Taken from the Grepon Mer de Glace. Note no summit piton on the Midi

Remarkably clear photo John, and no Midi rocket! I'm trying to work out exactly what I'm looking at in the foreground... is it the Pain de Sucre or am I in the wrong place?

... or the Blaitière Spencer Couloir? Or maybe just to the left of the Spencer Couloir? Which would make it the top of the Glacier des Nantillons?

I've been puzzling about this too since rediscovering the photo. Alain Iglesis says the Nantillons and I now agree. The Spencer lies on the other side. And we were climbing on MdeG side.

Yes, I think that larger snowfield on the extreme right is the top of the Spencer...

... and you must have been on the summit.

Yes.

And with the rocket -
/photos/dbpage.php?id=163913
:-)

That clearly shows the Spencer and was taken presumably after Charmoz Grepon?

As I recall, from the notch on the summit ridge of the grepon at around noon - fast ascent of the mer de grace face and appallingly slow descent (route finding on the rognon of the nantillons ending up abseiling and jamming a rope. Typical brit alpinist!). Or from the ledge about 30m below. I've been trying to find out when the rocket was installed, but all I could come up with was 1955 for date of build of the telepherique

Yes yours is taken from just slightly lower than John's, Peter.

... and a little bit further left!

Nice photogrammetry, Jon! Which would agree with it being taken while we were descending