<p>Hello,<br> I have a 1961 Canonet 19 (bottom winder) in perfect condition, apart from sticking iris blades. I have taken the from element off and flushed it with lighter fluid. It works fine for a minute but after i have the problem again. i can close down to f16 bu then when i try to open the iris, it stays at f16.<br> On this site I saw this input by Frank Wilson.<br> "On all older Canonet cameras I had removed the lens along with its attached mounting board and of course the lens assemblies were removed also. Then I left the lens set for one month in a covered tub submersed in solvent. Once a week I would remove the assembly and let it drain for an hour. Then I refilled the tub with fresh solvent again and soak it for another week. Every week I drained the solvent and let the lens assembly set out for one hour and added fresh solvent. After the 30 days expired I let the lens assembly dry out for a week and the shutter and aperture did work like new again. "<br> I PM'd him but got no answer. <br> Can anyone tell me what solvent he is talking about?<br> Also how do I remove the lens? Do i take off the three screws on the barrel? Do i need to take apart the Copal shutter? i hear it is the work of the devil and my tech knowledge is limited.<br> Could i place the camera upside down in a tray with lighter fluid at just the right level to soak the entire lens and do it that way?<br> If anyone has any tips, i would really appreciate it. the camera is perfect, even the auto exposure with the selenium cells works perfectly so i would like to have this iris blade issue resolved.<br> Many thanks, regards<br> alex</p>