In this post, we’ll review a desirable Pentax spotting scope that has changed the way we approach the hobby of birding. The Pentax PF-80ED-A is sophisticated optical instrument designed for high-magnification views of one of mother nature’s greatest observing challenges; birds.

The addition of a new optical instrument for birding will often result in a number of “ah-ha” moments, as your gradual progression and skills in the hobby become more well-rounded. Our experiences with the Pentax PF-80ED-A included a number of these moments, and in this post, we’ll do out best to explain how, and why they happened.

Pentax Spotting Scope Review

If you follow our YouTube channel and/or blog, you know our method of birding consists mainly of photography, where the only gear we take with us includes our cameras and prime lenses.

However, this year we have had the opportunity to expand on our traditional way of birding and experiment with some new types of observing gear, and it’s been an incredible learning experience for us.

Since our last video where we used Pentax Z-series binoculars to observe nearly 100 species of birds, we have grown more comfortable using “bins” to enhance our birding abilities and grow our list of recorded sightings.

Whether we are submitting our bird list to eBird, or simply keeping a tally in our heads for a particular location and time of year, bird watching is all about the thrill of discovering new species and the challenge of finding the birds in their natural habitat.

Similar to bird watchers with binoculars, we know there are a lot of birders out there who are very loyal to their spotting scopes and couldn’t imagine birding without them. After our birding trip to Costa Rica, where our guide only used a spotting scope, we were curious about the true capabilities of this optical instrument, and what we might be missing out on.

The reason birders use spotting scopes instead of a traditional pair of binoculars is to get a closer look at their subject from a great distance away. At first glance, a spotting scope looks like a telescope that was designed for celestial viewing, but at true spotting scope like the Pentax PF-80ED-A was designed for terrestrial viewing from the start.

Due to the high magnification of a spotting scope, hand-holding the instrument is not practical. Spotting scopes comes in two general configurations, straight-viewing and angled viewing. The angled barrel offers a more comfortable angle and does not require the tripod to sit so high, while the start viewing design is said to be more intuitive, and easier to use when viewing from a car.

The Pentax PF-80ED-A

In this post, we will discuss our early experiences with a high-end spotting scope for birding, the Pentax PF-80ED-A. One of 4 spotting scopes in Pentax’s impressive sport optics lineup, the Pentax PF-80EDA (The “A” stands for angled model) offers a balance between performance and portability.

This Pentax spotting scope has been around for a long time, and based on the vintage reviews we read, the design has not changed very much, if at all in the last 10 years (which in this case, is a good thing).

The PF-80ED-A sits between their 65mm (PF65ED/EDA II) and and 100mm (PF100ED) scopes, which are offered in both straight-line and slanted barrel designs. All of the Pentax spotting scopes feature ED (extra-low dispersion) glass objective lenses for impressive views.

The PF-80EDA features a large 80mm objective lens designed for clarity and contrast even when working in demanding, low-light conditions. The spotting scope is constructed with durable rubber armor over an all-metal housing. The optical design of the spotting scope itself is a classic porro-prism system with light that enters through the 80mm ED objective lens. 

With the 8-24mm eyepiece we’re using, this spotting scope has a magnification of 21X – 63X. The apparent field of view is 38°-60°, with a focus range of 5.8 meters (19 feet), to infinity. Pentax offers the PF-CA35 camera adapter (for Pentax K-mount 35mm cameras), which converts this spotting scope into a 1000mm super-telephoto lens at F/12.5.

The eyepiece receptacle has a clever layer of dust-shielding glass to retain the the air-tight barrel of the optical tube. The barrel is airtight and waterproof (rated JIS Class 6). It was injected with nitrogen at the factory, to protect the spotting scope from fogging internally.

The objective lens is protected from the elements, dust, and stray light thanks to an extendable lens hood, and is designed with internal threads to accept 82mm filters. 

Although this scope excepts all 1.25″ eyepieces (such as affordable astronomy variations), you’ll want to pair the 80ED-A with a high quality eyepiece for the best possible viewing experience. An interesting option available from Pentax, is their 8mm-24mm zoom eyepiece, that allows you to get a closer look at your subject once your dialed in.

The retractable lens hood keep the optics safe from the elements and prevents stray light from entering the tube.

Pentax PF80EDA Specifications:

• Product name: Pentax PF-80ED-A 80mm Spotting Scope
• Type: Porro-prism spotting scope
• Focus range: 5.8m
• Lens Construction: ED glass elements with 80mm aperture
• Weight: 3.5 pounds
• Eyepiece ring diameter: 31.7mm
• Waterproof rating: JIS Class 6

Pentax SMC 8-24mm Zoom Eyepiece Specifications:

• Product name: Pentax SMC Zoom eyepiece 8mm-24mm
• Magnification: 21X-63X
• Real Field of View: 1.8 – 0.95 degrees
• Apparent Field of View: 38 – 60 degrees
• Field of View at 1000m: 31-16.5m

What We Liked

Our very first impression of the Pentax PF-80EDA was that it was noticeably lightweight (even when connected to our tripod), making it portable and easy to carry due to the magnesium-alloy body. Now, we are both used to carrying around rather heavy telephoto camera lenses around for 6-8 hour birding trips. If you are more of a “8 x 36 binocular” type of birding, the experience of carrying around a system like this may not come as such a smooth transition.

Having a lightweight spotting scope is an important feature for us and the way we like to bird, because of the heavier the equipment is the more difficult it is to bird for long periods of time.  Something that’s comfortable to hold for an hour can start to feel pretty heavy after a a full morning of birding. To keep weight down, we attached the scope to a aluminium tripod that maintains maximize portability.

Here is an affordable tripod we found on Amazon that we found to be a great match for this spotting scope.

The Moman Aluminum Alloy Tripod and Ball Head (Amazon). 

As we mentioned earlier, we have the ED-A version of this Pentax spotting scope, meaning there is a 45-degree upward slant for the eyepiece. We found this particularly useful and made for an easier transition when adjusting for our height differences for looking through the eyepiece. A straight-line design model such as the PF 80ED (non-“A” model) would now feel a little awkward and impractical after using the angled version.

With a quick adjustment to the center column of our tripod, we can easily transition the height for either of us (a 1-foot difference) in the heat of the moment. Looking downward into the eyepiece on a 45-degree angle allows us to avoid looking to close to the sun with a peripheral vision as well.

The angled eyepiece design is extremely practical in the field. 

Another noteworthy feature is the 1.25″ diameter American standard eyepiece receptacle, making it compatible with not only Pentax but any other brand of eyepieces. The ability to interchange eyepiece options or brands is a big plus, especially if you have existing eyepieces in your equipment collection that you can use on the Pentax spotting scope.

The eyepiece locks safely into place using the twist-lock collar on the eyepiece receptacle. High quality eyepieces are not cheap, and can be very heavy. If the eyepiece is not secure, it would be easy to accidentally let it slide out and strike the ground. Luckily, Pentax made note of this potential disaster and included the locking collar to calm your nerves.

Achieving a tight focus on your subject is easy thanks to the smooth and accessible focusing knob. The positioning of this feature is at just the right spot to make the process of locking on to your target feel very natural while birding. You can even focus the spotting scope with the included protective case on the tube, as there is a Velcro opening so you can still access this area. 

The padded carrying case is a nice touch, and a feature that is well appreciated from a couple of birders that like to take great care of their gear. We often use the Pentax PF-ED80-A spotting scope with the padded bag wrapped around the tube on tripod. There is a zippered opening for the objective lens and the tripod mount.

Pentax Optics

Before taking it out for test drive, we did a lot of research on the quality of the optics offered by Pentax. It’s no secret that much like a camera lens, the quality of the glass and optics for a spotting scope and eyepiece are extremely important in image quality. Pentax has a rich history in the world of cameras and optical instruments, and it’s clear to us that the culmination of their previous successful products have been applied to the PF-80ED-A.

The PF-80EDA incorporates ED (Extra-low dispersion) glass to produce sharp, clear images with minimal chromatic aberration (CA) which occurs when a lens is unable to focus all wavelengths of color to the one point. The goal of the objective lens is to gather light and transmit it to the user’s eye.

Larger objective lenses, like those found in the Pentax spotting scope, typically involve different types of glass than those found in binoculars to achieve better image resolution and contrast. Objective lens quality can be thought of as the determining factor for overall resolution, contrast and colour. 

Although we did observe a small about of CA in extreme observing situations, the overall optical quality of this Pentax ED spotting scope is second-to-none. I welcome you to test the PF-ED80-A against any competing spotting scope on the market and see which model produces a better image.

Competing Models:

• Nikon 82mm Monarch 82ED-A Fieldscope
• Vortex Diamondback 20-60×80 Angled Spotting Scope
• Leica APO-Televid 82 Spotting Scope
• Celestron Ultima 80 – 45 Degree Spotting Scope

Optical Quality

The same optical elements that make for a sharp image from your camera apply to image quality and your overall visual experience in both binoculars and spotting scopes. Objective lenses are made up of multiple different elements, and each element affects the light as it passes through. High-quality lenses, such as the Pentax spotting scope, involve specific techniques and materials to maximize lens correction (i.e. chromatic aberration, distortion, vignetting).

This does not mean that you must go out and buy the most expensive lens or equipment there is, its a matter of figuring out what features of the lens are most important to you.  Just know that cheaper lenses do not have the same investments, and compromises must be made to offer a lens at a lower price. As a result, image quality is often one of the factors affected. 

In the case of camera lenses, oftentimes they are the most expensive part of your gear. The most basic camera body in the world fixed with a good lens has a better chance of capturing a good, clear image, then if you were to use a high-quality camera body and mediocre lens. Without suitable fields of view and optical quality, you won’t be able to maximize the best views from any objective lens.

Spotting Scope vs. Binoculars.

A spotting scope can deliver high magnification views (typically a higher “zoom” than binoculars) of birds that are a great distance away. Magnification is the biggest advantage a spotting scope has over a pair of binoculars.

• Average magnification using binoculars: 7-10X
• Average magnification using a spotting scope: 15-60X

There are certain situations where only a spotting scope can provide the magnification needed to identify a specific marking on a bird. An example of this scenario is a professional conservationist that needs to identify small markings on the band of a shore bird.

Binoculars, on the other hand, lack extreme magnification, but are a lot easier to manage and carry for extended periods of time. A good pair of binoculars (see our review of the Pentax Z-Series 8 x 43), sit comfortably around your neck and you almost forget they are there when not in use.

A spotting scope is a different story, as carrying a tripod and spotting scope is a different experience altogether. Like many things in the world of birding, it’s a trade off between convenience and performance.

Additional Spotting Scope Features

• Porro-prism optics 
• Eye receptacles have dust shelling glass to make the scope barrel airtight and waterproof
• Nitrogen injected barrel to prevent internal fogging caused by temp changes
• Built-in lens hood to cut excessive light and see objective lens clean and dust-free
• Effortless focusing via accessible focusing knob
• Built-in tripod socket with click-stop rotation mechanism
• Long 20mm eye relief 
• Camera adaptor – which converts it into a 1000mm F12.5 super-telephoto lens for use with Pentax 35mm SLR cameras
  
• Viewer friendly angled eyepiece design,
• Performs even in highly demanding conditions in the field

What We Didn’t Like

In scenarios of extreme, mid day sunlight, we did not some slight color fringing (chromatic aberration) in our views through the spotting scope with the 8-24mm eyepiece. Whether this is attributed to the spotting scope itself, the eyepiece, or a combination of both, we are not sure. This was observed when pointing the spotting scope towards the direction of the sun, looking at the bare branches of a tree against a bright blue sky.

We found that by extending the lens hood, this problem was much less severe. As a matter of fact, the lens hood should remain fully retracted at all times for the best visual performance. This simple element blocks stray light from entering the optical tube, which results in views with better contrast and clarity.

In the photography world, shooting in these situations is not common. However, there are times when a situation may arise that you need to point the spotting scope in an unflattering situation where a noticeable purple hue comes into play. In reality, the view of your subject in these scenarios is a nearly silhouetted image of the bird anyway.

Whether the weight of this spotting scope is too heavy for a comfortable birding experience is very subjective. We feel that the 3.5 lb PF-ED80-A and lightweight tripod are comfortable enough to spend the day bird watching, without sacrificing comfort or mobility. However, if keeping weight down is a top priority for you, a small pair of binoculars is your best bet.

The bottom line is, be sure to consider the overall user experience of carrying a spotting scope on a hike. A tripod and ball head are necessary to use the instrument, and the one you pair with the spotting scope with must be lightweight and reliable.

Using a Spotting Scope for Backyard Birds

Although the Pentax ED80ED-A was built for long excursions in the wild, the practicality and easy setup routine have resulted in a number of impromptu birding moments in our own backyard. Whether it’s right outside of our kitchen on the deck, or near the back of the yard for stealth positioning, a spotting scope is surprisingly useful to use for backyard birds.

A visit from a small raptor in a nearby tree will often result in a frantic moment of tripod leg extensions, to prepare the spotting scope for a high-magnification look. These experiences are a pleasant, unexpected outcome of our recent addition. The binoculars are still deployed for backyard birding moments, but when something a little more rare stops by, it’s fantastic to zoom-in for a closer look on the PF-ED80-A.

The Pentax PF8-ED-A set up for backyard bird watching.

Final Thoughts

It’s no secret that Pentax has a solid reputation for their optics and this was evident in the PF-80ED-A spotting scope. We have tested this spotting scope in a wide variety of observing conditions and locations. The low-light performance of this scope in heavily shaded areas of tree cover is impressive.

The 80mm objective helps to gather light and project it into the eyepiece for successful bird identification and enjoyment. The high magnification views offered with the 8-24mm zoom eyepiece make it possible to enjoy the undisturbed behavior of birds in the wild. This was a new experience for us, as the focal lengths of our camera lenses meant getting in closer, and would often alert the animal of our presence.

Digiscoping is possible with this 80mm spotting scope, whether you’re using a point-and-shoot digital camera, or your smartphone. Once you have found  the right angle and position of your camera lens, you may be surprised and how great the image is considering that a spotting scope was intended for visual observations.

Overall, we think the Pentax PF-ED80-A spotting scope is a sensational optical instrument that is well suited for traveling to remote locations. You would be hard-pressed to find a more practical choice for your next birding excursion, no matter what the conditions may be. As long as you have a realistic understanding of what it is like to use a spotting scope and tripod in the field for birding, we think the PF-ED80-A will far exceed your expectations.