I recently picked up the above lens in a Rapax shutter and I have a couple of questions. I plan to use it for 6x9 and 6x7 with my Wista VX and a sliding back so not really concerned with image circle although I would like to know what kind of IC the lens has. The Rapax shutter needs a cleaning and as I only paid $40 for the lens and shutter I would like to try cleaning this shutter myself. When I remove the lens elements I can see the inside of the shutter very easily. Has anyone used the old lighter fluid cleaning method with this shutter? All the shutter speeds work but some are very sticky and off. When I attach a cable release it will not trip the shutter, but when I stick a more narrow pin into the hole the shutter will fire. Does one need a special release cable to trip this shutter? Does any one know what size filters this lens takes. When I measure it comes out to about 29mm. Anyone know the exact size filter? I would like to get this lens working as it is coated and the elements are in descent shape. Any help would be appreciated.