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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

8x42 vs. 10x50 dawn/twilight (1 Viewer)

One thing I also do not understand completely. which one will be better during twilight? A 8x42 or a 10x42 of the same type, lets say the SLC?
The 8x42 has a bigger exit pupil. The 10x42 has more power, but a smaller exit pupil.
I would the 8x42 is better in that case, but I am not sure.
Better at what? The 8x should be a bit brighter (for most people) and show color better, but the 10x should show more detail.
 
One thing I also do not understand completely. which one will be better during twilight? A 8x42 or a 10x42 of the same type, lets say the SLC?
The 8x42 has a bigger exit pupil. The 10x42 has more power, but a smaller exit pupil.
I would the 8x42 is better in that case, but I am not sure.
Better at this.

Thanks. So you all agree that the 8x42 is a bit brighter than the 10x42. So probably about 10-15 minutes longer useful at dusk.
 
Better at this.

Thanks. So you all agree that the 8x42 is a bit brighter than the 10x42. So probably about 10-15 minutes longer useful at dusk.
842 is brighter than 1042? Depends. If so, is it enough to matter? Also depends.

".....minutes longer at dusk." How important is that? Light gathering, whether via coatings/glass/optical design components or exit pupil, (see Gils above) is useful throughout the day. Not a small point. With high sun or even one off to the side, not everything is perfectly illuminated, some stuff is in shade/shadow. Trees, brush, overhanging marsh grass all create darkness, whenever. Light gathering ability lets you see into and discern stuff. Picking out a scrambling Ridgway Rail as it shoots the curl of marsh grass covering a mud bank at mid tide is helped with light gathering, whenever.
 
Looking forward to doing some twilight comparisons with this group. All the way from 2.5, 3, 4 and then a big jump to 6mm.
So far my only large binocular is this 7x42 BR Ultravid, so that's my choice for a x42.
53DDF7E5-70D1-4119-A6C4-D5D1205B344B.jpeg
 
In a blind test, where folks do not know which glass they are looking (not sure how you would do that) I believe that the results would come out random.

I don’t think average human vision can distinguish a 5.25 mm exit pupil from a 5.00 mm exit pupil.

Any knowledge of which glass was which would bias the result. You would also need a fairly large sample, to avoid the pitfalls of small-sample statistics.
 
Yeah, but fortunately for the spec sheets, any good micrometer can.

What's your point and which posts are you even responding to?
The first sentences of the thread are "I wonder, which one will be better for dawn/twilight? Or would that be subjective?"

Perhaps I wasn't clear. I wasn't talking about measuring the exit pupils for a spec sheet, but distinguishing the two binoculars by actually looking through them and deciding which was the brighter.

My point was that I don't think anyone could tell which one they were looking through, using only the criterion of perceived image brightness.
 
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Like anything else, for modest differences probably not. But a 10x56 is clearly brighter in low light than a 32, much like 7x42 vs 21 here.

Lovely 6x24 by the way. Is the lack of phase coating very noticeable at 6x? Can you still find straps for those lugs?
 
Lovely 6x24 by the way. Is the lack of phase coating very noticeable at 6x? Can you still find straps for those lugs?
I just got four pairs of binoculars in the last few days, three of which are in that picture, so I haven't spent much time with them yet, and also wouldn't really know what to be looking for, but if I've understood correctly, the lower powered binoculars are more forgiving? I've got an idea of how I want to deal with the lack of a strap, but also probably won't be actually carrying it anyway, just using in from car or house.
 
I think differences which people can actually see are more relevant than differences on spec sheets.

Just because two things differ does not mean that they can be distinguished.
 
I think differences which people can actually see are more relevant than differences on spec sheets.
Just because two things differ does not mean that they can be distinguished.
Those are both correct. Spec sheets area of importance lies only in being able to convey information across distance and for comparative purposes. My 6x24 Trinovid which might look terrible on paper is an absolute joy to look through.
 
I just got four pairs of binoculars in the last few days, three of which are in that picture, so I haven't spent much time with them yet, and also wouldn't really know what to be looking for, but if I've understood correctly, the lower powered binoculars are more forgiving? I've got an idea of how I want to deal with the lack of a strap, but also probably won't be actually carrying it anyway, just using in from car or house.

Always use a strap , I learned the hard way LOL.
 
Always use a strap , I learned the hard way LOL.
Just a couple hours ago I was thinking about a workaround for the lack of the proprietary strap and until I do that it'll just be a house binocular.
There's quite a few of these old Leitz out there with the strap buttons and I'll post some pics when I finally get around to working it out.
 
I also have a Leica 10x50 BA, and the view is really special. You would enjoy it.....
Jerry
Ok, you've got me, Jerry, I'll have to give a pair of these a go...

I've been trialling a pair of 8x56 SLC's to use as my low light binoculars, but we're not getting on too well, mainly due to the lack of intermediate click stops on the eyecups. Yes, I could probably adapt them with o-rings, but I like a glass (especially an expensive one) to work for me straight out of the box, without having to be adapted. That's just me. Extraordinary glass in low light, really, but they've got to go. (I note William Lewis is letting his recently acquired copy go too, which surprised me).

I know eye relief will be tight, but having recently discovered that I can easily use (and see full FOV) an Ultravid 8x32 or Kowa Genesis 8x33 wearing glasses, I'm confident that these should work for me.

The search is on...
 
Ok, you've got me, Jerry, I'll have to give a pair of these a go...

I've been trialling a pair of 8x56 SLC's to use as my low light binoculars, but we're not getting on too well, mainly due to the lack of intermediate click stops on the eyecups. Yes, I could probably adapt them with o-rings, but I like a glass (especially an expensive one) to work for me straight out of the box, without having to be adapted. That's just me. Extraordinary glass in low light, really, but they've got to go. (I note William Lewis is letting his recently acquired copy go too, which surprised me).

I know eye relief will be tight, but having recently discovered that I can easily use (and see full FOV) an Ultravid 8x32 or Kowa Genesis 8x33 wearing glasses, I'm confident that these should work for me.

The search is on...
Hi Bentley 03

I didn't want to part with them but thankfully the wife has allowed them to stay, few financial bumps in the road!

I know what you mean about eye cup position on them though - tricky! I use the last but one click stop which is actually one click ( approx 2mm) further out than the last click stop - the difference between that and the final click stop seems the smallest gap between stops so I think I'm lucky that's the one that fits.

There's been some discussion recently highlighting that the eye cups for the 8x 10x and 15x are all interchangeable and I believe that swaro may well provide them free of charge so depending on your needs you may be able to find a "factory fit" work around.

All the best

Will
 

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