However, despite all the other positive feedback on the accuracy of fit, to let the only really hard to turn the panel despite having thoroughly set up. Even the wrong direction Replace (for transportation) cost right power so that I here only once the reception by reading if I had perhaps done something wrong to me. After a closer study of the thread on the lens and iris is me then noticed that, probably due to production, four small bumps occur on the lens hood. Here the thread is uneven, the plastic very rough and it was also the reason for these problems. Even though I was able to remove these bumps without problems with a fine file, my encounters the plastic in such a high price for a piece of bitter on.
Also I find the thread and the diaphragm itself now processed not as high quality as it was the case with the other lenses. The bottom line for me two points off, I hope I was the only one with such a Monday product. From now on I'll only watch me the third party before I reach again for Canon Aperture.
Hopefully I could help you with my reception :).