Originally Posted by séamuis 
nobody can explain LBA but in all reality unless you have an unlimited budget, you should focus on purchasing lenses for your particular use and style of photography. something that will best suit your needs.
Originally Posted by bruloup Seamus in an obvious moment of clarity!@!!!
that being said....
Super Tak 55 1.8
Forget all this clarity stuff!! Buy every lens you see. Max out the credit card, sell the house and live in your car if you have to. Try them all.
Or better yet get James King to adopt you. Then you have access to almost every lens known.
Seriously, I agree. At one time I was a lens hound as well. Then realized that you only need what you will actually shoot with. A pro wildlife shooter might need a 600 or 1200mm lens but the rest of us just need a decent kit that covers the range.
My essential kit is:
Pentax FA*300mm f4.5
Sigma 70-200mm f2.8
Pentax DA 16-45mm f4
Pentax FA50mm f1.4
Sigma 105mm f2.8 macro
Sigma 24mm f2.8
Sigma 10-20mm
Pentax AF1.7TC
I have a few others but when I go out, that's usually what's in the bag. I never find I'm wanting for anything else. I had the 3 amigos for quite awhile (31,43,77mm) and even though they are beautiful lenses (both optically and craftsmanship). They never got enough use to warranty keeping them. of course that could easily change....