History Lesson, Cho Duck-Hyun, RHA Gallagher Gallery until August 27th

Una Sealy, paintings, Ashford Gallery until July 27th

Fergus Feehily, paintings, Green on Red Gallery until August 6th

Full of It, Jeanette Doyle, Temple Bar Gallery until July 23rd

There is an in-built nostalgia to Korean artist Cho Duck-Hyun's huge, meticulous pencil and Conte crayon renderings of black-and-white photographs at the RHA Gallagher Gallery. The images are all portraits, from formal studio studies to something approaching casual snapshots. The people they depict have that universal quality of individuals in old black-and-white photographs: poignantly captured, in instants frozen in the flow of a time that is, perhaps like the subjects, long gone. Cho's drawings are photographic in the sense that they slavishly reproduce the photographic image in a simulacrum of an impassive photographic "skin". That is, they read like photographs rather than photorealist drawings or paintings, though we know, at least after a minute or two, that they are drawings. They come across as small, intimate family photographs writ large, even monumentalised.

However, Cho plays against the flatness of the photographic surface by aggressively framing his images in bold, three-dimensional and conspicuously material forms. He makes weathered-looking, rough-textured sculptural objects (sometimes incorporating real tokens, like uniform insignia) that often enclose the image completely, like a box or a room.

More, there is a sense of a grave unearthed in some of the pieces, with a lamp shining into the exposed interior of a coffin-like crate, while the lid lies on the ground. This mise en scene is dramatically very effective and turns the whole gallery into a slightly eerie installation.

The show is called History Lesson and the lesson seems to lie in the provision of an alternative, unofficial version of Korean history. Not that any great subversion is involved, but Cho gravitates from public spectacle to the personal memoir, and then imbues the personal and, specifically the personal filtered through women's experience, the scale, presence and pride of place usually accorded to statesmen and generals.

His exhibition, which combines elements of several related bodies of work, and taken together with a large companion piece, a group show The Sea & The Sky (which will be covered separately) marks the most ambitious and imaginative use of the enormous spaces of the Gallagher Gallery to date. The point is underlined by his cleverly enclosed - claustrophobically enclosed - installation, inspired by an archaeological discovery and featuring an extraordinary lifesize ceramic dog pack, which alone makes a visit worthwhile.

Una Sealy's paintings, at the Ashford Gallery, are strongly stated representational accounts of people, places and everyday things. There is an autobiographical, anecdotal flavour to the work, which is delivered with palpable energy and enthusiasm. She seems to like the dancing, shifting light of a typical Irish day with clouds scuttling across the sky, punctuated by brief spells of sunshine, though she also has a good stab at the strong sunlight of Valencia in one piece, and includes more subdued, evenly lit landscape studies of Valencia as well.

Her style is casually oblique and illustrative in an almost chatty way. The snag here is that she has a tendency to over-elaborate, to keep playing around with the paint when the job is done. This can lead to an over-emphatic, linear harshness, particularly noticeable in the portraits, which come across as being a little severe on the sitters. That said, mind you, one of the best pieces is the ambitious and remarkably successful Venus of Diamond and 24th, which encapsulates everything that is good about her approach and has a terrific, airy lightness and exuberance about it.

Fergus Feehily's work, at the Green on Red Gallery, arises from a two-year residency in Tokyo courtesy of the Japan Foundation. It consists of a set of minimally articulated painted MDF panels. The colours stay close to muddy beige, with the odd excursion to grey (in one very good gouache). From afar the effect is pretty much as Fehilly puts it: "One is almost unsure if they have been painted at all".

Yet the mood is easily rather than obsessively minimal so that when you look closely, you see how the surfaces are not entirely impassive but are woven and patterned in various subtle ways, usually by being built up from layers of brush strokes, and broken by odd interruptions, like dots whose regularity helpfully indicates design. A problem with Feehily's work in the past has been that it lacked the requisite density of presence to match up to its minimal form. For the most part he's dealt with that here, though in one case, Cup, he is on much shakier ground.

For one segment of her exhibition at Temple Bar, Full of It, Jeanette Doyle constructs contemporary still-lifes complete with packaged grocery products and supermarket receipts with clubcard points, the latter inscribed on polished plaques. In form and presentation, they parody Dutch still life in a museological setting.

Her still-lifes are painted, but we see them in the form of photographed paintings printed onto canvas-textured paper: imitation paintings. By this stage the whole procedure is so riddled with distancing devices, so absorbed in its own convoluted choreography, that it's a bit like trying to keep track of who's who in a John Woo movie. But, like the rest of her work, it's also agreeable enough as a barbed commentary on the way we live now and where we're at, culturally.