10-21-2013, 05:22 PM
No, there's no design problem with the lens - and I'm no Canon user.
Each lens manufacturer offers a variety of "better quality" (than some cheap eBay from Hongkong or Shenzhen products) filter line. There is no standard for length of filter threads, only for the diameter and thread pitch are standards. If I buy my filters not from Nikon, it's only my responsibility to check if they don't collide with the front element. If I bought it from the lens manufacturer I could be sure, this check was already done. And that one was a "ultra-slim" version for wide angle.
![[Image: snapshot-79-M.png]](http://sojujo.smugmug.com/Testshots/PZ-graphics/i-qbTRWj4/0/M/snapshot-79-M.png)
And as you also read in the article, Roger had to go through more than half a dozen filters to find one whose glass came close enough to the front lens. With high quality filters there will be no problem, because those filter glasses never go behind the front ring (behind the red line in the sketch) of the lens' filter thread. Cheap filters can be produced by glueing the filter glass into the threaded ring, so the glass surface is placed behind the front ring of the lens.
If you can't see the front lens looking over the front ring, a good filter will never touch it.
Don't get me wrong: There are high class ultra slim filters on the market, be it B&W, Heliopan or other well-known brands. But they come at a certain price. So if one doesn't need them - stay away in general. And if one does need them, get the best, not the cheapest.
Each lens manufacturer offers a variety of "better quality" (than some cheap eBay from Hongkong or Shenzhen products) filter line. There is no standard for length of filter threads, only for the diameter and thread pitch are standards. If I buy my filters not from Nikon, it's only my responsibility to check if they don't collide with the front element. If I bought it from the lens manufacturer I could be sure, this check was already done. And that one was a "ultra-slim" version for wide angle.
And as you also read in the article, Roger had to go through more than half a dozen filters to find one whose glass came close enough to the front lens. With high quality filters there will be no problem, because those filter glasses never go behind the front ring (behind the red line in the sketch) of the lens' filter thread. Cheap filters can be produced by glueing the filter glass into the threaded ring, so the glass surface is placed behind the front ring of the lens.
If you can't see the front lens looking over the front ring, a good filter will never touch it.
Don't get me wrong: There are high class ultra slim filters on the market, be it B&W, Heliopan or other well-known brands. But they come at a certain price. So if one doesn't need them - stay away in general. And if one does need them, get the best, not the cheapest.