How to determine max enlarging size for my setup?

[Ian C]

Magnification is

m = [d + squareroot(d^2 – 4df)]/2f – 1

d = negative-to-print distance

f = focal length

[MattKing]

If you need larger, one of the special purpose wide angle enlarger lenses will give that to you.

[Jeff Bannow]

Thanks all.

[Martin Aislabie]

You may find that the limiting factor to maximum print size quickly becomes the Enlarger Head to Column/Wall distance

Just something to look out for

Martin

[Jeff Bannow]

Definitely something I'll need to watch for. I assume for a 40" print the head needs to be 20" from the wall?