How many lenses? Well, use the FL/N rule, where FL is the focal length of a class of lenses, and N is an arbitrary divider. For instance, if N=2, then I'm right on target with 25 Nifty Fifty's, over-the-top with 16 Terrible Twenties, and way under target with only 7 each Thrifty Thirties and Wondrous One-Thirties.
Back in my wasted youth, I sometimes took day labor unloading building materials from boxcars in San Francisco. Manually. (Me: head that's weak, back that's strong.) Just across the street was a materials depot of Kaiser Permanente Gravel and Cement. We constantly saw their slogan: FIND A NEED AND FILL IT. We paraphrased that for the concrete business: FIND A HOLE AND FILL IT. That same slogan applies to LBA. Got a hole in your kit? FILL IT!!
Originally posted by Lowell Goudge I started out on the venture with a set of rules. never buy anything slower than what I already had as primes.
Ah, but sometimes slow glass is wonderful! For some quite different examples: the Tele-Takumar 200/5.6, and the Meyer Primagon 35/4.5 and Helioplan 40/4.5, and even the Sakar 500/8 mirror. All sharp and cheap and slow. And how many user reviews rate the 28/3.5 and 35/3.5 as better than the f/2 and f/2.8 versions?