I have just purchased the c4040 and would like to protect the lens. I bought the CLA-1 adaptor and the 43-55mm step up ring, but was dismayed to find that the 55mm ring obscured the lower portion of the picture composition through the viewfinder. Since then, I purchased an inexpensive 43 mm lens protector and placed it on the CLA-1 ring. I don't seem to be having any problems with vignetting, but was warned by other photographers that this would be an issue. The camera is certainly much less bulky without the second adaptor, but I don't want to compromise image quality. Has anyone else tried this combination to protect their lens and how satisfied have they been with the results? Thanks in advance for your guidance.--L1