The 600mm lens is about the sweet spot for serious long lens photographers. If you bird, chase field sports, or surfing, even shoot the moon, the 600mm is considered the minimum needed to do professional work, but also not so long that it precludes general use.

What does often limit its use is cost, size and weight. It is simply not an option for many people or situations.

These days, it is easy enough to achieve. There are plenty of zooms available that get there or longer cheaply and with a decent form factor in most formats, many of these are excellent even at quite affordable prices. They are however, not quite “pro”.

The things that make a true pro lens are;

• Weather proofing, because often the best shots come in the worst weather, no excuses.

• Tough build. Same as weather, the best shots are often hard to chase down.

• Compatibility with teleconverters without obvious optical compromise. A top tier lens should still be better with a converter than a zoom of the same reach.

• Premium quality results through the best glass, handling, stabilising and focus.

• Most importantly, decent light gathering. F4 is the benchmark and even though sensors and software are making huge in-roads here, there is still a benefit to having more lens speed. Most cars can do 150kmh, but a true sports car does it more easily, is safer and gets there faster.

In full frame terms this usually means a monster optic with a nice second hand car price tag, but if impressions make a pro, they do double duty.

For most of us, if full frame or a brand that best serves full frame format is your ride, then usually a decent zoom is the best entry point. Something like the excellent Tamron or Sigma 1XX-600 zooms, the top end 80/100-400 branded lenses on a crop body or even a decent shorter prime.

My old “trade secret” was the much missed Canon 400 f5.6L, which gave me over 600mm on a crop body or near enough to it with a 1.4x converter on a full frame. It had all the above benefits except lens speed for decent money and size. When I was shooting with Canon, the slower lens was limiting, but if I had held onto it, it’s ideal “time” is probably now.

After committing to the Olympus and Panasonic M43 twin systems, I lifted my game for sports to the EM1x and wanted a better lens option. I had the 40-150 f2.8, which I luckily managed to purchase back from a friend I had sold it to, but even with the 1.4 tc it was only a 400mm+. The little 75-300 Oly punches above its meagre weight, but lacks most of the other features listed above.

Contenders were the 100-400 Oly, new on the marked and well liked, the Panasonic Leica 200 f2.8 with matched 1.4 tc (560 f4, but also 400 f2.8), but I was aware of possible auto focus compromises on an Olympus body (I feel this was not the issue I had feared, but at the time I had little experience with newer Panasonic on Olympus and did not have a G9) or the 300 f4, a lens I had been aware of for a long time, but had not previously considered due, ironically, to relative price. Even at a decent $2-3000au over its life in the shop, the price was out of my comfort zone at the time.

On the day I went to get the 100-400, the 300 had become an option that very morning. I was walking the dogs and remembered the shop I was going to, the same one I had worked at, had a very early model of the lens that had been there since day one. They had little chance of selling it due to a small market and a niche brand/format (and the plethora of other M43 options), but I had played with it often and it was good.

The crunch time came and I did the most rudimentary of tests comparing the 300 to the 100-400 in shop and even just with a few images taken down the street. I could see a difference and that was with original firmware in the 300. This stuck out to me because I knew I could get great results from even the budget 75-300, so I had doubted there would be much to see.

So, a dud 100-400 or simply a better all around lens in the prime?

The reality is of course, Olympus over-made a very easily to make 300mm f4, something most brands have in their lineup, because of where it sits in their range. It is their 600mm f4, so it has a no holds barred, best we can do thinking applied. This is a flagship, the sort of lens that is designed to attract new customers or keep old ones.

This may seem at odds with the small and portable ethos of M43, but is it?

Fortune smiled, as it often has with M43. Occasionally I have questioned my commitment to the smaller format, but the results are the cure. The 300mm has never disappointed and seems to be getting better through a combination of my skill improving and the EM1x’s learning AF.

The three images below, all taken on the same morning, show the versatility of the lens.

I have owned an embarrassingly large amount of gear over a long period of time and I can list my very best lenses easily. The Canon 135 f2L, 100 macro (various, possibly the old F4 FD was the best), 50mm macro EF, Bronica 75mm, Oly 90 f2 OM Macro, Fuji 60mm Macro, Oly 75 f1.8 and this 300 are the best I have ever worked with. Plenty of the other lenses come close and most are professionally useable, even the little 40-150 Oly and 12-60 Pana kit lenses, but some are just transcendent.

The good.

It is very, very sharp, but natural looking with it and can also take sharpening well, so if a file is a little movement soft or out of focus by a hair, Capture 1’s sharpening applied, usually with a brush tool brings it back to ball-stitch perfect.

It has the reach of a 600mm full frame equivalent, but the depth of field of a 300mm, so you get a little wriggle room (basically F4 acts like F8 on a full fame 600mm). Chasing high speed sport in iffy light is a skill set that takes practice, but razor thin depth of field can make a two person deep composition impossible regardless. The image above was made possible by enough depth of field to allow for retrieval sharpening.

Colour and contrast are perfect for good light or poor. The 75-300 is well suited to strong light, which is where it is best applied and the 40-150 seems to have low light enhancement skills, but can run a little “hot” in bright light. The prime handles both well.

The dual stabilising and focussing are amazing. I can hand hold this lens on and off for hours with perfect steadiness. Add to this a silent electronic shutter and instant AF and the shooting process is a series of instant, silent, considered grabs, more like sniping than machine gun hammering.

My usual camera AF setting for sports is a stack of three boxes on one of five spaced vertical rows (linked to both orientations), which allows me to be single person precise, centred, off-centre or hard left/right at the flick of a thumb nubbin. I also have three horizontals, some clumps and the usual suspects, but the three stack is the most used. Sometimes I actually forget the thing is focussing. It just seems to be seamlessly “in” all the time.

Where my skill comes in is hitting the right point, so when I miss is the only time I see anything wrong (although something is always in focus). In the games pictured, I would expect at least a 90% hit ratio, with the misses down to me. As I have stated before, I shoot single shot, sometimes in sequence, but shot by shot by considered shot.

It is small enough to fit into a “normal” camera bag, takes normal filters and goes largely un-noticed*. It will go into my F802/804 Domke bags with a camera mounted or the little (often too little) Pro Tactic 350 with the 40-150, 1.4 tc, 75, 8-18, 12-40 and 2 pro bodies. That is pro grade 16-840mm coverage with depth in a bag that I often complain holds too little.

Weather sealing is top flight, an Olympus speciality. Use it in salt spray and wipe down with fresh water. All good.

The magical F4. No matter how much other factors improve, a brighter lens will always have an edge which is why they still sell $10,000+ full frame models. The fact that it is identical in performance at all apertures does not hurt.

Handling is ideal. I can carry it all day on a cross-body strap, never needing a monopod. I can change angle, run, lie down, use a second camera and lens with it, which all contribute to a lens you want to use, rather than one you need to use. This is particularly handy for group huddle shots at half time. I can jog between both teams and grab a series of head shots in a quarter time break.

When the other two photographers go out to do sport, they take their monster 400 f2.8’s often with a 1.4x TC on, mandatory mono pods or tripods and a single camera. They are limited in angle, movement and versatility. I take a one or two camera set-up and never break a sweat. If the light is anything other than semi darkness I will even use it with the tiny 40-150 f4, another giant killer.

Most of us can afford it. If you take your sport/wildlife photography seriously, you will likely spend at least a decent amount on a semi pro camera and decent long lens. With this system you can spend the same and get a seriously pro kit. A second hand EM1x and 300mm combo, can be had for under $3000au or new for under $6000. That s half the price of a Pro camera from the big three or less than half the price of their 600mm f4’s. Total saving is several trips or the car to far away places to use it. For me it was simply a matter of having it or not.

Anything less than perfect?

Flipping the 300 as a 600 thing, the lens lacks the ability to blur the background out as well as a full frame and 600mm at the same distance. The reality is, this is relative and subject to many other factors, but it is true that a shorter lens cropped to longer does not have as soft or smooth blur as the longer lens un-cropped. The trade off of more useful depth over softer blur is I think in favour of the Oly lens, but in direct comparisons it is often noted as one of the few differences.

Bokeh could be better. Pursuant to above, the blurring can sometimes be a little nervous. the semi-macro shot of the flower above is the best news, but it can be messy if the background is relatively close to the subject and very busy. I have found the sharpest Oly lenses tend to do that with the exception of the Bokeh master f1.2’s and the 75 f1.8.

So, to sum up, if you want a seriously pro-reliable and pro-performing, affordable, convenient go-anywhere, versatile long lens, this may very well be the best kept secret on the market. I use it with the EM1x, but the OM-1 is technically two generations newer, so the future looks bright.

As further incentive, how about a sub $1000 150mm f1.8 or a 300mm f4 pro (FF equiv) at the end of a zoom that can go into a pocket, or even an 18mm f1.7 that weighs less than 150grams? The lens above may be the answer to your needs, but the system as a whole needs to be considered also.

*A couple of weeks ago I remember hearing someone in the background at a footy match say something like “he won’t get much with that little lens”, while I was thinking it was a little long for the smaller than average ground! Often for Cricket, I actually find it too long especially considering the cropping potential, so I sneak the 75-300 along as well.