I like the 50/1.8 A1s semi-pancake for a particular reason. It's really a second-string design, but one stop down is fabulously sharp, is compact, and was inexpensive enough that I can travel with it without getting paranoid. My 55/2.8 is a better optic with better build. But I seldom shoot 35mm except for rainy days or brisk walks when I don't want to have to clean my big cameras afterwards.
And I don't generally use "normal" focal lengths. So a semi-pancake fits nicely into a little nook in the bag below the 85/1.4 I mostly use.
My multicoated 50/2 are sharper than older S. Sharp wide open and razor sharp two stops
Personally I prefer the 50/1.4 SC.
The 50/2 H (all versions, including the AI 50/2 - they're all the same basic lens, just a different barrel with longer throw helix on the rubber focus ring versions). I have a regular AF 50/1.8 (non-D, Japanese build), which is also a decent lens, but I do think the older 50/2 beats it. Alas, my current 50/2 H is still pre-AI, so it's only used on the FTn, FT2, and the F. I also have the two better non-AF 50/1.4's. The original S version with factory AI ring, and the AI version. For some reason, the SC and the big K versions tend to have a milky green cast, especially with Fuji film, which isn't there with the older S, nor the compact K version or the AI version.
Sorry, I'm not seeing anything that looks remarkably longer than anything else. Maybe I'm expecting the difference to be marked, not subtle. Which of the four lens on the last row is a longnose and which is a pancake? Are any of the lenses on the other rows so characterized?
Originally Posted by Vilk
Lenses 1 and 3 are long nose, 2 and 4 are pancakes.
Look at how much barrel there is between the silver ring and the top of the lens. Or, if you like this perspective better, look at the front element - in lenses 1 and 3 it is deeply recessed while in 2 and 4 it lies almost flat with the filter ring.
In absolute terms the difference is not remarkable. It's a 50mm lens after all. If you held them in your hands the difference would be obvious.