Text and photos by
Kevin Loughlin
Yardley, Pennsylvania
June 3, 2023
Holy freakin’ cow! I have uttered those words quite regularly, and rarely quietly, from the moment I unpacked my new Olympus M.Zuiko 150–400mm F4.5 TC 1.25x IS PRO. Olympus Camera is now OM SYSTEM (a division of the newly formed OM Digital Solutions or OMDS), after splitting from Olympus Medical in 2021. Olympus has been a leader in the Micro Four Thirds (M43) sensor mirrorless camera system, and OM SYSTEM will continue with this compact and lighter-weight format. The M43 sensor is roughly half the dimensions of a typical full-frame digital single lens reflex (DSLR) camera, which translates into a higher (two times) apparent image magnification with the same focal length lens. In other words, the Olympus M.Zuiko 150–400mm F4.5 TC 1.25x IS PRO offers an equivalent focal length of 300–800mm when compared to full-frame systems.
So what does the TC 1.25x in the name stand for? That’s another fun capability of this lens . . . it has a 1.25x teleconverter built in. Just flipping a switch multiplies your focal length by 25%, so the 300–800mm equivalent focal length becomes a 375–1,000mm f5.6 super telephoto birding lens.
As I unpacked my new lens, the first thing I noticed was the lack of weight. I expected a professional lens of this magnitude to have some heft, but instead I immediately checked to be sure the glass was intact. At just about four pounds, this lens sits comfortably in your hands, especially when attached to the flagship OM-D E-M1X body. The balance makes it quick to maneuver while following birds in flight. Matched with the E-M1X’s bird-tracking focus, my flight photo “hit rate” jumped exponentially!
My first adventure with the lens was on the Galapagos Islands, followed by 10 days in the Andes of Ecuador. What a perfect combination of situations and environmental conditions in which to test all the features and capabilities of this lens. From sandy beaches, ocean waves, and rocky shorelines full of cooperative birds and wildlife to high-elevation, rainy cloud forests with fast-moving hummingbirds, dark forest dwellers, and some cool bugs, this camera always excelled.
The OM SYSTEM upper-level camera bodies, along with their PRO series lenses, offer incredible weatherproofing. This new lens did not disappoint, as on one morning while I was taking long-exposure images at Gardner Beach on Española Island. The 150–400mm hung on my side as I set up my tripod when a rogue wave crashed into me at waist level, drenching the camera and lens in sand and salt water! Most photographers would cringe as tears welled up in their eyes in this situation . . . I, however, calmly opened my water bottle and rinsed my equipment off with fresh water and kept taking photographs. That was in Sept. 2021, and I have not had to send anything in for repair. I would, of course, recommend avoiding situations like this, but knowing this equipment has a good chance of survival when accidents happen is reassuring.

Some photographers may balk at the $7,500 price tag. But let’s do some comparisons with full-frame lenses. A typical Nikon or Canon 800mm lens has a maximum aperture of f/5.6 vs. the OM lens at f/4.5. The full-frame 800 f/5.6 lenses weigh about 10 pounds (4536g) vs. the OM at about four pounds (1814g). One of the biggest benefits, in my view, is the minimum focus distance of the OM lens at only 4.25 feet (1.3m). Compare that to the $12,000 800mm f/5.6 lenses from Canon and Nikon, whose minimum focus is nearly 20 feet or about six meters! The OM lens, especially with the 1.25x teleconverter activated, is great not only for birds in general, but especially for hummingbirds, as well as dragonflies and butterflies.

The weight factor alone allows this lens to be handheld. This light weight,coupled with the OM SYSTEM’s image stabilization, allowed me to take handheld images in the dark forests of Ecuador at shutter speeds as slow as 1/25 of a second. Using a monopod, even slower speeds were attainable, as long as my subject wasn’t moving too quickly. Not requiring a tripod for low-light images, I could move more quickly to get on birds I could not have captured with a heavy lens encumbered by a tripod.
While in Panama, I did some additional testing using the M.Zuiko MC-14 1.4x teleconverter and the MC-20 2.0x both with and without using the built-in 1.25x teleconverter. Using a tripod at reasonable shutter speeds, I photographed a cooperative Double-toothed Kite using the effective focal length comparisons of 800mm, 1,000mm, 1,400mm, and 2,000mm. Although the image was slightly soft at 2,000mm, I still considered it better quality than I ever got using my previous full-frame professional system and lenses with a 2.0x teleconverter. So even though I would not recommend shooting at 2,000mm all the time, the option could come in handy at times.

The sale of the Olympus camera division left a lot of people wondering if the M43 system would perish. I, however, was quite excited about the move. Having been part of the photographic world for more than 50 years, 30 of those involved in camera sales, I am more familiar than most with all sides of this puzzle. I look forward to what OM Digital Solutions will do with the OM SYSTEM. While I was writing this review, a new camera from the OM SYSTEM, the OM-1 (paying homage to the OM-1 film camera released 50 years ago) had just been announced. The new technology in this camera body will be a game changer, and I cannot wait to put it to the test with the M.Zuiko 150–400mm F4.5 TC 1.25x IS PRO attached!
This review first appeared in the August 2022 issue of Birding.
ooo
ooo

Kevin Loughlin, owner of Wildside Nature Tours, has traveled the globe for over 50 years to enjoy and photograph birds and wildlife. His images and articles have appeared in Birding, Living Bird, Nature Photographer, and Audubon. His new book, Galapagos: A Natural History, co-authored with John Kricher, will be available in November 2022.
Truly amazing photographs, thank you for sharing. Takes things to the next level for sure. The locations and clearly your skill made best use of this lens.
I’m relatively new to the Olympus m43 systems – nearing two years. While I currently have the Olympus EM1-3 and the EM1X mentioned here, I would highly recommend the OM-1, from OM Systems. I recently shot it along with the Olympus 40-150mm f/2.8, typically with the Olympus 1.4x teleconverter, or the Olympus 300mm f/4 lens, naked, or with the Oly 1.4x or 2.0x teleconverters. I come from shooting the best that Nikon offers, both in terms of cameras and lenses for wildlife. The Olympus m43 cameras and lenses handle most things as well, or better. The only real challenge is… Read more »
I’ve been using Olympus for about 3 years now (Nikon and Canon before that), just upgraded to the E-M1X and 150-400 this spring (that’s actually my rig in the first picture).
I’ve used it exclusively hand-held, and I have to say, it’s the best birding rig I’ve ever used.
I don’t doubt it would be great for birds. If one is used to shooting hummingbirds to elephants and everything in between – then it becomes a different question – and especially in the context of international travel. At the end of the day, it comes down to what a photog shoots and their willingness to carry more gear to cover the range of subjects they shoot. So far, for me, the Oly 40-150mm f/2.8 and the Oly 300mm f/4, along with the two Oly TCs covers the range well, and I typically have the 12-40mm along as well, for… Read more »
Mark, been using the OM1 and 150-400 since August. Seeing these posts now. Previously using Canon FF bodies and a EF 500 f4. Truly amazing in the difference. I appreciate your comment about a wider aperture and the benefits really in terms of DoF as you won’t gain that much in terms of lower light capability even down to 2.8 (widest aperture on any existing telezoom) from the 4.5 of this lens. But, remember that to move even to a 3.2 or even 4.0 aperture would require very different optics and likely a cost in terms of weight. As Greg… Read more »
You might have mentioned the 100-400mm as a budget friendly version for birders. Paired with a OM-1, it would be fantastic for birds. Particularly with Pro Capture for action.
I hear many folks are particularly fond of the PL version for autofocus and image IQ. Agree the 200-800mm FF equivalent of this lens is great, particularly for static birds. Under good conditions BIF seems quite doable in capable hands. Having tried my “hand” at BIF more since obtaining a 150-400, I find myself increasingly in awe of those who are able to produce good results in this genre of photography. Incredibly difficult and some of the shots I see I now appreciate even more what technical skill, timing, and planning go into creating these masterpieces.