[aurele]

I'll have to dig through my test data, but from memory I recall the transmission from that lens is somewhere in the vicinity of T=3.5

i did a shooting with some friends, long story short : the Pentax k-x with the DA*55 @f3.5 (same iso and speed) provide more or less the same result in luminosity than the p6x7 and the 105 @2.4. (tested on Ilford Delta 3200).

So thank you for the info which seems quite correct

It did allow me also to test an app from my phone that offer a "lightmeter" with all the problem of accuracy and angle of mesurement linked with any phone app withing the front camera. i know now, the ajustement i need to take in account.