With 368 items crammed into the lower galleries, the RSA's Open show suffers from lack of space, but there are plenty of gems to be found if you look hard. Venue: Royal Scottish Academy ,Edinburgh Wilhelmina Barns-Graham, a Scottish artist in St Ives The Derek Williams collection John Clerk Of Eldin (1728-1812) Venue: The City Art Centre, Edinburgh The RSA has diversified. The main focus of its activity used to be the annual open exhibition. Now it does a wide range of exhibitions during the year and also runs an ambitious programme of scholarships and residencies. It has also split its annual exhibition in two. A major show, occupying the whole of the RSA galleries, combines members" work with work by invited artists. Restricted to the lower galleries, the RSA Open is much smaller. Also, as its name indicates, it is selected from an open submission, as the major show used to be. Because of the constrained space, however, submitted work is restricted in size to 80cms (31½in) in any direction, including the frame. That is small. Even so, the 368 entries listed are a lot to squeeze into four rooms. The number accepted does, however, give some idea of the pressure the selectors are under because of the popularity of the open exhibition. There are a lot of artists out there looking for the break that it could give them, even if it is just the recognition of being accepted. More pragmatically perhaps, the RSA's main income is from sales. It is Christmas time. Small pictures make good Christmas shopping. Up to a point, too, the more you put on display the more you can sell. There is the law of diminishing returns, however. In places, at least, small, even tiny pictures have been hung four or five deep with frames almost touching. It does look a little like a Christmas bazaar. I don't think the quality of the individual works has suffered unduly, but I do wonder if this can be sustained. It is not an environment to attract successful artists. To name just a few, a superb still-life by Elizabeth Blackadder with two sardines on a plate with a yellow rim and a blue glass bottle, a relief of painted wood by Doug Cocker called Rack, and a lovely collage, North East from Crieff, by Philip Reeves are each hanging frame to frame with motley companions on all sides. It is not the treatment such artists are used to, or indeed are entitled to expect. I wonder how long artists like these will stay loyal and continue to send in work to be displayed in such conditions. The RSA doesn't want to take the place of the late and unlamented Glasgow Art Fair. In the 19th century, when this sort of hang was more normal, the painter William Nicholson, writing to the president ostensibly to complain on behalf of a friend whose picture was hung at the floor level, also pointed out that his own picture was 20 feet above the ground. He had a point. His friend really was worse off than he was. In the lower galleries, the ceilings are too low for a picture to be "skyed" and out of sight. Nevertheless, pictures above eye level are easier to see than those below. Those at eye level, or "on the line," do best. It was always thought that in these conditions, to be seen you need to be showy, but in fact here modest pictures do well. Ronald Buchan's Warriston Allotments under Snow, for instance, is quiet and straightforward, but holds its own in the clamour. David Forster's moody acrylic, He Lighted Himself a Fire (Corstorphine Hill), is equally unassuming, but manages to assert its own poetry in this noisy context. On the other hand, Stuart Duffin's print, The Errors of History, The History of Errors, appears to be an intriguing reflection on the history of Jerusalem, but is hung too low to be appreciated without sitting on the floor. Other distinguished prints include Kate Downie's Summer Studio, a single image across three overlapping plates, John McKechnie's Black River, a fine Oak Tree by Gordon Slater and etchings of two magnificent historic trees by Ian Westacott. RSA president Arthur Watson's suite of screenprints, United Colours of Scotland, are bold and simple and, suitably, as number 368 are the last item in the show. There are also a number of quite good photographs struggling to be seen. Commitment by Craig Buchan, for instance, a picture of a nun mowing the grass, and Salamander Street by Will Collier are both intriguing images. David Evan's An Afternoon in Pittenweem is a beautiful painting of a fisherman's house in Pittenweem rendered slightly surreal by the bright, flat light. The Self-Portrait by Richard Wiatrek, a painting of a girl doing her make-up in a mirror in a de Chirico townscape, is more directly dependent on its surrealist model, but is successful all the same. Sylvia von Hartmann and Ann Ross, though very different, take a more allusive approach to surrealist poetry, but to good effect. Where the walls are so crowded, sculpture wins. Tom Allan's Orbit, a standing ring of white Carrara marble, for instance, or Hironori Katagiri's Streamline - Bijin, a pointed monolith of black granite, are both imposing, yet could also be domesticated quite happily. I also particularly liked Hans Clausen's enamelled skip on a steel pedestal, Alasdair Thomson's Blouse, a marble relief of the eponymous garment hanging on a washing line, and John Brazenall's bronze vase of tulips. Wilhelmina Barns-Graham was an honorary member of the Academy, and Edinburgh City Art Centre is hosting a major retrospective to mark her centenary. After studying at Edinburgh College of Art, she moved to St Ives in 1940. Cornwall remained her home for the next 20 years, but in 1957, after inheriting a family home in Fife, she also reestablished herself in Scotland. She was a student at the College when Samuel Peploe taught briefly and then handed his class over to William Gillies. The work of both men is reflected in several early still-lifes. Later, even while she was absorbing the lessons of St Ives painting, in the superb Blue Studio of 1947 echoes of Peploe's brilliance contrast with the muted colour of her St Ives Sheds of c1940. In the 1950s, she began to paint abstract pictures, but her touch is not always secure. She learnt to draw at Edinburgh and was a fine draughtsman. This underpins her most confident and best work like Rocks St Mary's, Scilly Isles, for instance, and throughout her career she often returned to direct drawing, elaborating and refining an observed image to great effect as she does in St Nicholas Chapel, St Ives, for instance. Some of her more self-consciously abstract compositions like Expanding Forms, or Variations on a Theme, Splintered Ice, look a little stagey, or else are too close to the vision of other artists to convince. Nor was it just the St Ives painters she echoes, but other younger abstract artists too. Nevertheless, she can equally be quite brilliant. Wait, for instance, an intense blue ground with a single black rectangle and two supporting shapes in red and yellow, is dramatic and convincing. Black White and Grey No 1 is even more dramatic. It consists simply of two broad brush marks, one black, the other white, against a flat, grey ground. Appropriately, the Derek Williams Trust Collection, showing concurrently at Edinburgh City Art Centre, is a charming selection of smaller works by artists including Ben Nicholson, Henry Moore, John Piper and many others who were Barnes Graham's English contemporaries. In the same place, a show of John Clerk of Eldin's etchings is not to be missed. He worked in the late 18th century, and they are small but intense, and represent an early but significant moment in our preoccupation with the drama of our national landscape and the history that informs it. RSA Open until 31 January; Wilhelmina Barns-Graham until 17 February; Derek Williams Collection until 24 February; John Clerk of Eldin until 3 February