Model: L-398 Studio Deluxe
Visual Designer: Alpheus Maple
US Design Patent #: D154558
Price (new): $90
Cell type: Selenium
Measure type: 3D incident (2D incident and reflecting / averaging available with accessories)
If you recognize this guy, you've probably read The Many Faces of the Norwood Director. This was Sekonic's most recent major update (there's been a minor one since, the L-398M). Considering that they acquired the rights for this around 1958 and it's now 2008 as I type this, they got their money out of it.
Calling this a major revision is really overselling it, except that we're dealing with a Norwood Director and it has a long history of being tweaked and updated while retaining its essentials.
I don't yet have a couple of the intermediate steps, so I can only compare this to the L-28 Studio S , Sekonic's first version of this meter. The main differences appear to be that the meter scale is a bit longer (it tops out at 1,250 foot candles, whereas the Studio S only goes to 1,000). The calculator dial got yet another reworking and now includes a DIN scale as well as ASA. The earlier photosphere (the incident dome) and accessories used to be press-on, now they're bayonet-mount, but you can jam the old one on in a pinch and hold it with a little tape. The new slides are a tad larger so they don't quite fit the old meter, but the old ones will fit the new meter with a little wiggle room to spare.
The big change is the pointer lock. When I got this I thought it was broken until I inadvertantly pressed the button in the center of the dial, which releases the pointer and suddenly I had a working meter.
The only fly in the ointment here is the revolving top is missing its screws and is held closed with Scotch tape.