Tasco Sierra 10×42 Waterproof Binocular Review (Low-Budget Bino)

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tasco sierra 10x40 binocularsMagnification: 10X
Power Variability: Fixed
Objective Diameter: 42 mm
Close Focus Distance: 6 feet
Dimensions: not listed
Weight: 25 ounces
Field of View: 293 feet/1000 yards
Eye Relief/Exit Pupil: 15 mm/4.2 mm
Optics Coatings: Multi-Coated
Glass: BAK-4
Prism System: Roof
Focus System: Center
Waterproof/Fog-proof: Yes/Yes
Eye cups: Twist up
Tripod adaptable: Yes
Rangefinder: No

Best Uses: Hunting, For the Range, Birdwatching, Wildlife Observation

Our Rating: 3.9 out of 5 stars

Update - 2019.11.23Tasco are no longer making the Sierra Binoculars. A great alternative is the Tasco Off Shore 10×42 Waterproof Binoculars


Tasco Sierra 10X42 Binocular Review

This Tasco Sierra 10X42 binocular has every hunters ideal magnification x objective lens combo of 10X42 with multi-coated lenses. It has twist up eyecups, is fully waterproof and fog-proof, and is tripod adaptable on a roof prism platform.

Reviewers have strolled their way online to post a review about the roughly $40, all-purpose Sierra and they’ve given it a rating. It’s a better than average score, but not the best out there.

As the most expensive binoculars of the most popular Tasco’s online, it found a spot on this review. I also wanted to pick one binocular from the Sierra line, and it may as well be the ever-loved 10X42.

But, why doesn’t a binocular that looks great on paper do outstanding in the reviews? Here’s our Q&A to provide you with all there is to know about the weather-brave optic.

  • Price
  • Fully weatherproof
  • Tripod adaptable
  • Fully armored body
  • Very close focus distance

  • Quality control issues


Sierra 10X42 Binocular Q&A:

What kind of prism glass does this Sierra have?

This Sierra 10X42 has the obvious roof prism design that’s been constructed with BAK4 glass. BAK4 glass provides a very nice and round exit pupil and has a higher refractive index than BK7 glass.

Although you won’t see anywhere on Tasco’s website that this is built with BAK4 glass, it is. I got it straight from a Bushnell source. In fact, all of Tasco’s binoculars are made with BAK4 glass except for one.

The only BK7 binocular is the variable Essentials 10-30X50 porro prism binocular with Zip Focus technology.

Unsure what glass you want to go for? Check out our Glass 101: BAK4 vs BK7 article.


Is the Sierra 10X42 waterproof?

According to Tasco it is. The Sierras are fully 100 percent waterproof and fog-proof since they’re supposed to be the high-performing, all-weather binoculars of the entire Tasco binocular family.

The Sierra’s are the only options when it comes to weatherproof-ability.

But, out in the field it might be a little bit of a different story. The durable rubber coating is not only for easier gripping, it’s also for protection for the binocular itself from dings and bangs and from the weather.

While Tasco isn’t quite “up there” with world-renown brands as far as construction and quality build goes, this Sierra will hold up to a sprinkling and even some good rain. But, submersion? I wouldn’t place any bets on it.


What is the number one complaint of the Tasco binoculars?

If you receive your brand new Sierra and you find it’s more than difficult to get the two images to align into one well-focused image, this is called optical misalignment.

Just send in your Sierra to Tasco to be repaired or replaced under the warranty.

This seems to be a common issue for hunters who purchase the Sierra 10X42.

While not all of the Sierras have this problem, there are a few that must miss quality control steps to catch this malfunction before it ever reaches the customer. Boo Tasco.

But, good thing for you, this Sierra is covered by their Limited Lifetime Warranty.


How can I get the binoculars to become aligned myself?

I’m no technician and it’s not always advised for you to tinker around with the optical systems of your binoculars.

You could end up voiding your warranty and you likely don’t have the expertise to fix this issue, especially if you’re not mechanically-inclined like I am.

But, I did promise you a detailed review so I’ll include a couple of rig-it together type steps – if you dare try it.

> Remove the eyecup on the diopter side of the binocular
> Peel back the rubber armor
> Locate a set of three alignment adjustment screws near the center focusing wheel
> Rotate one screw to loosen
> Rotate the other two screws to tighten
> Look through the eyepieces to see for focusing
> If still unaligned, try tightening the other screw and loosening the other
> Keep repeating this process until image is focused

Notes to remember: After a few turns, you’ll figure out which screw to rotate and in what direction.

After each alignment change, allow your eye muscles to rest by briefly looking away in between adjustments.


What if there’s a rattling noise in the barrel?

If there’s rattling noises going on in the barrels of your binocular, the prism assembly is loose within the adjustment screws that are used to keep them in place.

> With a firm grasp, grab hold of the underside of the barrel where the eyepiece connects
> Unthread the eyepiece from the barrel
> Loosen all three alignment adjustment screws
> Allow the prism assembly to fall into its slot placement
> Re-tighten the alignment adjustment screws just barely enough to hold the now-aligned and evenly-sitting lenses in place
> Repeat the process mentioned above to now align the optics

Notes to remember: don’t tip the binocular upside down during this process. With the eyepiece removed, the prism assembly could fall out and you’d be done for.

Also, the screws are what holds the prisms in place.


Noteworthy Features:

  • Twist up eye cups for a comfortable fit for appropriate eye relief
  • Tripod adaptable for long range viewing and steady handling
  • BAK4 prism glass for excellent image quality
  • Multi-coated lenses for sharp, bright, and clear optical performance
  • Impressively close focus distance of 6 feet
  • Fully 100% waterproof and fog-proof for absolute weatherproof-ability
  • Durable fully armored aluminum body for protection in rugged terrain and for secure gripping
  • Backed by Tasco’s Limited Lifetime Guarantee


Our Verdict on the Tasco Sierra Binoculars

To glass it up, the Tasco Sierra 10X42 binoculars have the potential to be a star in the field. On paper, it has everything you need to really maximize the efficiency of your hunt. However, a few defective Sierras might be waiting on the shelf to be delivered to you. Fortunately, Tasco is no discriminator of their products. They have a warranty on all their binoculars – sweet!

For a larger objective lens package, the Tasco Essentials 10X50 is a great option. It’s almost the complete opposite to the Sierra, and we’re not just talking about its looks. You’ll have to check it out if you want to know what we’re talking about.

For another alternative not far out of this price range, the Celestron Outland X 10×42 will do you right. It’s very similar in optical specs and features, and come to think of it, they look quite similar, don’t you think? Maybe it has something to do with the parent company? If you’ve read our reviews and paid attention, you’ll know exactly what we’re talking about.

Whether you’re shopping for a new car, a new house, or a pair of new binoculars, the bottom line tends to depend on the price. In this respect, Tasco takes home the gold. Good thing for you, you won’t have to pay in gold for a stellar optic.

Update - 2019.11.23Tasco are no longer making the Sierra Binoculars. A great alternative is the Tasco Off Shore 10×42 Waterproof Binos
Tasco Off Shore 10x42mm Waterproof Porro Prism Binoculars, Black
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Tasco Off Shore 10x42mm Waterproof Porro Prism Binoculars, Black
  • Rugged 100% waterproof construction
  • Rubber O-rings and nitrogen-purged tubes ensure water and fog stays on the outside


Simon is an avid outdoor enthusiast who is passionate about bringing you the most up to date, accurate & understandable information on hunting, optics, and the outdoors.

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