Advice on Binoculars for Alaska Cruise

[RN_Prof]

If this is a one-time-use item, why not rent or borrow a pair?

[TanTien]

9 hours ago, RN_Prof said:

If this is a one-time-use item, why not rent or borrow a pair?

Because rentals may be low quality and hard to come by. If you can borrow a decent pair, you can try them out before going to your cruise. My earlier recommendations still are good guidelines. Smaller, waterproof, at or under 10 x and probably 32 MM objectives will be bright enough and compact enough for traveling.

[Heidi13]

15 hours ago, TanTien said:

Because rentals may be low quality and hard to come by. If you can borrow a decent pair, you can try them out before going to your cruise. My earlier recommendations still are good guidelines. Smaller, waterproof, at or under 10 x and probably 32 MM objectives will be bright enough and compact enough for traveling.

 

When dealing with binoculars with only a 32 mm objective lens, the "Exit Pupil" size becomes a potential issue, especially with higher magnifications.

 

The "Exit Pupil" is the binocular's virtual aperture, which restricts the light entering the eye. Exit pupil is calculated by dividing the diameter of the objective lens by the magnification. In the case of 10x32 binoculars, the Exit Pupil is 3.2, which is well below the optimum level, unless using binoculars in bright conditions.

 

A higher Exit Pupil is recommended, with 4 often considered the minimum, but personally, I prefer a minimum of 5, which is why I prefer 10x50 binoculars on cruise ships, which also have a wide field of view. 

[TanTien]

On 3/27/2024 at 11:16 AM, Heidi13 said:

 

When dealing with binoculars with only a 32 mm objective lens, the "Exit Pupil" size becomes a potential issue, especially with higher magnifications.

 

The "Exit Pupil" is the binocular's virtual aperture, which restricts the light entering the eye. Exit pupil is calculated by dividing the diameter of the objective lens by the magnification. In the case of 10x32 binoculars, the Exit Pupil is 3.2, which is well below the optimum level, unless using binoculars in bright conditions.

 

A higher Exit Pupil is recommended, with 4 often considered the minimum, but personally, I prefer a minimum of 5, which is why I prefer 10x50 binoculars on cruise ships, which also have a wide field of view. 

Agreed: a larger exit pupil is better and brighter; however, it will come at a cost of size and weight. I used to have USN 7x50 binoculars and believe me when I say that they were very large and heavy. Bright, yes, but because I had to use them at night on bridge watch. When I am cruising, I don't use my binoculars much at either early dawn or late in the evenings or for astrological events, so a good pair of 8x32 MM objectives (EP=4.125 - what I have and recommend) might well be enough. 10 x 32s exit pupil will depend on the quality of the optics, what you need them for and how old your eyes are. When you get older, you eye muscles will not be able to accommodate a smaller exit pupil, so you will need to calculate that ratio to see how your eyes can handle both the smaller exit pupil and the other factor of the eye relief. I have a 10x40 pair of near Alpha bins that are terrific, but they are also heavy and not something I enjoy traveling with as much as my smaller 8x32s. 

[Heidi13]

On 3/30/2024 at 1:00 PM, TanTien said:

Agreed: a larger exit pupil is better and brighter; however, it will come at a cost of size and weight. I used to have USN 7x50 binoculars and believe me when I say that they were very large and heavy. Bright, yes, but because I had to use them at night on bridge watch. When I am cruising, I don't use my binoculars much at either early dawn or late in the evenings or for astrological events, so a good pair of 8x32 MM objectives (EP=4.125 - what I have and recommend) might well be enough. 10 x 32s exit pupil will depend on the quality of the optics, what you need them for and how old your eyes are. When you get older, you eye muscles will not be able to accommodate a smaller exit pupil, so you will need to calculate that ratio to see how your eyes can handle both the smaller exit pupil and the other factor of the eye relief. I have a 10x40 pair of near Alpha bins that are terrific, but they are also heavy and not something I enjoy traveling with as much as my smaller 8x32s. 

 

The 7x50 binoculars on commercial ships are no doubt significantly cheaper and lighter than the USN specs, as are most consumer models that are readily available. I now use 10x50 and have no issues with the size and weight. 

[sr71_1]

Just bought the new ZEISS SFL 10x40's.  The big draw for me is the low weight at 22.6oz combined with a decent field of view & 90% light transmission.   We'll see. 

   

[TanTien]

9 hours ago, sr71_1 said:

Just bought the new ZEISS SFL 10x40's.  The big draw for me is the low weight at 22.6oz combined with a decent field of view & 90% light transmission.   We'll see. 

   

You got a really nice pair of bins! I've had my eyes on Zeiss for a while but couldn't afford them. And now I have too many. My best ones are Vortex Vipers 8x32 and Nikon SEs 8x32s. 😁

Enjoy your shiny new bins!