Olympus E-M1 Mark II vs. OM System OM-1
I wrote this review as a current user of the Olympus E-M1 Mark II. Therefore, I concentrated on the differences between OM-1 and E-M1 II, although I mentioned several times other Olympus cameras. I rarely use these cameras for video, so I did not mention video capabilities here.
In 2020, Olympus announced that they no longer wanted to make digital cameras, and sold their imaging division to Japan Industrial Partners (JIP), a large "private equity fund focused on corporate carve-outs" (but Olympus retained 5% of the ownership). JIP seems to have no experience in the camera business, but has very large economic resources, so much so that their purchase from Olympus is not even listed among their significant acquisitions.
Currently (August 2022), Olympus is in talks with the US-based Bain Capital private equity company to sell them the Olympus scientific instrument division, so the sale of their imaging division two years ago was not just a one-off reaction to low camera sales. While Olympus cameras are better known than Olympus microscopes and biomedical equipment to the general public, the latter has been the core of Olympus since its very start. If Olympus continues to shed off its most important divisions at this rate, it will not take long before it is reduced to just a brand name, like Kodak and Polaroid.
There are still plenty of "official" links to Olympus camera products on the web, but most of them now lead to pages rebranded "Olympus System". If this sounds confusing, repeat with me: Olympus System is not Olympus.
The new company was initially called Olympus Digital Solutions, but now most of the time it sports the name OM Digital Solutions, or sometimes just OM Digital. The name OM System is also increasingly used, instead of Olympus System. Perhaps the transfer of ownership was such a rushed affair, almost as chaotic as the US retreat from Afghanistan, that JIP did not have time to decide on a proper, permanent name for the new company, or perhaps this gradual shift away from "just Olympus" is intentional, to give enough time to photographers to learn that the new company is not an upstart but literally the heir to the Olympus camera legacy, expertise, product development teams, and factories.
The company name is not the only thing shrouded in confusion. The headquarters of Olympus Digital Solutions are said to be located in Shinjuku, Tokyo, while the headquarters of OM Digital are reportedly in the less glamorous, more picturesque Takakura-machi, Hachioji-shi, Tokyo.
Most observers believed that JIP only planned to liquidate piecewise the assets of the Olympus Imaging Division, like they did with other acquisitions. Quite the opposite happened: Not only did the new company continue to produce the current Olympus camera models at the existing factories, they introduced new high-end lenses, a new PEN camera, a new high-resolution digital sound recorder and, roughly one year after the ownership transfer, no less than a new flagship camera, the OM-1. I have just been informed that they will release a new 90 mm f/3.5 Pro macro lens, with in-lens IS working in tandem with sensor-shift IS and 2x maximum magnification (not 4x as erroneously reported by several sources, including the OM System marketing web site - note that it makes no sense to apply a format‑relative factor to magnification, it only creates more confusion, as we just saw in this case). They are also poised to introduce a new second-tier camera, a significant upgrade of the Olympus E-M5 line, albeit delayed by the world-wide long-term shortage of electronic components. It will use the same stacked sensor of the OM-1 and the same BLX-1 battery (see below), but a single card slot and probably a single image processor instead of the pair of the OM-1.
It is only natural that OM System eventually will stop producing the camera models that it inherited from Olympus. In fact, rumors are that it is now the turn of the E-M1 III and E-M5 III to be discontinued (3/4 Rumors). If you have been considering either model and the OM-1 is too expensive for you, you can now start to hunt for discounts on these two older models. Second-hand prices of both models should also decrease.
For several years, the early contributions by Olympus to Micro 4/3 were limited to low-end cameras and lenses targeted to occasional amateur users. Afterwards, starting with the E-M5, came the golden years of Olympus Micro 4/3, which combined highly innovative cameras and lenses with reasonable prices. Micro 4/3 was originally an offshoot of the Olympus 4/3 E-series DSLRs and became the first successful mirrorless system, with Olympus concentrating mostly on still imaging and Panasonic on video with their respective flagship models. This golden period came to an end in the years immediately preceding the sale of the Olympus Imaging Division, which showed a lack of vision by the Olympus leadership of the time. The 2013 E-M1 had been the first Micro 4/3 camera worth considering by professional photographers and advanced amateurs. The 2016 E-M1 Mark II had been a remarkable improvement over the E-M1 "Mark I" in almost every respect, but the 2020 E-M1 Mark III was such a modest improvement on the Mark II that it should have been skipped entirely. The 2019 E-M1X is a large, heavy and expensive dual-grip camera that gives up the Micro 4/3 advantage in size and weight, in return for an only moderately better performance and a small number of new features.
Today, the E-M1X sells for a recommended price just 150 € below the more capable and much smaller OM-1. I cannot see why anyone, today, would choose the E-M1X, except perhaps a few professional photographers who cannot live without a dual grip (albeit the OM-1 can be equipped with a battery grip if desired), or who need to impress customers with a camera bigger than anything else in the mirrorless world (at the time of introduction - this dubious record is now claimed by Canon).
The Olympus M-1 SLR was announced in 1972, half a century ago. When Leica complained loudly that the M-1 name was encroaching on their own M-series cameras, Olympus complied and renamed its new camera OM-1, then went on to make camera history with this small and lightweight SLR and its successors (various iterations of the OM-1/2/4/10/20/30). Decades later, Olympus re-used the OM name in its OM-D (OM Digital) series of mirrorless digital cameras, subsequently renamed E-M. Perhaps Olympus' E‑M (Electronic M) name was a link-back to the original M-1 name, and at the same time to the E-series, the Olympus DSLR system cameras. It is no accident that the new OM System flagship camera is called OM‑1. It is a statement that this is a new start, as well as a return to the original spirit of the OM series.
From specifications, reviews, and my experience with the camera, it appears that the OM-1 incorporates several innovations that Olympus designers wanted to introduce, while remaining true to the essence of the original OM-1 and of the Micro 4/3 system. Perhaps, the JIP leadership's lack of significant experience in the camera business is a good thing, in the sense that they left the former Olympus designers free to implement the ideas that had been stymied for years by their previous management.
As for me, the E-M1 Mark III was such a disappointment that I never upgraded to it. The E-M1X is too large for me to look at it twice. An important part of my decision, almost two decades ago, to switch from DSLRs to Micro 4/3 was the physical size advantage of Micro 4/3 cameras and lenses. Besides, both the E-M1X and E-M1 III use the same sensor as the E-M1 II, so the basic image quality cannot be much different from the one I already had.
A further, unsatisfactory peculiarity of the E-M1 III and E-M1X is that neither model has a full complement of features. For example, the E-M1X has Subject Tracking, but not the E-M1 III (in spite of the latter using one-generation newer processors). On the other hand, just to remain within AF-related features, the E-M1 III did get Starry Sky AF as a firmware update, but in the E-M1X this update is said not to be possible, because its graphic processors lack some required hardware functions. Why did Olympus expect buyers to choose among two different set of features, without being able to have one camera with the full complement of features? The whole idea of a flagship camera model is that a buyer gets everything and the kitchen sink in terms of firmware functionality, none barred among what is currently available. So why didn't Olympus provide one real flagship model, and instead two almost-flagship models with different and incomplete sets of features? Perhaps the plan was to introduce a successor to the E-M1X, but Olympus never got around to it (which in itself was a good thing in my opinion).
I cannot shake the impression that someone high up on the Olympus command chain decided the release of the E-M1 III just to show customers that Olympus cameras were not a dead end, but without giving the imaging division a sufficent mandate and resources to do a good job of it, and on the contrary intentionally crippled the E-M1 III features in order to prevent this model from competing in all respects with the supposedly flagship E-M1X.
The OM-1, on the other hand, is only slightly larger and heavier than the Mark II (599 vs. 574 g), uses two image processors like all E-M1 models after the Mark I (albeit much faster than in any of those models), and as far as I know has inherited or bettered all features of both the E-M1X and E-M1 III, including e.g. multi-shot live ND and subject tracking. The OM-1 also adds a new sensor and viewfinder. In particular, for the first time since I switched to mirrorless, when looking through the OM-1 viewfinder I have the same feel of looking through the optical viewfinder of a DLSR, without the color-shifts, delays and lower resolution associated with a relayed electronic image. In retrospect, my decision to hold back on the E-M1 III and E-M1X was fully vindicated.
Pixel count and light gathering of Micro 4/3 sensors
The "limited" pixel count of Micro 4/3 cameras (around 20 Mpixel for the past six years) is often presented as an argument for preferring cameras with larger sensors and a higher pixel count, usually full-frame (24 x 36 mm). I own and use both Micro 4/3 and full-frame cameras, the latter up to 42 Mpixel. First of all, let me state the obvious: A 42 Mpixel sensor is useless without lenses and camera-handling technique that match the sensor resolution.
Full-frame lenses capable of 42 Mpixel resolution are not cheap. When shooting with long telephoto lenses, full-frame requires a focal length about twice as long as Micro 4/3 in order to record a similar field of view. Thus, a Micro 4/3 photographer carries in the field a 300 mm f/4 in a 2.5 Kg backpack (easily carried for a whole day), and shoots hand-held in normal illumination conditions. This lens focuses as close as 1.2 m and provides a 0.24x subject magnification, well into close-up photography. Meanwhile, a full-frame photographer, to achieve the same field of view and exposure time, must carry a 600 mm f/4 (in the best case, three times the weight of the 300 mm) in a heavy backpack, and in most cases a suitably large tripod because shooting with the 600 mm hand-held or on a monopod is physically too taxing. This 600 mm typically focuses only as close as 4.5m, and the minimum field of view is 3.2 times wider. The 600 mm lens also costs multiple times more than the 300 mm. However, let's ignore these key factors in the following discussion.
Aside from printing poster-sized images that must be viewed at close range, or cropping away three-quarters of the image area in post-processing, I cannot really see practical uses for an actual image resolution exceeding about 20-25 Mpixel. 20 Mpixel, with high-quality lenses and good technique, provides far more image detail than required by 95% of the commercial uses of images. Additionally, for much of the remaining 5% of uses, sensor-shift multi-exposure techniques can effectively quadruple the pixel count (with static subjects), and AI-based post-processing resolution enhancements are beginning to produce convincing results. Therefore, I do not agree that a Micro 4/3 camera of good quality, like the OM-1, is intrinsically inadequate as a professional tool because of its "low" sensor pixel count.
Much has been written about the light-gathering properties of sensors of different sizes. Apparently, this discussion cannot be avoided while considering the purchase of a Micro 4/3 camera, so we can just as well get on with it. It is often stated that a larger sensor with the same number of pixels collects more light per pixel, which in turn provides a better signal-to-noise ratio in low light and dark portions of the image. Much as the above seems obvious, I am going to argue that this is not always true.
In this discussion, one must be careful not to compare apples and oranges (and this mistake is easily made when comparing sensors of different sizes). Therefore, we should start by comparing sensors of different sizes, but with a comparable pixel count. Needless to say, a full-frame sensor with a very high pixel count gives away any advantage of the larger sensor in low light, if the absolute pixel size is the same as on a Micro 4/3 sensor.
Let's therefore assume only a 20 Mpixel sensor resolution and Bayer sensors in the following discussion. The OM-1 quad-pixel structure notwithstanding, this camera does use, basically, a 20 Mpixel Bayer sensor (see below). We should also compare sensors designed and produced at roughly the same time. It would be unfair to compare a modern camera with a 17 year old Nikon D70s. We should also compare sensors at the same ISO. We can assume ISO 200, since this is the most common base sensitivity for the sensor of a system camera.
Subject at infinity
Let's examine first the light-gathering properties of a camera for a subject located at infinity (or at a distance equal to several times the lens focal length).
At the same lens aperture (let's say f/2.8) and in the conditions outlined above, the intensity of the light reaching the sensor, as well as the exposure time for a given scene, are the same regardless of sensor size and lens focal length. Intensity expresses the number of photons per unit of sensor area (not per pixel) and per unit of time. Thus, the larger area of a full-frame sensor receives four times the number of photons as a Micro 4/3 sensor. At the same sensor pixel count, the same difference applies to the light received by an individual pixel on either sensor: The physically larger pixel collects more photons than the smaller one. This may make a difference (although it is not necessarily visible in average shooting conditions), and requires a further discussion.
ISO and noise
I will assume that the electron well underneath a sensor photodiode is properly sized to receive the number of electrons collected by the photodiode during a normal exposure. This is a reasonable expectation. Therefore, an electron well in a full-frame sensor should be able to contain four times the number of electrons as an electron well in a Micro 4/3 sensor.
The quantum efficiency (i.e. the portion of photons converted to electrons) is 95% in green light for very high-quality sensors, and not far from 90% in consumer cameras. No significant differences in quantum efficiency should be expected among different modern consumer cameras and different sensor sizes.
A large number of electrons collecting in an electron well will eventually prevent additional electrons from entering the well (electrons repel each other, so the more electrons in a limited space, the higher the "pressure" that must be overcome to store additional electrons). When no more electrons can be added, the brightest portions of the image turn into white or a uniform color, and no image information can be recovered from them. This phenomenon is called saturation or clipping. In principle, saturation may occur also in the post-processing pipeline, but this is not likely if the camera electronics are properly designed, and ISO, contrast and exposure are properly set. In real-world photography, saturation is most likely to happen in the electron wells and in the brightest portions of an image.
The electronics used to read the electrons from an electron well and convert their number to an analog signal first, and subsequently to convert the latter to a digital value, are quite efficient and their noise is low. Typically, most of the noise accumulates in the electron well, and is caused e.g. by thermal noise (which increases with temperature), current leaks in the photodiode and well (which increase with exposure time), noise added in the pipeline transporting the electron charges from the wells to an analog to digital converter (ADC), and in the ADC itself. Once the signal is in digital format, it is essentially immune to further noise.
The discrete number of electrons contained in an electron well is, in itself, a stochastic source of noise. When this number decreases, the error grows bigger. For example, an electron well may contain 9 or 10 electrons, but not 9.5. Therefore, the signal read from this charge may intrinsically be off by up to ±5%, even in the absence of all other noise sources mentioned above. In adition, the distribution of photons on the surface of the sensor is not homogeneous but varies stochastically, especially at low photon counts, which increases the total error. Thus, even with a subject completely featureless and illuminated as evenly as possible, adjacent electron wells may contain a significantly different number of photons at the end of the exposure.
All the above means that a digital camera with a physically larger sensor, in the conditions set out at the beginning of this section, indeed records a higher number of photons, and therefore an image comparatively less noisy at low illumination and high ISO. In the prevalent, "normal" illumination conditions and low ISO, however, the intrinsic difference caused by sensor size affects image quality only slightly, or not enough to be visually detectable.
Subject in close-up and macro photography
In close-up and macro photography, the photographer usually selects a specific field of view, then frames and focuses the desired field of view before shooting. In this case, at the same effective aperture and exposure time, the sensor collects the same number of photons regardless of sensor size.
A factor that changes with sensor size is the magnification required to produce a given field of view. A smaller sensor requires a lower magnification to record the same field of view. While a full-frame camera requires shooting at 1x to record a field of view of 24 x 36 mm, a Micro 4/3 camera can do the same at 0.5x (allowing for minor differences caused by the different aspect ratio). Ignoring the effects of lens pupil ratio, when shooting at 0.5x the effective aperture is 1 stop slower than the nominal aperture (i.e. the aperture at infinity focus), while at 1x it is 2 stops slower. Thus, the smaller sensor can be said to have a modest 1-stop light-collecting advantage at the same nominal lens aperture and field of view, in the sense that it needs only half the exposure time to reach a proper exposure.
Diffraction on sensor pixels?
I remember reading somewhere, as an early criticism against Micro 4/3 cameras, that the pixels on their sensor, being physically smaller than in full-frame cameras, are subjected to a higher extent to diffraction taking place on the sensor, which reduces the actual image resolution. I have been unable to find again the source of this argumentation.
Individual pixels on a 20 Mpixel Micro 4/3 camera are arranged in a square raster with cell sizes of 3.47 μm, which is more than six times the wavelength of green light (0.55 μm). Microscopists know well that the smallest detail resolvable with a conventional optical microscope is half the wavelength of light (0.275 μm in this case). Therefore, diffraction on the sensor is negligible. It would take a really tiny sensor and/or an extremely high pixel count to run into this type of problem.
Physical camera appearance
As mentioned above, the OM-1 is still branded OLYMPUS on the front of the viewfinder (but there is no branding on the rear of the LCD screen, unlike in Olympus-made models). On the other hand, the image EXIF metadata identifies the camera maker as OM Digital Solutions. A small tag near the bottom right of the lens mount says OM System, and so does the plastic cap covering the lens mount, the battery, the USB power brick, and the SD card once it has been formatted in the camera. The camera strap is branded OLYMPUS OM SYSTEM OM-1, and a label at the rear of the camera, normally hidden under the LCD screen, says OM Digital Solutions Corporation. The OM-1 identifies itself as buildroot when connecting to a WiFi router. These inconsistencies in brand profiling are rather unusual in the camera business.
It is obvious that the external appearance of the OM-1 inherits several elements from the E-M1X. Compared to the E-M1 II, the front and rear dials are no longer at the top of the camera, and leave the top of the camera much less crowded than in the E-M1 II, in spite of the moderately larger mode dial. Both front and rear dials are now sunk into the body and no longer operable with two fingers. I also use two models of Sony Alpha cameras, which have dials very similar to the OM-1, so for me this change is a good thing. The top of the power switch mount, with its two buttons, is concave (versus flat in all Olympus models) and more difficult to operate accidentally.
The power lever itself is shorter but thicker than in the E-M1 II, with a more positive "click" feeling like in the EM-1X, but angled more unobtrusively to the right than to the rear like in the E-M1X. The three buttons on top of the power lever of the E-M1X are thankfully reduced to two in the OM-1, like in the E-M1 I/II/III.
The shutter button has been more clearly separated from other controls. It is also more flush with the surrounding surface and more difficult to trip accidentally by brushing against the camera. I am not quite used yet to this style of shutter button, and sometimes I need to fumble before finding it. A better tactile feedback, for example by texturing the button surface, or a ring in relief around the button, might help.
Among other small differences from the E-M1 II, the hot shoe on the OM-1 is no longer black but chrome-plated (like in the E-M1 III and E-M1X), which may conceivably make it easier to locate in low light, and probably is also more durable than the old black enamel.
The eye sensor for switching betwen LCD screen and viewfinder is placed under the viewfinder, instead of at its right side like in earlier models. As a result, the rubber eyecup now has a different shape.
Menu is the only button that has substantially moved with respect to the E-M1 II. The new position is similar to the Menu button of my Sony Alpha cameras, and of the E-M1 III (but not the E-M1X, which strangely exiled the Menu button to the bottom left of the camera rear). Most buttons on the rear of the camera are smaller in the OM-1 than in the E-M1 Mark II.
All cable connectors behind the rubber doors on the left and right sides of the body have remained the same, but the OM-1 comes with a lightly-built strain reliever than screws to the connector plate, keeps the rubber door open, and houses the USB and video connectors. Some third-party video cables have a connector shell too large to fit into the strain reliever, and the camera does not come with a video cable.
The handle is slightly larger than in the E-M1 II and fills the palm of my right hand better. This also means that brackets for the E-M1 II/III do not fit the OM-1. The thicker BX-1 battery, compared to the BH-1 of the Mark II/III/X, means that the door of the OM-1 battery compartment is also significantly larger, which makes it difficult to design a bracket exactly covering the outline of the bottom of the handle. The RRS base plate I use on the Mark II simply does not fit on the OM-1, because of the numerous dissimilarities in shape. For the same reason, the add-on battery handle for earlier Olympus cameras cannot be used on the OM-1 (the electronics and battery are incompatible, anyway).
Third-party accessory makers like RRS and Smallrig (see below) initially solved these problems by cutting off entirely the rightmost portion of the bottom plate. The unfortunate consequence is that, with the plates designed so far, the little finger of most male photographers is left partly floating in the air, unable to grip the handle. My hands are only medium-sized, and the handle of the OM-1, larger than in previous cameras, allows me to use most of my little finger, but not in a comfortable way. As a past user of the Japanese katana, I know full well the importance of the left little finger in holding and controlling a two-handed sword, and holding a camera similarly becomes much more comfortable when the right little finger can be used.
On their web page for the BOM-1 bracket, RRS silently replaced the picture of their prototype OM-1 base plate, with chopped-off right side, with a completely redesigned model that covers the entire base of the camera. At the time of writing, they only accept pre-orders.
Unlike in the past, manufacturers of camera plates and brackets seem to have little to no interest in producing a model for the OM-1. In fact, the only thing I found available online for the OM-1 is the Smallrig Cage. It is not a bracket or plate, it does not provide a gripping point for the little finger, and it is designed as a small and lightweight video cage, but at least it is available today and reasonably priced. The numerous attachment points are potentially useful for electronic flash and other equipment, especially in field macro photography, and the cage does not block access to the cable sockets on the left side of the camera (but the cable strain reliever that comes with the OM-1 is not compatibe with this cage). It also allows the articulated LCD screen to fully open (at least if no cables are plugged into the left side sockets). One more problem is that the rail on the left side of the cage is a NATO gun rail, not Arca-compatible (only the bottom plate is), so you need to attach an Arca plate to the left rail if you want to mount the camera in portrait orientation on a tripod head.
Controls layout and camera shape
The E-M1 Mark III is so similar to the Mark II that the only significant differences in external appearance are the addition of the 8-way joystick and a minor reshuffling of the buttons. The OM-1 inherits the joystick and button layout from the Mark III (like the E-M1X mostly did). The OM-1 does look thicker and more rectangular than the E-M1 II/III, especially when looking at the base of the camera. The more squarish frame of the viewfinder also contributes to this impression, together with the new location of the eye proximity sensor. It appears that most of the increase in volume of the OM-1 was achieved by "filling up" the corners and oblique surfaces of the preceding models and making the OM-1 surfaces more orthogonal. However, the OM-1 is only 19 g heavier than the Mark II, so the impression of solidity and larger volume of the OM-1 is, largely, just an impression.
The menu system is an important part of both the appearance and ergonomics of a digital camera. The unusually large number of settings and functions of the OM-1 has been arranged in a redesigned menu that moves the top-level tabs from the left side of the LCD screen in previous cameras to the top of the screen in the OM-1. These tabs are not very different than in past models, but they tell a little better what settings one can expect to find in each tab: Camera1, Camera2, AF, Movie, Playback, Gear, Wrench and My. A new thing is that each tab is color-coded in pastel colors. Each tab contains a number of pages, color-coded in the same color scheme. The title of each page tries to describe what types of settings are contained in the page, although not all page titles are successful in their aim.
One scrolls from tab to tab with the front dial, and from page to page with with the rear dial or with the left and right buttons of the 5-way selector. The menu wraps around automatically to the next or previous tab at either end of the page range of the current tab. The menu also wraps around from the last tab to the first one, or vice versa.
Each page displays all the settings available on the page. There are no hidden lines beyond the top or bottom of a page, that in previous cameras had to be brough into view by scrolling vertically. The up and down buttons of the arrow pad move between rows in the current page. The joystick also scrolls horizontally from page to page and vertically from line to line.
The center button (OK) of the arrow pad is used to move deeper into the menus and to accept choices. The Menu button brings the user one level up, or out of the menu. The INFO button often, but not always, displays a brief help on the current item.
Super Control Panel (SCP)
While in live view mode, by default pressing OK displays the SCP, like in previous models. This is the fastest way to access many of the commonly used shooting settings, including several that have no dedicated physical controls. In the Mark II, when I need to change a setting I go to the SCP first, and afterwards dive into the menu if I cannot find what I am looking for in the SCP.
In the OM-1, the SCP has been re-designed to use a larger portion of the LCD screen area (right to the screen edge on the sides and bottom) and to display a smaller number of settings (by default 22, compared to 29 in the Mark II) with thinner lines separating adjacent settings. As a whole, the SCP of the OM-1 feels more readable and much less crowded. In the Mark II, the SCP is further crowded by the wide unused margins between the sides of the SCP and the LCD screen edge, and of the bottom of the screen being occupied by a row of read-only settings (largely duplicates of the settings are also visible in the Live View screen overlays). As a whole, the SCP in the Mark II feels too crammed with settings to be reliably operated via the touch-screen, although in practical use this proves to be more of an impression than a real problem.
The most important improvements of the OM-1 over the E-M1 Mark II, in my opinion:
The sensor consists in practice of two chips separately manufactured, attached on top of each other and communicating directly with each other through multiple, physically very short and very fast pipelines. The top layer converts photons to electrons and stores the latter in electron wells, while the bottom layer quickly reads the electrons at the end of the exposure, strongly reducing the rolling-shutter problems, and does additional data processing before sending the picture data to the image processors on the motherboard.
The four, individually readable sub-pixels of each pixel open up several interesting possibilities, besides AF. The sheer number of subpixels does not slow down the reading of image data from the top to the bottom layer of the sensor, since the reading speed is much faster than in earlier cameras. In practice, reading the 80 million sub-pixels in the OM-1 takes half the time required to read 20 million pixels in the fastest earlier cameras.
The fully electronic shutter, called Silent (with its various modes) in the menu, is getting better and better in each new camera model. It is still not as good as a global electronic shutter, but the electromechanical shutter is not as good as a global electronic shutter, either, and has already been optimized to such an extent that further improvements become harder and harder to implement. The performance gap between electronic and electromechanical shutter is getting smaller and smaller, and in the OM-1 we are not far from the difference becoming irrelevant in most practical uses. With the OM-1, I find myself successfully using the silent shutter in many situations in which, with older cameras, I was forced to use the electromechanical shutter. The OM-1 also continues the Olympus tradition of allowing the use of the electronic shutter with electronic flash (several current and recent cameras, especially the Sony Alpha, still don't), and halved its sync speed with electronic shutter with respect to the Mark II.
The statement, sometimes found on the web, that silent shutter still produces an audible mechanical sound (of low intensity) is fully correct, and applies to the OM‑1 as well. There are two sources of sound when using the silent shutter.
The image processor is version 10, or in full a TruePic X Quad Core Processor. The OM-1 uses two processors (like all E-M1 models after the Mark I), but each flagship camera model has used a newer generation of processors, and each generation has been substantially more powerful than the preceding one. Note that the processors of the E-M1X are two generations older than those of the OM-1. We should expect to see new, creative camera functions added in future firmware releases, just in the same way as Olympus was releasing new functions in the free firmware updates of current cameras, that subsequently were incorporated and improved in newer cameras once extensively field-tested on the current models.
Additional AF information is derived from normal sensor pixels (apparently by processing the differential information from the 4 photodiodes composing each pixel) in a region of the sensor surrounding the active AF point. This increases the reliability of subject tracking and other AF-related functions.
AF is much faster and more accurate than in earlier camera models, including the E-M1X.
Computational imaging and subject tracking
Up to ND64 (6 stops) electronic neutral density filter. Several other enhancements of the computational imaging methods and AF processing, e.g. the use of image stabilization while shooting live composites, and subject-tracking AF on trains, cars, planes, helicopters, birds and pets (the subject category, however, must be manually chosen). Face and eye AF are also improved, but still cannot be used simultaneously with subject tracking. Although most of these capabilities were introduced in the E-M1X or E-M1 III, they are faster and more reliable in the OM-1.
Live Composite has a Lighten Composite sub-mode, which uses multiple-exposure sequences to increase the brightness of bright subject areas (e.g. individual stars), while not washing-out dark backgrounds (the surrounding sky). This is usable also hand-held.
In-camera focus stacking is faster than in earlier camera models.
I tested Subject Tracking with stationary or swimming birds with the Olympus 300 mm f/4 Pro and the Olympus MC-20 2x focal length multiplier, and found that this feature dramatically increases the number of keepers even in difficult light conditions. The only situation when Subject Tracking in bird mode is problematic when shooting single pictures (not sequences) in C-AF mode with multiple birds present in the frame, e.g. a group of swimming ducks or geese with individuals at slightly different distances from the camera. In these conditions, the subject is not tracked from shot to shot, and at each shutter tripping the Subject Tracking algorithm randomly chooses a bird (usually not the bird it had focused on in the preceding shot) and refocuses on it. Apparently, minor differences in head orientation and visibility of the eyes make the algorithm decide that it is better to choose another bird.
The easiest solution is of course shooting a sequence in C-AF, which ensures that the subject is followed from frame to frame (unless the tracking algorithm "loses" it, e.g. because the subject passes behind an obstacle or turns in such a way as to become unrecognizable - most often because its eyes are no longer visible). Once back in the studio, you will then need to select the best shots out of each sequence. SD cards are cheap these days, the OM-1 RAM picture buffer is large enough (I found mentions of 1.8 GB), I typically save only JPGs instead of RAW, do not find shooting more than 5-10 fps particularly useful, and the OM-1 battery seems to last forever (over 2,000-3,000 shots in silent mode). Perhaps the electronic shutter, which I prefer, uses far less energy than the electromechanical one.
For some reason, the second and/or third shot in each sequence seem to be the ones with focus most often perfectly nailed. I guess what I am seeing is the subject tracking algorithm using some of the information from the first recorded image of each sequence to predictively refine the AF before the following shot. If so, this is one more reason for shooting short sequences instead of individual images.
Photography with Auto ISO in M mode (where aperture and exposure time are manually set, and the camera automatically adjusts ISO) is one of the combinations of settings I initially did not have much success with. I used the settings recommended by Keith Wallach for bird photography on the Olympus learning site (except for the fastest lens aperture unavoidably being f/8 with the 300 mm and MC-20). In conditions of relatively low light (mid-day cloudy sky) it produced unpredictable results depending on the scene, exposing some scenes correctly, and underexposing other scenes by a good 2-3 stops. The above picture, for example, required a substantial application of Curves in Photoshop to become usable. Other than this, I applied no post-processing. Post-processing this image with modern AI-based noise reduction does substantially improve this image beyond what is possible with in-camera adjustments, but I do not show the results here because we are only discussing the camera itself.
It turned out that my misunderstanding was simple: Auto ISO is configured in two different places, i.e. Camera 1 > ISO-A Upper/Default > Upper Limit > 12800 and Camera 1 > ISO-A Upper/Default > Default > 200 for the upper and lower limits, respectively, and then for example in SCP set the ISO to ISO Auto *** (the actual value displayed depends on light conditions). The ISO Auto *** setting is located between the highest "hard" ISO value (ISO 102400 by default) and the wrap-around lowest "hard" value of ISO L80.
Birds in flight
I have not tested the OM-1 on birds in flight to the same extent as on stationary birds. However, with the same Auto ISO and bird tracking settings discussed above for stationary birds, I have noticed that the percentage of keepers is much higher than with the Mark II (which has no subject tracking). I find the 300 mm with the 2x TC-20 teleconverter too difficult to use for birds in flight without the EE-1 red dot sight. The main problems are initially locating the subject in the viewfinder, and then keeping it in the viewfinder while panning to follow its turns and dives. On the other hand, I find it much easier than I expected to track a flying bird with the 300 mm and 1.4x TC-14 teleconverter (keep in mind that the latter combination is equivalent, in field of view, to an 840 mm full-frame super telephoto, so your success in tracking a bird in flight while hand-holding may differ from mine). In either case, the success rate greatly increases when allowing for a wide margin around the subject, followed by cropping in post-processing.
Of course, subject motion is a much bigger problem than with stationary birds, and IS cannot completely stabilize the camera while the photographer keeps panning in different directions to try and follow the unpredictable changes in direction of the subject. Nonetheless, it is still possible to shoot birds in flight at ISO 200 in sunlight, as the above example shows. This particular subject had taken flight from the water surface less than one second earlier, as shown by the water droplets surrounding it, and I managed to capture it only thanks to the wide margin allowance surrounding its original position on the water surface.
The main "secret" with birds in flight is shooting relatively short sequences, and lots of them. Eventually, you will get a few images than will make your day. The OM-1 cannot increase your artistic skills, or improve your panning reflexes, but will help you by substantially increasing your keeper rate.
Viewfinder and LCD screen
The OLED viewfinder has twice the resolution of earlier models and refreshes at 120 fps. The 1600 x 1200 pixel resolution (5.76 Mpixel) is better than HD, and the delay only 5 ms. Up to a 0.83x magnification is available, depending on the viewing mode.
The LCD touchscreen has a 1.62 Mpixel resolution (1.04 Mpixel in earlier models). In spite of the relatively low resolution, its active area of 63 x 42 mm provides all the detail one can actually see by naked eye. As a whole, if you use the viewfinder, the amount of visible detail is noticeably higher.
In the past, the LCD screen traditionally used to have a better resolution than the electronic viewfinder. This situation gradually improved over the years, with the viewfinder getting better and faster in the top camera models. With the OM-1, the viewfinder has now exceeded the LCD screen in all respects. As I mentioned above, this electronic viewfinder looks and feels like the "real image" provided by an optical viewfinder. It's that good.
As mentioned above, four banks of custom settings are available, and can be recalled by setting the mode dial to C1…C4. The OM-1 Quick Guide suggests the following uses, although you do not need to follow them, nor the specific settings suggested for each mode:
C1 - Birds in flight
On the other hand, there is no way that I know of to assign a displayable name, or description, to each of these modes.
Battery and charger
In-camera battery charging is not an option. The camera comes with one BLX-1 battery, but no external charger. On the other hand, the USB brick supplied with the camera can simultaneously charge the battery while you use the camera. This USB brick is specified to provide 5 VDC 3 A and 9 VDC 3 A. An ordinary USB 5 V power bank cannot do both things simultaneously, although it does appear to be recharging the battery also when the camera is in use (most likely, not as fast as the battery is being depleted by using the camera, but still better than no charging at all). Carrying one or more spare BLX-1 would be optimal, but if the cost of a genuine BLX-1 gives you pause, and you prefer not to risk using a third-party cheapo BLX-1 lookalike in your OM-1, you might consider the power-bank solution, at least as a stop-gap measure.
If the OM-1 is connected to a USB 3 port on a computer, for example to use the OM Desktop or OM Capture apps, the battery still seems to recharge, albeit more slowly. Typically it cannot use the USB power to simultaneously operate the camera. However, the orange LED on the OM-1 is lighted (with both the camera off and on), and I do expect that even the limited charging current available through an ordinary USB port helps to increase the time the camera can be used before a full battery recharge is needed.
If you do need a separate BLX-1 charger, there is a remarkably expensive kit of one BLX-1 battery, plus an external charger that takes two batteries at a time. There is also a large number of third-party batteries and chargers that purport to be compatible with the OM-1. Some are very cheap, others only moderately cheaper than the genuine BLX-1 (and prices for apparently identical third-party batteries vary by almost one order of magnitude among end-sellers). I am somewhat skeptical of many of these claims of compatibility, given my past experience with third-party camera batteries leaking, overheating, swelling up and/or rapidly losing their charge if left unused. In particular, I strongly recommend against recharging third-party batteries in the camera - if you have no choice but using these batteries, charge them in their own chargers.
I found a statement on the web, repeated by a few sources, that the OM-1 can also use the BLH-1 battery from the E-M1 II/III/X. This is not true. The BLH-1 simply does not fit in the OM-1, and the BLX-1 does not fit in any of the earlier cameras. The OM System designers have made sure of it. The battery contacts look similar, but all three dimensions of the battery envelope differ between the two battery types.
I recently wished to connect my E-M1 II to the home WiFi in order to make use of the OM Capture and OM Workspace software to immediately transfer images from the camera to a PC without a physical tether betwen camera and PC and without swapping SD cards. No luck, the E-M1 II cannot do the simple task of connecting by WiFi to a home network. It only allows a one-to-one private WiFi network with a phone or tablet running a special Olympus app, and the OM Capture app for Windows complains loudly that it cannot pair with this camera by WiFi - only by USB.
This limitation, and the promise of a less restricted WiFi connectivity on the OM-1, became an aditional reason to purchase this camera a few months earlier than I was planning. In fact, configuring the OM-1 to use my WiFi access point was easy and problem-free. When you need to connect the camera to your PC via WiFi, you need first to start the WiFi on the camera ( > 6.WiFi/Bluetooth > WiFi Connection > PC Connection), then start OM Capture on the PC. The rest is pretty much automatic after the initial configuration.
As mentioned above, the OM-1 automatically identifies itself to a WiFi router as buildroot. Why not OM-1, which would seem far more logical? Probably a developer forgot to update the host name before releasing the final version of the firmware. The camera gets an IP address assigned from the router's DHCP pool. In virtually all home routers, it is of course possible to manually assign a name and a permanent IP address to the OM-1.
Even the OM-1 cannot do everything I wish in terms of WiFi networking. For example, the camera can transfer images to my PC via WiFi if I shoot with the camera connected via OM Capture or OM Workspace, but that is about all all it does. In particular, pictures I shot without the camera connected to either OM app are not automatically transferred to the PC once I connect the camera and PC. Remotely accessing Live View and controlling the OM-1 from a PC still only works via USB.
I already had a 10 m long USB 2 active cable extension installed between my PC desk and my lab bench, and installed a second, 10 m USB 3 active extension for remotely operating the OM-1 via OM Capture (which also works with the E-M1 II). This setup allows my PC to simultaneously display the Live View, remotely control the camera, and automatically transfer the pictures (with OM Capture via USB 3), and operate the Stackshot controller (with Zerene Stacker via USB 2). Importantly, the double USB cable avoids using an external USB hub, or a USB to WiFi media converter, which often is fraught with problems.
Price, availability and competition
At a recommended EU price of 2,199 € (body only), this is not a cheap camera. On the other hand, it is only about 15% more expensive than the E-M1 Mark II was at the time of its release in 2016. The OM-1 is a few hundred € cheaper than the E-M1X at the time of its release in 2019.
Getting hold of an OM-1, on the other hand, may not be a given. According to 4/3 Rumors, in April 2022 OM System announced that the unanticipated high demand for the OM-1 was causing a shortage of parts, in turn forcing a production speed insufficient to satisfy the demand. In late August 2022, I decided to jump the gun for a number of reasons (among them, only one OM-1 body-only was left available on Amazon in the EU at the list price), and managed to snag it. In early September, more body-only OM-1 became available, but their number is not high, and they seem to sell like hot cakes. Predictably, some Amazon sellers are taking advantage of this by marking up their OM-1 prices by 20-25% above the list price.
It is easier to find OM-1 kits with the 12-40 mm f/2.8 Pro II than body-only. However, I already have the first version of this lens, and the only difference is that the new version has a slightly updated weather sealing, not because it needed improvement, but just to obtain a better weather sealing certification for the camera itself.
As for alternatives, Olympus has always had an edge on Panasonic Micro 4/3 in still imaging, and the OM-1 is no exception. Against Olympus-branded Micro 4/3 cameras, the OM-1 wins hands down. If you want to find real competitors to the OM-1, you need to consider the flagship full-frame mirrorless models of Nikon, Canon and Sony. They actually belong in a different class than the OM-1, and their prices are substantially higher (not to speak of the price of a full-frame super-telephoto lens with the same reach of the OM System 300 mm f/4 Pro or 150-400 f/4.5 Pro).
How practical is it to use an OM-1 and an E-M1 Mark II together?
Using the E-M1 Mark II as a second body, together with an OM-1, requires a double set of certain accessories, not compatible with both cameras:
Most modern laptops are powered and recharged with a USB C AC adapter. There seem to be multiple, incompatible types of USB C chargers, so before attempting to recharge your OM-1 with your laptop AC adapter, make sure you know for a fact that the latter is not going to destroy the camera. Just because the laptop AC adapter has the same USB C connector as the OM-1 power brick, it is no guarantee that the voltages are also the same.
Should you sell your E-M1 Mark II/III?
For a professional photographer, having two identical camera bodies makes perfect sense, and in this case the most reasonable decision is buying two OM-1 bodies and selling older cameras. Quite a few advanced amateur photographers are likely to buy an OM-1, and in their case the question presents itself of what to do with one's older camera(s). For amateur photographers who don't need to sell an older camera in order to finance a new OM-1, buying a single OM-1 and keeping an older camera as a second body can be a reasonable choice.
If you are an amateur photographer with a newly-purchased OM-1, find the idea of having two bodies desirable, and already own an E-M1 Mark II/III, then I believe it is not immediately necessary for you to replace the latter with a second OM-1. The E-M1 II and III are capable cameras even by current standards, and unless you absolutely must use some of the new OM-1 features on both bodies, an E-M1 II/III as a second body will give you, in most "normal" photography situations, essentially the same image quality. Eventually, you might decide that you need a second OM-1, or perhaps a new camera will come out that makes an even better sense to upgrade to, but you don't need to decide in a hurry.
My situation is probably not typical among amateur photographers. I use digital cameras for generic nature photography, some birding and field macro, quite a lot of photomacrography and focus stacking in the lab, as well as photomicrography with a compound microscope. For these reasons, a single camera, or even two cameras, are not quite enough. Physically switching a camera between different devices is time-consuming, and even with separate banks of custom settings the process of reconfiguring a camera for each device is time-consuming and error-prone.
I use both Micro 4/3 and full frame cameras, of course with different lenses. In addition, one camera of each format is converted to full-spectrum imaging. For these reasons, my new OM-1 is not going to immediately replace any of my present cameras. If I had to choose, my E-M1 Mark I would be the first camera to get rid of, but at present it sits permanently mounted and ready-to-use onto a lab microscope, where it is perfectly adequate (not to mention that the second-hand value of a Mark I is quite too low to go through the hassle of selling it).
The OM-1 is a substantial improvement on the E-M1 II/III and X. In particular, the OM-1 substantially improves on the E-M1X, in a package of practically the same size and weight as the E-M1 II/III, and a price just 150 € higher than the E-M1X current price. At times it can be difficult to find an OM-1 at a non-inflated price, in part because of the much higher demand than anticipated by OM System. The price of the OM-1 is relatively high in a Micro 4/3 context, but definitely low when compared with full-frame flagship mirrorless cameras of other brands.