I bought a Canon AE-1 Program on eBay along with a 50mm f/1.4. The camera works well with other lenses, but the 50mm's aperture seems slow. Moving the bayonet (I think that's what it's called) takes much more force than on my other FD lenses.
As a result, the time between pushing the shutter button and the shutter releasing is sometimes hours. However, if I push the shutter button while holding the depth of field preview button, the shutter releases immediately. Similarly, if I push the shutter button and then push the depth of field preview button, the shutter releases. The depth of field preview button is very hard to push. Sometimes the shutter works as it should.
Do I need to lubricate it? How can I fix my lens?
Here's a photo of the lens. Notice the gunk by the bayonet. I'm not sure if this is a pure observation or if I'm imagining it, but it feels like the gunk is what's making the bayonet hard to push in both directions; for both my finger and the spring. It's like there's old oil or molasses in there. Obviously, I haven't cleaned the lens at all.