Animal magic?

It may not be immediately apparent why Paul Nugent calls his exhibition The Franciscan Series. Visitors are confronted with seven monochrome painted panels, of portrait format. With their impeccable delivery and tastefully sombre colouring, they look like minimalist abstracts. But people familiar with Nugent's work will be alert to the fact that all is not what it seems.

Stand in front of one of the paintings, let your eyes focus on its surface and, sometimes immediately, sometimes after a while, you begin to register variations in the tonality. There is a sense of a ghostly, underlying image manifesting itself in the apparently blank skin of the paint. To mention this is not like giving away the plot of a thriller, because the effect remains. Once you know, though, you are primed to look for it.

Nugent's portrait-shaped paintings are, it emerges, portraits. The repeated image of a seated figure becomes evident, though in most cases it is difficult to find clear traces of the head. The figure, in clerical habit, is a Franciscan, or at any rate someone dressed as a Franciscan. On past experience, we can surmise that Nugent dressed, photographed and painted someone in authentic Franciscan garb and then, just as meticulously, painted over the image.

The exhaustive methodology and the subtlety of the result amount to a metaphor for the artistic transaction by which we take it on faith that the artist is showing us something worth seeing. His process addresses the idea that a work of art has an import akin to a spiritual dimension or, as many would argue, an actual spiritual dimension. His paintings might also be read as a commentary on the history of Western painting, from the Renaissance to modernity, in the way they incorporate religiously spiritual and representational elements within the resolutely material and abstract. The linear narrative of modernism moves from religious patronage to humanism, from representation to pure abstraction. The Franciscan Series amounts to a rich and intriguing body of work in more senses than one.

There is a certain overlap, here, with Gerard Byrne's photographs of Lough Ness and its environs, from which the fabled monster is conspicuously absent. In In The News, Byrne quotes Walter Benjamin on the failure of photography to "reveal anything about reality". A photograph of a Krupps factory, for example, tells us "next to nothing" about the institution. Byrne provides an imitation Becher photograph of the Guinness brewery (the Bechers are two influential German photographers who photograph industrial architecture). In a piece of didactic, Eisenstein-like montage, he juxtaposes the factory with a view of the Guinness estate in Co Wicklow.

The images of Lough Ness are almost parodically ordinary and calm. Their titles, which consist of fragmented excerpts from reported sightings of the monster, allude to what is not seen, perhaps to what is not there: there are indications that Byrne has myth in his sights. There is a suggestion that we collude in the fantasy of the lough, elaborated in views of a stage set for the jury-room drama 12 Angry Men, a drama that could be viewed as being about the malleability or relativity of truth. More, though, the set and the drama comprise an agreed fantasy space.

Notions of real and fake are further explored in images of Archer's Garage in Dublin, illegally demolished, under reconstruction. Can you restore something destroyed? Isn't it a fake, a replica, another agreed fantasy? In interior views of the Natural History Museum, the subject is not the preserved animals but the people observing them, the art students making drawings - a bit of an in-joke, perhaps, as art students are habitually dispatched to the museum to draw. There is another dimension here, though, because the museum is itself a specimen, in the sense that it is a preserved slice of Victoriana. Plans to update its displays were abandoned on the basis that it is in itself an artifact.

Byrne clearly relishes the proliferation of ideas and possibilities that emerge in his sequence of images - more than it is possible to explore here. There are perhaps too many neutral views of Lough Ness, but he is clearly onto an exciting line of critical enquiry with his open-ended narrative method.

Paddy Campbell bravely shows series of landscapes and nudes in his first solo show at the Cross Gallery. Its punning title, Out Of The Frying Pan, refers to the fact that he has turned from business, as founder of the Campbell Bexley Group, to painting. The catalogue introduction mentions that he has studied with an academic teacher in Florence over a six-year period, and most of the paintings and drawings have the appearance of life-room studies.

Despite the apprenticeship, the show is premature. You feel Campbell has worked hard, and the unevenness of his output suggests he has progressed considerably. But apart from the drawback of some technical limitations, his attempts to move his imagery beyond academic exercises tend towards sentimentality and a kind of pin-up iconography. Occasionally, something more comes through. In Florentine, a straightforward nude with the awkward honesty of an Edward Hopper painting, there is some sense of a real person standing there, and Twirl captures movement effectively. Some good landscapes, perhaps more relaxed, look like a way forward.

Campbell is clearly serious about what he is doing, and he can take comfort from the fact that not for nothing is painting described as an old man's art. Experience counts.