Birding Optics
Binoculars and Scopes

Birdwatching Dot Com

Michael and Diane Porter are avid birdwatchers who have been reviewing binoculars and spotting scopes for over 20 years. They've surveyed hundreds of binoculars and scopes, testing them for optical qualities and noting the fit-and-feel characteristics of each instrument.

In many of these surveys, a team of Iowa birders participated by trying out the optics and contributing their impressions and opinions.

Using Optics provides info on adjusting optics to fit yourself and caring for optics. Also basics of how binoculars and scopes work.

LATEST REVIEW: Swarovski ATC smallest spotting scope  September, 2022


Binocular Reviews

Zeiss 8x30 SFL

Zeiss SFL — the 8x30, new in 2023

Hands-on Review ~  Recently I got my hands on the new Zeiss 8x30 SFL binocular. And now, when I reach for binoculars for a little birding, somehow it’s always the 8x30 SFL that goes out the door with me. It seems to know how to stay out of the way but be there when I need it.

Zeiss SFL

Zeiss SFL

Hands-on Review ~ It seems that Zeiss has landed in a sweet spot with the new SFL binocular. High quality optics. The right size. Comfortable to carry and look through. We compare its pros and cons with other high-end binoculars. 

Swarovski NL Pure

Swarovski NL Pure

Hands-on Review ~ It's stunning from the moment you meet it. We've never seen a binocular with a shape quite like the NL Pure. It seems it was made to fit your hand. It has the widest field of view of any top binocular.

Swarovski Curio

Swarovski 7x21 Curio

Hands-on Review ~ Swarovski has extended their legendary optics with a tiny new pocket binocular, the Curio 7x21. It's even smaller than the traditional 8x25 and 10x25 Swarovski pockets.

Zeiss Victory SF 32mm

Zeiss Victory SF 32mm

Hands-on Review ~ It knocked her socks off when Diane first looked through a Zeiss Victory SF binocular in 2015. How it felt in her hands! How it fit against her eyes! She only wished it came in 32mm. Now it does. Here is Diane's report. (2020)

Mid-sized binoculars 8X32 Binoculars

Hands-on Review ~ We review mid-sized binoculars that you'll always want to take along... because they're bright and clear but smallish and light in weight. Read this report on which are the best buys among 13 mid-sized binoculars, ranging from top of the field to the super-economical. (2019)

Leica Noctivid Binocular

Leica Noctivid

Hands-on Review ~ When you look at the pinnacle of binocular optics (Leica, Swarovski, and Zeiss), it's hard to see a difference in the view of a bird in the treetop. Optically, all three are superb. The Leica Noctivid excels by its size and weight.

Vortex Diamondbback HD

Vortex Diamondback HD

Hands-on Review ~ New in 2019, Vortex's Diamondback looks like the olderr version. But they say "HD," indicating higher quality optical glass. We compared the new and old HD 8x42 Diamondbacks side by side.

Zeiss Conquest

Zeiss Conquest HD 42mm

Hands-on Review ~ This is Zeiss's middle tier of the three lines of Zeiss binoculas. It costs less than half as much as the legendary Zeiss Victory SF binoculars. However, like the Victory SF line, it is hand made in Germany by a small team of skilled European technicians. It is a qualitative step up for many birders as they get more serious about birding.

Zeiss Conquest 32mm vs. Swaro Companion

Conquest vs. Companion

Hands-on Review ~ A high-quality 32mm-sized binocular in the $1000 price range seems hard to find. The Zeiss Conquest HD is one. It is available in 10x32 and 8x32. Its nearest competitor would the slightly smaller Swarovski CL Companion in 8x30 and 10x30. We did a careful side-by-side comparison, and here is what we found.

Spotting Scopes Reviews

Swarovski ATC scope

Swarovski ATC Scope Review

Hands-on Review ~ It's a new choice in a pocket scope with top optical quality. At 34.2 ounces and 10.2 inches long, the new Swarovski ATC scope is a smaller version of the esteemed ATX scope line. Rest your elbows on a table and you can get by without a tripod at all. It fits in a photo-vest’s cargo pocket. (2022)

Kowa 99A

Kowa 99mm Prominar

Hands-on Review ~ Kowa's new high-end spotting scope embodies the fluorite crystal objective lens and the fine engineeering that put Kowa Prominar scopes in the top tier of birding optics. With a 99mm objective lens, this is the biggest Kowa spotting scope. See how we like it compared to the 95mm Swarovski ATX scope. (2021)

Kowa TSN-553 Travel Scope Review

Kowa 55

Hands-on Review ~ In 2018, Kowa came out with a new 55mm Prominar travel scope. It is a remarkably small scope. It features the esteemed Kowa fluorite objective lens which has made the 88mm Kowa Prominar so popular. Here we compare the TSN-553 to four other travel scopes, including the economical Vortex Razor and the high-end Swarovski 65mm ATX.

New Swarovski BTX Review


Hands-on Review ~ The new Swarovski BTX Ocular Module lets you see through a superb spotting scope while using both eyes! Your brain is designed to compare images coming from two eyes to construct what you see. Using two eyes makes the image more real, richer, and more natural. Here is a guided tour through this revolutionary optical product.

Swarovski reinvents the spotting scope

Swaro ATX scopes

Hands-on Review ~ Before Swarovski came out with their ATX/STX oculars scope system, the usual approach was to make a small eyepiece and a long body. Swarovski's completely new approach is a modular design divides the scope in a new and unique manner. With many advantages. This article reviews looks at the construction and performance improvements of Swarovski's design.

Zeiss Conquest Gavia vs. Vortex Razor HD

Gavia vs. Razor

Hands-on Review ~ The Zeiss Gavia scope bears comparison to the Vortex Razor HD, both of which became availble around 2017. Both have 85mm objective lenses. Both focus using a textured band around the middle of the scope. Both cost in the $1500-$2000 range. This article compares their design and quality. 

Using Optics

The dumbell view is a dumb view. Interpupillary Distance

In the movies, somebody picks up binoculars and sees a sort of dumbell shape. Oh, so wrong! You want to see one image. Like you do in real life. Here is how to set your binoculars to get the right view.

Eye relief Eye Relief

Getting to see the big picture ... People who wear glasses can get cheated out of part of the image. A binocular should let you see the whole image. Yet some binoculars make lose the outer part of the image for a person wearing glasses. Here's how to tell if a particular binocular will work with your glasses.

Cleaning your binoculars

Wrong way to clean

More binoculars are ruined by bad cleaning technique than by being dropped. You've seen someone do it. Breathe on the binocular's eyepiece and then rub the glass with the corner of a shirt. Poor birder, he never knew he just degraded every image he would ever see with that binocular again. Here's the right way to clean your binoculars.

Diopter Adjustment

Diopter Adjustment

The main focus knob adjusts both the left and the right sides of the binocular at the same time. However, your two eyes may not focus at exactly the same distance, so you would be left with one eye slightly out of focus. In case yours eyes have such a difference, the diopter adjustment lets you change the focus of just the right side. Here's how to set it.

Out of alignment A question of alignment

If your binoculars are not fun to look through, if they give you a feeling of strain or a headache, they may be out of alignment. Here's a simple way that you can test if your binoculars are grossly out of alignment.

Field of view Field of view

You usually get a wider field of view with an 8-power binocular than you do with the same model in 10 power. A wider field of view makes it easier to spot a songbird among the branches (or a seabird on the waves. This is especially important in visually complex situations such as forest birding.

Telescope demonstration How binoculars work

Wonder how binoculars work? Here's an easy demonstration you can do. All you need are two ordinary magnifying glasses and a piece of tracing paper.

Scopes Straight or Angled Scope?

This article discusses why most birders choose angled scopes rather than straight models. How it affects the steadiness of the image. Why it's easier to share the view. How it helps you look up or down.


Here are some reviews and articles from the Birdwatching Dot Com archives.

When 8 is more than 10 ~ How to choose between 8x and 10x binoculars. 2021

Clash of the Titans ~ A comparative review of top Leica, Swarovski, and Zeiss Binoculars. 2015

Top Binoculars Review Update ~ Review of the updated Leica, Swarovski, and Zeiss Binoculars. 2017

Pocket Binoculars Review ~ Review of 14 pocket binoculars in all price ranges. 2018

Affordable 8x42 Binoculars ~ Detailed survey of 14 mid-priced binoculars, most still being sold. 2016

The First Telescope ~ A brief note on the inventors of the telescope. And what they saw through it.