Panasonic Leica DG Vario-Elmar 100-400mm f4.0-6.3 Field Review

Over the last year a number of wildlife photographers have been asking when I’ll be reviewing either the new Olympus 300mm f4 lens or the Panasonic Leica 100-400. It certainly surprised many of those people that a review of the Olympus lens has never been forthcoming. That’s because (despite being a brand ambassador for Olympus) I’ve never so much as laid eyes on one. Some time ago I sold my Panasonic 100-300 lens to make way for something longer. As time has gone on I’ve realised I won’t be getting the Olympus 300mm and my need is such that I’ve recently taken delivery of the Panasonic 100-400. This lens has certainly been receiving good reviews across the Internet and on forums. As a demanding user I was curious as to whether it would live up to its hype – after all, this is not an easy thing to build (or to shoot with).

But before I go further, let’s get things into perspective. The micro four thirds PL 100-400 gives whopping magnification, and before considering a lens like this it’s very important that you understand how to use extreme telephoto optics. There are a number of factors which influence sharpness so if you feel that a refresher is in order do read the article on my portrait site: How To Get Sharp Images. Handholding this lens at 400 mm means you’re seeing the equivalent of 800 mm of magnification (in FX/full frame terms). It’s worth brushing up on the kind of settings you’ll need before going into the field, as well as practising your holding technique.

Before I get going on my findings there are a few things we need to consider:

Lens Bench Testing vs Field Testing

Bench testing can be fairly scientific and usually involves locking your camera and lens combination to a sturdy tripod and testing sharpness/resolution at various apertures and focal lengths. I very rarely engage in bench testing (unless I suspect a lens is faulty) because for me what matters are results gained in the situations and environments in which I work. There’s no point buying an ultra-telephoto lens if you’re naturally poor at managing high magnifications and of course the handling of any piece of equipment is paramount. Focusing speed is also best measured in the circumstances which have dictated your purchase.

It’s also helpful to determine what your comparison benchmark might be. In this case it’s the Olympus 40-150 f2.8. This lens is tack sharp throughout its range with extremely fast focusing. It’s the bedrock of my business, covering me for portrait sessions (I work outdoors) as well as nature and wildlife photography. In the latter case I pair it with the x1.4 teleconverter and I see no noticeable loss of sharpness. For the DSLR users amongst you, the performance of the Oly 40-150 f2.8 lens is very similar to my previous favourite lens which was the excellent Canon 70-300L.

Effective Lens Focal Length and the Downsides of Teleconverters

The PL 100-400 lens is special because it affords the Micro 4/3 user an effective focal length equivalent to 200-800mm, in a fairly small and quite lightweight package. For full frame or APS DSLR users we might historically have gone for something like a Canon 100 to 400 f4.5 to f5.6 MkI. Used with a x1.4 extender, on a full frame camera, the Canon would give us a focal length of 140-560 f6.3 to f8. If we mounted a x2 extender the focal range goes up to 200-800 f9-f11. The Canon 100-400 when used on an APSC Canon camera would be offering 224-896 with a x1.4 extender. That’s fine, if you don’t mind the size and weight – and the fact that there may be some compromises with image quality, as well as autofocus failings. In general, that isn’t a combination many people would happily carry around for several hours at a time, and so specialised lenses with ultralong focal lengths have historically been for occasional usage.

Depth of Field and the Benefits of Cropped Sensors

Some of you will know that, due to the x2 ‘crop’ (sensor size) Micro 4/3 cameras have around two stops of additional depth of field vs a full frame camera at the same aperture setting, and about two thirds of a stop of additional depth of field vs an APS-C DSLR. This can be pretty handy at times, especially when photographing animals since many don’t have flat faces like humans. Therefore in depth of field terms the Panasonic 100-400 will give you an ‘equivalent depth of field’ of f9 to f13 vs the same kind of lens paired with a full frame camera. In terms of APS-C equivalence, you won’t really see much of a difference. It should also be said that focal length, with close camera to subject distances, can result in immensely shallow depth of field even at midrange apertures like these. When I was out testing the Panasonic 100-400 I had to constantly check that enough of my subject was in critical focus, the depth of field was so thin even at f6.3.

As I mentioned earlier my existing nature and wildlife lens is the Olympus 40-150 f2.8 with teleconverter. Mounted to one of my Olympus cameras this combo gives me a literal focal range of 56 to 210mm. Due to the x2 magnifying nature of a Micro 4/3 sensor we know this visually translates to 112 to 440 at f4. The PL 100-400 is an f4 to f6.3 lens. At 150mm the PL 100-400 is at f4.6, at 210mm it’s f5.1, at 300mm it’s at f5.7. You can immediately see that when compared to the Oly 40-150 at its maximum reach with the x1.4 teleconverter, the PL 100-400 is only about two thirds of a stop slower.

Sharp Results with ultra Telephoto Zoom Lenses

Where most telephoto zoom lenses are concerned it’s not uncommon to find that maximum optical sharpness often lies towards the shorter focal lengths with sharpness tailing off at the extreme end. Sharpness is certainly subjective and back in our film days we didn’t have the opportunity to pixel peep – although we could run a loop over a contact sheet or print. In reality your image only needs to be sharp enough for the intended output medium and output size. If your photographs mostly go on the web at 700 pixels, or are made into 7 x 5 prints, then you really don’t have much to worry about. If you’re printing at poster size and above (as I do a lot of the time) or entering top-level industry competitions (that, too) then sharpness will become more important.

Sharpness can also fall off with distance (mostly when you’re at maximum zoom) because critical focus under those conditions can be harder.

Olympus camera bodies have a built-in stabilising feature called IBIS. Many Panasonic lenses have an OIS switch so you can choose whether to use the lens stabilisation or the body stabilisation when mounted to an Olympus camera. If using a modern Olympus body (post EPL5 with up to date firmware) with the lens OIS switched to the ‘on’ position, this will override the camera’s own stabilisation settings – IBIS will be auto disabled. In other words, there is no need to select ‘lens OIS priority’ in the camera menu (save that for Panasonic lenses which lack the OIS switch). Adendum: Bodies such as the Panasonic GX8 and upwards offer ‘dual stabilization’ with certain Panasonic professional lenses. In brief, both the lens stabilization and the body stabilization (IBIS) work together to bring additional benefits.

This is the point at which I should mention a phenomenon known as ‘shutter shock’. This can be evident depending on the particular body and lens combination and tends to show up at medium-slow shutter speeds (usually up to around 1/360 sec). We need to be able to distinguish shutter shock from an out of focus image, camera shake, and motion blur. Shutter shock appears as a slight doubling of the image. Speaking personally, I’ve never encountered it, but others certainly have so it’s worth mentioning. Some modern cameras do have an ‘antishock’ setting which may help, or else better results may be reported by invoking the silent/electronic shutter on your camera (be aware that in certain conditions with moving subjects this may introduce motion artefacts).

Success with long lenses depends to a great extent on the technical abilities of the photographer. We have to be able to handhold our equipment effectively. It goes without saying that ideally you also need to ensure you have a shutter speed suitable for your chosen focal length (to avoid camera shake) and obviously a shutter speed relevant to subject movement (to avoid motion blur). Successful handholding is going to vary by the individual. The old school rules would normally dictate that, at the maximum zoom of 400 mm (equivalent to 800 mm magnification in FX terms) you would ideally have a shutter speed of 1/800. However with modern body or lens stabilisation you can in fact gain sharp images at substantially lower shutter speeds (assuming your subject is static and your technique is very good).

A limitation in field testing is the fact we’re often battling higher ISO values. This in turn affects perceived sharpness. There’s no way round that here in the UK much of the time. It reflects real life though, and is a feature of pretty much every non-summer wildlife shoot. The main thing is that we can make comparisons with different lenses used in the same conditions.

Autofocus Accuracy at Extreme Focal Lengths

Generally speaking a large lens with a lot of glass to move around will not focus as quickly (or necessarily as accurately) as a small lightweight optic. As a general rule, the longer the focal length, the less accurate autofocus can be if you’re using a zoom lens, and accuracy can also fall with greater lens to subject distances (particularly if the light is less than perfect). If a lens is fitted with a focus limiter, this can speed up focus over a particular range.

How I do my Lens Field Testing

The field test photographs below were specifically taken to mimic the conditions under which I mostly shoot. That is; variable light, subjects which often move, situations where extreme focal lengths may be necessary together with cropping (in fact some of the photos are 100% crops from the original and I have indicated that where necessary). And fur/hair – which can be difficult to get sharp and at times difficult to focus on if you don’t have time to focus on your subject’s eyes. Shiny fur is also a pain, in my opinion. In terms of RAW processing there has been my usual simple Curve bump in Lightroom and my usual minimal amount of capture sharpening. I was having to shoot at ISO values ranging from 400 to 2000. All in all I put the PL 100-400 through some fairly demanding conditions. I’ll discuss my findings after the pictures but I suspect you can draw your own conclusions.

Panasonic Leica DG Vario-Elmar 100-400mm f4.0-6.3 Field Review Findings

The build quality is lovely and the PL 100-400 does have weather sealing. When I first received it I thought it was doomed – turning the zoom ring took some effort. I know a lot of other people have complained about this. However, it turned out that I hadn’t been fully unlocking the lens barrel – once I did that the zoom became smooth and fluid.

With this particular lens I found the lens OIS to be even more effective than the excellent five axis stabilisation built into my EM1. In fact I was pleasantly surprised at how sharp my images were at slow shutter speeds.

Focus is extremely fast in good light with a little hunting if shooting in poor light at extreme magnification – but the lens always locked on perfectly after a couple of seconds. I use the smallest focus box and it was very easy to gain accurate focus on small subjects high up in trees, in quite dense foliage.

It should be pointed out that since I was photographing some small and potentially timid animals, I had my EM1 set to silent/electronic shutter. Some rudimentary tests have shown that I do get slightly sharper images at the longer focal lengths using this feature. That’s unsurprising, as an electronic shutter doesn’t vibrate.

This lens is extremely sharp – in fact up to around 370mm it appears pretty much indistinguishable from my ‘pro grade’ optics. As expected it isn’t as razor sharp at 400mm, but it’s plenty sharp enough. For small very distant subjects over 150 meters away, these subjects remain extremely sharp at shorter focal lengths but are not critically sharp at 400mm – again that is to be expected. For the sake of a comparison – with the extender attached the Oly 40-150 f2.8 will give you 420mm maximum ‘equivalent’ reach at f4. At the same focal length the PL appears to be virtually as sharp with only a small loss of aperture, and only marginally slower focusing speed. I was quite surprised by that. Does that mean I’ll be using the Oly lens less? For nature photography, yes. But for portraiture the Oly is superb.

Panasonic have achieved an extraordinary feat of engineering with this piece of equipment – this lens opens up a whole new world of opportunities. It’s now possible to photograph virtually anything we want to, without hauling around a trolley load of kit. And best of all it’s FUN, I’m able to gain pictures I previously couldn’t have dreamed of. You can argue that it is possible to use a shorter and very sharp optic and simply crop your image. Yes, I have often done that, and then enlarged that photograph if I have to. But this lens is so sharp through the vast majority of its range that it’s rather nice not to have to go through those manipulations.

Going back to its most obvious competitor, which is the Olympus 300mm f4 lens, I cannot offer up a comparison since I haven’t used that lens. But it should be understood that a beautifully optimised prime telephoto lens should always perform better than even the best ultra-telephoto zoom. But if you need the flexibility of an ultra-zoom, I don’t think you’ll do any better than the lens I’ve just reviewed.

I’ve included some tight crops with the sample images below.