This is the sixth of a series discussing bird photography.

For the final post in this series, I wanted to list out the µ4/3 lens options suitable for doing the type of bird photography I have been discussing.  To be clear, I don’t claim to be (nor aim to be) a meticulous lens reviewer, nor am I an expert on µ4/3 lenses.  Please don’t think of this post as a definitive lens comparison.  I can only provide deeper personal insight on the few lenses I have used, and I am only judging them in how they fare in bird photography.  For the many lenses that I have not used, I am only writing what I have gleaned from their on-paper specs, and in a few cases what seems to be the prevailing opinion on those lenses.  I certainly welcome comments from folks who have used some of these other lenses as a means to fill in those gaps.  Although I don’t have sample images for most of the lenses discussed here, all of the images posted (save two, which are marked) are shot with Olympus OM-D E-M1 or E-M5 MK I versions and Olympus lenses.

I’ll start by explaining why bird photography is so much of a challenge on lenses, and why certain lens specs are so important.

Like all photography specs, there are no hard lines, and that is true of nature as well.  So when I say so much reach or light gathering capability is needed, that spec will matter much of the time, but there will also be times when less will still work.  (On a couple of bizarre occasions, birds in the wild have allowed me to get close enough to use my 12-40mm, paying me no mind and just carrying on in what they were doing.)  Hearkening back to the second and third posts in the series when I discuss the different styles of doing bird photography, it’s more about having the freedom to shoot in all sorts of situations.

Birds in the U.S. alone typically range from 3 inches high for the smallest hummingbirds and warblers to 6 feet tall for the largest waterfowl — 24 times the size, and everything in between.  The vast majority of them move around often and unpredictably (although experience helps here), and don’t want to be close to humans.  Many stay high in the trees and/or under the cover of leaves and branches.  The combination of small size, speed, shadows and distance means that bird photography will require more of your lenses than any other photography genre I know: the longest focal length, widest aperture and best IQ manageable in the smallest package.  The longer-ranged, sharper and faster these lenses get, however, the heavier and more expensive they are.  No lens comes without some sort of compromise(s).  So which lens to buy or bring along is all about determining the conditions you will be shooting in, and what lens compromises would matter the least in that situation.  Next, I will list out the lens characteristics to look for, in what I feel is the order of importance.

(1) Focal Length:

Reach is the first priority.  In my opinion, a telephoto lens of around 150mm (in µ4/3 terms) is generally needed to scrape by in situations where the birds are willing to get a little closer to humans (zoos, parks or backyard feeders), and I don’t intend to discuss any lenses under that focal length.  For most of the types of bird photography I discuss below, however, a better focal length would be more like 300mm or more, and the truth is bird photographers rarely have enough reach.  While one can always crop an image down in post, it is advisable to minimize severe cropping as much as possible to avoid pushing the camera’s limits on noise and resolution.  I won’t say that there will never be a time where a smaller focal length will do (and I provide plenty of photo examples to prove the exception), but if you are buying a lens with birding in mind, it is better to prepare for the norm rather than the exception.  Refer back to the second and third posts of this series on various types of birding excursions, which outlines the situations in which I think smaller focal lengths will work, and was one of the main points of those posts.

The major compromises that generally accompany reach are portability and price.  One aspect of reach to add is that there two native Pro lenses as well as some 4/3 lenses that can take a teleconverter, increasing their reach by x1.4 or x2.  As everything, though, teleconverters come at a cost.  In this case, it is one or two stops of light gathering speed as well as some sharpness, and I believe they have an indirect adverse affect on focusing speed as well.  My personal opinion is not to use them for challenging bird photography.

(2) Light Gathering Ability:

The light gathering capability of a lens is probably the second-most important factor.  Birds are commonly in the shade of trees and/or moving a lot, requiring large apertures and high shutter speeds.  Among the µ4/3 and 4/3 lenses discussed below, the best maximum apertures are in the f/2 and f/2.8 ranges.  These will serve extremely well, and it goes down by increments from there.  For use with a µ4/3 sensor, I still consider f/3.5 and f/4 to be decent, but the bulk of the lens options are in the f/5.6 range, which is still usable, but starting to get on the slow side.  The slowest apertures of the bunch are in the f/6.3 to f/6.8 range, which will have even more noticeable drops in performance in low light situations.  Lastly, several of the zoom lenses will have apertures that vary depending on the focal length.  I would focus on the slowest focal length, as it is the longer ranges where most of the shots will be taken.

While smaller-aperture lenses can be offset by increasing ISO, the noise this induces will become problematic sooner for µ4/3 than it does for APSC or full frame.  Setting ISO aside, the common compromises for a high maximum aperture are price and portability.  Even one more stop of light gathering ability can make a dramatic difference in both, but its also fair to point out that faster glass is usually accompanied by other features, such as professional build quality and coatings and exotic lens materials that improve image quality.  If you only will be shooting on sunny days, and/or if there is not a lot of tree cover in your environment, larger apertures become less important.

(3) Portability:

The true importance of this factor depends on one’s personal tolerances for weight, but if you are using µ4/3, it is likely that you value smaller and lighter gear.  Portability is also one of the most common trade-offs with the other factors, so the µ4/3 advantage can really make a difference.  Trekking with a heavy lens can take its toll, to the point where a too-heavy lens might no longer be reasonably considered hand-holdable and a tripod is needed — further increasing pack weight.  The smaller the lens, though, the lower the reach and light gathering capability.  If you are not planning on long walks with the lens, or want to use a tripod, or perhaps don’t mind the exercise of carrying a heavier load, portability might not be as important.

While the smaller sensor of µ4/3 means that its lenses can be made much smaller than those of its DSLR counterparts, this advantage unfortunately diminishes somewhat with longer-ranged lenses due to the physics of lens design.  Nevertheless, I find that the advantage is still very noticeable.  The 75-300mm f/4.8-6.7 is the size of a soda can.  The 300mm Pro f/4 (1.5 stops faster) is the largest µ4/3 lens to date, but still hand-holdable, and lighter than my Canon (which is still hand-holdable).  At only 1 stop faster, though, the much larger and heavier legacy 4/3 300mm f/2.8 is too large to be considered a hand-held lens, and is generally used on a tripod.  I provide the weights of each of the lenses in grams, to give an idea of how they relate to one another.

(4) Sharpness:

Even though I put sharpness near the bottom of the factors list, that doesn’t mean it isn’t good to have.  For years I used a µ4/3 lenses not known for exceptional sharpness, and was happy with the results I got from it, until I started using a noticeably sharper lens, and never went back.  Sharpness brings out the feather detail of the bird, greatly enhancing the shot.  A sharper lens can also allow a little more cropping, extending the reach a bit.  That all said, sharpness is only one factor in the subjective pursuit of image quality, and its importance can vary depending on the size and quality of the medium the image is viewed.  Emphasizing this point is why I’ve included so many shots from the Olympus 75-300mm.  Crisp feather detail is nice, but it doesn’t make or break an image.  Getting the high-quality glass and coatings needed for great image quality will cost a lot more, and add to the price and weight as well if there are more elements in the lens.

I need to foot-stomp a caveat here.  I don’t have any reason to believe that any of the lenses discussed below are not sharp.  My 75-300mm is not as sharp in comparison to my Pro lenses, but it is still sharp enough for me to have used it for years.  When I say that sharpness can be a tradeoff for other characteristics, or that most of the medium telephoto lenses are not sharp enough to overcome their lack of range, please understand that those are very nuanced statements.  I am going off of the premise that these lenses are being used for normal birding applications, oftentimes at ranges their focal length are not really meant for.  I am not saying that these lenses are not sharp enough to do what they are designed to do, and I certainly don’t want to be quoted as saying, “lens ‘X’ is not sharp,” especially if it is a lens I have never used before.  All I am saying is that to mitigate some of the costs of the heavy cropping that would oftentimes be necessary when birding with a medium telephoto lens (unless we are talking an unusually close encounter), lens sharpness is one of the key factors to how much cropping is available before the resolution becomes unusable.  It would take an exceptionally sharp lens to make that exercise worthwhile, and even then, there are limits.  For lenses I have used, I make my claims confidently.  For lenses I haven’t (the bulk of the lenses here), I am going off of the reputations and online reviews of the lenses, and the observation that some of these lenses have not been lauded as exceptionally sharp. I welcome the feedback of owners of those lenses to fill in the gaps even more.

(5) Focusing Speed:

Birds’ constant movements, particularly when flying, means that a lens also needs a snappy and precise autofocus motor.  I put this factor second-to-last because this is not a problem when birds aren’t moving about, and technique can mitigate some of the issue.  Moreover, continuous autofocusing speed and accuracy is not a strong point for µ4/3 camera bodies (for the time being, anyway), so the lens can only do so much.  That said, this factor can increase the number of BIF hits you get, which makes the activity far more enjoyable.  I don’t have any data on how severe it is, but I would say that price and perhaps portability are the only offsets.

Like sharpness, focusing speed is another area where I feel more than a little uncomfortable characterizing many of these lenses, since I have never used so many of them.  Also, since we are talking very fast focusing speeds as it is, and the environment the lens is being focused to can have an impact, I won’t be doing any scientific measurements down to split seconds.  I will say that my current belief is that for most µ4/3 and 4/3 lenses, focusing speeds range from decent to good, and for most applications will be sufficient.  But for catching birds in flight, focusing speed has to be exceptional.  Again, I welcome the feedback of others on specific lenses.

(6) Build Quality:

Some lenses, such as the Olympus Pro series, are built to withstand the elements and some amount of banging around.  Their all-metal construction and water-resistant designs can be important for photographers who take their hobby into the wild, but such designs also increase price, size and weight.  Aside from the Pro lenses, the Pan Leica 100-400mm and some of the 4/3 lenses will also have durable designs, and of course there are all sorts of adapted lenses available.  The rest of the lenses I mention in this post will be mostly made of high-quality plastics, and could be vulnerable to some degree to moisture or cold.  For the most part, build quality (as I am narrowly defining the term) does not effect image quality; so while for some people this can be a very important factor, for others it either might be considered a small concern or even a detriment, if price and price portability are more important.

Price:

Price is, of course, the ultimate trade-off for everything else.  I didn’t want to rank it because of how personal and subjective its importance can be.  For some folks it will be the main factor, for others less so.  Telephoto lenses are expensive.  Good lenses that meet all the criteria I laid out are very expensive.  There is no way around this, though it can help a little to wait for a lens to go on sale or show up in used or re-furbished listings.  Aside from that, I have provided µ4/3 telephoto lens choices of all price ranges for this post.

In photography (maybe in a lot of things) there a definite diminishing return with the price-to-quality ratio.  When comparing more and more expensive gear, their differences in quality and performance start to shrink — to the point where the best and most expensive lenses are only a smidgen better than the next in line.  I suppose that could be due to both marketing strategies as well as limitations in physics.  Higher-end gear presses up against current limitations in technology.  They require more exotic materials and exacting design and craftsmanship.  Fewer are made because fewer are expected to be sold, raising the price higher to mitigate the R&D and production costs.  There are examples where a company actually takes a financial hit on these types of sales, figuring they can make up the loss in other areas, helped by the interest the high-end gear generates.  In any case, what it means is that the adage, “you get what you paid for” can feel less true the higher you spend.

There are a lot of factors to lens prices I don’t have visibility into — for example, what is marketing strategy versus true R&D, materials and productions costs of high-end lenses, particularly if they won’t be made in large quantities or benefit from economies of scale.  Given the personal subjectivity of the topic, I think it is nearly impossible to get a consensus on what a “right price” ought to be.  I have seen a lot of people complain about the expensiveness of all of the Pro lenses (but particularly the 300mm), as well as (to a lesser degree) the Pan Leica 100-400mm.  Oftentimes these lens prices are compared to models of lesser quality, and/or older DSLR versions that have gone down in price as their product life cycle comes to a close.  While it is certainly true that buyers needs to make purchasing decisions based on what is right for them, I think the comparisons themselves are unfair in that they suggest unsubstantiated blame on Olympus for artificially inflating prices.  While Olympus is certainly in the business to make money, these lenses have undergone tremendous R&D to deliver such high (and innovative, in the case of the 300mm Pro) performance in such small packages, and are similar in price to new models being put out by other companies.  The only way Olympus could have made the 300mm Pro cost as little today as some of these legacy DSLR lenses is if they had made it 15 years ago.  Does that mean its price is right?  Only you can say for yourself.

The focal length equivalency issue also enters the “right price” debate.  To some, a 300mm µ4/3 lens is really a 600mm lens in what it delivers in full frame terms, and 600mm lenses are two to four times more expensive than the 300mm Pro.  This camp feels they are getting a bargain.  Others point out that in terms of lens design, it is a 300mm lens and the production costs are only that of a 300mm lens.  Whether or not this point was considered in Olympus’ pricing strategy, I have no idea (though they do mention it in advertising).  While I see both sides of the debate, I weigh on the side of the latter camp.  However, as I mentioned above, since I still think the prices are comparable to most DSLR lenses of similar age, specs and quality, it doesn’t matter to me much.  To offer yet another perspective, the 300mm f/4 Pro is less than half the price of its legacy ED 300mm f/2.8 predecessor, and by the many criteria I laid out the only advantage the older model has over the 300mm Pro is one stop of light.

The Birding Angle on the Primes Versus Zooms Debate:

I prefer zooms over primes in general because I don’t like to swap lenses, but that is only a personal preference, and I don’t overlook the advantages of a good prime.  There is certainly a lot to recommend them for birding.  Size and apertures are generally better with primes, and oftentimes that is true for sharpness as well (though not necessarily).  Wider aperture means faster light gathering speed, which translates to more versatility, the ability to shoot in dimmer lighting without raising ISO too high, and still having a high enough shutter speed to get a sharp picture even with subjects that rarely sit still for long.  Smaller size means that you can buy a longer focal length lens that is still light enough to shoot hand-held.  For example, the 300mm Pro f/4 was Olympus’ balanced solution for the sweet spot of focal length, aperture and portability, possible in part because it is a prime.  A small argument might also be made that zooming is just one more thing the user has to control.  There have been times I have taken shots from far away with a zoom lens, and didn’t realize I wasn’t at maximum zoom.  As idiotic as that sounds, in the rush of catching split-second action, idiocy happens (for me, at least).

Yet there are much more important arguments favoring zooms when it comes to birding.  Generally, we will spot a bird with our naked eyes and then bring our cameras up to shoot.  Finding the bird again amidst the foliage using the viewfinder can be a challenge, especially with a tight focal length.  It is helpful to zoom out, re-locate the bird, and zoom back in to get the shot (though this can be less of a problem if the bird is far in the distance).  Also, the more focal range you have, the more you can adjust to changing environment as you walk through it.   A wide open space may require much longer reach, while being amidst foliage a much lower focal length can help.  The adage for primes is “zoom with your feet.”  Usually with bird photography, though, this isn’t practical.  The time it takes to do so generally isn’t available before the bird starts to move again, and moving closer to birds will spook them nine times out of ten.  In some places there are legal and/or moral limits to how close you should get, usually in nesting season.  Terrain can sometimes limit space frontwards or backwards, and sometimes the birds are simply high above you, where your feet can’t go.

The flexibility of zoom lenses is extremely valuable for birding.  While the prime’s advantages of light gathering, focusing speed and sharpness are always important (particularly for BiF), they won’t matter if you can’t locate your target or get it all in frame.  A prime sacrifices the zoom’s ability to quickly scan and hone in on the target, as well as its versatility.  This can be compensated for with skill, or with use of the red dot sight.

All that said, the bottom line is a repeat of what I said earlier: most times you won’t have enough reach to fill the frame with a bird.  So, in the spirit of cropping as little as possible, its the longer focal length lens that usually wins for most birding situations.  If the prime has longer reach than the zoom, it will mean less “zooming in with your feet,” making it the stealthier and more agile option.  This won’t always be the case, depending on the environment you’re shooting in.  As I said in my second post, parks, zoos and backyards can be shot in shorter focal lengths, but for the majority of wild situations longer is king.

Olympus 40-150mm Pro:

This versatile zoom lens is one of the best in the lineup. For our birding criteria, it has everything going for it except for focal length.  In in-close situations, such as an aviary, park or backyard bird feeder, it performs perhaps the best of all.  But in wider and wilder spaces, it’s short reach makes it highly limited for all but very large birds, despite its sharpness allowing for more aggressive cropping.

Since it came out in early 2015, Catherine has been using the 40-150mm Pro (880g), sometimes with the MC-14 x1.4 teleconverter attached providing 210mm. While this lens (and the 300mm Pro I will review next) is large for µ4/3, and may be too large for µ4/3 shooters who prize compactness over everything else, it is still small and light enough to hand-hold for long periods of time without fatigue, and is still much smaller and lighter than its DSLR equivalents.  More importantly, its advantages outweigh the extra weight.  When it is shooting within a certain range, the 40-150mm Pro is amazing, but that range is just too short to be a primary birding lens.  It only served to whet our appetite for the 300mm Pro, which provides similar portability, speed and sharpness but with double the reach.

The dual voice coil focusing motors (whatever those are) allow for blazingly fast AF capable of catching BiF — huge improvement over the Olympus 75-300mm f/4.8-6.7 Mk I we used for years.  The constant, much wider aperture increases its shutter speed, low light performance, and ability to control background separation — all improvements to IQ that become even more pronounced at longer focal lengths.  The lens is razor sharp, and the focal length is short enough that IBIS works well enough not to require any additional support.  However, the max reach is only borderline long enough for a few kinds of bird photography, and too short for some.  It can be used for the stalking method of birding, but some shots will be lost to its diminished reach.  It is ideal for parks, aviaries and zoos where the birds are much closer (as a zoo lens in general, it is superb).  If you like to show more of the environment in your photos, this focal length also becomes more usable.  We otherwise generally have been finding that many of the shots we do get need to be cropped to varying degrees, which it is sharp enough to handle.  In enclosed spaces or when shooting larger birds like Herons and Egrets, it serves very well — every bit as good as the Canon.  There have even been times, such as with the wild Australian Broga on the left, where the 300mm Pro was too long for me to get the shot, and the 40-150mm Pro’s shorter focal range was necessary.

Overall, we prefer the experience of using the 40-150mm Pro over the 75-300mm Mk I (our first telephoto lens, which I review a little later).  Its sharpness and speed (both in focusing and light gathering) really stood out in comparison.  We have had a lot of success with it.  One of the dynamics I suspect is going on with the 40-150mm Pro and our love for it is that its shorter focal length expands its depth of field so much that it is actually contributing to sharpness, which helps when doing BiF.  To be clear, the birds are often still pretty far away (another factor for deeper DoF), and heavily cropping really close to the bird oftentimes does not result in usably sharp images, but for environmental shots of BiF, the 40-50mm Pro’s combination of speed, sharpness and slightly under-sized focal length is very effective.  We have gotten extended range and still some success with the x1.4 teleconverter, but I leave that off with BIF, as it slows the process down too much.

Olympus 300mm Pro:

This is the most technically impressive lens I have ever owned, and birding was certainly one of the primary applications in mind for its design.  While it is the biggest and heaviest native µ4/3 lens to date, it is still an excellent compromise between highest-end performance and portability.   In some ways, the lens’ performance would likely pair better with the E-M1 Mk II than with the current generation flagship camera.  On the downside, it is very expensive, and the fact that it is a prime lens makes photographing birds a bit more challenging.

The 300mm f/4 Pro (1475g) is the latest and greatest for Olympus and wildlife photography.  It is, as I mentioned earlier, what Olympus deems as the best compromise between size and performance ratio, and they added a number of new features and uncompromising quality to make it what they have dubbed the best lens they ever made (with an accordingly high price tag).  Certainly, from a technical standpoint, it delivers.  I still have more practicing to do with it, as I’ve only have had it for a few months and have not been able to do a lot of photography of late, but I think I have seen enough to at least give a general rundown.

First off, the the Sync IS is incredibly effective.  In an earlier post I debated whether it is better to leave IS off, and I speculated that the Sync IS would be such a game-changer that it was worth the processing price to keep it on.  I still think this is true.  The stability it provides is practically magic (easily the best in the business), and keeping a bird in center frame is a lot easier for it.  The IS and size mean that this lens simply does not need a tripod for effective long-distance shooting.

Secondly, it is the sharpest lens I have ever owned.  It is so sharp, I find myself being able to crop far more than I ever thought possible with µ4/3.  I can crop so much with it, I find there is no advantage to having a teleconverter.  I can only imagine what sort of cropping will be possible with the higher mega-pixel E-M1 Mk II, in or out of the rumored hand-holdable Hi Rez mode.  To put this lens’ sharpness in perspective, I found that whenever I shot with it, my personal expectations were so (perhaps unrealistically) high, that whenever they weren’t met (due to user error or whatever) the failure was more glaringly painful than it normally would be.  I’ve found myself on a few occasions disappointed with this lens performance in shots that, when I sat back and thought about it rationally, were shots my Canon couldn’t do either.

This 300mm Pro focuses as quick or quicker than all my other Olympus lenses.  I had mentioned in earlier posts that to really judge µ4/3’s AF capabilities for BiF, I hoped this lens’ fast focusing speed would allow me discount it as a factor and isolate the E-M1’s PDAF competency.  I think that I have accomplished that, but the results were still a little disappointing to me.  Shooting a bird flying over a clear sky was quite successful, proving that with the right lens the E-M1 really is fast enough to follow a bird in flight (not so much with the slower 75-300mm).  However, it then revealed that the E-M1 (when a larger block of focus points is engaged) is not sophisticated enough to reliably track a bird when there are other objects in the background, such as trees or water.  The focus points seemed to always grab the biggest object as opposed to the closest or center-most one, which is what PDAF cameras are generally programmed to do.  The alternative is to use only a single center focus point, but one has to have almost perfect panning aim to keep it locked (for which the Sync IS is a great help, but depending on the bird an distance can still be a challenge).  To be fair, even my Canon system doesn’t always succeed with cluttered backgrounds.  On the bright side, I am convinced that Olympus’ two Pro telephoto lenses are fast enough for the job, and the rumors that Olympus is improving the AF tracking ability for the E-M1 Mk II means that we may get an able-enough body as well.

An important test that I have yet to do is to try calibrating this lens as well as the 40-150mm Pro and perhaps even my old 75-300mm, any of which I could conceivably be using with the E-M1’s hybrid CDAF/PDAF system.  This is a bit of an unusual situation.  Lens calibration is not normally something µ4/3 users have to worry about, since we are generally shooting with CDAF.  Certainly, the lenses perform as advertised with CDAF.  It is much more difficult, however, to tell if mis-calibration is a culprit in the E-M1’s PDAF performance against the uncontrolled and imprecise challenge of birds in flight.  (Remember, the E-M1 only engages PDAF with these lenses if using continuous AF, something I personally only do with BIF.)  I’ve only tried the calibration process once, and didn’t see any changes necessary, so I can’t even be sure I did it right.  I didn’t really feel the need for calibrating the 40-150mm Pro before, perhaps because I am generally shooting with a larger DoF with it, making perfect calibration less important.  Since getting the 300mm, however, I feel more compelled to isolate as many variables as possible.

I should also mention that the combination of a smaller aperture than my Canon and a longer focal length than the 40-150mm Pro mean that the 300mm’s depth of field characteristics has required some getting used to.  That’s not a criticism, just something to account for with any new lens.  I went through the same process with the 40-150mm.  One can do the homework and calculate a shot’s DoF beforehand, but I rarely take the time to do so.  For me, it is more a matter of feel and getting to know the lens.  I am also a creature of habit and usually shoot wide open.  There are sample images in this post and the previous one where I probably could have gotten all of the bird in sharp focus had I stopped down a little more.  Aperture and focal length were not the only factors, of course.  The close focusing distances of both cameras can create shots where the DoF is shorter than more normal birding situation.  In those cases, I probably would want to stop down aperture to f/5.6 or so when I am shooting at closer targets.

The physical aspects of the lens are what should be expected for Pro level gear.  It is built like a tank, which makes it heavier than otherwise, but able to withstand considerable rigors.  Like the 40-150mm Pro, it is large for a µ4/3 lens but small for what it does.  It also takes the MC-14 x1.4 teleconverter to reach 420mm.  I love the Arca-Swiss compatible lens foot, and wish all lens feet had that feature.  That said, the 300mm Pro’s controls required some getting used to, and this is a bit of a criticism.  I agree with some other reviewers in that the designers should have swapped the locations of the focus limiter switch and IS switch.  The focus limiter is the control that needs to be accessed most often, but they instead put the IS switch in the prime real estate where my thumb rests.  Getting to the focus limiter requires me to stretch my thumb’s reach over the IS switch and higher up the barrel.  It’s a small thing, and one that will diminish with practice, but on several occasions it has cost me to miss shots because either I couldn’t switch the focusing range in time, and/or I had accidentally turned IS off instead.

Specifically for use in birding, the fact that it is a prime lens means the 300mm Pro requires more skill than either my Canon or my 40-150mm Pro to get a shot.  The overall result is a lens that can either produce beautiful successes or frustrating misses — and early on in my usage there have been more of the latter.  The advantages that I mentioned earlier for zooms is readily apparent in its lack here.  Finding a target through the lens is not as easy as it is with a zoom.  Spotting and pointing the lens at a distant bird requires disciplined and practiced form in bringing the camera to my eye at just the right position, while never taking my eye off the target.  This is the sacrifice, however, to get a brighter aperture in such a small package, and I suspect I will get better at it in time.  This is also where Olympus’ EE-1 Red Dot Sight (reviewed here) becomes helpful, but even this takes a bit of getting used to.  I have tried to use the dot sight as the primary viewer while tracking and shooting a flying bird, but have decided that for the level of precision needed for that application, this technique lacks too much feedback.  I couldn’t tell for certain whether my focus point was spot-on the bird from moment to moment, and this problem was compounded by how easy it is to get inconsistent results with the EE-1, and how challenging BIF is to begin with.  It resulted in a bunch of missed opportunities.  So, I would not recommend this technique for birding, with the possible exception of a very specific situation where all focus points are engaged on a bird against a plain sky, theoretically maximizing the chances that the camera will catch the bird even if it isn’t center-frame.

Panasonic Leica 100-400mm:

While most people are saying that the Olympus 300mm Pro is sharper and faster (particularly sans teleconverter), I nevertheless suspect the Pan-Leica 100-400mm might very well be the ideal birding lens for µ4/3.  Its wide (and natively longer) zoom range and small size are huge benefits, and they come at a lower price point.  Its aperture is a bit slow for the genre, and I don’t know about its focusing speed.  At the very least, it is an across-the-board upgraded version of the two lenses I will discuss after this one.

Panasonic and Leica have collaborated on another promising lens, a 100-400mm f/4-6.3 (985g).  I can’t review it because I don’t own it, but I am seriously considering buying this lens for Catherine, as it is small, light, quite sharp by most accounts, and has a really nice focal zoom range — the longest I have reviewed here.  If I ever decide to sell the Canon (not yet, by the look of things), I will buy this lens so that we still have two birding kits.

I have seen some reviewers express dissatisfaction with the Pan-Leica 100-400mm’s sharpness, but I suspect there are some explanations for this that don’t have anything to do with lens performance.  Most people praise it as very sharp, only slightly less so than the 300mm Pro.  In any case, as I mentioned, I have experienced plenty of disappointing pictures with the 300mm Pro as well, which I know from my own tests is ridiculously sharp — and found the explanations elsewhere.  The fact that it is a zoom and has an extra 100mm over the next longest focal length are its biggest advantage for birding applications.  A few aspects made me choose the Oly instead.  First, I have not seen much by way of reviews on how fast the lens focuses.  Secondly, while the lens has Panasonic’s version of Sync IS (called Dual IS), the two brands do not use compatible technology here, so using this lens on my E-M1 would only have OIS (the same is true for the 300mm Pro on a Panasonic body).  Since I only own Olympus bodies, this was an issue.  The final concern was the f/6.3 max aperture at 400mm, which is decidedly on the slow side, though in bright conditions it should be fine.  Lastly, with the x1.4 teleconverter, the Olympus 300mm Pro regains the edge in reach at the cost of its one stop of light advantage, though I can’t say which is sharper — the Pan Leica or the 300mm Pro with the teleconverter.  I have since found this last point moot, however, as I feel teleconverters (both the Canon and Olympus x1.4 teleconverter I own, anyway) lose too much in sharpness and speed to be worthwhile for birding.

The “Soda Can” Zooms:

After using it for years, I would recommend the Olympus 75-300mm (and perhaps the Panasonic equivalent before that) as a starter bird lens, or one for people who want a telephoto but don’t want to go all out in price and size.  They are good in sunny conditions, but performance drops off rapidly in low light.

The most compact super-telephoto offerings for µ4/3 are the Panasonic 100-300mm f/4-5.6 (520g) (which I have never used) and the Olympus 75-300mm f/4.8-6.7 (423g) (including the Mk I version I started with and used for years).  On the positive side, both are only the size and weight of a can of soda, and acceptably decent in terms of sharpness.  Many shooters have complained that the image quality does degrade a bit at the longest ranges.  While it is true that neither of these are high-end offerings, I know from experience that the Olympus is actually sharper than it gets credit for, and I am willing to bet the same is likely true for the Panasonic.  The reason I say this is because while there likely is some technical degradation at longer focal lengths, that generally isn’t the biggest problem.  A more common culprit at work is users mistakenly believing these lenses can be shot from the hip at such long ranges, just because their small size makes it feel like they can.  For one, both lenses decrease aperture the further they are zoomed out, taking a hit in either shutter speed or ISO, either way impacting image quality.  This is made worse by the fact that standard IBIS is strained too much at super-telephoto ranges to reliably hand-hold the camera and get a sharp shot. Lastly, it can be counter-intuitively harder to get good stability with lighter lenses.  With all three forces at work, such a small and light package can easily mislead the photographer into expecting to be able to shoot long ranges hand-held without problems, but in reality a more stable platform is needed at around 250mm or more.  If used with a monopod or tripod, and not trying to capture motion and so allowing for slower shutter speeds, these lenses can get extended mileage.

Even then, their slowness will catch up to them (the Olympus is slower than the Panasonic).  In bright daylight they work very well, but when the light begins to drop their performances take dramatic nose dives.  This strains their use in shadowy forests, or in the early morning or late evening when birds are most active.  Lastly, they are not the fastest of focusing lenses, so shooting flitting birds or BIF is made even more challenging.  We used the Olympus 75-300mm Mk I for years and got some great shots with it, but found we were limited in what we could do.

Just based on specs and not really knowing how the Panasonic performs, I would still probably recommend it over the Olympus equivalent if birding is the primary purpose (for more general purposes, its a toss-up).  The extra 25mm on the Olympus may make it a more all-around versatile lens, but that short end won’t impact birding at all.  Furthermore, while not much different, the extra half-stop of aperture means better light gathering and shutter speed for the Panasonic — important for birding.  I can say that for the price and small size, either one makes for an nice starter lens for birding.

Other Native Hand-Held Options:

Although I haven’t used them, I would not highly recommend the many medium telephotos available as birder lenses over the 40-150mm Pro or one of the below 4/3 lenses, but there are plenty of options in this category.  While their small size is nice, in my opinion their shorter reach and slower apertures are not up to demanding birding situations, and these lenses lack the exceptional sharpness and the teleconverter option of the 40-150mm Pro to mitigate that somewhat.  I guess that to my mind, lacking in one area can be worked through, but if a lens has several shortcomings the problems become too great, and it is likely not the ideal lens for the task.  That said, just like the 40-150mm Pro, if you are planning to only photograph birds in closer situations such as parks or your backyard, and the lighting is decent, these lenses can work.  The Panasonic 45-200mm f/4-5.6 (380g) might be the first option in this range to try.  The Panasonic 45-175mm f/4-f/5.6 (210g) and the two Olympus 40-150mm f/4-f/5.6 options (190g and 200g) are probably the last lenses on my list that could work in limited (bright and close) birding situations.  I am sure, however, that there are folks who have captured some nice bird images using these lenses.

4/3 Lenses:

After renting it for a week, I can say the 300mm f/2.8 is truly a great lens.  It is, however, still the most expensive in the lineup by far, and the extra stop is has over the 300mm f/4 Pro is not enough to justify the huge price difference.  Some of the other adapted 4/3 telephoto lenses are also very good for birding, offer bright apertures, and are cheaper than some of the other competition.  On the downside, they are heavier, and don’t focus quite as quickly on the E-M1 as some of their native µ4/3 counterparts. 

While designed for an older and now discontinued system, Olympus Zuiko 4/3 lenses can be used on the E-M1 at reasonably competent capacities with the use of the MMF-3 adapter, thanks to the E-M1’s hybrid AF system.  A lot of Olympus shooters have had some great success with these lenses, particularly the higher-end Super-High Grade (SHG) versions, which are reputably among the best lenses Olympus has ever made.  With the exception of those SHG lenses (which are also hard to find), many of the 4/3 lenses are also fairly inexpensive relative to their µ4/3 cousins.  Their larger size relative to native M.Zuiko lenses means that they naturally pair well with tripod use.

The best lens of all for this application is the stellar ED 300mm f/2.8 (3290g).  By far the largest and most expensive lens in the Olympus line-up, it is the only lens so heavy that it would truly require a full tripod and gimbal head setup to really handle well.  I rented it in 2013 (along with a gimbal head) and was very impressed with its marvelous IQ and amazing background separation.  That said, with the appearance of the 300mm Pro, I simply don’t see the logic in paying so much for the 300mm f/2.8 — as its only advantage over the 300mm Pro is one stop of light.  Perhaps if the E-M1 Mk II had dual-cross focus points only usable with f/2.8 lenses (as my Canon does), that extra stop of light would become more significant, but I highly doubt Olympus would go that route.

My one-week experience with the ED 300mm f/2.8 was hindered in two important ways:  The first was that this occurred before firmware upgrade 4.0, so BIF performance was more limited then that it would be today.  The second problem was that I was ignorant at the time of the need to calibrate PDAF lenses, and in retrospect I believe this copy was in sore need of it.  I recall relying on manual focus a lot.  When I was able to get a nice shot, however, the lens was absolutely stunning.  The comparison images on the right are interesting for several reasons.  Hopefully, not too much image quality was lost in processing these images for the blog.  Obviously, the ED 300mm f/2.8 image on the left is superior in sharpness and has a much more pleasing depth of field.  But the cost of getting that shot compared to the one on the right — requiring a tripod because the lens was so heavy and cost ten times the price — is a good case study for the diminishing returns point I made when discussing price.

The other 4/3 lens for tripod-mounted bird photography would be the ED 90-250mm f/2.8 (3270g).  The 4/3 lineup also has a compact 70-300mm f/4-f/5.6 (615g).  This 4/3 version is a little larger than its µ4/3 “soda can” cousins I mentioned in the above section, but at least on paper I would assume it functions similarly.  There are also several medium telephoto 4/3 lenses that could be used, at effectiveness I would think very comparable to the 40-150mm Pro.  The 150mm f/2 (1465g) would be interesting for close work, and the 50-200mm f/2.8-f/3.5 (995g) could also work well for more general birding, given its decently long zoom range.  The EC-14 and EX-20 x1.4 and x2 teleconverters are not compatible with most of these lenses mentioned here, only for the 300mm f/2.8 and the 50-200mm f/2.8-3.5.

I’ve generally heard good things about the 4/3 SHG lenses, but having only used the ED 300mm f/2.8, I would welcome the thoughts of others who have more experience with the other 4/3 options.  Just going off of what I have heard, and my experience with the 300mm f/2.8, I do not believe that 4/3 lenses focus as quickly as the modern Pro lenses do on the E-M1 (perhaps not ever), though they still focus fairly well and quickly.  Even in glass, technological progress is relevant, which is the reason my predilection has been to stick with newer, native glass.  For example, Olympus itself claimed that the 300mm f/4 Pro is the sharpest lens it has ever created, meaning that it has dethroned the 300mm f/2.8 — and it did so at less than half the cost.  Granted, the 4/3 version is one stop faster, but is also much (much) heavier.  While the 300mm f/2.8 also lacks the 300mm Pro’s amazing Sync IS, it does have OIS, and most people would find it is limited to tripod-use anyways.  But none of that is to say that the 4/3 lenses don’t perform very well, and given the few all-round suitable µ4/3 telephoto options, I rank them rather high in the list.

Non-Native Lenses:

The last category of lenses is the use of legacy lenses from other manufacturers by way of an adapter.  I have used only one myself, a Tamron Adaptall 2 300mm f/5.6 prime lens with a Tamron-to-µ4/3 adaptor. While using only one amongst a sea of choices hardly makes me an expert, I feel that the sacrifices are too great to recommend for anyone seriously looking at bird photography with Olympus.  Adapting legacy lenses is, however, by far the cheapest of options, especially for people who already own adaptable lenses.  My understanding is that while some are decently sharp (particularly for the price), not all will be as effective as they were with their original system, or hold up to modern-day standards, for that matter.  Many adapted lenses are limited to manual focus-only (as was the case for the Tamron I used).  As birds move around so much, and particularly with BIF, a good AF is an invaluable tool to even get within the ballpark focus zone for starters, and I wouldn’t want to be constrained to MF only when doing bird photography if I didn’t have to be.  Furthermore, a number of useful modern features are disabled with a lens that has no electronic connections to the camera, such as focus peaking and aperture control (which is oftentimes adjustable on the lens).  If I am going to shoot birds with manual focus, I am going to want focus peaking.

That all said, there are certainly people who use legacy glass with great success by virtue of their high level of skill, and of course, before autofocus was invented everyone had to shoot that way.  In fact, there are times AF can get in the way of bird photography — particularly when attempting to lock onto a bird perched deep amidst tree branches.  Even with the tightest focus points and accuracy, the AF will oftentimes lock onto the surrounding foliage, requiring manual adjustments to zero in on the bird.  Also, adapters are getting better and more complex, so in a few cases maybe some of these obstacles are surmountable.  But I would not expect adapted lenses to ever provide top-end performance.

Another point to consider with adapting lenses is that they are the exact definition of a crop system (as is my Canon kit).  This will invariably involve a lens that was designed for a larger sensor to be put on a smaller-sensor body.  The result is that some of the image the glass captures will fall off the sides of the sensor, unused.  It is a minor quibble of mine that native µ4/3 glass used on µ4/3 bodies they were designed for involves no such image cropping whatsoever, which is why I feel the term is a misnomer for systems like µ4/3 (I have other posts that go into this in more detail).  The problem is not a hit on image quality (there is none, and in fact the lost sides are the least sharp parts of the glass), but it does mean the user is carrying around more weight than they need to.

Conclusion:

That sums up the various types of lenses available for birding with µ4/3.  I do not know of any plans to introduce more super-telephoto lenses for µ4/3 at this time.  While how large and close the subject of course can change the calculus, unless you have something very specific in mind, I recommend preparing for more challenging birding scenarios, in which case some of the above-mentioned lenses might be pushed beyond the capabilities they were designed for.  If you can afford it, I think the Olympus 300mm Pro or the Pan-Leica 100-400mm are excellent choices.  The several 4/3 lenses I mentioned are probably the next best for general bird photography, along with the 40-150mm Pro, though I think the 300mm f/4 Pro has made the ED 300mm f/2.8 practically obsolete, considering the price difference.  The Olympus 75-300mm and the Panasonic 100-300mm make for acceptable beginner level options, but they are limited by their focusing speed and aperture, and are not as sharp as my higher picks.  I would only recommend some of the medium telephoto lenses for very limited circumstances, such as close-up encounters in good lighting.  I do not recommend adapted lenses for birding, unless you are exceptionally accomplished (or looking to be) with old-school manual focusing, price is a major obstacle, or you are just looking to get some extended mileage out of lenses you already own.