The catch
Vortex Diamondback HD 10x42
Eye relief is shorter at 15 mm
Side by side
Vortex Diamondback HD 10x42 vs Vortex Diamondback HD 10x50 Compared: At 8.7 oz more carrying weight, 10x50 adds exit pupil and eye relief
Quick verdict
Walking, close feeders, or a shared user with eye spacing below 60 mm all point to the Diamondback HD 10x42. The 10x50 is the choice when its 5 mm calculated exit pupil and longer eye relief justify 8.7 oz more weight and a larger body.
Before you buy
Why, and what it costs you
Bigger objectives can shut out someone sharing the pair
The 10x42 fits a measured eye spacing of 58 mm, but the 10x50 can’t reach it. That’s a fit restriction no amount of extra objective size can overcome.
Where this comes from
The ranges for adjustment are 55–73 and 60–75 mm. Only the first one contains the 58 mm example.
The catch
Vortex Diamondback HD 10x50
Brings 8.7 oz more and a larger body
Vortex Diamondback HD 10x42
- Why pick it
- Someone sharing the pair measures 55 to 59 mm eye spacing
- Your walks are long, or a feeder sits about 5.5 ft away
- The catch
- Eye relief is shorter at 15 mm
Vortex Diamondback HD 10x50
- Why pick it
- Every user falls within the 60–75 mm adjustment range
- You value the larger geometric exit pupil above carrying weight
- The catch
- Brings 8.7 oz more and a larger body
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What this page compares
Vortex Diamondback HD 10x42 vs 10x50. Moving up to the larger model adds 8.7 oz and requires eye spacing of at least 60 mm. If the pair is shared, check fit before opting for bigger objectives.
An upgrade to larger objectives at the same 10x magnification, where the consequences for carrying and shared fit matter more than size by itself.
Which one fits
Pick the situations that sound like you
Two users, with a measured eye spacing of 58 mm among them
The 10x50 can’t close far enough.
- Vortex Diamondback HD 10x42
- Better fit
- Vortex Diamondback HD 10x50
- Not suitable
A long trail with close-up stops again and again
The 10x42 weighs less and focuses a foot closer.
- Vortex Diamondback HD 10x42
- Better fit
- Vortex Diamondback HD 10x50
- Caution
A set spot for evening viewing
The exit-pupil geometry isn’t the same, yet this research doesn’t name a winner for low-light image quality. Compare the view and eye fit for yourself.
- Vortex Diamondback HD 10x42
- Depends
- Vortex Diamondback HD 10x50
- Depends
At 10x, you want more eye-relief allowance
The 10x50 lists 17 mm. It does not list 15 mm.
- Vortex Diamondback HD 10x42
- Depends
- Vortex Diamondback HD 10x50
- Better fit
In practice
Differences you will notice
Bigger objectives can shut out someone sharing the pair
The 10x42 fits a measured eye spacing of 58 mm, but the 10x50 can’t reach it. That’s a fit restriction no amount of extra objective size can overcome.
How we worked this out
The ranges for adjustment are 55–73 and 60–75 mm. Only the first one contains the 58 mm example.
At the same power, the carrying penalty is large
The 10x50 carries 40.8% more binocular weight and no more magnification. Its larger exit pupil is a deliberate trade on a walk, and it comes at that weight cost.
How we worked this out
The weights are 21.3 and 30 oz, an increase of 8.7/21.3, or 40.8%. Both are 10x.
Only the smaller model works for the nearer stop
A subject at 5.5 ft is covered by the 10x42 but not by the 10x50. On a walk that mixes close insects and distant views, the larger body gives up one useful task.
How we worked this out
Minimum focus distances are 5 and 6 ft, with the same 10x on both.
Option A
Vortex, Diamondback HD 10x42
Diamondback HD 10x42
Like the 8x version, the 10x42 focuses as near as 5 ft. The price of the closer view is a narrower field and 15 mm eye relief.
- Best for
- Someone sharing the pair measures 55 to 59 mm eye spacing
Facts we checked
- Eye-spacing range: 55–73 mm
- Weight: 21.3 oz
- Closest focus of 5 ft
- Eye relief of 15 mm
Option B
Vortex, Diamondback HD 10x50
Diamondback HD 10x50
With 50 mm objectives, the calculated exit pupil is 5 mm. Before you see this as an easy step up from the 10x42, look at the 60 mm minimum eye spacing and the 30 oz weight.
- Best for
- Every user falls within the 60–75 mm adjustment range
Facts we checked
- Eye-spacing range: 60–75 mm
- Weight: 30 oz
- Closest focus of 6 ft
- Eye relief of 17 mm
Spec by spec
Where they really differ
| Spec | Vortex Diamondback HD 10x42 | Vortex Diamondback HD 10x50 | In practice |
|---|---|---|---|
| Eye-spacing range | 55–73 mm | 60–75 mm | Before moving to 50 mm objectives, check every user. |
| Weight | 21.3 oz | 30 oz | 40.8% more with the 10x50. |
| Closest focus | 5 ft | 6 ft | Only the 10x42 suits a subject at 5.5 ft. |
| Eye relief | 15 mm | 17 mm | The bigger model gives 2 mm extra. |
| Calculated exit pupil | 4.2 mm, calculated | 5 mm, calculated | It describes geometry and isn’t a measured light-transmission result. |
Trade-offs
What each pick costs you
With Vortex Diamondback HD 10x42
- Calculated exit pupil is smaller, with the same 10x
With Vortex Diamondback HD 10x50
- Some users are excluded by a 60 mm minimum eye spacing
Change of plan
When the answer changes
What decides it is walking weight or fit for a shared user at 58 mm
Go with Vortex Diamondback HD 10x42. Both constraints are solved by the 10x42.
Everyone fits, and at a fixed viewing spot the 10x50 suits your own glasses better
Go with Vortex Diamondback HD 10x50. After a personal trial, the candidate with longer eye relief can justify the extra weight.
A user’s eye spacing measures 74 mm
Go with Vortex Diamondback HD 10x50. The 10x42 stops at 73 mm, while the 10x50 reaches 75 mm.
Decision guide
How to decide
The Diamondback HD 10x42 fits walking, close feeders and any shared user below 60 mm eye spacing. Go for the 10x50 if the 5 mm calculated exit pupil and longer eye relief are worth 8.7 oz more weight and a bigger body.
Bigger objectives can shut out someone sharing the pair
An eye spacing measured at 58 mm fits the 10x42, and the 10x50 cannot reach it. No amount of extra objective size gets around that fit restriction. The adjustment ranges are 55–73 and 60–75 mm, and the 58 mm example sits inside the first range only.
At the same power, the carrying penalty is large
Magnification stays the same, yet the 10x50 carries 40.8% more binocular weight. Its larger exit pupil is a trade you make deliberately for a walk and not a free upgrade. The weights are 21.3 and 30 oz, an increase of 8.7/21.3, or 40.8%, and both are 10x.
Only the smaller model works for the nearer stop
A subject at 5.5 ft is within the 10x42's range and outside the 10x50's. On a walk that mixes close insects with distant views, the larger body takes away one useful job. Minimum focus is 5 and 6 ft, and magnification is the same 10x on both.
What this page can’t tell you
- The basis is manufacturer specifications and comparisons you can reproduce. It does not include hands-on testing of sharpness, steadiness or brightness.
- Because exit pupil is only objective diameter divided by magnification, it cannot establish measured light transmission or declare a low-light winner.
- A published eye-relief figure or body size cannot promise that the pair fits your glasses or clears space in a packed case.
By the numbers
What the data shows
What we found across the binoculars we compare, plus the checked facts behind each finding.
Show the facts and the math
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| Vortex Diamondback HD 10x42 |
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| |
| Vortex Diamondback HD 10x50 |
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Ready to buy
See today’s price and what owners say
Open either model on Amazon for the current price, customer reviews and delivery options.
Vortex Diamondback HD 10x42
Someone sharing the pair measures 55 to 59 mm eye spacing
See price & reviews on AmazonVortex Diamondback HD 10x50
Every user falls within the 60–75 mm adjustment range
See price & reviews on AmazonEach link opens in a new tab.
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