Using Visual Extinction (MTF0) testing on a 4x ISO 12233 chart at 18 metres, the OM 50-200mm f2.8 with MC20 at 800mm FFE resolves 23 LPI — matching the OM 150-400mm and out-resolving the Sony 200-600mm at 21 LPI when that lens is cropped to reach 800mm. The OM 50-200mm with MC20 at 800mm loses only one LPI unit compared to the bare lens at 300mm, confirming that the 2x teleconverter is not meaningfully degrading resolution.
Across nearly 11,000 shots on Red Kites at Gigrin Farm, the OM 50-200mm f2.8 + MC20 achieved 93% focus accuracy and the OM 150-400mm achieved 92% — both ahead of the Sony 200-600mm at 90%. The Sony 400-800mm scored 98% but from only 808 shots, because at 2.5kg it was impossible to hand-hold for extended periods; the OM 50-200mm, weighing 1.2kg without its tripod collar, generated more than 2,700 analysable shots in the same session.
Testing the OM 50-200mm f2.8 (Little White) and 150-400mm f4.5 (Big White) across multiple sessions, the MC14 teleconverter imposes almost no focus accuracy penalty on the Little White — the combination remained above 90% in conditions where the bare lens achieved 93%. Background type turned out to matter more than ISO: birds against clear sky consistently outperformed the same lens against foliage by a wider margin than raising ISO by two stops.
Long exposure hot pixels are caused by cosmic ray-induced sensor defects that accumulate continuously over the camera’s lifetime — a known phenomenon that affects the OM-1’s smaller pixels more than the Nikon Z7’s larger pixels after several years of use. On1 PhotoRaw 2024 and Lightroom Classic both remove these automatically in post-processing, making in-camera noise reduction unnecessary and halving the time required for 2- to 6-minute exposures.
Testing the 300mm f4 prime against the 150-400mm f4.5 TC (Big White) at matching focal lengths using an ISO 12233 resolution chart at up to 20 metres, the 300mm f4 was unequivocally sharper than the BWL at every focal length, including with the MC-20 attached. More surprisingly, the 40-150mm f2.8 with teleconverters was also as sharp or sharper than the BWL — results that confirmed the smaller, lighter combination was the right choice and that there was no image quality price to pay.
Over two days at the Hawk Conservancy Trust with over 6,000 test shots, the OM-1 achieved 75% focus accuracy in the morning session and 81% in the demanding afternoon session — versus 63% and 39% respectively for the Sony A9 with the 200-600mm, and 61%/45% for the EM1x. The afternoon advantage is the key result: in situations requiring instant focus acquisition on suddenly appearing birds, the lighter OM-1 and 300mm f4 snapped to focus within 2–3 frames while the heavier Sony system frequently missed the window entirely.
The Nikon Z7 has no exposure timer, no live feedback during long exposures, and requires 39 dial clicks to switch from a test shutter speed to bulb mode — three failures that make it extraordinarily frustrating for long exposure work. The OM-1 reaches bulb mode in one dial click, shows a live histogram during the exposure, and in my dark-frame noise tests at ISO 200 equalled or outperformed the Z7 at its base ISO of 64 across exposures of 2, 4, and 6 minutes.
Dark-frame noise tests at 2, 4, and 6-minute exposures showed the OM-1 at ISO 200 producing clean results while the Nikon Z7 at its base ISO of 64 showed luminance spots at 4 minutes and colour noise at 6 minutes. This means the OM-1 needs no in-camera noise reduction for long exposures of this length — halving the time required for every shot compared to older Olympus cameras where NR was essential.
Testing 11,467 shots of Gannets at Bempton Cliffs over two days, the 1.4x teleconverter on the 40-150mm f2.8 caused almost no accuracy penalty — 73% hit rate versus 74% without it, a result that means the 1.4TC can stay on permanently. The same 1.4TC on the 300mm f4 halved the hit rate from 78% to 39%, and a 5-stop reduction in ambient light dropped the 300mm’s solo accuracy from 78% to 60%.
At Bempton Cliffs using ProCapture L and Bird AI tracking together, I took 4,382 shots of Gannets landing in 61 minutes with a 76% focus hit rate — and 12% of those in-focus shots were portfolio-quality landing captures, a result I had never come close to achieving in previous trips without ProCapture. The pre-capture buffer captures the frames before your finger fully presses the shutter, which is the only way to reliably catch a Gannet at the exact moment it drops its feet.
Across four Sony cameras and two copies of the 200-600mm lens, the pattern was consistent: the A7R4 produced 100% out-of-focus shots at Gigrin Farm and 97% out-of-focus at Andover with a replacement lens, while the A9 and A6400 performed better but still fell well short of the Olympus system in demanding conditions. The same autofocus failures appear across all four cameras with both lens copies, ruling out user error or a single defective unit.
Detailed analysis using AFV.exe to check the focus point location for 1,600 A9 shots showed that even when the camera placed a focus point directly on the bird, the resulting image was out of focus 40% of the time — camera error, not user error. The afternoon session hit rate of 39% reflects a genuine limitation in demanding conditions, not the test methodology.
