The Four Outstanding OM System f/4 PRO Zoom Lenses: We Review the Range

The Four Outstanding OM System f/4 PRO Zoom Lenses: We Review the Range

In photography, faster lenses are better, aren’t they? Many struggle to see the benefits of having a range of f/4 lenses. But, if you start using them, you’ll realize there are good reasons for challenging that assumption.

I recently wrote about why so many photographers are jumping to Micro Four Thirds and, specifically, the OM-System. So, why are the OM System f/4 PRO range of lenses so appealing?

You Can't Ignore the Laws of Physics, But You Can Use Them to Your Advantage

Firstly, there are the laws of physics and the design of every lens. At very wide apertures, all lenses exhibit aberrations to a greater or lesser extent. These are the flaws that are seen in the final image. Without going into too much technical detail, the most common and widely known of these is chromatic aberration, the green or purple fringing you can see along high-contrast edges.

It’s caused by the lens's inability to converge the different wavelengths onto a single point, so the white light is split as it would be through a prism. Spherical aberration is caused by light rays entering the lens that don’t converge at the same point, so incoming light at the edges of the lens hit the sensor at the wrong angle. Those aberrations, as well as other optical issues, are most prevalent at wide apertures.

Shot with a low-budget third-party lens, even at f/5.6 chromatic fringing is clearly visible around high contrast edges.

There are things that camera manufacturers do to limit these faults, but most photographers are aware of their lenses’ sweet spots that sit a long way from the wide-open aperture. Consequently, a lens already stopped down to f/4 has inherent sharpness at its widest setting.

Admittedly, modern glass technology has made this argument redundant on the system’s PRO lenses; even their fastest lenses perform exceptionally well at wide apertures. So, there must be more to it.

Scalpel Sharp Images From the Lenses

Exceptional sharpness is especially noticeable with the OM System f/4 collection because they are built to the high standards of the PRO lineup. Consequently, they benefit from the exceptional quality glass, fast and accurate focusing resulting from the advanced engineering, and the beautiful bokeh from the diagram that comprises circular aperture blades.

Even at f/4 at 150 mm, and cropping the image to 100%, there is no chromatic aberration visible using the OM System M.Zuiko 40-150 F4 PRO lens.

Besides being quick and accurate to focus, they are silent in operation too. That’s a massive advantage for wildlife, event, and wedding photographers alike.

Ease of Focus

Especially at longer focal lengths, f/4 lenses are also easier to focus correctly than fast lenses because there is an increase in depth of field (DOF).

A mistake many rookie photographers with a fast lens makes is to always shoot wide open, thus having too little of the subject in focus and losing the context in the background when it would be welcomed. They also miss the critical focus because the camera locks on to the tips of the eyelashes or insect tentacles and not the eye. Moreover, if the photographer moves slightly between locking focus and releasing the shutter, that focus is lost. In those situations, experienced photographers stop down to give a bit of leeway.

The OM System Olympus M.Zuiko 8-25mm F4 PRO is fabulous for landscapes. Much smaller than the Olympus M.Zuiko Digital ED 7-14mm f/2.8 PRO Lens that I currently use, It's gives plenty of DoF and it doesn't have the convex front element, making it suitable to take ND filers. 

Aperture, of course, is only one contributing factor to DOF, and it is still perfectly possible to achieve that sometimes clichéd look if that’s what you want. However, shooting at f/4 also means you can get an entire bird or person’s face in focus.

Yet, it is still possible to get a very narrow Don and a blurred background with the OM System f/4 range of lenses if you know what you are doing.

A shallow depth of field is achievable with the OM System f/4 lenses.

M.Zuiko f/4 Lenses and Low Light

Another factor is that new sensor technology has made a vast difference with low-light, fast shutter photography perfectly feasible because of the superb noise control in the most modern cameras. Even with older cameras, AI-based noise reduction has revolutionized high-ISO photography. Furthermore, the OM System cameras, such as the OM-1 and the OM-5, also have outstanding image stabilization, so low-light shooting that doesn’t require a fast shutter is possible too.

Further Advantages of These Lenses

Hang on, I hear you ask, could you not just buy a faster lens and step it down to f/4? You could, of course, but there are other advantages too.

The M.Zuiko 12-100 F4 PRO is a fabulous walk-around lens with a close focusing distance of 0.49ft (15 cm).

Firstly, there is the size. One of the big advantages of the OM System is the small dimensions of the gear, especially the lenses. It is so much smaller than other systems’ equipment, making it ideal for photographers who want lighter, less bulky, and more discrete photographic gear. Having access to their PRO lens performance in an even smaller package makes them ideal for most genres of photography.

The Olympus 12-45mm 1:4 PRO lens. Small, well made, that gives excellent optical results.

The Compromises of Getting Smaller

If you want smaller, high-performance gear, there are compromises to be made, and that means leaving some of the extra features that usually are featured in the OM System PRO lenses.

Let’s compare the two 40-150mm PRO lenses. The excellent Olympus M.Zuiko Digital ED 40-150mm f/2.8 PRO Lens has a focus clutch that lets you quickly and easily swap from auto to manual focus, and an additional programmable function button. It weighs just 1.67 lbs (760 g) and its maximum length is 6.28" (159.5 mm), much smaller and lighter than achieving equivalent reach with full frame lenses; because this is part of the Micro Four Thirds system, it gives the equivalent reach of an 80-300mm lens on a full-frame camera.

The highly regarded Olympus M.Zuiko Digital ED 40-150mm f/2.8 PRO

However, the f/4 equivalent, the OM SYSTEM M.Zuiko Digital ED 40-150mm f/4 PRO Lens, weighs just 13.5 oz (382g) and is just 3.9” (99mm) long. Like its big brother, it retains a constant f-stop throughout its zoom range. Furthermore, it’s far cheaper, currently retailing at $699 at B&H. To achieve that smaller size, it lacks all those bells and whistles. But it is still a fabulously sharp lens and the one that is usually attached to my OM-1.

The range of f/4 lenses are well suited to the smaller OM-5, but they also fit well on the OM-1.

When I travel, I can put a couple of f/4 lenses in my hand luggage along with an OM-1 and not worry about being overloaded. But just because the lenses are small and light doesn’t mean they are not well made. They have a sturdy all-metal construction and a smooth professional feel to the zoom and focusing rings reminiscent of the quality lenses we used to get in the heyday of film photography.

The M.Zuiko 40-150 F4 PRO, my go to lens, is weather sealed to the IP53 standard.

It's a Good Time to Buy OM System f/4 PRO lenses

B&H currently has a sale on these f/4 lenses, saving around $200 per lens.

Olympus M.Zuiko Digital ED 12-100mm f/4 IS PRO Lens: $1199

Olympus M.Zuiko Digital ED 12-45mm f/4 PRO Lens: $699.99

Olympus M.Zuiko Digital ED 8-25mm f/4 PRO Lens: $899.99

OM SYSTEM M.Zuiko Digital ED 40-150mm f/4 PRO Lens: $699.99

In the UK, there is currently a £175 cashback deal on the lenses. One can expect similar promotions in other parts of the world too.

What I Like and What Can Be Improved About the Lenses

It’s hard to fault this series of lenses. They are made to be portable and sharp. I use the M.Zuiko Digital ED 40-150mm f/4 PRO Lens on one camera when shooting weddings and events because it is fast enough to use indoors in low light and small enough to be discrete.

Like all the OM System lenses, they are splash- and freeze-proof, in most cases to IP53 standard, which matches the OM-1 and OM-5 cameras.

The pocketable OM-5 with the M.Zuiko 12-45mm F4 lens, shot using an OM-1 with the M.Zuiko 40-150 mm F4 lens (40mm, f/9, 1/20 ISO 200 handheld). As I shoot on the beach in all weathers, the dust and splash proofing is essential.

Although not macro lenses, they can focus close and are silent when both zooming and focussing.

Because of their even smaller size and weight, they are probably produced with the OM-5 owners in mind, and they are well-balanced on that camera. However, I happily use them on my OM-1 and my older E-M1 models, and they don’t look or feel out of place on those cameras.

OM-5 with the M.Zuiko 40-150mm f/4 lens is a great, lightweight combination for both adventurous photography and for getting those ad-hoc shots like this one I captured on an early morning stroll.

There are situations they are less well suited for. I probably would not choose an f/4 lens for astrophotography, where we want to get the maximum amount of light possible onto the sensor. If you want extra stops of brightness, then other lenses are available. As with everything in photography, whatever we choose to use, there is always a compromise. However, these are fabulous, lower-cost, professional-grade, precision lenses.

For most photography, these are no-nonsense, high-quality lenses I can highly recommend to accompany any Micro Four Thirds camera.

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

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Great overview of the f4 optics Ivor, but one correction is in order. The f2.8 40-150, while excellent, does not have built in optical stabilization. One of my workhorse lenses.

Oh my word, sorry. My mistake. I was originally going to write about the new 90mm there, which does have it, but changed the text to the 40-150 and forgot to edit that bit out. Oops. Thanks for letting me know. I'll ask the editors to correct it.

It's fixed now, Peter. Thanks and sorry!

The 8-25 might be one of the best cityscape travel lenses of all time. Small, sharp and free extra DoF thrown in. On the OM-1 you can still shoot a ludicrously low shutter speeds. Fantastic combo.

Yes, I agree. It's a fantastic lens. I keep thinking about swapping my Olympus M.Zuiko 7-14 f/2.8 PRO for that smaller, more versatile lens.

The thing that is most important to me in any lens is the maximum magnification ratio. I clicked the link on each of these lenses and looked in the "SPECS" section to see what the ratio was for each lens:

12-100mm 0.3x

12-45. 0.41x

8-25mm. 0.21x

40-150mm 0.41x

I do realize that images taken at MFD with these lenses will "look like" images taken at double these ratios with a full frame camera. But there really is no cheating the system - magnification ratio is magnification ratio, regardless of what size sensor the image is being recorded on. So it is most accurate to compare actual magnification ratio and not factor in what size we are expanding the images to when we view them on a screen or print them.

For my purposes, the 0.41 ratio that the 12-100mm and 40-150mm lenses have is marginally useful, and would enable me to take many of the close-up images that I want to take of small critters. A true 1:1 achieved natively is infinitely more useful, but thus far there are not many such true macro lenses being made for micro 4/3 in wide angle or zoom configurations.

Hopefully as micro 4/3 gains popularity and sells more and more units over the coming years, lens manufacturers will start to make more oddball, specialty, and niche lenses for the M4/3 mount.

Thanks Tom. Yes, most lenses that are marketed as macro are 1:2 or 1:3, so not true macro at all. None of the OM System f/4 lenses pretend to be macro though.

However, the good news is that the new OM SYSTEM M.Zuiko Digital ED 90mm f/3.5 Macro IS PRO Lens offers better than 1:1, 2:1 i.e. 2x magnification. If used with the MC-14 or MC-20 teleconverters, the effective maximum magnification can be increased to 2.8x or 4x, respectively. That's more microscopic than macro!

It's a fabulous lens I am saving up for (it's second in line after the M.Zuiko Digital ED 150-400mm f/4.5 TC1.25X IS PRO Lens. Very soon I will have paid off the mortgage!)

The previously most popular MFT macro lens was the 60mm f/2.8 which was 1:1.

Both of those allow focus stacking in camera.

Excellent article. I have the 12-100mm f4.0 and it is a awesome for all of types of photography. I love that it syncs its stabilization with my OM-D E-M1 Mark III. I am saving to buy the 8-25mm. With this combination I can cover super wide to telephoto range.