Binocular Help (1 Viewer)

Hello, Everyone!
I'm Miraj Hussain and doing my research in birds of tropical semi-evergreen forests of Southern Assam (India). I have a query regarding choosing a pair of binocular for my current research. Currently, I am using binocs of 8x 42mm of Olympus (Porro-prism) and wanted to buy an another pair of 10x42 mm. Can you suggest me which one of these will be better, Celestron Outlander X, Bushnell H20, Bushnell Powerview, Hawke vantage, Hawke Nature-Trek, US Camel and Nikon Prostaff 3s? As the budget is a constraint so, I have chosen these and all of them are Roof-prism binocs having 10x42 mm magnification but some have Bak-4 or Bak-7 prism.
Thanks for helping me in advance.

Hello Miraj,

Welcome to the forum.

I have tried two or three on your list. One thing I should point out is that as far as I can see, only one of those models lists phase coating as part of their specification. This is important for a roof prism design, as without it there will be a significant reduction in brightness and contrast. This may not be obvious in bright condition, but is particularly detrimental at twilight. For instance the Bushnell H2O looked OK for the money when looking outside the shop window, but it was impossible to read the labels on products at the back of the shop that were quite clear with more expensive models. Your Olympus porro would have that kind of advantage too.

US Camel is a new name for me. The UK Amazon site claims it has both phase and dielectric coated prisms. You would normally need to pay three to four times their price for those features. Their Chinese website gives no details. Sounds a little suspicious to me.

I understand the preference for a roof design, and I imagined the better weather proofing would be an advantage. The Bushnell Powerview and Hawke Nature Trek seemed quite reasonable on a sunny day, but you will nead to increase your budget I fear, to match the capabilities of your porro.

Good luck,

David

Nikon Prostaff 3s 10x42 is quite good. I have one. Very large FOV and light weight, very comfortable to look through.

choosing a new binocular

I think water proof is essential for your work.
Bak4 is the best glass for binoculars followed by BAK4 and then Bk7.
For roof prisms to be as good as porro when everything else is equal, they need to be phase corrected.
8x42 will give an exit pupil of 6mm.
10x42 will give 4.2 and as the laws of physics use the square rule the difference in light through an 8x42 will be the square of the difference of the 10x42 so a lot brighter in dim lighting conditions.

8x42 exit pupil 5.25mm. If full aperture available and unvignetted.

(7x42 gives 6mm exit pupil).


(10 squared divided by 8 squared equals 100/64 1.5 times plus brighter if observer's pupil 5.25mm or greater).

(Or 5.25/4.2 squared. 1.25 squared, Same thing).

Best regards.

Welcome to BF.

Talking only about the binoculars on your list, the only really field worthy candidate is the Nikon Prostaff 3. If these are the ones you can find locally, then that is where I would go.

The Hawke Nature trek may or may not be phase corrected, depending on what source gives specifications. Unless you know for sure it is, stay away.