Bests & Worsts Reviews from Amazon

I have had this lens about 2 months. I've used it 4 or 5 times. The results are quite good for a lens retailing for under $200. As others have noted, the build quality is not superb, but it felt and functioned like a reasonably sound piece of gear, though the f/stop ring has been "sticky" since I got it. This Tuesday morning, while shooting the eclipse of the moon, I found that the internal rectangular mask had rotated about 50 degrees. This results in part of the image being blocked from the camera sensor, and renders the lens useless. If the lens had not failed physically, I would have rated the performance a 4 as good-for-value performance for a low cost lens. I've contacted the seller, but so far based on this failure my purchase has been a waste of money, and rates a 1. UPDATE: Two weeks and two emails later, the only response from 47th Street Photo has been one automated response that they were "closed for a holiday". Disappointing. I have now contacted Opteka to see how they honor their 1 year warranty. UPDATE: I gave up on 47th Street photo (they never did answer my queries.) HOWEVER Opteka warranty service answered my email within a day. I provided proof of purchase and had an RMA the next day. About 10 days later I have a replacement lens, which works great. I'm increasing my review to 4 stars. UPDATE: Sept 2019 - I am still happily using this lens for night photography. In Lightroom I use the Rokinon 14mm/f2.8 lens correction option since there is no Optika setting - it works fine. Because of the f2.8 aperture it is possible to get reasonably exposed images in 15-25 seconds, keeping the star-trail problem to a minimum on my canon 5DSR (full frame). I've attached two images from a recent trip to Glacier National Park as examples.