"After all a 42x8 bino has the same twilight factor as an 8x42."
Where can you buy a 42x8 bino? I have never seen one.
-
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Binoculars Poll - What format do you prefer ( 8x32, 10x50 etc. ) (1 Viewer)
- Thread starter Andy Bright
- Start date
Where can you buy a 42x8 bino? I have never seen one.
A 12x50 would be the "King" at night for seeing detail. Better than an 8x56 even.
Last edited:
PeterPS
Well-Known Member
"After all a 42x8 bino has the same twilight factor as an 8x42."
Where can you buy a 42x8 bino? I have never seen one.
Amazon sells a number of binos with strange specs, such as 100x100, and I wouldn't be surprised if there also is a 42x8 among their offers, but I tell you, you won't be able to handhold it, or even find the EP for that matter.....
Last edited:
100x100! REALLY! I want one!:-O
Conndomat
United States of Europe
"As discussed elsewhere, binoculars for the dusk should have at least 5mm exit pupils, and night glasses should have exit pupils of more than 6mm."
http://www.eyry.eu/miltec/documents/fernglaspraxis.pdf
What is the exit pupil of a 10x42?
Andreas
http://www.eyry.eu/miltec/documents/fernglaspraxis.pdf
What is the exit pupil of a 10x42?
Andreas
Conndomat
United States of Europe
Where is the 8x32?
I think the American colleagues use a different selection than the Europeans, the 15x56 is pretty far behind, only the 12x50 is sold even less.
Andreas
I know their sales numbers are interesting aren't they. The SLC 15x56 is popular! For astronomy and tripod use in observation probably.
The 10x42 has an exit pupil of 4.2mm. Even though the 8x42 has a bigger exit pupil of 5.25mm you will see more under low light with a 10x42.
Conndomat
United States of Europe
Conndomat
United States of Europe
That would contradict the contribution of Holger Merlitz and my observations are also clearly 8x42.
Andreas
In the UK one of our most prominent dealers reports that his sales of EL32 far outstrip EL42.
Lee
Conndomat
United States of Europe
Hi Lee,
I have also seen such a list before, but no longer knows where, there was the 8x32 also at the top and the 12x50 at the bottom, we Europeans just do not have so big countries ...:smoke:
Andreas
Many here often comment on perceived brightness, but Leinhos and Köhler (Zeiss) actually studied apparent acuity which gave rise to the Twilight factor. While they didn't didn't have eithr a 8x42 or a 10x42, it seems that over a specific range of twilight light levels the 10x42 would have a slight advantage on level of detail. Berek (Leitz) on the other hand used threshold of detection for his study which showed the 8x42 would have a slight advantage on visibility at a similar light level. I've have seen a situations, usually by moonlight where both would appear to be true. A 10x56 beats both an 8x42 and 10x42 by some margin by both criteria as you might expect.
One thing I have noticed that wasn't investigated in either of those studies is that both the thresholds for detail and detection appear shift considerably when the target is alive and kicking! Unfortunately the local wildlife is rarely sufficiently obliging for a more detailed comparison, but for my eyes at least a 10x56 would take some beating for a bit of badger watching.
David
Yes, it might become more representative if more than one option could be entered.
I'm going to have to put my hand up and admit I prefer different formats for different jobs.
8x30/32 - probably the size I use the most (8x32 FL, various 8x30 porros). Love their light weight, compactness and excellent field of view. Probably all that's really needed for 80% or more of the birding most birders do. Good ones have great optical quality.
8x40/42 - preferred where 8x magnification is used in more demanding situations (poorer light, longer distance, long duration). 8.5x mag works really well in these situations and the 8.5x42 Swarovski is probably the best all rounder optically I've found. It's probably not a coincidence that the 8.5x44 Audubon is/was also highly regarded.
10x40/42 - where more magnification (10x) is needed/desired in a not too big binocular.
10x50 - for demanding (long distance and long duration) observation where the 5mm exit pupil and optical performance are more important than weight and bulk.
8x30/32 - probably the size I use the most (8x32 FL, various 8x30 porros). Love their light weight, compactness and excellent field of view. Probably all that's really needed for 80% or more of the birding most birders do. Good ones have great optical quality.
8x40/42 - preferred where 8x magnification is used in more demanding situations (poorer light, longer distance, long duration). 8.5x mag works really well in these situations and the 8.5x42 Swarovski is probably the best all rounder optically I've found. It's probably not a coincidence that the 8.5x44 Audubon is/was also highly regarded.
10x40/42 - where more magnification (10x) is needed/desired in a not too big binocular.
10x50 - for demanding (long distance and long duration) observation where the 5mm exit pupil and optical performance are more important than weight and bulk.
IAN JAMES THOMPSON
Well-known member
I can’t see the poll.
Ian.
