wdgodwin

<p>I got the same error message with my trusty and heavily used workhorse EF-S 17-85 4-5.6 IS USM. When I got the error I would switch camera off, unlock lens and rotate lens back and forth in the mount to scrub contacts for electrical circuitry. I cleaned the contacts with Goo Gone, rubbing alcohol and lighter fluid - nothing worked long term. It's not a problem until you are photographing something that can't be repeated... that's when it will fail you (Murphy Moment). Just the aggravation of, oh maybe, relight the birthday candles, can you do that pose again, everybody smile..... hold the smile... keep holding... to the point of 'can we go to a commercial break'.<br> Sent to Canon for repair. Replaced module in lens. Cost $143.00. Time shipped to Canon and returned to me under 2 weeks. Back in business, good as new. Cleaning contacts was not the problem. Cheaper than buying new lens.</p>

<p>I love my SF 150mm. Used it for a couple of frames for bridal close up images during each session. No need to retouch. Studio strobes were metered for f8.0. When doing close ups at f4.0 I dropped a 2 stop ND filter in the bellows filter holder. For mid and full length poses shot at f8.0 with no ND filter. A little difficult to focus since you are viewing through the lens with aperture wide open. The magnifyer was a great aid for focus.<br> It's different from soft filters screwed in the front of the lens. The filter softens everything and all detail is softened, nothing is sharp. It was my understanding the SF lens is ground/polished for sharpness in center and not so much around the edges. When shooting at f4.0 (max softness), you actually use all the front element to get a slighly out of focus (outer element) image together with an in focus (center element) on the same frame that yields a soft image with detail. The only downside is you can't have both softness and DoF.<br> I have the discs set and shot a test series with each discs at each lens aperture when I first got the lens. After that, never used them. I just used f4.0 for the max, f5.6 for a little effect and then f8.0 and 11 for a sharp image.<br> Hope you enjoy yours.</p>