We Review the Top-of-the-Range OM System M.Zuiko Digital ED 150-400mm F4.5 TC1.25X IS PRO

We Review the Top-of-the-Range OM System M.Zuiko Digital ED 150-400mm F4.5 TC1.25X IS PRO

I’ve always wanted to get into wildlife photography. Although no expert, I love taking pictures of birds. So, when I was in the position to invest in one of the best lenses on the market today, I jumped at the chance.

It’s only recently that the OM System M-Zuiko Digital ED 150-400mm 1:4.5 TC 1.25x IS PRO has become widely available. OM Digital Solutions was overwhelmed by the demand for the lens when it was first released, which was far, far higher than anticipated. Then, with the subsequent release of the OM-1, the combination of that camera and this lens produced something that wildlife photographers previously only dreamed of: exceptional image quality and portability.

What Does That Name Mean?

Yes, that name is quite a mouthful, isn't it? However, it is descriptive of what the lens is.

M-Zuiko refers to it being a Micro Four Thirds lens under the Zuiko (Light of the Gods) brand name first used in 1936. Digital is obvious. ED refers to the Super ED lens elements. It is comprised of 28 lens elements in eight groups, including one EDA, four ED, two ED, 2 HR, and one HD, with OM System’s excellent Z Nano Coating.

1:4.5 means this lens has a constant f/4.5 aperture across its entire zoom range. This goes up to f/5.6 when one engages the internal 1.25x teleconverter, which is what the TC 1.25x means. IS refers to the built-in image stabilization. Combined with the five-axis In-Body Image Stabilization (IBIS) of the OM-1, you get eight stops of stabilization. PRO means it is a professional-grade lens.

Unboxing the OM System M-Zuiko Digital ED 150-400mm 1:4.5 TC 1.25x IS PRO

The lens arrived boxed well packaged. For a premium product, it’s what you would expect. However, I didn’t open it until I was sure my business insurance had it covered. I had a nightmare thought of it slipping out of my hands and crashing onto my kitchen's unforgiving quarry-tiled floor.  

With insurance in place, I fitted the lens to my OM-1 and was about to go out birding when it started to rain for three days. The lens is IP53 weather-sealed, the same as the camera, and I have no objection to getting wet, but it wasn’t ideal conditions for a first shoot when I would be testing it. So, my next few days of frustration were spent playing with the lens indoors to see how it worked and what I could achieve with it.

First Observations of the Lens

The lens is bigger than any other lens I have owned. However, at just 12.4 inches long (31.43 cm,) it’s still far smaller than the closest equivalents from other brands. I say "closest" because as far as I can see, there is no other lens that combines that fast aperture for an 800mm full frame equivalent lens, let alone a 1000mm equivalent with the teleconverter activated, certainly not with these dimensions and weight (just 1.87 KG), with the professional level performance of sharpness and focussing speed, and with built-in image stabilization too.

The light weight is partly achieved by the lens' alloy barrel construction. It is white, which helps with heat dissipation. The zoom and focus rings are rubberized with good grips. They are wide too, making them easy to operate even when wearing thick gloves. The two rings move with equal resistance, which is just enough, and there is no sudden lurch when you start to turn them. I found that I could turn the zoom ring with my thumb and forefinger, and the focus ring with my ring and little fingers, without changing my grip.

Focus and zooming is carried out inside the lens. Therefore, the lens stays a fixed length during operation, and I could not detect any change in balance.

The zoom turns from 150mm to 400mm in a quarter of a turn, making it very fast to zoom in. Manual focusing from 1.3 meters to infinity requires a similar quarter turn. Consequently, both of these actions can be accurately performed in a single movement.

Between those two rings are programmable L-Fn buttons. These can be set to one of many different functions. With my camera’s custom mode set up for wildlife, I program them to turn the camera’s subject detection on and off.

On one side of the lens are five switches.

The first of these adjusts the focusing limits. There is a choice of 1.3 meters to 6 meters, from 6 meters to infinity, and from 1.3 meters to infinity. Note that it has an exceptionally close minimum focusing distance of 1.3 meters that applies across the entire focal range, including with the teleconverter activated.

Next, there’s an AF/MF switch, an image stabilization on and off button, and a switch to turn the focus notification beep on; I always leave the beep turned off.

The L-Fn/PRESET switch changes the function of the L-Fn buttons in the left-hand position. Then, in its PRESET position, it changes the buttons' function to lock focus at a pre-determined distance. That distance is programmed by using the set button which is on the other side of the lens, just above the teleconverter switch.

I operate the teleconverter button with my right-hand middle finger, which I can do with my forefinger on the camera’s shutter release button. It moves with a reassuringly solid action and can be locked into place with a sliding switch.

There is a tripod mount collar with an integral ArcaSwiss compatible foot that perfectly balances the lens and OM-1. The collar unlocks by loosening a knob and rotates. With each 90-degree turn, there is a solid stop.

The lens takes 95mm filters. There are also two strap loops. I fitted my Peak Design strap anchors to these. The metal lens hood is reversible for storage and the lens cap is inside a padded nylon cover that fits around the hood and is fastened with Velcro. There is also a wider, more padded strap provided than the one that comes with the OM-1. The lens was also supplied with a high-quality carrying bag.

As you probably gather, this is a fabulous lens and a lot of work has gone into its design. It’s solidly built but incredibly light for what it is. I’ve been shooting with photographers who own Sony and Canon full frame cameras, and they were amazed by its lightness, usability, and ease with which it could be handheld.

Click to open in lightbox. Tight crop to show sharpness, ISO 200, f/4.5, 1/1600 s, (-1 EV exposure compensation), 306mm.

The OM System M.Zuiko Digital ED 150-400mm F4.5 TC1.25X IS PRO in Use

I consider myself a novice wildlife photographer. Real wildlife photographers know the Latin names of what they photograph, as well as the behaviors of their different subjects. It is something I want to improve because I really enjoy being out in nature and seeing wildlife. I am a great believer in having the best possible equipment. That is why I bought this lens, and it has impressed me.

Mostly, I am going to be photographing birds, including birds in flight. I found this camera and lens combination quick to lock onto the subject, even when it was partially obscured or on a cluttered background. I used twelve focus points in a cross formation with continuous autofocus, tracking, and subject detection switched on.

Focusing was fast and accurate. Using continuous shooting, it only occasionally missed a frame or two with fast-moving birds when there was a busy background, but mostly, it tracked and stayed in focus.

Cormorant 500mm (400mm + 1.25x teleconverter), ISO 2500, f/5.6 1/1600. This is handheld and 1000mm full frame equivalent.

There are some situations where any camera would struggle to find a subject. For example, I used it as a digital spotting scope to identify distant birds on a far rocky shoreline. It was an impossible situation for any bird detection to work. So, I swapped the camera to manual focus and then used the focus assistance and tried using one focusing point and single autofocus. Both worked well.

This is a tight crop of turnstone flying approximately 110 yards (100 meters) from where I was standing. ISO 250, f/4.5, 1/1600 s, -1.3 EV, 350mm. The camera and lens combination easily tracked these fast-moving birds despite the cluttered background.

On another occasion, in low light before sunrise, I photographed some roosting turnstones that were partially obscured by rock. The focus was perfect.

280mm, ISO 1,600, f/5.6 1/1000 s, cropped

Where my colleagues with larger camera formats relied on monopods or tripods, handholding was no issue for me with this lens. Firstly, the rig was light enough to carry for long periods without discomfort. Secondly, the image stabilization made it superb to stay on the subject. Furthermore, holding it up to my eye for long periods was painless.

Changing the switches on the body of the lens could be done without looking. To do that, of course, takes a little while to learn which switch is which. It was reminiscent of learning a new chord pattern on my guitar. With practice, it becomes second nature.

Juvenile razorbill. ISO 200 f/4.5 1/1,600 s (-1 EV exposure compensation), 400mm

Image Stabilization Tests

With this lens on the OM-1, I was able to handhold the camera for one second at 150mm and 1/4th of a second at 400mm, albeit sitting down and resting my elbows on a solid surface. Free standing and not leaning against anything, I achieved 1/5th of a second at 400 mm. In a real-world situation, I am unlikely to work to those extremes; I’m usually aiming for at least 1/1,600th for photographing birds and increasing the ISO in low light.  Needless to say, when I was out in the field, none of my images suffered from camera shake.

Although I could handhold the camera and lens at very slow shutter speeds, in reality, I am more likely to turn up the ISO to increase the shutter speed and thus stop the subject's movement.
ISO 12,800, f/5.6, 1/1,250, -1EV, 500 mm (400mm + 1.25 x teleconverter)

Image Quality of the OM System M.Zuiko Digital ED 150-400mm F4.5 TC1.25X IS PRO

As I expected for a lens at this price point, I was blown away by the sharpness of this lens when shooting wide open right across the focal length range.

Besides the extra reach afforded by it, the other advantage of Micro Four Thirds cameras, such as the OM-1, is the extra depth of field, which allows an entire subject to be in focus without having to stop down the aperture. ISO 200, f/4.5, 1/2,000 s, -1EV, 400mm. Click to open in lightbox.

I watched one review that pixel-peeped a comparison between this lens and the OM System 300mm f/4 prime lens, and the reviewer detected a tiny difference with the 300mm. In my tests, I couldn't see it; the images were perfectly sharp. Nevertheless, one would always expect a prime lens to be sharper than a zoom. Everything in photography is a compromise. However, those professional photographers that I know who own both, now solely use the 150-400mm. It was their advice that persuaded me to buy this lens and not the 300mm f/4 prime.

Feral Pigeon. ISO 4,000, f/5.6 1/600 s, -0.3 EV, 500mm (400mm + 1.25x teleconverter)

There was a very slight softening on some of the photos when I activated the 1.25x teleconverter, but I had to pixel-peep to see that. Furthermore, it was nothing that could not be corrected in software.

There was no sign of lens distortion, and I only detected a slight vignetting with the teleconverter activated at 500mm. This was automatically fixed by PhotoLab 6.

Color rendering through the lens was great, and I would not anticipate anything less because of the OM System’s Olympus heritage; it is a brand well liked for its color rendering.

The out-of-focus area was pleasant, too, thanks to the nine rounded aperture blades.

What I Liked and What Could Be Improved

What I Liked

  • Image quality
  • Image stabilization that works in conjunction with the camera’s IBIS giving a total of eight stops
  • Relatively small size and weight
  • Exceptional build quality that combines lightness with robustness
  • Easy to reach and use controls
  • Absolutely silent in use
  • Fast and accurate focusing

What Could Be Improved?

  • There was single-use plastic in the packaging which could be reduced

My Conclusions About the Lens

There were two more things I didn’t like, but it’s not the fault of the lens. Firstly, other people, not just photographers, keep stopping me to ask me about the lens and distracting me from taking photos. I’ve missed a lot of shots because of that.

Secondly, because I am a novice wildlife photographer, I am employing the OM-1’s Pro-Capture, which buffers images so I capture the action before I fully press the shutter. I am also using continuous shooting. At the OM-1’s 50 frames per second with continuous autofocus, I am spending a lot of time culling images. But, I am getting photos I am very pleased with.

This is the best lens I’ve ever used, and at its price point, I would not have expected anything less. It’s not a cheap lens, but one would not expect it to be. You can buy the lens here.

Be quick, because there is still limited stock and there is an ongoing high demand. It has certainly inspired me to photograph wildlife.

Ivor Rackham's picture

Earning a living as a photographer, website developer, and writer and Based in the North East of England, much of Ivor's work is training others; helping people become better photographers. He has a special interest in supporting people with their mental well-being through photography. In 2023 he became a brand ambassador for the OM System

Log in or register to post comments

I was really interested reading this, then the pros and cons.
Is it really necessary, in a review of a lens, to include a virtue signalling remark about the 'single use plastic inn the box.'
In real life, most of us couldn't care less.


Maybe you should though. Right now you're starting to ingest micro plastics with almost every meal because we've put so much of it into the world. It's not like there aren't any alternatives to plastic packaging.......

Single-use, disposable plastics are a plague on the environment and it seems legit to point this out.

Kind of crumby of you to just dismiss this as virtue signaling too. That implies you know the author's mind and are accusing him of stating this for selfish reasons rather than a concern for pollution.

lmao buddy,

In real life most people do care - that's an irresponsible and antiquated attitude you have there pal.

Another internet troll hiding behind a false identity tries to make up for his lack of talent by picking holes in others. The comment history says it all.

Is it "single use"? Did you throw all the packaging away? Or did you keep the box for future resale?

What's worse environmentally? Some protective packaging or receiving a damaged lens due to inadequate packaging? A damaged lens that has to be transported by land, air and sea back to a repair facility. I'll take the extra plastic bag and styrofoam, thank you..

It's actually sitting in my loft. A lot of gear I receive now comes in entirely cardboard and paper-based packaging and nothing has been damaged in transport. It's also possible to provide biodegradable plastic bags.

There's some irony in the fact that you didn't want to take the gear out in the rain. Olympus users be pounding their chests about weather sealing but when push comes to shove....

I'm confident that my camera and lenses will take more of the weather than I am willing to subject myself to.

I bought both of my EM-5 III bodies and most lenses used so don't baby them at all (EM-5 are also not as robust as (E|O)M-1 series). I'm also frankly clumsy despite best intentions, so have accidentally dropped them in puddles, and onto concrete, watched one tumble down a hill for what felt like an eternity after a bike crash, slipped into the ocean, used in rain countless times, and while they look well worn, still work fine, so.. 🤷‍♂️

Thanks for giing me the opportunity to address the excellent weather sealing again.

If you read again what I wrote "The lens is IP53 weather-sealed, the same as the camera, and I have no objection to getting wet, but it wasn’t ideal conditions for a first shoot when I would be testing it."

It was me that didn't want to go out in the rain, mainly because all the wildlife here would be in hiding. The camera is perfectly capable in a deluge.

Here the camera is when I took that shot in a heavy rain: https://www.instagram.com/p/CutzrU9ICvT/

"I consider myself a novice wildlife photographer. Real wildlife photographers know the Latin names of what they photograph, as well as the behaviors of their different subjects. It is something I want to improve because I really enjoy being out in nature and seeing wildlife."


I love that you wrote this!

A love - no, an obsession - with the animals is what truly makes one a hard core nature photographer. It's not really the gear one uses, or the exotic/faraway destinations one travels to, but rather a deep love for the animals that lives down in your soul.

You know you're a hard core wildlife photographer when you spend an entire day online researching one species, and create video playlists of biological documentaries of that species, and email the world's leading expert on the species, to ask questions that you can't find the answers to anywhere, and phonecall and email other photographers to talk with them about their experiences with that species. When you spend hours, days, and weeks, just learning more about a species, then you know you've become the real deal!

You are absolutely right. I love taking photos of animals and birds, but appreciate I have a long way to go. There's always more to learn. Thanks, Tom.

Just got this lens and love it. Compared its images to a full frame 800mm prime and camera that I rented. Similar price, half the weight of the full frame. Image quality at 800mm may be even better than the full frame prime. Certainly on par.

M43 community is always proud of their cost effectiveness and compactness in size and weight but as you can see, the higher quality and faster aperture, the bigger and more expensive the lens is. Just make a simple comparison about cost between the Z8 + the 800S F6.3 = $10,500 and the OM-1 + this lens = $9,700. With a little extra $800, you get what you pay for and the difference in image quality is extreamly huge.

You're missing the point of the lens (in fact of any zoom). I've always been a prime guy but on safari - it's a zoom (Sony A7r5 + A9 + 200-600 and 35-150) because of the nature of the environment and unpredictability of the appearance of animals (last month in SA I had a leopard at 3m and lions at 2m) !! And 800mm is of very limited use in that environment.

As a birder of many years I'd love an 800mm ! But even then they are of very little use (compared to this 150-400mm) when birds are close in. So I wouldn't buy one unless I knew I would mostly be shooting in conditions that warranted it. And the wife agreed (highly unlikely) :)

As for the cost ? Take the lens out of the equation and the Olympus OM1 (awesome camera) is around $2,000, with a huge range of excellent lenses from 4-5 manufacturers, mostly at $200-$500 but the absolute top of the range lenses are around $1,000.

I shoot mostly Sony but my new M43 setup cost $4,000 for the OM-1 + 8 wonderful lenses (covering FF equivalents of 12mm - 600mm) and yes size and weight is vastly reduced (along with the cost). I'll rent the 150-400mm for future safaris/wildlife trips.

Compare that to Sony, Nikon (I previously had D3s, D800e, D800, D600 etc with a 500mm) & Canon. I won't sell off my core Sony kit but if you are in a position to have both then it's definitely worth exploring the options, I think most people will be pleasantly surprised.

Wait, how much does the z8 + 800mm weigh?

Far more, Shar. The z8 weighs 2.01lb and the 800mm f/6.3 5lb 4 oz. = 7lb 5.1 Oz. It's also slower and lacks the versatility of the zoom. The OM-1 weighs nearly 2lb less: OM-1 1.32 lb and the lens 4.13lb = 5.45 lb.

Whenever we review a lens, there is always someone trying to make a comparison with another setup that's completely different. That prime is also significantly slower and costs $800 more, and has a plastic body.

Of course, the lens costs more money. It's a highly specified, hand-built, precision instrument.

The prime is slower yet in real life, it will produce better background separation and lower noise. So, higher f stop is not an argument in favor of the zoom. I don't want to start again this endless crop factor discussion but f4.5 on m43 gives you the performances of f9 on full frame, this is how physic works, 4 times more sensor area, 2 stops of light, period (comparing the same sensor technology). And the AF is also 2 stops more sensitive so f4.5 m43 will not give an advantage for AF neither.

I'm not against m43 at all, I've been shooting with it for 10 years... Now, I shoot FF and carry a heavier backpack but get better results! Though, I've never tried OM-1 + 150-400 f4.5 so I cannot speak about this one but it looks like a nice combination for mountain wildlife when you have to walk a lot!

Thanks for the comment, Jean-Francois.

I have a different opinion to yours. I see the extra depth of field is an advantage for MFT, as it's possible to get the entire subject in focus without stopping down. A lot of inexperienced full frame photographers always shoot wide open and blur out a significant amount of the subject, which looks a bit rubbish in a lot of situations. They therefore have to stop down and lose the shutter speed.

If you put any F/6.3 lens alongside any other set to f/4.5, if the ISO is the same, then the shuttter speed will be faster with the f/4.5 lens. In other words, with this lens you can shoot wide open and get a faster shutter than you would with the Nikon lens quoted.

Also, with a lens of this length, getting the background separated really isn't an issue, as I demonstrated in the pictures above. Also, the noise control in the OM-1 is superb. I can happily shoot at higher ISOs than I ever need. Photographic technology is reaching a point where the camera outperforms the needs of the photographer.

You don't get 2 stops with the Z8/Z9 vs OM-1. The pDR is exactly the same at ISO 200-400, and 1 stop better after that. This means you'd get exactly the same IQ at f/6.3 vs f/4.5 from ISO 500 and higher.

It's absolutely rubbish to say AF is 2 stops more sensitive with FF. AF depends on individual AF detection sites (Z8/Z9 has less than half of OM-1), not the whole sensor size. According to specs, the Z9 's normal AF sensitivity is -7EV which is inferior to the OM-1's -8EV, both at f/1.2. With 1 stop brighter aperture, the 150-400 zoom will AF better to darker light level than the 800/6.3.

Ok, after a quick look, it seems that indeed the Z9 is a bit below the other FF in terms of sensor performances. In the other hand the OM-1 gets the most outside of the 43 sensor which reduces the gap. I rarely shoot 200-400 for wildlife. Even taking into account the f4.5 of m43 that mean 400-800 on full frame, sometimes I shoot this range when there is good light and subject not moving too much (for BIF I'm often in the 1600-6400 range).

For the AF, it seems again that the Z9 is below the best FF and the OM-1 is on top of what be be achieved on m43.

I think the problem with your comparison is you comparing one camera and A lens with another camera and A lens. You are leaving out a the range of lenses that somebody is using on the camera compared to the range of lenses used on another camera. Adding lens to camera and comparing size and weight the Olympus/OM System comes out better in terms of weight across the board.

Also, the Olympus/OM System cameras have at least one feature other cameras don't have. Live Composite. Unique features may be a reason to choose one brand over another. In that case, who cares what lenses are available on other cameras? You go with what is available for the camera you chose.

My first camera as a teenager was an OM1 back in the 70s. When I started my career as professional fashion/beauty photographer I kept using Olympus all the way until I switched to digital. I always was the odd one out with my OM-cameras in a world of Canon and Nikon, but it saved me from carrying a lot of extra kilos and the results were just as good to great.

Though my digital cameras weren't Olympus, I always kept track of them and for personal work I purchased the Pen-F. It was again brilliant.

A year ago, I gave my daughter an OM-1 as a birthday gift together with a 12-40 and 40-150 PRO lens. She adores it and the results are stunning. I even used it a couple of times for professional work and the art director of the magazine didn't even notice a difference with my usual cameras.

Cameras and lenses like these are the best testament of how alive and valid MFT still is. Together with Panasonic's G9II and their great Leica lenses, MFT is a very valid option for both stills and video. Once this silly 'shallow depth-of-field' rage is over, I hope others will see that too. With the newest Noise-AI tools, you don't even need to worry about higher ISO either. My advice: look at the size and weight (also of the lenses!) and only buy what you're willing to carry.

Thanks for the positive comment, Jacob. I hope your daughter continues to enjoy it. She's a lucky person having a dad who would give her such a great present.

it is not an 800mm equivalent..it is a 400mm cropped image...

No, the 35mm sensor with a 800mm lens is squashed down to be equivalent to 400mm on an MFT sensor! Equivalent means equivalent field of view.

I can say it is a beast worth all its cost. was second in Italy to get my hands on it (have pestered my dealer since the mockup was presented at the Frankfurt exibition) and used it extensively, considering I am no pro photographer. Compared to other super tele zooms this one can do without tripod or monopod thanks to the sync IS. If only I could remove the arca swiss foot....

The foot can be unscrewed to remove and save a few grams. The ring is not removable however.

check out my article https://fstoppers.com/gear/5-simple-and-surprising-things-can-make-your-... It has an alternative solution to unscrewing it.

Turning the ring a quarter or upwards is what I normally do when I use it handheld - wich is about almost always - else I use the screw holes on the staff to screw in the blackrapid sling

Superb article. I've been playing with a friend's gear who has exactly this. It's amazing. Some ludicrous and uneducated comments though. How do you put up with them?