Low Light Glassing Question

[Trumpkin The Dwarf]

I was out glassing a cut cornfield last night with some Nikon Monarch HG's in 10x42, and the Kowa 773. First of all, wow, that Kowa continues to amaze me. Secondly, my binoculars seemed to run out of gas with at least 10 minutes of legal light left, while the spotter was crisp to the last second. It got me wondering about binocular configuration, as this isn't the first time my 10x42's have seemed to fade out earlier than I'd expect for binos that get really good reviews.

Is this a byproduct of my binoculars being 10x42, or not being top tier glass? Hunting in Texas there are antler restrictions, that make it dangerous to shoot a doe at last light to find out it's actually a baby 2x2. And in the timber, the binos start to fade out even earlier. Would I gain more minutes of light by switching to a mid level 7x50 /8x42 configuration, or by upgrading to 10x42 alphas?

 

[gr8fuldoug]

Take a look at the Kowa Genesis series which are available in 8.5x44 and 10.5x44

 

[robby denning]

I was out glassing a cut cornfield last night with some Nikon Monarch HG's in 10x42, and the Kowa 773. First of all, wow, that Kowa continues to amaze me. Secondly, my binoculars seemed to run out of gas with at least 10 minutes of legal light left, while the spotter was crisp to the last second. It got me wondering about binocular configuration, as this isn't the first time my 10x42's have seemed to fade out earlier than I'd expect for binos that get really good reviews.

Is this a byproduct of my binoculars being 10x42, or not being top tier glass? Hunting in Texas there are antler restrictions, that make it dangerous to shoot a doe at last light to find out it's actually a baby 2x2. And in the timber, the binos start to fade out even earlier. Would I gain more minutes of light by switching to a mid level 7x50 /8x42 configuration, or by upgrading to 10x42 alphas?

Possibly not top glass, and one more reason I run 7-8x. See if you can borrow some other glass to compare


Sent from my iPhone using Tapatalk

 

[Wapiti1]

Swaro El's transmit 90%. I'd be surprised if HG's don't transmit a number close to that. Dropping the mag to get a larger exit pupil is going to help the most.

And/or bump up to 50 or 56mm objectives. Unfortunately those get heavy. Meopta and Minox have some 8X56 models that I'm thinking would be about as good as you will find.

Jeremy

 

[AkMtnRunner]

There's probably not a noticeable amount difference in light transmission due to the glass difference. However, between the 10x and 8x in the same 42mm platform, there is a significant difference. I have owned both the 8x and 10x Nikon HGs and compared at the same time . . . and I sold the 10x. I really wanted to like the 10's so that I would have a little more reach but I think the increased brightness of the 8's actually brought out more clarity and I could notice just as much or more detail than with the 10's.

 

[willfrye027]

Exit pupil is one aspect of apparent brightness but twilight factor will help you determine detail in low light.

For example in low light you can resolve more with my 15x50 duovids than with them at 10x50. They are brighter at 10x50 but if I needed to look at antlers the 15x50 will show more detail.

I have been involved in some pig depredation hunts at night. 10x42 or 8x32 in a quality bino is plenty of exit pupil to spot pigs at night if they’re in the open. No experience with the nikons...but I don’t think exit pupil is your issue. You are probably noticing either inferior glass, or realizing the better twilight factor of the higher mag in the spotter.

 

[LaHunter]

There several factors that impact the image quality of optics, but better optics are better optics. One of the main reasons they are better is that they provide a better quality image in low light. Alpha glass cost a lot of $$ for a reason. It is more than just exit pupil size. Better glass, prisms, coatings, engineering all come into play.

 

[binoman]

You should notice an improvement in low light performance where two identical sized binoculars eg. 10x42 have different transmission levels of light, particularly over the lower end of the spectrum where blues and purples are dominant in twilight. Refer to allbinos.com where they publish transmission graphs. As an example you can see that a Swarovski SLC 10x42 has significantly better transmission at the low range than the Nikon HG 10x42.

 

[DaffyDuck77]

I would consider going up in power actually. There is something called twilight factor where basically more power helps see detail in dim light. Brightness is more aesthetically pleasing however. If your eyes no longer dilate enough to make use of big lens/wide exit pupils then trying the power approach may help.

 

[DaffyDuck77]

Whoops, I see #6 already mentioned twilight factor.

 

[BjornF16]

Try some alpha glass.


This link infers coatings today much more relevant than twilight factor.

Optics Myth 9 - "Twilight factor" is key to performance in dim light

www.birdwatching.com