If your Sekonic can measure incident lighting then you can probably get by without buying the spot metering attachment. I recommend reading the BTZS by Phil Davis.
Originally Posted by Ara Ghajanian
You can get by with only one back as well. The way to do this is to target your normal development for a grade three contrast. Use paper grade four and occasional selenium intensification of the negative for N plus (low inherent contrast) subjects. This method will give you up to an N plus one and one half density range increase without the typical increase in grain. You can then use proportional exposure for your N minus (high inherent contrast) subjects. This will give you a N minus two to three contraction of density range while maintaining good print high value separation.
All of the above amount to adjustments in exposure and maintaining a definite and consistant development procedure. The Zone system as proposed by AA and others requires altering development times. It is possible to accomplish the same or better results without going down that road.
Aren't you happy that you now have to spend no additional money to produce prints of incredible luminoscity and brilliance.