'Michaelangelo and Sebastiano' at the National Gallery

The current blockbuster exhibition at the National Gallery is about Michelangelo and Sebastiano and their friendship and collaborations. You know who Michelangelo is but you might not know about Sebastiano del Piombo, one of Michelangelo's friends and collaborators in Rome and beyond. Sebastiano was from Venice so was trained in that style but came to Rome at just the right time to support Michelangelo in his challenges with Raphael and that seems to have been the start of a long friendship.

The exhibition is in the North Wing of the National Gallery rather than the Sainsbury Wing which makes a nice change and the Gallery has done a good job of adapting the rooms to create a good space for this exhibition. It includes paintings, reproductions, sketches, letters and some statues to demonstrate the range of work. I particularly liked some of the letters, such as a moaning later from Michelangelo about the lack of rain that means the barges with his marbles can't come down the Arno to Florence from Pisa.

I was already familiar with the Michelangelo paintings in the exhibition since they're part of the National Gallery collection. Even so, it's good to see them in context and with supporting sketches and letters. He didn't always finish his paintings and I do like this one were you see the layers of paint being worked up from the gesso base. He started on the right and didn't get to paint the angels on the left. We see Jesus and John the Baptist as toddlers with Mary and angels. I like that one of the unpainted angels has its hand resting on the shoulder of its friend, a very naturalistic pose.

There were no sketches of this painting which is a shame since it would be good to see what Michelangelo's vision for this painting really was. We see more with Sebastiano.

The painting I was excited to see was Sebastiano's 'Raising of Lazarus' in which Jesus raises the dead Lazarus from the grave.  This is part of the National Gallery collection so you've probably seen it but not presented like this, in its new frame. I attended a lecture about it last year, about how the painting was moved and how a new frame was built for it based on fragments from where it originally stood in the church. Those foolish old French people scraped off the wooden panels it was painted on and then glued it to a canvas backing. That makes it unstable so it's now been placed into a metal base to hold the painting and the new wooden frame was added around it. The new frame incorporates fragments of the original frame and the rest has been reconstructed. It looks fab.

There's so much going on in that painting and I wonder how often viewers notice this. I'd always focused on the foreground and the figures of Christ and Lazarus until I actually looked and saw so much more. Lazarus's sisters are front and centre - Mary and Martha - with one praising Jesus and one turned away due to the smell of a dead body. Other women are covering their noses and turning away. There are groups of men pointing in astonishment and the gossip that something's happens spreads way back to travellers on the river banks - 'what is it?' 'I don't know, it happened over there' and points. It's an astonishing painting and some of the sketches nearby show that Michelangelo offered poses for the figure of Lazarus.

Another set of sketches by Michelangelo were offered to Sebastiano for his figure of Mary clasping her hands and looking to the skies in the 'Pieta'. Michelangelo used a male model to get the figure just right and Sebastiano seems to have retained the masculinity of those drawings as he converted them to a painting. It's a night scene but there's still quite a lot of detail in the landscape background. Better, I think, is the body of Christ lying dead on the ground at Mary's feet, very realistic and limp.

This painting is also displayed so you can see the wooden panels at the back of the painting and the sketches and graffiti that have been added. It's so rare to see the back of a painting - it's one thing knowing it's painted on a series of wooden panels held together and it's quite another to actually see them.

It's well worth visiting this exhibition to find out about this friendship and the collaborations it spawned, as well as seeing some astonishing paintings and sketches. It's such a shame that the pair grew apart in their older years but that happens.