My ‘Becker Country’ is finished and is now drying – it has a month to do so before being exhibited. Its structure remains much as it was a month ago but, while it was ‘cooking’, it became a very different painting. The visit I mentioned to the area around the village of Wenhaston, although undramatic at the time, proved quietly inspirational in subsequently giving me two pointers as to how to lead the work towards an appropriate local finale: the weather-worn brick redness of the two main buildings at Old Hall Farm, where Becker lived for a while, and the realisation that most of the farmland is on sand.

I have a collection of various sands in the studio for precisely such an opportunity and so a suitably darkish yellow sand from an old quarry in the south of France, mixed with pigment from an adjacent source and some oil, now gives body and texture to the painting overall, with red peeping through. Whether it works or not is for others to judge, but that’s it as far as I’m concerned. Now to get on with the ‘Sizewells’.

Meanwhile, perfection on an extensive scale: I don’t normally rave about country houses and their parks, having acquired a rather jaded palate for the genre through perhaps over-frequent visits in National Trust days, but I found one I had not even heard of until recently, Houghton Hall, stunning. The Hall lies just off the A148 between King’s Lynn and Fakenham in northwest Norfolk. It was built in the 1720s by Britain’s first Prime Minister, Sir Robert Walpole. Not surprisingly, therefore, it has an architectural grandeur in familiar Palladian mode, with French twiddles and the like enlivening its exterior – I did not explore the interior – but it is the Versailles-like extent of parkland with avenues, vistas, ha-has, temples, gardens and modern artworks, the whole with not a leaf, not a blade of grass out of place, that I found almost overwhelming. Yet in this most massaged of man-made landscapes, obviously looked after with the utmost care, attention and sensitivity by, one would have thought, a small army of outdoor staff, in four hours there I found but one man working out in the landscape – and he was an electrician attending to the floodlighting of a tree.

In fact all the above was a bonus for I had actually been taken to Houghton to see the exhibition by James Turrell called ‘Lightscape’. This is breathtaking too. Indoors and over the landscape are not just installations to look at from outside but experiences to participate in; and you reel away, rubbing your eyes and wondering not only whether what you have just seen is ‘art’ or ‘illusion’ but also, more profoundly, whether ‘reality’ based on visual evidence is in any sense ‘real’. I don’t want to spoil the experience for any one who might go after reading this but I sat in one darkened room for 20 minutes during which I ‘saw’ the darkness slowly dissipate as a pre-sunrise light began to tint the screen from the left and grey clouds edged back to the right; yet the sunrise did not happen and the greyness moved back to the left to obliterate its traces. It was difficult, when told afterwards, to accept that nothing happens in that darkened room except in the mind of the expectant viewer.

And it is not just the darkness which belies – or reveals: lie facing upwards in daylight looking out through the aperture in the centre of Turrell’s ‘Skyspace’ dome and see a fragment of sky, now with the shape of the aperture providing a frame round it as with a painting or a fluorescent light installation. In  ‘Skyspace’, neither the artist nor a technician are fiddling with the changing image, with what you are seeing, yet surely what you are seeing is ‘art’ in some sense? What is a painting? Why paint?

‘Lightscape’ exhibits till 24 October, 2015. Go.