2015 not a vintage year, thus far, for calm days.

It is official, the UK Meteorological Office confirms that 2015 to date has been pretty windy, there have only been 8 days when at least 20 weather stations across the UK have recorded a maximum gust speed of 10 Knots (11 mph) or less and none of these days has fallen in May, June or July so far.

http://blog.metoffice.gov.uk/2015/07/24/has-2015-really-been-that-windy/ graphic courtesy of the Met Office

It explains why several wild camping trips have bitten the dust, as the winds forecast at higher levels, along with rain, low cloud and hill fog have dampened any enthusiasm I've had for trips to the hills.

http://blog.metoffice.gov.uk/2015/07/24/has-2015-really-been-that-windy/

Gear review - In praise of Meindl boots

I recall once seeing an anatomy diagram of the foot and thinking that there was an awful lot of complexity going on down there, until that point I knew a foot consisted of 5 toes, sole, heel and an ankle joint and an achilles tendon courtesy of Homer. A school saturday job working in a shoe shop and I became aware of just how diverse feet can be; the surprising difference between feet attached to the same body; the variety in a population; why there's a very good reason for laces and how people will endure agony to wear the latest fashion brand/style.

http://www.aireurbano.com/foot-anatomy-diagram-tendons/foot-anatomy-diagram-tendons/

From my mechanical engineering perspective, the human foot is a tour de force of biomechanics and anything that complex needs a detailed set of operating instructions, to ensure trouble free operation over its intended design life. Sadly, there are no operating instructions. Faced with this problem an engineer would consider the best approach would be to design a device affording suitable protection and support.

http://www.healthandcare.co.uk/
Physio boot for stabilising foot

I learnt the expensive way, that buying the heavily marketed and celebrity endorsed brand of walking boot might deliver short term comfort and safety, it didn't necessarily equate with durability. Finally I received an unsolicited recommendation to try Meindl Borneo Pro MFS  boots from someone who knows these things, hard wearing, comfortable and some sage advice on boot TLC. 10 years ago I bought my first pair, they are still worn for walking in the woods, the treads worn too far down for the hills, but not worn enough to send for resoling. A 2nd pair were bought 4 years ago for hill duty. What can I say, except they've provided exemplary service from the peat bogs and heather bashing in Wales to pounding talus in the Cuillin's and through the quartzite block fields of the NW Highlands. Though not stated as a winter boot, they're still stiff enough for C1 crampons. The leather boots have been regularly cleaned and waxed keeping my feet dry, except when I've immersed them into water too deep for the Borneo height. A top tip is to wear Merino wool socks washed in natural soap to maintain the wool loft, even when wet, wool will keep feet warm, a better tip is to carry a spare pair of merino wool socks to change into, it's surprising how a wetted Borneo boot still feels OK, emptied out and a dry pair of socks worn. Those who have worn a boot for any length of time know that you can move across the landscape without staring fixedly on the ground you are about to step on, a quick glance suffices and the feet 'sense' or 'feel' their way, the Borneos have acted like a 6th sense. You do need strong walking pole(s) to accomplish this feat safely, as occasionally the feet will be deceived and the walking pole(s) will prevent you planting your face on terra firma. The Borneo soles are just stiff enough to angle up or contour short sections of steep hill slopes and high enough to 'wade' through 5" depth of water/bog. What's not to like?

http://www.aireurbano.com/diagram-of-the-foot-tendons/

Well, in more entertaining and rough terrain - wide expanses of tussocky grass, vegetated boulder fields, relict stream beds, morainic debris, contouring for extended sections of steep hill slopes, my feet were suggesting that 1. I needed to take more interest in map symbols and contour lines and 2. boot soles really needed to be stiffer for rougher terrain. For a few years I'd noted better performing footwear worn by those whose job demands they traverse rough ground. It wasn't quite a case of 'monkey see, monkey want', but on my wanders and when opportunity arose, I'd stop and chat to gamekeepers and stalkers, about this and that. I'd also make a point of enquiring on the performance of their outdoor footwear and the same names cropped up. As one stalker wryly noted about the job, you need 'good boots and a good bed. If you're not in one, you are in the other'. Even hardened to the prices of boots, I'll confess to sticker shock.

Meindl Dovre Extreme GTX
http://www.meindl.co.uk/products/dovre-extreme-gtx

A trip to Norway, inside the Artic Circle in September 2014 finally settled matters, walking over snow blanketed terrain and in the space of 2 days, I turned the same foot on the sides of hidden rocks 3 times, painful, but not serious, but a warning. The Norwegian hunting season was in full swing and hunters were conspicuous by wearing high visibility bibs over their camouflage gear, I'm guessing hi viz attire was the result of an incident involving the words 'misidentification, fatal, shooting, accident'. All the hunters were wearing the same boot style as the Welsh gamekeepers and Scottish stalkers. Back in the UK, desensitised to the sticker shock, and having established with Meindl that I could extrapolate the fit of the Borneo to the Dovre Extreme GTX boots, I ordered a pair.

Meindl Borneo and Dovre boots 2005 to present 

Putting on the new Dovre's and I was reminded of AA Milne's words “When you see someone putting on his Big Boots, you can be pretty sure that an Adventure is going to happen”. Size 11 boots weigh north of 2 kg, some low level, low gradient walks soon recalibrated the legs and I can't say I've noticed the weight or any fatigue, the Dovre's do feel good on the feet though. But then I'm not running, more a case of ambling along, taking in the views and noting the flora/fauna in the way. The increased height of the Dovre means a deeper depth of water can be crossed dry shod and there have been a few swollen 'allts' and 'nants' where I have crossed dry shod wearing the Dovres and would have had to empty the Borneos. So far the boots have met all expectations in walking over snow, slush, wet bog, quartzite block fields, morainic debris, contouring steep wet/snow mantled slopes and I'll update this review some time in the future for durability etc.

Update : a new post on Meindl boots July 2016

'One pound on your foot is equivalent to five pounds on your back' Really?

Rough bounds of Moidart

Read anything on outdoor walking footwear and sooner or later you'll come across the mantra 'One pound on your foot is equivalent to five pounds on your back' and usually associated with the review of fabric boots or latterly trail shoes and adjectives including awesomeness and amazing. Coincidentally reading the blogs and posts by light footwear advocates, I'm aware of the attrition rate of foot injuries and ailments. Google : plantar fasciitis, achilles tendinitis, metatarsalgia ...

So is there any science behind the statement of increased footwear weight equivalent to increased backpack weight? There is indeed. A study report published in 1983 by the US Army Research Institute Environmental Medicine, titled "The energy cost and heart-rate response of trained and untrained subjects walking and running in shoes and boots" Bruce H. Jones, Michael M. Toner, William L. Daniels and Joseph J. Knapik.

It is an often cited report by advocates of light footwear, less so the actual summary and almost never the results or discussion.

The summary reads :
To determine the difference in the energy cost of walking and running in a lightweight athletic shoe and a heavier boot, fourteen male subjects (6 trained and 8 untrained) had their oxygen uptake (V O2) measured while walking and running on a treadmill. They wore each type of footwear, athletic shoes of the subjects' choice (average weight per pair = 616g), and leather military boots (average weight per pair = 1776g) at 3 walking speeds (4.0, 5.6 and 7.3 km ° h-I) and 3 running speeds (8.9 10.5 and 12.1 km h 1 ). The trials for running were repeated at the same three speeds with the subjects wearing shoes and these shoes plus lead weights. The weight of the shoes plus the lead weights was equal to the weight of the subjects' boots. The VO 2 values with boots were significantly (p< .05) higher (5.9 to 10.2 percent) at all speeds, except the slowest walk, 4.0 km/hr. Also, O2 with shoes plus lead weights were significantly (p < .05) higher than shoes alone. Weight alone appeared to account for 48-70% of the added energy cost of wearing boots. The relative energy cost (Va02, ml * kg - I min - ) of trained and untrained subjects were the same at all speeds, but heart rates for the untrained were significantly higher (p<.05) in both shoes and boots except at the slowest walking speed (4.0 km/hr ). These data indicate that energy expenditure is increased by wearing boots. A large portion of this increase may be attributed to weight of footwear. In addition, the increased energy cost of locomotion with boots appears to place a limiting stress on untrained subjects.

And in the discussion

"HR (heart rate) during boot trials were higher than shoe trials at all speeds except the slowest walk, 4.0 km/hr"
"The data from this study indicate that for an increment of weigh:.equal to 1.4% of body weight carried on the feet the average energy cost increased 8% or 5.7 times what one would have expected for the same weight carried on the torso (Soule and Goldman 1969). Most importantly, the energy cost is significantly increased by wearing boots rather than shoes for walking and running at speeds above 4.0 km / hr"

OK, but what about the ladies?

Ergonomics. Volume 29, Issue 3, 1986
The energy cost of women walking and running in shoes and boots. B H. Jones, J J. Knapik, W L. Daniels and M M. Toner

Abstract
The purpose of this study was to determine the difference in energy cost for women walking and running in shoes versus heavier boots. Seven subjects wore athletic shoes (mean weight = 514 ± 50g) and leather military boots (mean weight = 1371 ± 104g) at three walking speeds (4·0, 5·6 and 7·3km/hour) and two running speeds (8.9 and 10·5 km/hour). During each walking and running trial oxygen uptake ([Vdot]O2 ml kg−1 min−1) was measured. The [Vdot]O2 for women wearing boots were significantly higher (P < 0·05) than for shoes for both walking and running, with the exception of the slowest walking speed. The average increment in energy cost was 1·0% per 100-g increase in weight per pair of footwear. These results are similar to those reported for men from other studies which found increments in energy cost of 0·7 to 0·9% per 100-g increase in weight of footwear.

A vast expanse of wet peat bog and tussocks, Cambrian Mountains

The science points to 4.0 Km/hr as the point at which lighter footwear is significantly better for men and women, walking and running on a treadmill.  Strangely enough you don't read anywhere that there's an insignificant difference between light and heavy footwear below a walking speed of 4km/hr.  4.0 Km/hr (~2.48 mph) is a walking speed that in my opinion is an aspirational a very respectable speed for a landscape photographer in the hills, laden with the hill kit and photography gear. Throw in the wild camping kit and food, and 4 km/hr is probably only exceeded on a gentle descent with the car in sight. Come to think of it, for a 7 hours hill walking trip, with an hour for stops, that's a walk of 24 km at a sustained pace of 4 km/hr, I would speculate that there's a high percentage of hill walkers who walk at speeds less than 4 km/hr and/or stop for far longer than an hour. Walkers and backpackers maintaining walking/running speeds greater than 4 km/hr, could make an empirical and justified scientific case for lightweight footwear, for everyone else it seems dubious if 'one pound on your foot is 5 pounds on your back' actually applies, as the research data inconveniently point out the human body's biomechanics of leg muscles and tendons have an inherent energy tolerance threshold for footwear weight, that threshold is reached at a walking speed of 4 km/hr.

'one pound on your foot is 5 pounds on your back' is a memorable line though. Put 5 lb of weight into a backpack and lift it, yup you can feel it. It doesn't take a genius to work out that a pound of weight on the other foot is another 5 lbs of weight on your back, 10 lbs in total!  Pick up a pair of heavy boots and lighter boots, you can also discern the weight there too. It is odd though that when you put the heavy boots on your feet and walk around you soon forget the weight, the fit and comfort are more apparent and light boots when new are generally less stiff and 'comforting' than new heavy boots.

I can't find any research for temperatures/climate where breathability of the boot and its physiological effect is measured, but in hot conditions there's good empirical evidence to indicate a fabric allows better breathability and 'cooler' feet and are much preferable to 'hot' feet or better still even wear sandals.

Heather bashing on the Moelwyns

So away from people on the internet advocating light footwear for hill walking, what do people who actually work outdoors wear on their feet? Actually there's not that many professions requiring sustained exposure to hill terrain and elements day after day. Of those professions left, it has been my good fortune to meet gamekeepers and stalkers, in the hills and have a 'wee blether' about the land and weather, I've also taken the opportunity to enquire about clothing and footwear worn day in, day out on the hills and moor in all weather, contouring the slopes below ridge lines whilst stalking game across terrain that rarely sees walkers who aren't lost. The same boot names came up time and again. The boots aren't fabric and they are heavy, so they are never written about by backpackers and hill walkers, instead I'll write more about these boots in a future post.

Landscape photography aesthetics - Atmospheric hills

What the UK's hills lack in stature they make up for in atmosphere, courtesy of North Atlantic weather systems, driven by the jet stream. The atmosphere manifests itself as precipitation, cloud and wind, that provide the opportunity for atmospheric images and pose genuine questions of a landscape photographers endeavour, gear and technique, in the field.

Personally there's some appeal in making images in dynamic weather in the uplands and with a slice of good fortune, the cloud breaks to let sunlight through and play over the land as just reward for the effort and perseverance, it helps offset the days when things didn't quite go to plan. It was heartening and refreshing to see Mark Littlejohn's image of Glencoe awarded the LPOTY title, which captured the nature of that Glen well.

Average annual rainfall exceeds 4 metres on the higher hills in Wales, England's Lake District and the North West Highlands of Scotland. The summit of Ben Nevis reportedly clocks up on average,  250+ days annually with gale force winds over 50 mph and even down at 400m asl on lower hills and upland areas, there's still over 2.5 metres of rainfall annually and winds over 50 mph are not uncommon. The true nature of the UK's hills and uplands is a wet and windy one, as anyone who takes an interest in the Mountain Weather Forecast will attest.



The prime reason for monitoring the weather forecast is the hostility of the UK's weather, the only historic data I could find was from the Cairngorms automated weather station data which gives an indication of the weather severity in the hills.

Caingorm AWS

From the wind chill table above, an increase in windspeed and drop in temperature, changes the weather in July on the Cairngorm summit from pleasant to something potentially serious, if clothing is wet. It seems surprising that mountain hypothermia or the Cold Wet Killer was a phenomenon little understood until relatively recently from research precipitated by a tragic incidents. Two incidents come immediately to mind, in 1951 4 mountaineering club members died walking along the Uisge Labhair to the Ben Alder Cottage and in 1964 the deaths of 3 walkers on the Four Inns walk in the Peak District. The Four Inns Walk tragedy initiated medical research into the physiology of hill walking exposure. The risk of exposure, emphasises that in upland environments, outdoor gear is worn and carried that is proven fit for purpose and kit also packed to deal with an emergency, which with camera gear makes for a heavy backpack. A piece of kit that differentiates the upland landscape photographer, is the use of a technical backpack, instead of the frankly lame and marketing hyped, expensive, PoS, dedicated camera backpack.

There's also some pragmatism needed with upland weather, as there will be trips where all that results is an enhanced respect for the ability of native fauna to cope with the elements, the performance of outdoor gear given a field test and the joy of navigation with compass bearings. When deciding on what outdoor wet weather clothing to buy, an excellent starting point would be that used by unsponsored mountain guides or better still Mountain Rescue Team members as to the brands that actually perform in the hills. It's also interesting to note the choices by MRTs operating in different seasons and areas. If you ever get the opportunity, gamekeepers are well worth engaging in conversation, once you get past their dour exterior, they're really quite friendly and possess a wealth of practical knowledge of the outdoors and particularly of 'their' hills and moors.

My preference for camera gear is similar to my outdoor gear and is biased to weather sealing and build quality, which carry a weight penalty. Before wasting time and effort expended in the hills, it is well worth testing new gear at low levels in strong wind/rain to identify any weaknesses and/or establish the limits of the field performance. If you consider that a tripod is an essential component of your kit for composition and enabling long exposures at stopped down apertures and low iso, then tripod legs and heads are definitely worth investigating to ascertain the optimal weight/stability/ruggedness/height ratio.

It might just be me, but for a few years now,  I have been more interested in landscape photography emanating from hill walkers, backpackers and other outdoor communities, part of the reason is their empathy with the landscape and weather which manifests itself in some compelling work.

Landscape photography aesthetics - wet rock surfaces

There's a natural optical phenomenon where the colours of rock are more vibrant and subtle nuances of texture revealed. The phenomena is usually associated with a weather forecast of sustained rainfall, shower or drizzle, it is the effect of a wet surfaces on colour saturation and luminosity.

Temperature, pressure and time. NW Highalnds

The scientific explanation of the effect of wet surfaces on light and colour saturation, gets 'deep' quickly with terminology such as surface reflectance, albedo, roughness profiles, water film thickness, absorption, material porosity ...  It is much simpler to conduct an empirical test, by collecting a smooth surfaced rock and a rough piece of rock, examine them dry, then apply water and observe the colour change between wet and dry surfaces and light reflectance from different view points in relation to differing natural lighting regimes.

Erratics and glacial scouring, NW Highlands

The curious landscape photographer should make a point of picking up the odd rock on their travels and then at their leisure photograph the rock collection when wet/dry with blue sky and cloud overhead to observe the effect of colour saturation and light reflection and draw their own conclusions.  My own aesthetic preference is from wet, damp and lastly bone dry rock, which probably explains the popularity of polarising filers for photographing desert scenery and why overnight rain or dew contributes to the vibrant colours of dawn.

Dawn colour, Snowdonia NP

The roll out process and reviews

I received a phone call from Clifton Cameras, to inform me they had availability of the 5DS R to fulfil my preorder, I explained I would rather test the 5DS R with Leica R lenses for mirror clearance on a demo model in the shop, rather than me return a model with marks on the mirror and also test to my satisfaction the colour rendition against the 1Ds3,  they understood and confirmed a demo model would probably be available in the shop sometime in September. Demand and sales are going well apparently. One thing I'm conscious of though, is that my expectations from the initial announcement, are gradually being eroded by actual information on build, performance and images, as the roll out continues and photographers put the camera through field testing.

One of the very few online photographers I rate highly for gear reviews is Ming Thein, http://blog.mingthein.com/2015/07/02/canon-5dsr-review-part-1/ in part 1 of the review there are images made with the 5DS R of scenery and lighting that I can relate to, the UK. All I can say is that the foliage and some cloud colour appears too yellow/mustard, to my eyes. It could be summer foliage wilting under the recent heat wave and the clouds may be picking up colour from underlying mustard coloured countryside, or it may be RAW conversion software? There is nothing that suggests 'wowza' colour though, quite the opposite. So, I'm more than happy to sit on the sidelines and watch events unfold, which should be interesting with 'no skin in the game'.

EDIT 23/08/15 A phone call from Ian at Clifton Camera to say my 5DR S was in and I visited Clifton Cameras 22/8/15 with the intention of trying out the 5DS R they had in stock with R lenses and testing against 1Ds3 colour, I never even got to that point as I'd made up my mind to stay with the 1Ds3, which despite its age and deficiencies, I can live with for my limited needs and the the prospect of spending £3K+ for more MP, slightly better Live view against a reduction in battery life and weather resistance/build quality I couldn't quite square. In store I apologised to Hannah and mentioned why I was cancelling. There was a 10% discount off binoculars at the store and flushed with saving £3k+, I picked up two pairs of Leica binoculars and a new 1D series battery, so some compensation for the loss of a 5Ds R sale and I'll note again I have been impressed by Clifton Cameras service, help and professionalism.

Landscape lens odyssey part VI - Optical design & Engineering

The 6th post in a series looking at how I arrived at a stable of lenses for my landscape photography as a Canon 1Ds3 owner and dedicated tripod user. 

I had been contemplating an upgrade from the Canon 70-200/4 to the the IS version, which everyone online raves about, even though the MTF charts don't suggest a radical improvement in areas where the non IS version is found wanting. OTOH the IS version may be a stellar performer in the 80-190mm region, if so, Canon might wish to reconsider presenting their optical data similar to the way that Leica does, as the 70-200mm f4 is a much better lens away from the ends of the zoom range.

20 lens elements in 15 groups

10 and 30 lp/mm % contrast curves  blue colour f8- solid lines sagittal,  dashed - meridional. Canon MTF charts for 70-200mm f4 IS

There were a few Leica R lenses that interested me, but a used Vario Elmar 80-200mm f4 was the one that I purchased first to test the water, mostly because I was looking for better performance from a tele zoom and could make a direct comparison to my copy of Canon's 70-200mm f4 in a woodland setting, where there would be 'high spatial frequency detail' over most of the image. There were also theoretical MTF measurements from the manufacturers and actual MTF measurements from tests at  www.photodo.com.

16 lens elements in 13 groups

10 and 30 lp/mm % contrast curves  blue colour f8- solid lines sagittal,  dashed - meridional. Canon MTF charts for 70-200mm f4

10, 20 and 40 lp/mm % contrast curves solid - sagittal,  dashed - meridional www.photodo.com MTF chart for Canon 70-200mm f4

10, 20 and 40 lp/mm % contrast curves solid - sagittal,  dashed - meridional www.photodo.com MTF chart for Leica 80-200mm f4

Leica tech data Vario Elmar 80-200mm f4 @ 80 mm

Leica tech data Vario Elmar 80-200mm f4 @ 100 mm

Leica tech data Vario Elmar 80-200mm f4 @ 135 mm

Leica tech data Vario Elmar 80-200mm f4 @ 180 mm

Leica tech data Vario Elmar 80-200mm f4 @ 200 mm

12 lens elements in 8 groups 

Testing of zooms, at stopped down apertures, at infinity, on scenery with randomly orientated 'high frequency spatial detail' in my opinion needs a wooded valley of some width and a variety of views across and along the valley axis with sky lined branches / horizon. On my doorstep, the topography of the Forest of Dean and Wye Valley fortunately has a few elevated locations for telephoto zoom lens testing, which is handy when the infinity focus at 200mm and f8 is ~140m. There were also elevated view points inside the woods where image comparisons at the wider end of the zooms could be made. Testing setup was tripod positioned on hard ground, MLU, cable release and manual focus in live view @10x magnification across the image to ensure everything was in focus. I'll add that when testing lenses for resolution, wind can be a pain on subject matter and good air clarity.

The quality of both lenses needed Pixel peeping of test images to establish the resolution capability,   which subjectively determined that -

The R displayed minimal chromatic aberrations.

It was a close call for resolution in the dead centre of the image, but not at all focal lengths.

Sometimes the L lens, sometimes the R, away from the centre the R outresolved the L for fine detail across the image into the edges and corners.

I never noticed any effect of field curvature effects stopped down and live view focusing.

The lenses were also tested over some manually set white balance settings and in my opinion the Leica images had more vivid colour. The analogy I'd use would be to compare an image file in Adobe RGB improperly converted to the sRGB colour space and the colour takes a hit through a smaller gamut envelope.

I didn't test specifically for flare resistance between the two lenses, but subjectively I'd say the Canon has better flare resistance and the Leica has a built in hood for good reason, it's worth employing the hood at all times in all lighting.  Typing of hoods and there's a good reason Canon doesn't show the hood attached in any marketing information, it makes for a great weathervane in any wind ...

Build quality of the Leica R zoom was impressive, in a different league to the Canon L lens, as was the manual focus compared to the Canons, to be fair to the Canon though it can auto focus and has electronic aperture control.

The Leica is slightly physically smaller, but is heavier than the Canon (1.05 kg incl leitax adapter and caps vs 0.81 Kg incl hood and caps).

Leica R 80-200/4, Canon L 70-200/4 and lens hood

Some caveats to the testing.  The Canon was a hands down winner over the  70-80mm focal length. The L lens was purchased from new and has seen heavy use, I've no idea on the Leica zoom history of use. I didn't notice vignetting as being an issue for either lens and never checked for distortion, the woodland scenery was mature oak and beech, with downy and silver birch trees, not subject matter that lends itself to distortion analysis. Over 6 years of use, the Canon lens had seen some exposure to wet weather and dusty/pollen conditions and despite its reported environmental sealing limitations, the internal glass is clean and I've had no issues. I could find no information on the Leica environmental sealing. There's also the consideration of a lens mass produced for a photography market requiring autofocus capability vs a far lower production volume lens for a niche of manual focus photographers.

What I found interesting was how optical lens diagrams didn't correlate with actual optical performance. The 12 element 8 group optical design of the Leica R zoom and the 15/12 and 20/15  optical designs of the Canon L f4 zooms.  I had been led to believe additional lens elements groups were used to correct for higher aberrations, this wasn't the case from my subjective testing. Anyone researching Leica R lenses will end up reading the observations and insights of Erwin Puts, and it soon becomes apparent that he has an enquiring mind, has some knowledge of Leica's history, products and access to Leica's designers and engineers, more importantly he writes from the perspective of a photographer, not a marketing drone. The review of the 80-200mm f4 mentions six elements with anomalous dispersion glass and/or high refractive index and a total of eleven different glass types used.  The lens rendition of colour was also a surprise and not something I had expected, I've no idea why the colour was better - coatings, exotic glass types, better colour correction, fewer lens elements reducing the number of air/surface interfaces or maybe a combination of factors, oh and engineering tolerances?

Those who know about these matters state that manufacturing and assembly tolerances can have the greatest impact on image quality, from precision grinding of a lens surface, to alignment of lens elements inside the lens barrel, there will be an engineering tolerance build up. Which could create a Catch 22 scenario, where increasingly complex lens designs aimed at improving optical performance actually degrade image quality through engineering tolerance build up. Those lenses that pass quality assurance - inspection and testing - of a defined performance point should demonstrate some variability in performance courtesy of tolerance stacking. The excellent www.lensrentals.com blog has a few posts demonstrating the variability of lens performance.

http://www.lensrentals.com/blog/2013/09/there-is-no-perfect-lens

http://www.lensrentals.com/blog/2015/03/a-quick-zoom-variation-demonstration
http://www.lensrentals.com/blog/2015/06/measuring-lens-variance

And it seems optical performance variation also exists within 50mm f1.4 primes, the Zeiss Outus 55/1.4 variability might be due to a complex aspherical element ...
http://www.lensrentals.com/blog/2015/07/variation-measurement-for-50mm-slr-lenses

Landscape lens odyssey Part V - Divining MTF charts and cinematographers lens evaluation

The 5th post in a series looking at how I arrived at a stable of lenses for my landscape photography as a Canon 1Ds3 owner and dedicated tripod user. 

Canon produces a publication titled 'Lens Work' with a chapter on Optical Terminology and MTF Characteristics, which unusually for texts on optical matters is remarkably lucid in describing what a layman needs to know and one of the few publications that refers to a lens Colour Contribution Index. An ideal MTF chart illustrates the measurements of contrast of an actual lens optical performance under a test environment and can potentially indicate areas of the lens strengths and weaknesses. MTF charts provide no information on colour rendition, flare, distortion and build quality.

A little knowledge is dangerous, as I could appraise Canon's calculated mtf charts with images made by the lenses I owned and observe how the optical performance indicated by the 30 line pairs per millimetre (lp/mm) of the sagittal and meridional curves appeared to correlate with the resolution of fine detail in an image, with the difference between the sagittal and meridional curves indicating astigmatism and a nod to field curvature, astigmatism, chromatic aberration and an assumption my technique was adequate.

It was an exercise that provided an insight into correlating actual performance with theoretical, I'd be lying if I said, I didn't try and visualise what the image might look like if the 30 lp/mm curves were closer together, higher up the %contrast scale and flatter across the image. My eyes also suggested that my copy of the 17-40 was better away from the ends and not that bad focused in the corners and stopped down at 20mm, performance at the tele end was also visibly better when stopped down to f11, which for landscape photography is not a bad thing at all.

Every article I have read on divining mtf charts has a caveat that charts shouldn't be compared with other manufacturers nor across different focal length lenses. It appears that some manufacturers charts are not tests of actual lenses, but are calculated curves; some manufacturers calculated measurements, may be more theoretical than others and may or may not, include design tolerances, assembly tolerances, geometric losses etc. Some knowledgeable commentators hint that a lens could be designed to produce a respectable mtf characteristic that wouldn't necessarily be reflected in actual performance.  So ideally, it would be good if someone independent had the wit to test and measure real lenses and correlate manufacturers MTF charts with reality. It just so happens that a photography website once did just that http://www.photodo.com/browse-lenses/sort-mtf-score-desc and graded lenses to some criteria and also published the actual MTF charts of lenses tested by Hasselblad and the 10, 20 and 40 lpm spatial frequencies at full aperture and f8, at infinity focus. The downside was that the lens tests dated back to 1990's/early 2000's, but they did highlight, to my eyes, some potentially high performing lenses that could be adapted to the EF mount. Just an observation from analysing the photodo MTF's, but if the 40 lp/mm sagittal and meridional curves are above 60% contrast across the image width at f8, there's a high probability the lens is highly regarded in the photography community.

Leica's MTF chart for the Macro Elmarit R 60mm f2.8

Back in late 2011, despite Canon's extensive lens line up, the future in my eyes suggested more image stabilised lenses, faster autofocus motors and a suspicion Canon was focusing on video cameras and cine lenses. So, I decided to look elsewhere for lenses to meet my desired angle of view and optical performance. For a few years EF mount landscape photographers had migrated to Carl Zeiss ZE lenses, legacy 35mm and medium format film lenses that could be mounted on the EF mount by using adaptors. In my opinion there's an entrenched tribalism to photography brands and gear, which unfortunately manifests itself on photography gear forums, as highly subjective opinion based on pseudo science/delusion/personal agendas/prejudice and anecdotal evidence. There are some genuinely useful opinions, but it is a dispiriting search for pearls of wisdom

Leica's MTF chart for the APO Macro Elmarit R 100mm f2.8

Cinematographers were also starting to seriously test and evaluate legacy manual focus 35mm lenses for their needs, their incentive was driven by the price of cinematography lenses and the fact that 35mm DSLR's were incorporating video and increasing capability. The evaluation of legacy and current lenses by the cinematographer community was insightful and informative for its transparency and reliance on characterising a lens performance on actual images under varying subject and lighting scenarios. 

Leica's MTF chart for the Vario Elmarit R 28-90mm f2.8-4.5 @ 70mm

Based upon the manufacturers published MTF correlation with photodo's actual MTF testing and the insights gained from the cinematographer community evaluation, the surprising upshot was that Leica's R lenses would be the ones to further investigate.

Leica's MTF chart for the Vario Elmar 80-200mm f4 @ 135mm

Landscape lens odyssey Part IV - Primes or zooms?

The 4th post in a series looking at how I arrived at a stable of lenses for my landscape photography as a Canon 1Ds3 owner and dedicated tripod user. 

For all practical purposes a lens imposes a field of view constraint on a landscape, the camera viewfinder/digital sensor imposes an aspect ratio, the height of the tripod will determine the view point. It is the landscape photographer who positions a tripod, chooses an aspect ratio and selects a lens field of view to compose the scenery and when the lighting is right, make an image. It is also the landscape photographer who has to schlep their camera gear on top of an outdoor walking kit, food and water, into the landscape and they alone will make a judgement call based on their fitness, nature of the terrain, weather, distance walked and most tellingly the height ascended from the car boot.

Snowfall, Glen Affric, 2013 ~ 80-200mm

It is also worth reflecting on the amount of fine detail (high spatial frequency subject matter) present in landscape scenery, I can think of flora, geology, geology structures, fences, rime and that's about it, there are no eye lashes, fur, hair, feathers etc.  At the other extreme are woodland landscapes, with bark, branches, twigs, leaves, stems, grasses, flowers, ferns, moss, lichens etc. fine detail all over the image, well into the corners and woodland landscapes are usually made when there is minimal wind and diffuse light, which encourages the viewer to concentrate on the fine detail, colour and textures.

Squall light, NW Highlands, 2011 ~ 45mm TS

There's an almost undercurrent of elitism when it comes to making an image with a prime, compared to a zoom lens. Zooms are perceived to encourage a fast and loose approach to framing a composition, whereas a fixed field of view, forces the landscape photographer to use their feet to 'zoom' in the field, exploring the scene until finding the composition which works and the warm glow of satisfaction from having made an image with a fixed field of view prime lens. Well, adopting a pragmatic approach, there's nothing stopping the zoom user using the same principles and disciplines required to compose a scene to that of a fixed focal length.

Clearing rain,Snowdonia, 2009 ~ 24mm TS II

There seems a consensus that zooms are close to the performance of primes when stopped down,  though there are still weakness in many zooms, the variability and inconsistency over the range of focal lengths, with 'sweet spot(s)' which can be the middle of the range, the extremes of the range or just an end only. I'm also of the opinion that prime lenses optimised for infinity and stopped down performance are superior to an equivalent zoom focal length, due to the higher resolution of fine detail.  Would I like to use a set of primes in the hills? Yes. Am I prepared to carry a set of primes into the hills? Nope. Would I use a mix of zooms and primes in the hills? Maybe, depending on the nature of the landscape. Is it a disconcerting experience to change primes in inclement weather? Yes. Am I prepared to cart a set of primes for woodland landscapes into the woods? Yes. Would I use zooms in a wood? It depends on the woodland and season.

Squall sunset, Glamorgan, 2009 ~ 17-40mm

So, some years ago I decided my landscape lens needs would be best met by adopting a horses for courses selection.

EDIT : Oh, I forgot the environmental factors such as dust, pollen, spores, spindrift, driven rain and sensor contamination. A zoom lens means far less lens changes, which may or may not be an issue depending on season, weather or the environment you are out in.

A woodland soil seed bank

One of the Forest of Dean's great wildflower displays is courtesy of timber harvesting operations, when the woodland soil is disturbed and the change in light regime on the woodland floor from tree felling, breaks the dormancy of seeds buried in the soil. A couple of years after harvesting operations in most areas of the Forest of Dean, a carpet of Foxgloves will rise, until the canopy closes in again, shades out the flowers and seeds again lie buried and dormant in the soil, awaiting another timber harvesting operation to begin the cycle again.

I was fortunate enough to time a visit with minimal wind and some drizzly rain to make some images of a Foxglove carpet in a planted ancient woodland site and tick off another item in an ongoing project on the Forest of Dean.

Landscape lens odyssey Part III - Optical aberrations and phenomena affecting landscape image quality

The 3rd post in a series looking at how I arrived at a stable of lenses for my landscape photography as a Canon 1Ds3 owner and dedicated tripod user. 

The most succinct observation that I've read is that optical lens design is - 'the art of shifting aberrations somewhere where they are least seen' 

For an introduction on lens aberrations with illustrations and insight this link is worth a read http://www.lensrentals.com/blog/2010/10/the-seven-deadly-aberrations

I hadn't intended posting this as I'm not an optical designer and make no claim to have any profound insight into optical design and some of what follows may be well intentioned, but highly erroneous thinking. There may be optical aberrations and phenomena that I've discounted, that actually do impact on landscape imagery. Nonetheless, what follows is a highly subjective probably erroneous and abridged overview of lens aberrations, optical phenomena and their potential impact on images of landscape scenery that I prefer to photograph. 

Lens distortion -  I can't recollect an image being affected by low to moderate levels of pin cushion or barrel distortion, if you stitch panoramas you may feel differently.

Coma (Comatic aberration) - A concern for astrophotography, being honest I've read the terminology and am still no wiser on any effect for normal landscape scenarios at stopped down apertures.

Colour fringing (Axial and Lateral chromatic aberrations) -  What is perplexing is the nature of colour fringing isn't easily characterised by aperture, focal length, subject, it's a heterogenous phenomena in my experience and can show up anywhere in an image, but generally shows up towards the edges/corners of an image around high contrast edges. Snow patch edges, horizons, highlights and skylined foliage are prime candidate subjects for colour fringing, with the signature fringing of magenta, purple, green, red, blue and yellow.  Some colour fringing can be easily removed from some image subjects in post and at other times it is a tedious, time consuming if not impossible task to remove in other subjects. There is some speculation on the cause(s) of colour fringing on the internet, even sensors are suspected, but there are lenses that exhibit minimal colour fringing they are designated as being very expensive apochromatic or nearly apochromatic slightly less expensive.  I'll confess to an acute sensitivity to purple tree branches.

Flare, veiling flare, ghosting etc - not desirable and very challenging to correct, best avoided in my experience, unless the lens has the coatings up to the task, use of the lens hood and/or shading the font lens elements with a hat/hand is advisable.

Field curvature and astigmatism - manifests itself as unfocused and partly focused areas and elements in an image.  

Illustration of Field Curvature and why focusing in the corner, (the blue intersection point of lines) is a good idea with the lens stopped down (increased depth of field). Also a reason why MTF charts can show a drop in performance across the image.
Arribution : By BenFrantzDale (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

If you want to verify the effect of field curvature, it is best to give some thought to an actual landscape view that has subject matter which will highlight field curvature/astigmatism, visit it and with careful live view manual focusing across the image from the corners to centre, make a series of images, recording the focus distance  and repeat through an aperture range. You will have characterised your lens copy and established how field curvature afflicts that lens, what apertures provide enough depth of field to mask the effects of field curvature and the actual minimum focusing distance to achieve near/far sharp landscape images. Wide angle zoom lenses present an interesting challenge as field curvature and astigmatism will vary across the range of focal lengths, as there is a power law relationship with the angle of view ~ double the angle of view and field curvature/astigmatism increase by a factor of 4.

There's also evidence to suggest that some lenses have different field curvatures for different spatial frequencies, so fine detail should be carefully examined/pixel peeped.

Colour rendition - It could be an elephant in the room, emperors new clothes or a white elephant scenario. There are 'cool', 'warm' and 'neutral' colour lenses and this may potentially enhance or adversely impact a landscape image. I don't know if a lens colour rendition is relevant with digital sensors, colour filter arrays, camera digital white balance, colour saturation settings and RAW software, lens profiles ... but I could speculate that a lens colour contribution must have some impact on an image. There are ISO standards for the colour contribution index of a lens, limited manufacturers literature, some speculation that getting better colour involves investing in lenses that include the words APO, exotic glass, aspheric lens elements and marketing material which proclaims 'vivid' 'crisp colour' 'natural rendition'. There is a price to pay as normally the lenses are expensive.

Sharpness/resolution/acutance - I'll define it as the ability to resolve fine detail across the whole of a landscape image, at stopped down apertures and manually focused in live view to allow for field curvature. I can easily trade some centre sharpness for improved edge/corner performance.

Diffraction - with a 21mp sensor I once took a set of images between F5.6 and F22, pixel peeping unsharpened images and a loss of sharpness can be detected, in print with appropriate sharpening the difference was far less apparent. I've since read articles online by other photographers who have reached a similar conclusion on far bigger print sizes etc etc I believe; lens aberrations; insufficient depth of field; technique shortcomings and atmospherics, all have a bigger impact on image quality, imho.

Sunstars - The number of aperture blades for some landscape photographers is a critical aspect, I rarely incorporate the sun into compositions, so it isn't an issue. Aside from sunstars, I've no idea if  there's any benefits to 5,6,7,9,14... aperture blades.

Vignetting - I can live with moderate amounts at stopped down apertures, if you are stitching images this may be more important.

Focus shift - where the point of focus moves as the aperture changes. It may be astigmatism or field curvature, a combination of either or something else, I've no idea. Another reason to check focus in live view, having recomposed a scene and to test out in the field.

Rendering of out of focus areas - is something that I've never considered, as I'm normally trying to maximise depth of field to keep everything in focus. 

Prime or Zoom lenses - this is a subject deserving a blog post all of its own, as it defines to some extent a landscape photographers philosophy on image capture in the field. 

My own philosophy on lens quality is a pragmatic one, which concerns those lens optical aberrations and phenomena with the aperture stopped down, that adversely impact in my subjective eyes close scrutiny "print sniffing" of an A3 print of landscape scenery from a 21MP sensor. Some may consider this a low bar, I'd counter that there's a surprising number of lenses that fail to meet this remit.