I came across an Auto Makinon 135mm f2.8 lens for €20, the focal lenght, the f2.8 aperture and the price peaked my interest. I've never heard of the brand Auto Makinon before, searching on the internet information is scarce, what I could find is that they manafactured camera lenses in the 70's and 80's and kinda like Samyang nowadays their lenses are sold under different brands like Vivitar, they didn't seem to make high quality glass, but for the price I was willing to take a shot. When I got to the seller he let me try it out, first thing that came to my mind is that it was smaller than I thought it would be for a 135mm lens, second thing I noticed was that the lens feels great in the hand, zooming is smooth, the glass is mint condition, I was getting excited, maybe a little too excited, I forgot to check whether it had a working aperture. Anyhow when I got home I found out that the lens is stuck at f2.8, I would like to have the option to stop down, wide open the lens is kinda soft and I get an overly blueish tint in some areas of pictures taken, especially in dark areas, could also be caused by the lens coating, but still having working aperture would be great. I'm looking in repairing the stuck aperture myself, seeing that it has an Canon FD mount I looked for DIY aperture repair guides and found this on Youtube: http://youtu.be/ejSlJ0b7iC0 Looks doable, however when I removed the front glass, it doesn't look the same as in the youtube post, besides the front element it has a second element, probably because it's the 135mm Macro version, I can't remove the second element from the front, or I don't know how. My question is whether anyone can help/advice me on the procedure with this perticular lens and if getting to the aperture is allways from the front or could it be different depending on the brand. Other option is bringing it to a camera lens repair guy, but that's probably going to cost me 5x or more than what I payed for.