Art reviews: Alison Turnbull | James Cumming | Angus Reid: 6 Peaks | Derek Robertson: Ruaridh Agus Ruaridh Eile

Alison Turnbull’s work takes the night sky as a starting point, but, in abstracting the material, she also takes away some of its sense of wonder

This is a great month for the amateur stargazer, with five planets said to be visible to the naked eye on a clear night, and a dramatic conjunction of Venus and Jupiter. Even if you are no expert – and I’m not – it’s easy to be seized by the wonder of what the old hymn writers call “the spacious firmament on high”.

Many of the large paintings in Alison Turnbull’s exhibition take the night sky as a starting point. Some began as reworkings of pages from a sky atlas made by Czech astronomer Antonin Becvar in 1948, the first attempt to map the entire night sky as seen from telescopes. Turnbull meticulously reproduced Becvar’s maps in paint, sometimes on carefully drawn grids, using different shapes, sizes and colours of marks and shapes to indicate the different types of celestial bodies.

However, at some point during the making, the drawing and measuring and reproducing, something else took over – we might call it art – and the project became less about precisely conveying information and more about shapes and colours, ideas and emotions, about the act of seeing, and about what it means to be a painter.

In paintings such as Observatory and See the Stars, she transforms Becvar’s lexicon of shapes and colours into an artistic language. She draws attention to the fact that paintings, too, are vehicles for coded information, but they can’t be decoded with reference to a key in the way that Becvar’s maps can. The raw material – star charts, maps, architectural plans, cross sections of light houses – is abstracted into building blocks for the artistic process. The paintings are densely worked, meticulous, a precise and time-consuming act of making by hand in a digital age.

We see the process clearly in Turnbull’s drawings. Three glass “drawing tables” contain examples of works on different types of graph paper and gridded paper which she collects, each named after the city where it was purchased or found. It is as if the structure on the paper becomes the starting off point for the work, the lines or checks suggest a rhythm which she then takes up and runs with.

She is as interested in how we codify the world as in the world itself. One of the most charming works in the show is Orto Botanico (2002/2010), in which a sumptuous black and white photograph of a botanical garden is placed next to a colour chart (similar to the kind you get when buying paint) naming the colours found in the scene: “roses in November”, “dusty old green hose”, “vermillion goldfish”. The words become a kind of evocative poetry.

For the Talbot Rice show, she has made a new site-specific work in the Round Room which takes as its starting point Werner’s Nomenclature of Colours, produced in Edinburgh in 1814. It is a kind of manual to aid scientific classification made in a time when scientists were beginning to observe and codify, seeking to establish common standards of measurement (Darwin took a copy on The Beagle). The book itself is exquisite. Each colour (painted by hand by flower painter Patrick Syme) is accompanied by a description of where it is found in animal, vegetable and mineral. “Gamboge yellow” for example, can be found in the wings of a goldfinch, yellow jasmine and high-coloured sulphur. Turnbull also displays a set of coloured minerals, which were used in teaching at the University of Edinburgh in the 19th century, and are now in the National Museum of Scotland. Her own work, Various - coloured snapdragon reproduces these and other colours from the book in a dancing sequence of lines and dots on the walls of the Round Room.

Yet somehow it lacks the poetry of the book itself, in the same way that her night sky paintings lack the wonder of staring up at the stars. In abstracting the material, Turnbull also removes it from the spirit of the original: those earnest, eager, early scientists, or the astronomers trying to map the heavens in their entirety for the first time. It is this spirit – the notion that the whole world is out there waiting to be classified and understood – which helps to make the material compelling, and in the modern world, the outlook is very different. Her paintings are accomplished, restrained and self-aware, but they keep a cool distance from the bigger questions of understanding the world and one’s place in it.

By contrast, a mysterious sense of otherness is frequently present in the paintings of James Cumming, currently on show in the Georgian Gallery. Cumming, who died in 1991, was a tutor at Edinburgh College of Art, and an artist who needs to figure in any history of post-war painting in Scotland. This show, which includes rarely seen works from private collections, takes in a broad range of work, from figurative to abstract and all shades in between.

Some of Cumming’s most important work was done in the 1960s when he lived for a year at Callanish on Lewis. In a community both remote and deeply aware of its traditions, he created a body of work which is part figurative, part abstract, in which myth is rarely far away, and larger-than-life human figures (The Callanish Man, The Lewis Poacher) are on the verge of becoming mythic themselves. His signature style, building up an image through layers of paint, seems ideal for these images which work on a range of levels.

Then, at the height of the success with the Lewis paintings, he was introduced to images from a new electron microscope by an Edinburgh neighbour, a surgeon, occasioning another important shift. Ovule (1971) could be cells on a microscope slide; Chromosomes (1) (1970), turns the shapes of microscopic bodies into a language, like cuneiform or hieroglyphs. Unlike Turnbull’s restrained, precise shapes, he can’t resist giving them colours, features so they look like symbols or animals. They also acquire a sense of movement and seem to dance.

An art gallery in Dundas Street might not be a place one expects to find poetry, but Angus Reid’s ambitious installation at Axolotl (sadly, part of the gallery’s final show) shows how well the two can work together. 6 Peaks is a poem sequence inspired by a walk to six summits in the Pentlands on a wild, windy day, a hard journey, “walking off a broken heart”.

The work captures both that walk in savage weather, and Reid’s writerly reflections on it. The poems are on the walls, directly above a panorama of the hills where the walk took place. The raw directness of the poems (“it took six peaks to walk away from you”) is balanced by an intricate structure: the line endings form an independent set of poems, a kind of counterpoint to the main narrative, and the clean lines of the Georgian room facilitate this as clearly as lines on a page. It’s an elegant coming together of landscape and experience, internal and external, word and image.

Part of the reason Reid’s show works so well is that the poems are clear enough to read from a distance, where one can also take in the visual panorama. One of the challenges of showing poetry and image together is the practical difficulty of leaning in to read small text then leaning out again to appreciate the picture. This is a drawback when viewing the collaboration between Gaelic poet Rody Gorman and artist Derek Robertson, being shown as part of the StAnza Poetry Festival in St Andrews.

However, it is worth persevering because Robertson, who is best known as a wildlife artist, has space here to expand his range, and has created a set of beautiful collages of images in watercolour which mirror the kind of free association which often happens in a poem. The best collaborations are not about one artist illustrating the work of another, but about creating a place where each brings their own ideas, memories and associations to bear, and this is the case here, with Robertson’s explorations of landscapes and old farms in Fife striking remarkable synergies with Gorman’s poems about Skye.

ALISON TURNBULL ***

JAMES CUMMING ***

TALBOT RICE GALLERY, EDINBURGH

ANGUS REID: 6 PEAKS ****

AXOLOTL, EDINBURGH

DEREK ROBERTSON: RUARIDH AGUS RUARIDH EILE ***

ST ANDREWS TOWN HALL

• Alison Turnbull and James Cumming run until 5 May; Angus Reid until 7 April; Derek Robertson until 31 March