Just disassembled my 150mm to clean fungus off the inside of the rear element. Looks good as new now! Thanks for the excellent step by step video!

Thank you for the passion you share with us in every video tutorial. God bless you!

Thank you so much, i just repaired my 150mm f4 because of this great video!

nice job but demounting the whole lens was unnecessary (except for showing how to). Once the front lens element has been removed, the whole blade system is accessible and allows for a nice. My lens has two out of three VERY sticky screws on the rear mount system and I had to let it be or I'd damage the screws. the front lens element was also glued with some kind of fillet brake. I had to unscrew the very fist lens in order to create enough contact surface for the rubber cones to grip. I'd also need to lubricate the focusing system but so far had no luck in figuring out how to disassemble the barrel. Thanks for these video.

One more lens repaired thanks to you :) Thanks!!!

I'm in the process of renewing my m645 set as many have stiff focus rings. Your videos seem like a good place to start, but you don't mention re-greasing the helical - is this something you would normally do?

Do you do any services where one could send in a lens?

I know it's an older video but I'm trying my luck - I'm trying to disassemble the front lens element, the one you removed at 6:30. removed it but I'm trying to to clean it from some fungus under the first lens, but can't get the ring to turn, any advice on how to do it?... And thanks for the helpful videos, I learned so much!

Thanks! That was very helpful. I got a Mamiya NC1000S with a 50mm f1.7 really cheap just to find that the aperture wouldn't work at all. It took me a while to figure out what's wrong. I've never seen this mount before. The CS lenses have a small pin that is being pushed in to close down the aperture. The force transmission is horrible. The lens was so full of oil, there was oil right from the first part, the plastic ring. Luckily the 50mm is a much simpler design. I was actually surprised when I realized I was already holding the aperture blades in my hand. Now it's all clean and as good as new. Well, almost. It was really hard to keep the dust out while re-assembling the lens. I was kind of surprised you didn't even mention that.

I have a question, I am not sure belongs here. But maybe I am in luck and someone has an answer. I just bought the Mamiya Sekor C 500mm/5,6 and the image circle doesn't fits on Medium Format. And I don't understand how this is possible, because it should be a Medium Format lens. Does anybody has an Idea what I am doing wrong?