alberto greco Posted April 3, 2009 Share Posted April 3, 2009 Dear friends, I own a Canon 17-40 USM L bought in October 2005. It seems to me that its quality has decreased over years. Is this in any way possible or is just my eye which is getting used to IQ standards of this lens? Thank you Alberto PS. I am mainly talking about home made B&W prints made out of negs developed by a lab. Link to comment Share on other sites More sharing options...
fotograf Posted April 3, 2009 Share Posted April 3, 2009 <p>I've used two different 17-40 L lenses in a two year period and they both performed exactly the same, when shot in different light settings and at different apertures. I shoot in film- so, don't know if that makes any difference, although both lenses(one of them was a Canon refurbished 17-40)performed exactly the same. Contrasty and sharp.</p> Link to comment Share on other sites More sharing options...
mike_hitchen Posted April 3, 2009 Share Posted April 3, 2009 <p>Can you compare two shots - one from three years ago and one recently?</p> Link to comment Share on other sites More sharing options...
mark_pierlot Posted April 3, 2009 Share Posted April 3, 2009 <p>The internal elements would have accumulated some dust over the past 4-1/2 years, but that would likely have made little discernible difference in the image quality. An even less likely cause of image degradation could be that the elements have come slightly out of alignment, but the consequences of this would be more obvious than those you're experiencing. As Mike suggests, it might be useful to compare before-and-after shots side by side, but the subjects and exposure values of the shots would have to be pretty similar for any such comparison to reveal whether or not there's been any IQ degradation.</p> Link to comment Share on other sites More sharing options...
w_t1 Posted April 3, 2009 Share Posted April 3, 2009 <p><em>I am mainly talking about home made B&W prints made out of negs developed by a lab.</em></p> <p>You don't say if you are scanning and then printing digitally, or if you are printing traditionally in wet darkroom. Perhaps look at your process there from a QA/QC standpoint - lots of variables , have you changed papers, inkjet printers, enlargers, enlarger light source, enlarging lens, scanners, film, labs, etc? BTW I am still using many FD lenses on film that I purchased in 1980-1984, with no decrease in quality. I would start with comparing negatives from 2005 with 2009, assuming it's same film, if the negs are same quality, then next step. Regards, Tom.</p> Link to comment Share on other sites More sharing options...
alberto greco Posted April 3, 2009 Author Share Posted April 3, 2009 <p>Thanks for your answers.<br> I print in my own darkroom and over these years the printing process has been always the same. I generally use the same film (Delta 100) too. I have to say that some time ago I changed the light of the enlarger because the previous one stopped working correctly. The new one seems to project a stronger light (I did experience different exposing time for same pictures when reprinted with the new light).<br> Do you think this may be the cause...? can a new stronger light of the enlarger affect sharpeness?</p> Link to comment Share on other sites More sharing options...
alberto greco Posted April 3, 2009 Author Share Posted April 3, 2009 <p>Thanks for your answers.<br> I print in my own darkroom and over these years the printing process has been always the same. I generally use the same film (Delta 100) too. I have to say that some time ago I changed the light of the enlarger because the previous one stopped working correctly. The new one seems to project a stronger light (I did experience different exposing time for same pictures when reprinted with the new light).<br> Do you think this may be the cause...? can a new stronger light of the enlarger affect sharpeness?</p> Link to comment Share on other sites More sharing options...
w_t1 Posted April 3, 2009 Share Posted April 3, 2009 <p>The light varying could have some effect, yes. Did you switch between a cold light vs. condenser enlarger, etc? I would recommend looking around the BW Darkroom forum here or on apug, there are lots of varying opinions on light head and sharpness. If there is a way to develop your own film, you could cut out the lab variable. I find my 17-40 is "sharpest" with film around f8, but that's hightly subjective.</p> Link to comment Share on other sites More sharing options...
PuppyDigs Posted April 3, 2009 Share Posted April 3, 2009 <p>My 17-40 is 6 years old and IQ hasn't changed. However my cameras have improved.</p> Sometimes the light’s all shining on me. Other times I can barely see. - Robert Hunter Link to comment Share on other sites More sharing options...
david_littleboy__tokyo__ja Posted April 3, 2009 Share Posted April 3, 2009 <p>What Puppy Face said. On the 5D, at f/16, the 17-40 was OK. On the 5DII it can't produce a sharp corner at any f stop or any focal length. Sigh.</p> Link to comment Share on other sites More sharing options...
g dan mitchell Posted April 5, 2009 Share Posted April 5, 2009 <p>A lens can go out of adjustment over time, particularly if it gets bumped or jarred. If the image quality of your 17-40 has decreased on the same camera, it could be a good idea to send it in to Canon for adjustments.</p> <p>Dan</p> Link to comment Share on other sites More sharing options...
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