Latitude and light envelopes

The graph below illustrates the solar elevation and azimuth for 56 degrees north and has some profound implications for landscape photography at that latitude. Sunrise on the summer solstice will illuminate north east facing subject matter and sunset on the winter solstice will illuminate south west facing subject matter.

Illustration for a point 56 degrees North
By Deditos (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

A look at the solar elevation for the summer solstice on the 56th parallel suggests the camera will not be required for much of the day, unless some 'weather' puts in an appearance. However on the winter solstice there is nearly 7 hours of daylight and a maximum solar elevation of ~10 degrees, which means there is theoretically photogenic lighting all day. But what about the rest of the year?

Copyright https://www.esrl.noaa.gov/gmd/grad/solcalc/

The US National Oceanic and Atmospheric Administration has an excellent solar calculator for investigating the potential of a locations light envelope. Some user interaction is required, but the time window of the 10 degree solar elevation can be gleaned and the azimuth of the 10 degree elevation established. It's a sad reality that many locations will never be illuminated by light at the extremes of the day but can be illuminated by photogenic light when the sun clears whatever it is that is masking sunrise/sunset and the NOAA solar calculator in conjunction with maps is a useful aid in determining when that might happen. Twilight duration can also be investigated by entering times before/after sunrise/sunset and noting the negative value of solar elevation.  I've used it for a number of years and have no hesitation in recommending it.

Nic photographing in the Graian Alps ~ 30th June 2014

The vagaries of upland weather

The last two trips have perfectly illustrated why it's best to adopt a phlegmatic approach to landscape photography. The first one Nic accompanied me to Y Mynyddoedd Duon (Black Mountains) and a walk up onto and along the Ffawyddog ridge. The walking was enjoyable in warm sunshine with a cooling breeze, heather moorland in bloom and natures larder of bilberries were deliciously sweet.

It became apparent the area encompassed by the Ffawyddog ridge, Vale of Ewyas and Hatterall ridge was a magnet for clear skies, whilst trains of photogenic cloud formations rolled in from the NW further east and to the west over the Gaider Fawr ridge.

Photogenic cloud

I have no great enthusiasm for landscape photography with overhead clear blue skies due to their propensity to drain colour from a landscape and whilst black and white photography would rescue some images it holds no interest for me. When I belatedly decided to explore the moorland vegetation with a macro lens, the wind increased in strength and as sunset drew near a visibly long bank of slow moving cloud appeared to the NW that would mask the best light. The last of the sunlight was utilised for an image of photogenic cloud and then the walk back to the car unassisted by head torch light. The lack of any sunlight on distant hills confirmed the early departure was a wise decision.

The second trip had a rather enticing weather forecast of heavy showers and spells of sunshine with the wind from the SW or the distinct possibility of heather moorland illuminated by fleeting light under stormy skies and the chance of a rainbow. Except the cloud never broke up, towards dusk the rain squalls were heavy and persistent. To be fair the wind strength was spot on with winds of 30 mph (Strong breeze/near gale) and gusts to 40 mph (gale force intensity). The weather and exposed location meant I was relieved to have packed the winter jacket, over trousers and gloves.

Calluna vulgaris and Ulex Gallii

Photography ambitions were restricted to leeward ground and then ground level macro photography before rain curtailed this activity. Chatting to a hill walker descending from a nearby summit it seemed that further south, the cloud was breaking up and sunlight breaking through, this kept me enthused until it became apparent with sunset approaching that this trip would also be curtailed. So two successive trips made where the landscape photography rewards would have been very good if the locations chosen were just a couple of miles distant, c'est la vie!

A trip to a heather moor.

The flowering of heather (Calluna vulgaris) marks the end of a self imposed break from visiting the hills in Wales as the welcome addition of purple hues to the vegetative colour palette of greens and yellows transforms the uplands in late summer.

Eventually a number of weather forecasts aligned to give some confidence to what the weather might be and importantly the words 'excellent visibility' and 'cloud breaking up' were prominent.  The one downside was the wind strength of a northerly 'fresh' to 'moderate' breeze that would induce vegetative movement, although a positive would be the suppression of the resident winged insect population. Suitably inspired and motivated an excursion was made to the National Trust property Mynydd Pen-y-fâl an outlier of Y Mynyddoedd Duon (The Black Mountains) in the Brecon Beacons National Park.

Harebells (Campanula rotundifolia)

The ascent route wasn't the planned one, but the convenient one due to the bracken (Pteridium aquilinum) growth. The relatively low winds, increased warmth and sunshine that characterised the early summer of 2017 were optimal for bracken growth and in places exceeded over 2.0 metres in height. However the weather subsequently reverted to the heavy rain and high winds that have afflicted recent summers in the UK. The adverse weather had collapsed the bracken, obscuring the minor paths, necessitating taking a well trodden route to the hills. The consolation of which was chancing upon a colony of Harebells by the side of the track under bracken.

Heather (Calluna vulgaris) and Bilberry (Vaccinium myrtillus) re-colonising a burned area of moorland.

With height gained the bracken covered slopes changed to open moorland and by mostly keeping to vehicle and sheep tracks, footfall was minimised on the vegetation. The moorland is actively managed for conservation by creating a mosaic of varying aged vegetation, the methods employed appeared to be controlled burning and in the absence of charred material on the ground presumably by cutting or flailing. Whilst heather dominated the moorland vegetation there were areas where other plant communities also put in an appearance : Western gorse, bilberry, grasses, rushes, sedges and bracken.

Western Gorse (Ulex gallii), Bilberry (Vaccinium myrtillus) and wind blown Wavy hair grass (Deschampsia flexuosa)

Eventually the cloud started to break up and allowed some welcome sunlight to play over the landscape.

The one downside of the location at this time of year is the curtailing of last light by the main bulk of the Black Mountains massif and the last of the direct sunlight was used on a less exposed area of moor with a mosaic of moorland vegetation modified by conservation management.

The wind negated any dusk twilight photography and a revisit will be made at some point in less windy conditions.