .

Perhaps you can find some reviews of the Gold Ring zoom that will provide additional insight. Another approach is to contact Leupold's customer service and ask to speak with a optics technician. You may get lucky and be able to talk with someone at Leupold who is familiar with both models of binoculars.

. . .

Other than the above, I am afraid I cannot be of much help to you.

...Bob
Kentucky, USA

Apologies for the bino-geekish answer ... you now know what we're like.

But SteveC (who is the only person here who I know owns a Switch Power) should be along to give an proper opinion.

On a more general note the brightness of a bin during the day is not governed by the size of the objective as the eye's entrance pupil often "stops down" the bin i.e. the entrance pupil of the eye is smaller than the exit pupil of the bin. The size of the exit pupil is objective diameter divided by the magnification e.g. 8x40 == 5mm and 8x32 == 4mm.

The problem of brightness with compact bins (with smaller objectives) crops up as twilight hits and the entrance pupil of the eye grows to be larger than the exit pupil of the bin. That's when a compact can look dimmer than a full size bin.

Most of the time it's not an issue though perhaps in fall and winter in Halifax (44° N) it might be more of a problem than further south.

Then again I'm in Seattle (48° N ... that's a bit of a pub bet being 4 degrees further north than Halifax ) and I don't have a problem with compacts here through our dreary gray fall/winter so long as I stop birding by sunset.

The following may not be helpful but I have compared the near dark detail on wildlife between three binoculars: Zeiss Fl 8x32 & Nikon 8x32 SE versus the Leupold Cascade porro 8x42. The extra 10 MM allows for more detail (just slightly more), This was done on a rock steady platform going back and forth between binoculars. Of course the Zeiss has substantially more field than the Cascade and has a smidgen more brightness than my Nikon 8x32 SE. My opinion. If you can live with a relatively narrow field, the Cascade porro is an extraordinary glass for the money.

John

Thanks for the great replies!

Yes, we are actually south of you! This is the farthest south I've ever lived in Canada, most of my life was spent in the far North, were the days get real short. I spend quite abit of time in Norway as well for work so shorter days and low light come into play.

I hope this isn't a taboo subject, but I'm also an avid hunter (nature lover, any excuse to be outdoors, I like to just watch and photograph out of season) and the binos are used for this activity as well, and as most activity occurs at first and last light, the extra brightness can give me a few more minutes of viewing.

fyi,

Astromart has a powerswitch 7-12x32 for sale today for $US 800

not mine or connected to me in any way,
edj

John Dracon said:

The following may not be helpful but I have compared the near dark detail on wildlife between three binoculars: Zeiss Fl 8x32 & Nikon 8x32 SE versus the Leupold Cascade porro 8x42. The extra 10 MM allows for more detail (just slightly more)

Click to expand...

I agree totally John. It all depends how important that few minutes (15 minutes to perhaps 30 minutes maybe even more further north with heavy cloud cover).

I had this illustrated one morning going out to band Cooper's Hawks in Seattle. I'd been rotating around different bins (Zeiss FL 7x42, Victory 8x40 and FL 8x32) on a different but similar overcast days starting just before dawn. The location itself was under trees and on the western side of a hill so shade from the sunrise. It was obvious that in the dull, overcast, predawn under the trees both of the larger bins outpaced that smaller for usable brightness for perhaps 15 minutes or more.

The trade off here really is weight (for all day use) versus pre-dawn brightness. Once again, only the bin user can know.

343150 said:

I hope this isn't a taboo subject, but I'm also an avid hunter (nature lover, any excuse to be outdoors, I like to just watch and photograph out of season) and the binos are used for this activity as well, and as most activity occurs at first and last light, the extra brightness can give me a few more minutes of viewing.

Click to expand...

And that's exactly the "use case" that requires 5mm exit pupil (8x40) bins rather than compacts.

Kevin Purcell said:

I agree totally John. It all depends how important that few minutes (15 minutes to perhaps 30 minutes maybe even more further north with heavy cloud cover).

I had this illustrated one morning going out to band Cooper's Hawks in Seattle. I'd been rotating around different bins (Zeiss FL 7x42, Victory 8x40 and FL 8x32) on a different but similar overcast days starting just before dawn. The location itself was under trees and on the western side of a hill so shade from the sunrise. It was obvious that in the dull, overcast, predawn under the trees both of the larger bins outpaced that smaller for usable brightness for perhaps 15 minutes or more.

The trade off here really is weight (for all day use) versus pre-dawn brightness. Once again, only the bin user can know.



And that's exactly the "use case" that requires 5mm exit pupil (8x40) bins rather than compacts.

Click to expand...

And that's also why I disagree when it comes to hunting, not birding. You are talking about .68 mm difference in exit pupil here between a 7 x 32 and an 8 x 42. If you can't tell what your target is with a 4.57 exit pupil you probably shouldn't be shooting at it after you've used a binocular with a 5.25 exit pupil either. It won't hurt to lose 15 minutes of hunting in the morning and another 15 minutes in the evening. The risk might be small, but it isn't worth it.
Bob

343150 said:

. . . I'm also an avid hunter (nature lover, any excuse to be outdoors, I like to just watch and photograph out of season) and the binos are used for this activity as well, and as most activity occurs at first and last light, the extra brightness can give me a few more minutes of viewing.

Click to expand...

343150 of Halifax, Nova Scotia...

I frequently observe White Tail Deer at dusk and in the dark. My binocular of choice to do so is the Vixen Foresta porro center focus 7x50 (7.1mm exit pupil)--an inexpensive binocular designed for quality viewing in low light situations.

I want an observing experience that is more than just spotting the animals in low light. I want to observe their grazing habits and interaction with other deer in their herd. I also like to count the points of the antlers among the bucks. I am fortunate, at this time, to have a herd of ten deer that come up from a nearby river and wooded ravine to roam our neighborhood after dark to graze. Several neighbors feed and observe our growing herd.

I have tried 4mm and 5mm exit pupil binoculars for this type of dusk and dark viewing. However, I enjoy the added brightness I receive with a 7mm exit pupil binocular.

. . .

Some hunters say large apertures with extra magnification produce better results than 7x50 or 8x56 binoculars. The Swarovski SLC 15x56 WB appears to be a favorite among hunters with deep pockets (lots of cash to spend on optics). Minox is another brand they seem to prefer. Maybe some hunters will come into this forum and give you their opinions.

There are some interesting photos posted by Patriot222 showing the Swarovski SLC side-by-side with a 35mm camera: http://www.birdforum.net/showthread.php?t=149804. Scroll down toward the bottom half of the thread and click on his photobucket links.

Among the non-alpha (cheaper) brands, I think Leupold incorporates many of the benefits sought by hunters in some of their models. Just a personal opinion. Alpha users will probably disagree.

. . .

Something that has not been mentioned in this thread is eye pupil dilation of the observer during dusk and dark viewing. My eye pupils have been measured to open to 6.5mm in the dark. My age is 60. This dark adaptation (night seeing) measurement may vary from observer to observer. A couple of the issues are age and eye color of the observer.

Yes, according to my eye doctor, individuals with blue eyes, as they age, tend to retain larger eye pupil dilation during dark viewing situations. In the younger years (up to age 40 or so), most people will have eye pupil dilation of 6-7mm in the dark, and as they age this pupil dilation size diminishes. Not so with the blue-eyed crowd, according to my eye doctor.

Like many issues dealing with optics, the issue of eye pupil dilation (dark adaptation, night seeing) can get complicated. However, the fact that you are aware of the need for brighter optics during dusk and dark observing hours may indicate you already ponder such things.

. . .

I don't think I ever answered your original question: Brightness of Leupold Switch/Power 7-12x32 vs. Mojave 8x42? In my opinion, I do not think the Switch/Power will be as bright as your Mojave during dusk and dark observing situations. However, my opinion in this matter should not be followed too closely, as I have never looked through either of these models. As I said in my previous post, you may not know for sure unless you get both models in hand and do a side-by-side comparison of the animals and landscape you want to observe during the dusk and dark viewing times that fit into your personal viewing activity.

. . .

343150 of Halifax, Nova Scotia--once again, welcome to the Bird Forum. I hope you continue to enjoy viewing animals at dusk and in the dark. It can be a great way to spend time outdoors during off season. Night sky observing of the Milky Way stars, moon, and planets (binocular astronomy) may be another night time activity to consider during off season.

...Bob
Kentucky, USA

Bob - My pupils won't reach 4MM in a coal mine at midnight. My eyes are dark brown. I had never heard of the blue eye variable. Interesting.
John

Thanks guys. Very informative!

I used to shoot tons of slides living in Northern Ontario/Quebec, and all those slides have been sitting in storage for years (shot with a Canon Elan with a 500mm Sigma for the most part) and I just rediscovered the collection. I just dropped off about 200 to be converted to high-res digital and I should be able to share the works within a week or so! Really excited me to rediscover those! I sat in a blind for hours for some great (in my opinion) pelican shots, plus lots of various ducks and geese, deer, bears, elk, mountain goats....

I know this isn't really the place but here's a sample of my travels in Norway;

http://smg.photobucket.com/albums/v222/darcyhoover/Norway/?albumview=slideshow

and offshore Nova Scotia (I fly helicopters);

http://smg.photobucket.com/albums/v222/darcyhoover/Offshore Nova Scotia/?albumview=slideshow

No birds though, but those are coming soon!

This is the place, especially when you have great photos like you do. :t:

. . .

I noticed many of your photos show dark, overcast skies. Larger exit pupils also help on those days.

I think you should stay with larger aperture: 40mm or larger.

...Bob
Kentucky, USA