Last Week for Marilyn Monroe at the National Portrait Gallery

'Marilyn Monroe: A Portrait' closes at the National Portrait Gallery on Sunday 6 September. It opened on 4 June, marking a century since Monroe's birth on 1 June 1926, and was mounted in association with her estate. If you have been meaning to go, this is the week you have left.

The gallery has been extending hours on demand: until 9pm every Thursday through August, and until 10pm on 28, 29 and 30 August and again on Friday 4 and Saturday 5 September, with last entry an hour before close. Read that list carefully, because of what it leaves out — there is no 10pm opening on the closing Sunday, when standard hours apply and the doors shut at 6pm.

Curated by Rosie Broadley, the gallery's joint head of curatorial, the show sets painters against photographers. Andy Warhol, Pauline Boty, Marlene Dumas, James Gill, Rosalyn Drexler and Audrey Flack hang alongside more than twenty photographers, among them Cecil Beaton, Eve Arnold, Richard Avedon, Philippe Halsman, Inge Morath, Milton Greene, Sam Shaw, André de Dienes and George Barris. Warhol's screen prints derive from a publicity still for Niagara; Boty's The Only Blonde in the World is from 1963; Joseph Cornell's memorial boxes are here too, with scripts and clothes.

Time Out's three-star review: 'Portraits are tricky things: can you ever really sift the individual from the image?'

The most affecting room is the last of her life. The show includes previously unseen Life magazine photographs taken by Allan Grant at Monroe's Brentwood home the day before her death in August 1962, made alongside her final interview with the magazine's associate editor Richard Meryman. Grant shot 432 frames that day. Eight were published.

Tickets are £25 off-peak Monday to Thursday and £27 peak Friday to Sunday, free for members, £5 for under-25s through CLUB NPG, with pay-what-you-can entry on Mondays from 10.30am to 2pm. St Martin's Place, WC2H 0HE, until Sunday.