Autofocus becomes slightly slower with the teleconverters, especially in challenging conditions. Again, in my tests, the Olympus 300mm f/4.0 IS PRO on its own focused on the distant wall in 0.52 seconds on average. With the MC-14, that jumped to 0.72 seconds, and with the MC-20, it took 0.87 seconds on average to focus on the same wall in the same light conditions. This difference was definitely apparent when using the teleconverters in real-world situations, too. I would recommend using them only when the light is plentiful. DC-G9 + M.300mm f/4 + MC-14 @ 420mm, ISO 400, 1/400, f/5.6 In the Field: Wildlife Photography As for the lenses, the Olympus holds its own. It is sharper then both Nikon’s (not surprised by that – all the Olympus pro glass is super sharp. Now, as this is a user experience as opposed to a generic review you won’t find test charts, corner crops and sharpness comparisons. That’s simply not an effective or enjoyable use of Alpha Whiskey’s 24 hours. I don’t have a gear fetish or spend hours fantasising about features on a lens or camera; I simply like to go out and shoot. Other reviewers of this lens have shot copious examples of its sharpness and I won’t have anything original to add. It’s pretty sharp. This is the fabric of a cushion cover at 100% crop at F/4. The surface was not completely flat and depth of field was shallow enough that some parts of the image are out of focus. Jessops kindly replaced the lens three times and eventually got it nearly right. I am not 100% happy with it yet.

Being able to focus so closely, and setting the focus limiter to focus between 1.4m to 4m meant I could capture some dragonflies while waiting for the kingfishers. (My friend Natalia gets full credit for spotting these. That girl has eagle eyes.)I found the 300mm f/4 to performed superbly in low light, a problem often encountered by wildlife photographers, because the f/4 maximum aperture is higher than you’ll usually find at 300mm for the M4/3 system. I found myself able to shoot well after sunset and still handhold my shots. At times, I was shooting at slow speeds between 1/60th and 1/100th and still catching crisp photos. The image stabilization system is definitely working hard. Additionally, when this lens is paired with the newer Olympus bodies like the OM-1, the lens and camera work superbly together with excellent image stabilization and autofocus. The stabilization is most effective when paired with Olympus bodies, where synchronized image stabilization will give you up to 6 stops stabilization. Wildlife photography simply became much easier with a modern lens/camera combo like this. Close Focusing Ability Thanks for review AW! Nice lens/system, but personally I don’t like the rendering of the out of focus areas. It looks too harsh for me. I should add that uploading the lower image to my blog seemed to soften it a bit, the image is actually even sharper than this. That was an interesting article, and I was particularly interested in your size comparisons. This lens isn’t on my wish-list since i don’t usually need that focal length, but I thought that your photographs were very good. In fact, it inspired me run around the house taking pictures of all of our cushions. Just kidding – I really did enjoy seeing your photos.

You’re right in the sense that a 300mm f/4 lens will always be 300mm f/4, regardless of the sensor behind it – but the concept of a crop factor is still useful in practical terms. Nicholas is right that it applies to both focal length and aperture. (It also applies to ISO, but with a [crop factorI wanted to keep the aperture wide to keep the ISO low and depth of field shallow, and thus if the shutter speed wasn’t fast enough I would have to rest the lens onto a surface or crouch down and hold it tight. On some occasions where the subject was moving or there was not enough light under the forest canopy I had to ramp up the shutter speed and swallow the increase in noise. This is one area where larger sensor cameras and their equivalent lens would have an advantage with better performance at higher ISOs allowing a faster shutter speed to be used if so required.

However, keep in mind that crop factors also apply to aperture; so, using this lens is akin to using a 600mm f/8 on full-frame.’The 300mm focal length may not sound very long at first, until you consider the 2x crop factor and high pixel density of Micro Four Thirds – it’s a 600mm full-frame equivalent. However, keep in mind that crop factors also apply to aperture; so, using this lens is akin to using a 600mm f/8 on full-frame. I’m not complaining – that’s simply why this lens is so much smaller, lighter, and less expensive than a full-frame 600mm f/4. DC-G9 + OLYMPUS M.300mm f/4 @ 300mm, ISO 500, 1/200, f/4.0 Performance No, that’s not true. The aperture will be THE SAME. If you measure the exposure trough this lens wide open on any M4/3 camera, and then the same scene with any FF 300 or 600mm lens open to f/4 and mounted on any FF camera – with same ISO you’ll get the same exposure time as on Olympus. Aperture is a physical property of lens, not a sensor. F/4 lens will be always f/4, no matter how big is the sensor inside the camera you’ll mount it on: for example, if I mount my full frame 70-200/2.8 Pentax lens on K-1 II or my APS-C K-3 III – it always will be f/2.8 maximum aperture lens.

The Olympus 300mm f/4.0 IS PRO is a prime lens fixed at 300mm. There are longer options available for Micro Four Thirds that reach up to 400mm. However, the Olympus 300mm f/4.0 IS PRO is so sharp and high performing it feels like it is over 300mm, simply because the increased sharpness allows more cropping compared to the Olympus 100-300mm f/4-5.6 that I previously used.

All these images were shot RAW and converted to JPEGs in Lightroom. Minor adjustments to exposure and white balance were made but not to sharpness. No one could ever accuse Alpha Whiskey of being a gearhead or techie (or even a photographer for that matter), but I obviously appreciate that certain lenses enable one to capture certain subjects with greater ease and accessibility. This lens was ample proof of that. Even with the teleconverter attached I was pleasantly surprised by how much detail could be captured with this lens. An autofocus range switch is located on the side of the lens. It can be switched from 1.4-4m, 1.4m-infinity, and 4m to infinity. This helps limit any autofocus hunting behavior; I found it especially helpful when photographing subjects at close range. There is also an image stabilization switch on the side of the lens, as well as an LN-f function button.