It’s the start of a new dawn as Olympus transitions into OM System and the brand’s first camera is a brand new flagship model called the OM-1. It’s release comes almost exactly two years after the launch of the E-M1 Mark III. But what are the key differences between the two cameras and which is right for your photography? We’re taking a deep dive into the specifications sheets to highlight the changes, improvements and upgrade on offer to help you make an informed decision…

One – Sensor design:
As you may suspect, the new OM-1 stays true to the Micro-Four-Thirds sensor that served Olympus so well and will continue to serve OM System well. Maybe surprisingly, the resolution count from the 17.4x13mm sensor stays at 20-megapixels, just like the older E-M1 Mark III but the new model features a key difference. While the older camera uses a standard CMOS sensor, the OM-1 uses a back-illuminated stacked sensor, which should return much higher image quality, particularly in lower light situations.
Two – Focus Points:
Many people who consider both the E-M1 Mark III and the OM-1 will be interested in capturing fast action photography. To boost your chances of capturing a sharp image, the higher the AF point count, the better. While the EM-1 Mark III returns a good offering of 121 (all cross-type) points, this figure is simply blown away by the new OM-1, which offers photographers 1053 AF points spread over the sensor – all of which are the more sensitive cross type, which deliver an amazing autofocus experience.

Three – Burst rate:
In sports and wildlife photography, every split second counts and if you have a slow camera, it may well mean that you miss that crucial moment. The E-M1 Mark III is an incredibly fast camera and is capable of offering a maximum burst rate of 60 frames per second. This should be more than enough for the everyday action photographer. However, the OM-1 takes things to a whole new level and offers a max burst rate of 120 frames per second. This is a mind blowing figure, meaning photographers using the OM-1 can shoot stills faster than some cameras can shoot video – wow!
Four – Battery life:
One of the common bugbears about mirrorless cameras in the early days was the battery capacity or rather the lack of battery in comparison to DSLR alternatives that typically boast much higher capacities. Well, the OM-1 does deliver an improvement to this area. While the E-M1 Mark III could offer 420 shots on a single charge, the OM-1 increases this figure to 520, However, this doesn’t tell the full story – these figures are just CIPA ratings – in reality, photographers are going to be able to shoot far more imagery on a single charge and there’s always the option of adding in an additional battery grip.

Five – EVF and LCD:
Mirrorless cameras offer two ways to compose a scene; either by using the EVF (Electronic Viewfinder) or by lining up the subject using the LCD. Both options have seen big improvements in the OM-1, with the EVF resolution increasing from 2360k dot to 5760k dot. What’s more, while both cameras offer a large 3-inch vari-angle LCD – which is great for lining up awkward high/low compositions – the OM-1’s version is also higher res at 1620k got (up from 1037k dot).

Six – AF Tracking:
Although there’s only an age gap of two years between the models, a lot has changed in 24 months and technology has moved on – particularly in the realm of autofocus. While the E-M1 Mark III offers a very competitive autofocus set-up and includes useful features such as Eye-Detection AF, the OM-1 moves things on even further and introduces next generation features such as Animal Eye AF and Vehicle Tracking AF – both features are designed to make capturing sharp and accurate shots even easier.

Seven – Video limits:
Despite their small size, both cameras are excellent options for recording video. In fact, both cameras can even record high-quality 4K footage and also offer ports for a mic and headphones so enhanced audio can be both captured and monitored. There is a difference in this area however because while the E-M1 Mark III can record video clips up to 30 minutes in length, there is no recording limit on the OM-1. This will come in especially handy if you are filming news, documentary or event films where you will be shooting for an extended period of time.
Eight – Weight and size:
Despite all the new and expanded features in the OM-1, both the cameras are actually fairly similar in scale and payload. The EM-1 Mark III tips the scales at 580g and measures 134 x 91 x 69 mm while in comparison, the newer OM-1 only adds 19g, weighing 599g and measuring only 135 x 92 x 73 mm. Both cameras are small, lightweight and suitable for travel photography thanks to their portable credentials.

Nine – Max ISO:
Thanks to the advances in the sensor and process design, the OM-1 is able to offer a much higher ISO ceiling than the E-M1 Mark III. This will come in handy when shooting in low light conditions – especially when you have no tripod and need to handhold the camera. In fact, while the E-M1 Mark II offers ISO 25600, the OM-1 has a ceiling of ISO 102400 – a huge leap forward.