Dear list members: I have a question for the group and would appreciate any feedback I could receive. My new Canon 16-25mm lens has improved dramatically after I exchanged it for another lens. However, I continue to notice a great deal of vignetting primarily when the lens is wide open at 16mm focal length. I took a shot with the blue sky in the background and the vignetting was so intense that after using the vingnette corretion under lens correction in Camera Raw to its maximum it could still be noticed. My impression is that this is being cause (at least in part) by the filter I am using. When I purchase my camera I asked for Heliopan multicoated UV filters for both lenses. The reseller gave me by mistake the single coated filters and I didn't notice this until I got home. When I hold the multicoated filter I have on my Nikkor 17-35mm and the single coated filter I have on my Canon 16-35mm both against the light in a angle it is easy to see that the single coated reflects a lot more light than the multicoated. Could this associated with the curvature of the lens and the light fall out effect that has been discussed here in the past for full frame sensors cause this problem ? What are your opinions ? I have also looked at B+W's Kaesemann multicoated polarizer and it barely reflects any light on its surface. It seems it would be a good aid in avoiding or reducing this vingnetting I am seeing. The only trade-off is the 2 f-stops lost using this polarizer. What are your opinions on this subject ? How many of you have the same Canon lens or a similar lens and have experienced this type of problem ? What solution have you found ? Last but not least, I have spoken to some photographers who say they don't use any filter at all with wide lenses such as this 16-35mm because any type of filter independent of how good it is will cause image problems at such wide angles. How many of you use lenses without filters to protect them ? Isn't that a little risky since you can damage the front element of the lens ? How many of you have actually had lenses damaged because of the absence of a protective UV filter ? Thank you in advance for your replies and help. Best regards, Joseph --- Dr. Joseph Chamberlain Oral and Maxillofacial Surgery
