This last few months have been particularly difficult in the light of climate change induced bushfires here in Australia and now the spread of the Coronavirus (COVID 19). It would in the light of compulsory lockdowns, quarantines and restrictions on social gatherings and travel easy to be filled with dread and let feelings of hopelessness pervade our lives. I myself have had further restrictions imposed as I’m in the process of recovering from spinal surgery and am fighting off the temptation of feeling sorry for myself and collapsing in a heap.
There is an antidote to this. Firstly instead of just being passive and feeding our psyches with all the negative news we can find in the media endeavour to do something creative. Creativity is important, it feeds the soul, gives a sense of achievement and allows you to express yourself. All of this has a positive effect on your psychological well being. It doesn’t matter what it is – paint, draw, knit, cook, write, photograph, sing. Although singing could be problematic depending upon your living arrangements and how well you can sing. My partner has issued me with an ultimatum; if I sing Bohemian Rhapsody at full volume in my usual tone deaf manner then lockdown or not I will be looking for alternative accommodation which I think is a little harsh. Secondly reconnect with nature. This one could be a bit hard depending on what the local authorities are imposing, but it can be done. If confined to the house take time out in the garden, encourage wildlife to come into the garden and watch them. Plant things and watch them grow. If possible go a walk in the park or woods (maintaining correct social distancing of course), go bird watching, fungi spotting it doesn’t really matter. Bonus points if you can combine this with doing some creative as this will allow you to enter a flow state. Sounds poncey but “it is the mental state in which a person performing an activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by the complete absorption in what one does, and a resulting transformation in one’s sense of time” (Mihály Csíkszentmihályi, 1975). The benefits of this are that intense and focused concentration on the present moment that you become so totally engrossed in the experience to the extent that other needs or concerns become negligible and this makes you feel in control over a situation. Do this a few times a week and your mood will lift.
I’ve taken my own advice this week. As I said I’ve been laid up at home and not doing much so I hauled my carcass down to the Avon River a couple of times to photograph some birds in the dawn light. It was well worth it. Stalking birds and photographing them required too much concentration and I was able to forget about my own circumstances and the worries of the world and just enjoy being in the moment. It was so enjoyable that I’m going to get out and do some more over the next week.
Right that’s me done I’m off to try and bake a lumberjack cake.
A review of the Sigma 16mm f/1.4 DC DN lens for m4/3
I’ve said many times on this blog that my favourite focal length is 35mm (35mm equivalent) which give a diagonal angle of view of 63.4º To me it is a relaxing normal view, I find 50mm a bit too tight and 28mm a bit too “loose”. So when I migrated from so-called full frame to micro four thirds in 2010 one of the first lenses I bought was the Olympus m.Zuiko 17mm f2.8 pancake lens. Actually at the time there were only three lenses in the system the 17mm, a 14-42mm kit lens and the 40-150 telephoto kit zoom and I ended up getting them all.
The 17mm was equivalent to 34mm in in full frame terms and has a diagonal angle of view of 65º, so close enough as not to make any real difference. It wasn’t a well received lens despite being what initial advocates of the micro four thirds said they wanted – pancake lenses. It’s slow maximum aperture of f2.8, slow and noisey auto focus combined with less than stellar optical performance put many people off and they went for the much more expensive Panasonic 20mm f1.7 which had the virtues of being optically better, and having a faster maximum aperture. It still wasn’t great in the AF department though. But hey these were the early days of mirrorless technology and AF systems were not very quick and accurate then. But anyways I got the Olympus in a kit with my Olympus EP2 and I actually loved it. I could slip it mounted to the EP2 in my pocket which made it a great stealth camera combination and I used it to shoot my TransPerth-Transhumance project. I still use the lens today, mainly on my EP5. The area where I felt it was absolutely hopeless was video. The AF was too slow, too noisy (think angry wasp stuck in a jar) and I wanted a bit more subject isolation than the f2.8 aperture could give.
So fast forward a few years and I’m shooting more and more video and I decide to get myself a better 17mm lens. In the intervening years Olympus had produced the very favourably received 17mm f1.8 and the eye-wateringly expensive f1.2 version. Panasonic had also come to the party with their Panasonic Leica Summilux 15mm f/1.7 lens. In fact I went to my local (if you can call 110Km away local) camera dealer to buy this lens and it was always out of stock which made me want it even more. But in the end I went for an outlier in the form of the Sigma 16mm f/1.4 DC DN lens. The reasons being that f1.4 is faster than f1.9, it was cheaper than the f1.2 and the difference between f1.2 and f1.4 is slight, and my dealer had it in stock. So what makes it and outlier? Well to put it bluntly it’s bloody huge. It has a 67mm ⌀ filter thread which compares to 37mm for the Olympus 17mm f2.8. It is bigger than the Olympus 12-40mm f2.8 and the Panasonic Leica 8-18mm f2.8-4 while being only a little shorter than the Olympus 75-300mm f4.8-6.7. The 16mm focal length equates to 32mm on full frame with a diagonal angle of view 68.1º so is a bit wider, but when used with the Panasonic G85 for 4K video this isn’t much of a problem as the camera crops in slightly. So how come this lens is so lardy I hear you all ask. Well this lens wasn’t designed for micro four thirds, it was initially designed for the Sony 6000 series cameras with an APS sized sensor where it equates to being a 24mm in full frame terms. To get a wide angle lens that’s fast and a good optical performance means lots of glass and glass is heavy, and this lens is large and heavy for APS format cameras. To get some additional return on their investment Sigma decided to offer the lens in micro four thirds mount hence it seeming a funny focal length and being bigger than necessary.
Olympus 17mm f2.8
Sigma 16mm f1.4
Diagonal angle of view
6 elements in 4 groups
16 elements in 13 groups
5 rounded blades
9 rounded blades
Minimum focusing distance
maximum magnification ratio
⌀ 57mm x 22mm (H)
⌀ 72.2mm x 92.3mm (H)
In the hand the Sigma 16mm feels very dense and substantial. The lens body is made out of what Sigma calls a Thermally Stable Composite (TSC) which is substantially stronger than conventional polycarbonates while having similar thermal expansion properties to aluminium. The lens mount is made of chromium plated brass which should ensure a long life. The Sigma 16mm is advertised as being dust and splash proof but on closer reading of Sigma’s spec sheet there is only one seal and that is at the lens mount. The lens comes with a bayonet mount petal lens hood which has a ribbed grip to make attaching and detaching easier. While it is good that the lens comes with a hood it’s not the best implementation and feels quite insubstantial and can be fiddly to attach as it can foul and not lock home. There is a ribbed rubber focus ring of the fly by wire type – it feels smooth and easy to use. There are no other controls or switches which means if you want to switch between AF and manual focus you will have to use the camera controls for that.
The Sigma 16mm has an optical construction of 16 elements in 13 groups with 3 FLD (“F” Low Dispersion) glass elements, which offers performance equivalent to fluorite which exhibits less chromatic aberration than those utilising a traditional flint glass. There are 2 SLD (Special Low Dispersion) glass elements which also help to minimise chromatic aberration and 2 ASPH moulded glass aspherical elements which work to reduce optical aberrations. According to Sigma’s website the ASPH elements are polished with a tolerance of under 10 nanometers or 0.000001 millimetres which according to Sigma reduces onion ring bokeh.
In terms of autofocus the stepping motor is fast and accurate and very smooth when shooting video. I tested the lens on the OMD EM1 mk ii which has on sensor phase detect AF and on the Panasonic G85 which uses DFD technology – a variant of contrast detect auto focus that requires the lens to provide a profile to the camera to ensure fast and accurate AF. The Sigma does not have such a profile as these are limited at present to only Panasonic’s own lenses. Despite that there were no problems and I could detect no discernible difference between the Olympus and the Panasonic. The only downside in the AF department is that I can’t use the Pro Capture Low setting which gives up to 18 fps with auto exposure and AF tracking. This is no fault of Sigma’s as the option is only available with Olympus lenses.
Optically – well straight from the get go the Sigma is impressively sharp wide open corner to corner. The performance improves slightly (and it is only visible on my 4K screen at 300%) as you stop down. Diffraction sets in at f16 and this does soften the image. In terms of chromatic aberration, well wide open in high contrast situations it is apparent albeit slight and it is easy to correct in post. The lens is reasonably resistant to flare – but if you have a specular light source in the frame you will experience some veiled flare and ghosting. If you turn off the built in lens profile you can observe a slight barrel distortion, but switch on the profile and it is not visible. The bokeh balls this lens produces are more or less round when shooting wide open even at the edges of the frame and the transitions are nice and smooth. There is some onion ring bokeh which is the result of using moulded aspherical lens.Vignetting is not a problem and is very slight in the region of 1/2 stop.
Being designed to have an image circle much larger than micro four thirds requires means that you are using the best performing part of the lens and this really shows. Just for giggles I compared the Sigma with my old Olympus. The Olympus is noticeably soft in the corners at all apertures and just average in the centre. It suffers badly from chromatic aberration. Vignetting is very apparent, in excess of 1 stop in the corners with the lens profile switched on and getting on for 2 stops when switched off. Physically, optically and figuratively the Sigma stands head and shoulders above the little Olympus. The only area where the Olympus wins out is its small size and that is why I’ll continue to use it when I want something small and compact. For every other occasion I’m reaching for the Sigma. The knock on effect is that I’m seriously wondering about replacing my Olympus 45mm f1.8 with the Sigma 56mm f1.4.
It’s that time of year again. The farmers of the Wheatbelt are burning their fields in preparation for sowing. The smoke hangs thick over the Avon Valley and makes for a quite unpleasant experience for anyone who suffers from respiratory ailments. The upside is that the smoke particles in the air make for rather splendid sunsets. I snapped this one on my phone while cycling home. The next few were all shot while going out to get some beer on my Olympus OMD EM1 with 12-40mm f2.8 lens.
While making for some tremendous photos the practice puts a lot of carbon up into the atmosphere. Unfortunately Australian farmers will not stop the practice as this a far cheaper way of clearing fields than tilling. Profit always wins out.
On 7th October 2018 I put a video up of me unwrapping the Panasonic Leica DG Vario-Elmar 100-400 f4-6.3 ASPH Power OIS and my initial impressions of it. Well after six months of use this is my opinion of the lens. I don’t know if it has won the title for having the longest model name, but if not it should be a contender. For brevities sake I’ll just refer to it hence forth as the PanaLeica 100-400. At the outset I’ll say that this is my lens bought with my money and I’ve only used the one copy of it
First off let’s set things straight – this is a very specialist bit of kit that you either have a need for or you don’t. I’ll also say that there is a very good argument to adopt the micro four thirds system just for this lens alone. No I’ve not stopped taking my meds, this lens should be a contender for anyone who shoots wildlife, particularly birds, and travels a lot. A long time ago someone said to me, and I’m not entirely sure who it was, but I’ll attribute it to Hugh Graham who’d been a Fleet Street photographer, that you should choose your camera system on the basis of the lenses you’ll use. I think Panasonic were very smart when they designed this lens because this leverages all the benefits of the m4/3 system. It uses the two times crop factor and small size to produce a lens that is just not available in the 35mm full frame world ie a compact lightweight 200-800mm zoom lens. Recently a muppet on YouTube pronounced that micro four thirds is dead but this lens proves that the system is very viable indeed. Lets compare the PanaLeica 100-400 to some of its rivals.
Canon EF 800mm f/5.6L IS USM Lens
Sigma 800mm f/5.6 APO EX DG HSM Lens
Sigma 300-800mm f/5.6 APO EX DG HSM Lens
Nikon AF-S 800mm f/5.6E FL ED VR Lens
Or lets look at it another way. My Panasonic G85 with battery grip, two batteries, a memory card and the PanaLeica 100-400 weighs in at 1.829 Kg. A Canon EOS 550d with a Sigma 150-600mm F5-6.3 DG OS HSM Lens which has the same equivalent angle of view is 2.958 Kg and my Canon 6d with the same Sigma lens is 3.345 Kg and doesn’t have the same range. To get the same zoom range the 6d would need to be paired up with the Sigma 300-800mm f/5.6 APO EX DG HSM Lens and the combination would weigh 7.1 Kg. Now if you sit in a bird hide all day with your camera on a tripod then you might be prepared to sacrifice weight, expense and portability to get high image quality. But if like me you walk around anything up to 20 Km in a day looking for birds and are willing to work around the issue of the smaller sensor and it’s inherent poorer performance at ISOs over 6400 (and coming from the days of shooting slide film at ISOs between 50 and 400 I can’t believe that I see 6400 as a problem) then you will be very happy. The argument about image quality is very spurious if you only look at your images on an iPad or phone. So you can see why I think that this lens is enough to persuade people to adopt the m4/3 system – it has enormous reach, is lightweight and is very affordable.
100-400mm (200-800 35mm equivalent)
f4-6.3 to f22
20 elements in 13 groups
9 circular blades
Ultra sonic stepper motor
Close focus distance
The Leica designation denotes that Leica had input into the design but the lens is made by Panasonic at their Yamagata lens factory in Japan. The PanaLeica 100-400 retains the same design cues as Leica’s own lenses and the other Panasonic lenses in this series such as the 8-18mm f2.8-4 ie it uses the same fonts and the same ribbing for the focus and zoom rings. It features an all metal body construction and is listed as being weather proof. However, there is no rating as to the extent of the weather resistance. It is a very attractive lens to look at and has a satisfying heft to it which reinforces the fact that this a quality bit of kit. In November 2015 I blogged about the Olympus m.Zuiko 75-300mm f4.8-6.7 mk ii which I bought when I first started dabbling in wildlife photography, with its plastic construction it makes the PanaLeica 100-400 look like a luxury item.
With regards to the physical controls on the lens body working backwards from the built in mini lens hood (a separate full-sized one can attach to this but I have never used it) there is a narrow focus ring. As per usual with Panasonic this a fly by wire ring with no direct physical coupling to the lens heliocord. Behind the focusing ring is ring which locks and unlocks the lens mechanism to prevent zoom creep. This can be applied at any point in the focal range. The zoom ring is nice a broad enabling a good grip and is quite smooth with a little resistance to movement. It has a ninety degree throw and works very nicely when shooting video. The lens body extends outwards as you progress through the lens range. The front lens element, however, does not rotate which is good news for users of polarizing and variable neutral density filters. The tripod foot and collar is really a rather clever piece of design. There is no collar as such, the rear part of the lens rotates 90 degrees to allow users to change from horizontal to vertical orientation. The foot screws into the lens and can be completely detached. In another nice touch you don’t need the foot to attach a tripod plate as you can attach it directly to the lens body which reduces the profile of the lens considerably. Just before the lens mount there are three physical switches. The first is a focus limiter which offers two positions, full focus range and 5m to infinity. Below that is a switch for AF or manual focus, and below that a switch for the optical image stabilisation system. The lens mount is metal and there is an o ring that provides some sealing against water and dust ingress.
Without a doubt the PanaLeica 100-400 is a very complex lens with 20 elements in 13 groups, 1 ultra low dispersion element, 2 extra low dispersion elements and 1 aspheric extra low dispersion element. From this we can see that it is corrected against chromatic aberration and optimised to produce high contrast, high-resolution images whilst maintaining a compact form factor. Although each group is positioned precisely within the lens barrel it is impossible to do this perfectly so the three lens groups that are most acutely effected by tilt and centring defects and therefore impact most upon image quality are the only ones that are adjustable. This has meant that repair or adjustment of the lens is very difficult and only Panasonic’s Yamagata factory is able to do this which means warranty repairs are sent back to Japan for assessment and then are usually replaced. If your lens fails outside of the warranty period customers are offered a refurbished lens at a discount rather than a repair. To further complicate the issue Panasonic in most countries contracts out its customer service and it is very difficult to access and there have been quite a few accounts of poor service on various camera forums. So my best advice would be to buy this lens from a bricks and mortar store with a good returns policy and then thoroughly test the lens, because if you have a problem it could be quite difficult to resolve.
The image quality is very good from 100-300 and just gets a little softer towards 400. This is not unusual for zoom lenses. At all focal lengths the edges of the frame are a little softer wide open but sharpen up nicely as you stop down. Diffraction becomes apparent at f16. There is next to no chromatic aberration, and the only times that I did observe it a simple click in Lightroom fixed it. Flare is remarkably well controlled on a lens with so many glass elements. I have shot a lot of frames into the light and have found that I don’t need to use the full-sized screw on lens hood, I just use the mini sliding hood that is built into the lens. Filter users be aware that this lens is very fussy about filters as many long lenses are. I’ve had no problem with multi-coated B+W and Heliopan filters. For giggles I tried an uncoated Fotga variable neutral density filter and using a combination of the lens on both a G85 and an EM1 could not get focus. This is not a fault of the lens but shows the effect that using cheap uncoated filters can have on lenses. My Canon 70-200mm f2.8 IS L does exactly the same with the Fotga filter. I’ve never understood why people will spend $2K on a lens and then slap a cheap $10 filter on it. If you are going to use filters use good ones.
After six months of use and a few thousand exposures I think I’ve got a good handle on this lens. The inbuilt optical stabilisation combines with Panasonic’s Dual IS bodies (at the time of writing the GH5, G9, G95, G85, GX85, and GX9) to give impressive results, around 5-6 stops. When shooting 4K video with the G85 it is very impressive being able to shoot handheld with such a long lens. The video below has footage using the lens on both the G85 and EM1 as well as more stills examples. Unfortunately the OIS does not combine with the IBIS on Olympus bodies so it’s a case of either or. I have my EM1 set up with the IBIS permanently on and have selected Lens IS Priority in the custom functions. This means that when a lens with inbuilt stabilisation is detected the camera switches IBIS off. The reason for this is with shorter lenses IBIS is more effective, but with longer telephoto lenses lens based stabilization works best. The OIS works well enough to get fairly good handheld 1080 video with the EM1, but it’s obviously not as smooth as the G85. The hybrid AF system in the EM1 (a combination of contrast detect and on sensor phase detect) is more confident than the DFD (depth from defocus) of the Panasonic. With small subjects against busy backgrounds I’ve found that the G85 and the PanaLeica just hesitates that little bit as it tries to acquire focus and with small birds that slight hesitation is difference between getting a shot or not. The EM1 is very quick to acquire focus and that is why I’ve ended up favouring it more for bird photography. Now I’m perfectly happy to accept that this just might be a shortcoming of the AF system in the G85 and having read the Lumix GH5/Gh5s/G9 AF Guide Book things might improve significantly if I were to use one of those bodies. But for now I have the quandary of superb image stabilisation versus better AF and I’d sooner have better AF and use faster shutter speeds.
If you are already invested in the m4/3 ecosystem and are interested in photographing birds then this is a no brainer. The PanaLeica 100-400 is streets ahead of the Olympus 75-300 and I would imagine the similarly priced Panasonic 100-300mm. It’s absolutely the muts nuts for walking around in the bush photographing birds and larger insects. Now if you’re interested in wildlife and nature and either don’t have a camera or have another brand I’d really recommend giving this lens and a micro four thirds camera some serious consideration. The image quality is very good as long as you’re not a pixel peeper and are honest with your self on what you’ll do with the image. It is very liberating to walk through the bush unencumbered by heavy camera kit that cost the equivalent of the annual GDP of a small Pacific Island nation. My only wish is that there were more compatibility within the micro four thirds system so that the image stabilisation worked across brands, the zoom rings turn in the same direction and that Panasonic adopt the clutch mechanism on their lenses for manual focus with hard stops.
Away down south in the DenmarkWalpole region the other week. It was blissful with temperatures in the low 20s rather than the high 30s and low 40s we have in York. We had a great deal of fun walking around Wilson and Nornalup Inlets spotting and photographing birds. Here are three of the photos I took. All of them were taken with the Olympus OMD EM1 and the Panasonic Leica 100-400mm f4-6.3 Asph Vario-Elmar lens, of which I’ll have more to say in a little while. It is a lightweight combination that makes wandering around like this much more enjoyable than carrying my full frame Canon set up.
Originally the song was a track on the 1977 album Exodus and its release as a single in 1980 was somewhat of a surprise as Marley had released the Uprising album also that year. The song was well liked globally and is one Marley’s most popular songs – it’s feel good factor and catchy melody puts an instant smile on your face and before you can catch your self you find your self singing the chorus. Within 8 months Bob Marley had died from malignant melanoma. I remember the day very well, in fact I was still at school, Chichester High School for Boys Sixth form, and the next day one of my class mates, Chris Goodwin, gave a eulogy for him in the sixth form assembly much to the consternation of some of the staff. Chichester was an incredibly conservative place back then, people would joke that if there was a pig wearing a tory blue rosette it would be voted in as the Conservative MP for the town. Bob Marley left a powerful legacy as a third world performer who transcended his start as a niche world music performer to become a global superstar who spread a message of hope and love.
Being originally from England I automatically associate Christmas with cold weather, and by association Robins as they are part of iconography of the festive season. So when walking along the Avon River on a 40º C day seeing these Red-capped Robins seems a little incongruous. For such a small bird they are as bold as brass and will let you approach quite closely. The other confusing thing about Australian robins is that they don’t just come in red.
When we were in Tasmania we had proper winters with snow, and that meant we had robins in their proper setting, but not at Christmas. Oh it’s all very confusing!
… with flowers. Definitely not Julie Andrews and the ghastly singing Von Trapps.
When people think about Australian biodiversity and nature hot spots they automatically think of the rainforests of North Queensland, Kakadu National Park in the Northern Territory or Cradle Mountain-Lake St. Clair National Park in Tasmania. If prodded a little bit Western Australians might mention the Stirling Ranges National Park. But what if I were to tell you that there is a very significant region of biodiversity, a landscape that is still in its pristine state (i.e. has never been cleared) that is less than two hours drive from Perth? That it contains more than 1400 species of flowering plant, 24 of which are unique and not found anywhere else, there are 78 different species of bird, and there are ancient Aboriginal artefacts. So where is this place? Wongan Hills.
The name Wongan Hills comes from the Nyoongar Wongan Katta which means talking or whispering hills. The range of hills, which are about 10 north-west of the townsite are the largest single area of natural vegetation remaining in the northern wheatbelt. It is spring when everything happens – there is a truly spectacular display of wildflowers. I focus on native orchids and it is absolutely gobsmacking the number of different species and the sheer quantity of them. In the space of a morning’s walk around we found ten different species and they were totally new to me. Below are the fruits of that trip.
… with the Panasonic Leica DG Vario-Elmarit 8-18mm f2.8-4 micro four thirds lens which will be referred to hence forth as the 8-18 for brevity’s sake. For those who prefer video there is a video review at the bottom of the page.
The 8-18 was introduced as part of Panasonic’s Leica branded f2.8-4 lens range in April 2017. I was immediately interested as I wanted a wide-angle zoom in m4/3. I had discounted the existing Panasonic 7-14mm f4 and the Olympus 7-14mm f2.8 because they wouldn’t accept screw in filters and the Olympus 9-18mm f4-5.6 because the collapsible design means the lens is prone to failure due to the internal ribbon cables breaking. The new 8-18 presented itself with a high quality metal construction that was splash proof and a modest 67mm filter thread. I wanted to use the lens for video work and so the ability to take a variable neutral density filter was a must. So when the lens became available here in Australia I plonked my cash down and got one.
My first impression on opening the box was that it is a quality bit of kit – it feels nice in the hand with a cool metallic feel and satisfying density. The bulbous front element is well recessed and combined with the excellent locking lens hood means that it is protected from stray light and from being physically damaged. The lens barrel has two ring controls – the front being for focus and the rear for zoom – and a switch for selecting auto or manual focus.The focusing ring is of the fly-by-wire type that twiddles endlessly – I wish that Panasonic would follow Olympus’s lead and have the pull back clutch type focusing rings with hard stops. The zoom ring is nicely damped and travels in a smooth 90º rotation. Another gripe is that both Panasonic and Olympus are members of the m4/3 consortium so why oh why can’t they agree on which way the zoom ring turns? Both zoom and focus are internal which is nice as it does not affect the centre of balance while using a gimbal. The lens body is finished in a smooth black satin with the engravings done in the Leica font and colours. The lens mount is metal and looks to be chrome plated brass. So full marks to Panasonic for presentation.
8-18mm (16-36mm 35mm full frame equivalent)
angle of view
62º – 107º
minimum focusing distance
number of lens elements
number of lens groups
The lens construction is 15 elements in 10 groups with 1 aspherical extra low dispersion element, 2 extra low dispersion elements and 1 ultra high refractive index element. Combined with the nano coatings they should reduce internal flare, distortion and chromatic aberration. Control of distortion and chromatic aberration is also aided by an internal software profile that is baked into the image file. A lot of people don’t like this approach as they feel corrections should be made optically. The main criticism is that there is too much of an image quality hit in the corners with this approach. Hasselblad was the manufacturer to take this approach with their H3 camera and when that was introduced there were few complaints about image quality. The reality is that using lens profiles means lenses can be cheaper, smaller, and lighter than their optically optimised brethren.
The 8-18 has a variable aperture and unfortunately it quickly steps down as you zoom in as can be seen by the chart below.
I’ve done my standard teststo look for distortion, chromatic aberration, and sharpness at 8mm, 12mm and 18mm to give an indication of how the lens does throughout its zoom range. I have just for interest sake posted images with no profile correction to give an idea of what the lens is actually doing. Click on the images to see them at full size.
At 8mm without any inbuilt lens profile applied there is very obvious barrel distortion and vignetting at f2.8. With the profile applied there is still a very slight barrel distortion and the vignetting remains until f5.6. In terms of sharpness well at f2.8 the centre of the image is nicely sharp and contrasty and remain so until f16 when diffraction kicks in and softens the image. In the corners the story is different, at f2.8 the corners are significantly softer and less contrasty than the centre, they improve a little as you stop down reaching best performance at f5.6 and then get worse at f16 with diffraction. A small amount of chromatic aberration is present throughout the aperture range and is easily corrected in post.
At 12mm we can see no distortion when the lens profile is applied and the vignetting is about 1/2 stop and is barely discernible. Wide open at f3.4 the centre of the image is sharp and contrasty and the best performance is at f5.6. In the corners the image is softer and has less contrast than the centre. The best performance is at f8. Diffraction starts to set in at f11.
At 18mm there is some pincushion distortion in the profile corrected image. There is also a tiny bit of vignetting at f4 but this clears up at f5.6. Sharpness at f4 is very, very good in the centre throughout the aperture range only deteriorating at f16 due to diffraction.The corners are remarkably sharp at f4 but have slightly less contrast than the centre. Peak performance sets in at f5.6 and then again diffraction rears its ugly head at f16 and spoils the party. Chromatic aberration is very well controlled across the whole range and is very, very slight.
Like most wide-angle zooms the 8-18 is prone to flare. In order to reduce this the engineers recessed the front lens element and then provided a decent lens hood. The Panasonic 7-14mm f4 caused purple blobs on Olympus cameras when there was a specular light source in the frame. Some people pointed the finger at the difference in UV coatings between Panasonic and Olympus cameras. Others said the thickness of the Olympus sensor stack caused the problem. Anyway the 8-18 is thankfully free of those artefacts. Shooting into the sun there is some veiling flare and ghosting.
Auto focus is done via a stepping motor and it is designed to work with Panasonic’s Depth From Defocus technology that is basically a contrast based auto focus system that is enhanced by software profiles for each Panasonic lens. Single point autofocus in single shot drive mode is incredibly fast and accurate. I decided to check the Continuous Auto Focus by continuous shooting at medium speed wide open on the Panasonic G85 with a person walking slowly towards the camera at focal lengths of 8mm and 18mm. All the shots were in focus. Then I tried to see how the lens would perform on a camera without DFD – in this case an Olympus OMD EM1 mk i. At 8mm and f2.8 all the images were in focus. At 18mm shooting a burst of 10 images the camera lost focus on the last 2 images of the burst. So this very limited test shows that the autofocus of the lens does perform better on Panasonic cameras with DFD.
Ok I’ve had the lens a year now and I’ve used it for stills, time lapses and video shooting on the afore-mentioned EM1 and G85 along with an EP5 and EM10 so what can I say. The in camera lens profiles make a huge difference in terms of distortion, but most people won’t see this as they’ll see the corrected images. I did expect this to have some impact on sharpness in the corners but was pleasantly surprised to find that not the case at all. Most zooms perform best at the short end and become softer at the long end. With my copy of the 8-18 this lens is very good at the long end and it is a little softer at the short end. The ability to use filters is a boon for landscape photography and video. The 67mm filter size does not make filter purchases onerous and with the wide-angle filter holder you can use the Cokin P filter system with rectangular filter with an 85mm width. It is really nice not to use filters the size of dinner plates with this lens. I’ve been caught in a couple of downpours while using the 8-18 and have had no problems. I have found the lens immensely satisfying to use and have put it to more uses than I originally thought I would. In all I feel it is a very good lens if you can live without a fixed aperture. I would definitely recommend it.