Intro

The OM System OM-3 from OM Digital Solutions is a compact weather-sealed mirrorless camera based on the Micro Four Thirds system with a 20.4 Megapixel stacked sensor. Announced in February 2025, it slots between the OM-5 and OM-1 Mark II in price and features. In terms of size and design it’s closer to the OM-5, albeit with a flat front, but inside you’re essentially getting the OM-1 Mark II with the same sensor, processor and autofocus, not to mention the latest menu systems too. Phew.

So you can think of it as delivering the quality and autofocus of the OM-1 Mark II, but in a smaller and more affordable body. There are of course feature and handling differences I’ll mention in a moment, but that’s the essence. I spent some time with an early OM-3 sample, as well as a final production OM-1 Mark II to bring you an initial review in the video below, but if you’d prefer to read the written highlights, keep scrolling!

Olympus fans will also notice a resemblance to the classic flat-fronted OM-1 film SLR from the front, albeit swapping the self-timer crank for the Creative Dial from the PEN-F.

So I may as well address the elephant in the room right now. Many of us have been asking – begging even – for an updated PEN-F, and hoping it would be the next OM System body. But instead we have a new OM body with some design-nods to the PEN-F, such as the flat front and Creative Dial. I’m told the reason boils down to weather sealing which apparently isn’t possible on the PEN-F body, so instead we have a sealed OM body with some PEN-F styling.

While the absence of weather-sealing was one of the major downsides to the original PEN-F, I don’t think I’m the only one who’d still be interested in an updated model with the latest sensor, AF and menus, even if you had to be careful in bad weather. Lest we forget, lack of sealing out of the box hasn’t exactly held back Fujifilm’s X100 series, and I feel OM Digital had the real possibility of pitching an interchangeable lens alternative to that model. Never say never, but I suspect that particular boat has now sailed.

But the OM-3 remains a great-looking camera, especially when paired with a silver lens like my old Olympus 17 1.8 here. Oh by the way OM Digital has new splash-proof Mark II versions of the 17 and 25 1.8, but they’re in plain black. I prefer the look of my original all-silver 17.

Placing a Fujifilm X100 next to the OM-3 for comparison and you’ll see the former is a little smaller in every dimension, but not a World apart in a bag or coat pocket. If you can find the latest X100 VI in stock, it has a similar price to the OM-3, and while it lacks an interchangeable lens mount and full weather sealing, it does come with a lens, a hybrid viewfinder and a larger, higher resolution APSC sensor.

Or if you’re looking for a compact full-framer, how about Panasonic’s Lumix S9 perhaps coupled with a Sigma 45mm f2.8, one of the smallest L-mount lenses right now. It lacks the viewfinder and weather-sealing of the OM-3, but packs a considerably larger full-frame sensor at a lower price.

If you’re committed to Micro Four Thirds, Panasonic’s Lumix G9 II costs the same as the OM-3, while sporting a slightly higher resolution sensor, twin card slots, a better viewfinder and superior video capabilities. They are very different looking cameras though and I think a decision between the two will be greatly influenced by that.

At this point, it’s worth remembering one of the benefits of Micro Four Thirds is the wealth of lenses available, with some great options on the used market. When shopping for used camera gear, I always check MPB first as unlike many auctions or private sales they’re very clear on the condition of a product, what it comes with, and crucially provide a six month warranty. So here are some of my favourite lenses for the system.

First the lovely Olympus 17mm f1.8, a fast and compact prime lens available in black or silver, the latter a perfect match for the OM-3. Yours for £289 in like new condition. Oh and I’m quoting pounds as I’m in the UK, but MPB also operates across Europe and the US.

For a standard prime I’m rather fond of the original Leica 25 1.4 at around £200 in excellent condition and delivering some really nice rendering. Fancy a mid-telephoto for portraits? I’ve always liked the Olympus 75 1.8, selling for around £400 in like new condition and providing excellent background separation. Or if you prefer a telephoto zoom, how about the Olympus 40-150 f2.8, available from around £650 in good condition. Check MPB for used gear!

Let’s now take a closer look around the OM-3 body, starting at the front where the Creative Dial dominates the grip side. Inherited from the PEN-F, it provides direct access to the ART Filters and a wealth of colour or monochrome adjustments, and is not customisable to other functions. This proved quite controversial back in 2016 when the PEN-F came out, but now we have other companies, most notably Fujifilm, offering dedicated dials to directly access their effects or profiles.

It all boils down to personal preferences, but I like this dial, not just for its tactile feel, but also the innovative user interface for adjusting the colour and monochrome profiles. You first select a particular setting with one of the top dials, before then fine-tuning it with another, guided by a clear graphical representation.

Turning to the top surface, the OM-3 is packed with physical controls, which will delight those who – like me – enjoy flicking switches and turning satisfyingly clicky dials. On the upper left side is a dial dedicated to the three shooting modes: stills, movies and the S&Q mode, alongside a small but snappy power switch.

To the right of the viewfinder head and flash hotshoe is a lockable exposure mode dial with the usual PASM positions along with Bulb and five Custom modes. It’s possible to dial-in shutter speeds from 1/8000 to 60 seconds using the mechanical shutter, or up to 32,000 with the electronic. 

Meanwhile the Bulb Timer lets you preset long exposures up to 30 minutes, or even up to six hours in the Live Composite mode. These work in the same way as previous OM and Olympus bodies and are a highlight for long exposure photographers.

Alongside the mode dial are the finger and thumb wheels, both perched atop the body and the former with the shutter release in the middle. I found the half-press on the shutter a little ill-defined at first, but you get used to it. But bonus points to the feel of all four dials on the top surface which may be small, but turn with very positive clicks. Again personal preferences, but I think Olympus and now OM System is one of the best for implementing decent, tactile dials on a small body – Fujifilm take note.

Round the back to the right of the viewfinder you’ll spot a new control labelled CP for direct access to six of the non-Bulb based Computational Photography modes including Live ND and High Res Shot. These are all still available from their own dedicated menu page, but the switch and button lets you access them more quickly.

I’ll be showing you the High Res mode in a moment, but just as a reminder, here’s the kind of effect you can get using the Live Graduated Neutral Density Filter. They’re digital simulations of course and purists will still prefer optical NDs and grads, but these effects are still fun to use and can deliver interesting results.

Moving on, annoyingly there’s no joystick on the rear, but you can use the buttons as a joypad to move the position of the AF area, or of course just tap the touchscreen. Speaking of which, the screen itself employs a 3in panel with 1620k dots, mounted on a side-hinge which lets you flip it out, twist it up, down or forward to face you, as well as back on itself for protection.

Meanwhile the viewfinder employs a 2.36 million dot OLED with 0.68x equivalent magnification. This appears to be the same spec as the OM-5, giving the OM1 II an advantage in both size and detail. I realise there’s still a lot of cameras which use 2.36 million dot EVFs, but for me the size and resolution of the OM-3’s viewfinder is one of its weaker specs, especially as the similarly-priced X100 VI has a 3.69 million dot panel. But before I go, bonus points to OM System for letting you change the colour of the optional alignment grid – a considerate feature.

Moving on, the ports are found behind three flaps on the left side. First are 3.5mm microphone and headphone jacks behind their own flaps, followed by Type-D Micro HDMI and USB-C ports. The USB C can be used for power, charging, data transfer, tethered shooting and also using the OM-3 as a standard UVC UAC webcam, although it won’t support external SSDs. Meanwhile the HDMI can output 12 bit 4k RAW video to compatible recorders if desired.

On the grip side behind a door is a single SD card slot. I realise space is tight in a small body and this is a differentiator for higher-end models, but I’d still have liked dual slots squeezed-in here. To be fair, most of its small rivals are no different.

But while many small cameras rely on a correspondingly small battery, I’m pleased to report the OM-3 is powered by the same BLX-1 pack as the OM-1 Mark II, rather than the smaller BLS-50 of the OM-5. That’s very much appreciated, and bonus points for a tripod thread that’s in line with the optical axis, unlike the X100 series which is off-centre.

At this point, I think it’s worth noting the key differences between the OM-3 and the OM-1 Mark II as they certainly have a lot in common. Most are physical, with the OM-1 sporting a chunkier body with decent sized grip on the front versus none at all on the OM-3. It’s one of the most comfortable cameras I’ve used.

The OM-1 Mark II also sports twin SD card slots, faster mechanical bursts, a sync port and a larger and more detailed 5.76 million dot electronic viewfinder, not to mention having an optional battery grip that I don’t think is available for the OM-3. There’s also control differences, such as the OM-1 having a joystick, albeit lacking the Creative Dial of the OM-3.

Both are however weather-sealed to the same degree with OM System quoting IP53 for both, which means being protected from dust as well as water spray that’s less than 60 degrees from vertical. OM System and Olympus before them, are one of the few companies to actually quote an official IP rating, and I welcome this transparency rather than the usual more ambiguous mention that a product is sealed against dust and moisture.

Ok, now for the quality and the TL-DR version is that the OM-3 delivers essentially the same photo, video, autofocus and electronic burst speeds as the OM1 Mark II. So while I’m limited in what I can show you from my early sample, I can point you towards any OM-1 Mark II images you can find, as they should be the same. After all, the OM-3 shares the same 20.4 Megapixel Stacked BSI Live MOS sensor with Quad Pixel AF, coupled with the same TruePic X image processor. 

The sensor is stabilised inside the body, with OM System claiming 5.5 to 6.5 stops for unstabilised lenses, or up to 7.5 for those which support Sync IS. I rarely achieve anywhere near the quoted maximum from any IBIS system, but personally find OM System’s one of the more effective on the market. One of the benefits of having a smaller sensor to shift. I was able to handhold sharp results at shutters of 1 /5 with the 75mm or 0.8 seconds with the 17.

The maximum image size with a single frame is 5184×3888 pixels in the 4:3 shape, coincidentally similar in vertical resolution to 3:2 shaped sensors with 24 Megapixels, albeit narrower in width.

As with earlier models you can highly customise the resolution and compression of JPEG files, but there’s only one type of RAW file, typically about 18MB each, and no HEIF option either.

If you’d like more detail, there’s two high resolution modes that exploit sensor shifting to make a composite image in-camera in a few seconds later. The tripod mode can generate up to 80 Megapixels, while the handheld version delivers 50. The process can also help reduce noise and colour artefacts, but obviously has to also deal with any subjects in motion during capture.

To compare the potential quality, I took a single frame with my OM-3 sample using the 12-45 Pro zoom at 25mm, and zooming-in for a closer look, you’ll see similar real-life detail to other cameras in the 20-24 Megapixel region.

Comparing it to the High Res mode in the handheld version you’ll see visibly greater detail around static areas. Switching that for the Tripod mode version looks a little better still. Like all pixel shift composite modes, there’s varying success with any subjects that were in motion, such as people moving around, or even the surface of the Sea. Some look quite natural, others much less so. 

But in the static areas, I found an impressive boost in detail and overall crispness. I really like the look of these High Res modes, and love the fact they’re generated in-camera in just a few seconds with the choice of JPEG and or RAW files. Perfect for archive, still-life or mostly static compositions.

In terms of sensitivity, the OM-3 has a standard range of 200 to 25600 ISO extendable between 80 and 102400 ISO. As expected for the sensor size, you’ll want to stick to the lower values for the best quality, and it’s worth mentioning if your subject is static, you can exploit the excellent IBIS to handhold quite slow shutters, in turn allowing you to use mostly lower ISOs. 

But if you need to freeze action in low light with fast shutters and demand the cleanest results at high ISOs, then you’ll be better-served by a larger sensor. By this point, the pros and cons of each format are well-known so if you’re this far into the review, you’ll know what you’re getting.

Like earlier bodies there’s a wealth of bracketing options, including three, five or seven frame exposures, ISO, white balance, flash and art filters, as well as focus bracketing up to 999 frames with optional flash, and the chance to stack smaller sequences in-camera with a handful of compatible lenses.

There’s also multiple exposures, albeit only two frames, and the cunning Live Bulb, Live Time and Live Composite modes beloved of long exposure photographers. I’ve covered all these in detail in previous Olympus reviews.

I’m also happy to report the OM-3 inherits the full subject tracking options of the OM-1 Mark II, which means there’s separate modes for human, cars or bikes, planes or helicopters, trains, birds and animals. Note the updated menu system from the OM-1 Mark II means human is now found more sensibly on the same list as the other subject types.

I tested the OM-3 fitted with the Olympus 17mm f1.8, using human detection across the entire frame area and continuous AFC. In this example, it momentarily lost me as I turned away or was at the furthest distance in my garden, but it quickly reacquired my torso or face when they were large enough.

In my own tests I’d rank Sony and especially Canon as being better at staying locked onto a human subject when they’re smaller on the frame or turned away, and those systems also offer the chance to register and prioritise specific faces. But in general portrait or street use the OM-3 didn’t hold me back, and I also liked that you could assign subject selection to a spare button, then push it while turning the rear dial to cycle between multiple targets.

How about more action-packed scenarios? The OM-3 offers fairly modest mechanical bursts up to 6fps, but inherits the much quicker electronic bursts from the OM-1 Mark II, up to 50fps with continuous autofocus or up to 120fps with fixed focus. Slower bursts are also selectable.

There are however caveats, with 50fps and autofocus only supported on a handful of Pro lenses from OM System or Olympus, which frustratingly excludes even the new Mark II version of their 100-400. For those non-pro lenses, the top speed with autofocus reduces to 25fps, and according to the specs, the potentially more accurate cross-type AF isn’t supported in any of the SH2 electronic bursts.

The other big question is how practical is the electronic shutter when it comes to skewing. So I shot a mechanical burst at 6fps taken while panning the camera and using a 17mm focal length; I’ve tried to match the coverage, subject distance and panning speed with my recent reviews of other bodies for comparison. And then using the electronic shutter mode at 50fps where the pan looks much slower as there’s so many more frames being captured. But the important part is the bottle and whether it’s leaning to one side.

Comparing frames from the mechanical shutter on the left and electronic on the right, I’d say the latter is exhibiting a tiny amount of skewing, but the stacked sensor is doing a very good job at keeping it minimised. It’s certainly much better than most cameras I’ve tested which don’t have stacked sensors, such as the X100 series.

To find out how well it works in a real-life scenario, I headed to the seafront with the new 100-400 Mark II zoom. Limited loan stock meant I didn’t have the big zoom at the same time as the OM-3, but I did have a final production OM-1 Mark II to try it out on. Since both cameras should share the same photo quality, electronic burst and AF modes, it should be a fair substitute at least for now.

In the video you’ll see a series of bursts taken with the OM-1 Mark II and 100-400mm Mark II zoom, using the silent electronic shutter. As mentioned, this was shooting at a top speed of 25fps with continuous autofocus, and I selected bird as the subject type and allowed the camera to evaluate the entire sensor area.

In terms of recognising the birds, the combination did a fair job once they were sufficiently large on the frame, I’d say similar to Sony, but both falling behind Canon’s latest which can identify smaller subject sizes with greater confidence. I certainly appreciate the compact size of the body and this lens, given the effective 200-800 reach, although of course the aperture meant I was never going to achieve much background blur in this scenario.

Moving onto video, the OM-3 inherits much the same options and capabilities as the OM-1 Mark II. So you can film uncropped 1080, 4k or Cinema 4k video in 24 to 60p, with a choice of compression options. There’s no higher resolutions than 4k, nor any Open Gate which records the full height of the sensor. If you want that, look at the Panasonic G9 II or GH7.

Also note selecting H.265 unlocks 10-bit, but appears to subsequently record everything in OM Log 400 or HLG, so if you prefer non-Log footage, you’ll need to shoot with H.264 encoding in 8-bit. Also, All-i is only available for 1080 video and limited to 24-30p.

Meanwhile the S&Q mode lets you unlock faster frame rates for 1080, up to 240p for a 10x slowdown when played at 24p, although footage from 100-240p incurs a mild crop.

I filmed several clips filmed with my OM-3 sample fitted with the 12-45 Pro zoom at 24mm, starting in 1080 at 25p, and next at 50p which remains uncropped horizontally and shares the same detail. Next for 4k at 25p where there’s a boost in detail with the coverage remaining uncropped, and finally 4k at 50p, again uncropped and with the same detail as at 25p.

Now back to 1080 25p before having a look at the S&Q slow motion modes, first in 100p playing back four times slower than normal on my 25p timeline where you’ll notice a crop in the field of view, and next in 200p, where it represents an eight-times slowdown, again sharing the same crop as at 100p. I would say the degree of detail is similar to the normal 1080 modes though.

I then made some video autofocus tests starting with a simple focus-pull using a central AF area, with the 12-45 zoom at 17mm f4. Not a tough challenge, but a fine result none-the-less.

So I switched to an older and brighter lens, my original Olympus 17 1.8, wide-open. There’s a shallower depth of field, but the focus pull is still performed smoothly and without wobbles.

I then tried a mostly human subject, again with the old 17 1.8 and with the OM-3 set to face detection across the whole frame. There’s some minor pauses as the AF system on this old lens catches up with me, but I’d be happy using it for mostly static pieces to camera. Newer lenses can be more responsive.

And finally hold onto your lunches as it’s time for a rolling shutter test, starting in 1080 25p where the stacked sensor is keeping any skewing to a minimum. Likewise in 1080 50p here where there’s very little skewing to mention.

Next in 4k 25p where again the sensor remains well-behaved, minimising skewing from rolling shutter despite the vigorous shaking back and forth. And likewise at 4k 50p, proving the OM-3 is performing well in this regard. There may be a little skewing in extreme cases, but in general use it shouldn’t be an issue. Certainly on par with other stacked sensors I’ve tested in this way.