Lightdow 900mm F8.0 Telephoto Mirror Lens + T2 Mount Adapter Ring for Sony Alpha A9 A7 A7R A7RII A7S A7SII A6000 A6300 A6500 A5100 A5000 Mirrorless Digitial SLR Camera

This Lens is not bad but for my needs it did not work as I need very high resolution. I spoke to the seller and they agreed to refund me. The lens is light and easy to use. For good lighting/day time photography its great but for my night photography it did not work out.

I would be better off using my 90 mm sony lens and digitally scaling it than to use this lens.I had high hopes for this lens. One should be able to make a mirror lens much more cheaply than a refractor, since one would only need the main mirror polished and aluminized on one face, and a secondary flat mirror also polished and aluminized on one face. At worst one would use an optical flat for the secondary mirror aluminized only in the center. This would require no corrections for chromatic aberrations since mirrors have none.Unfortunately the lens I got has serious astigmatism problems. I have attached a test photo that shows this problem. I have reduced the resolution by half, and I'm sure that Amazon will compress it even more, but the astigmatism is so bad, it should still be clear in my attached photo.The adapter this camera came with was missing a set screw, and the other two were loose. I was able to replace the set screws, but unfortunately the E-mount side was loose on my camera. I ordered a replacement that fits snugly to give this lens its best chance, but this did not help.I tried contacting the manufacturer to see if there was any adjustment for the astigmatism, but they never replied.I will not be sending this back as I want to dissect the lens and see if I can see an assembly error, or if they just did a really bad job grinding the mirror. This lens is cheap enough to be considered disposable which is why I ordered it in the first place.I was using a Sony ARII camera, and I turned off the image stabilization because they had settings for 800mm, and 1000mm, but not 900mm. The photo was taken on a tripod with a 10 second delay on the trigger to allow the vibrations to die away.I am very disappointed.

Not sharp, otherwise ok. Sue has reach!

I hoped some of the other negative reviews were just isolated faulty lenses and I would fair better. Could be a great lens if it would focus, but it will not. When focused in to the optimal position the image is quite blurry. I got a much better image with a cheap 500 mm lens digitally enlarged and it cost half as much. Shipping back to China was $45.00 of my own money, could only be done through a post office and after a month I'm still waiting on a refund. I tried several similar lenses in this price range and got the best results from the Vivitar Universal 500MM Preset Lens, which I picked up for $44 on ebay.

So shot a pic of the moon that wasn't too bad. Took it on trip to Maine, tried some distant shots, and couldn't focus it. I can get close to focus but still have some blurr. I knew it was a gamble purchasing something so cheap.

It is impossible to manual focus. The focus ring is so tight when you turn it the T adapter comes loose. Since it is a manual focus lens it is impossible to use. Very poor product.

Como el enfoque es manual y es F8, basta con apoyar levemente el dedo en el arillo de enfoque para cambiar el enfoque lo suficiente como para perderlo.Dicho esto, lo uso con una APS-C de 30mp y con tripié y velocidades de obturación rápidas (250 o más)resulta que es bastante bueno para lo que cuesta!En la luna, alcanza para enfocarla bien sin tener que hacer un crop posterior, sin embargo encontrar el foco correcto es un reto porque la luna sale de cuadro muy rápido.Para obtener mejor resultado en tripie, hay que usar timer, o hasta obturador electronico, para evitar las vibraciones, ya que en 900mm, son muy notables!

I paid for this lens thinking it would be a great zoom lens. It's such poor quality, even the clearest views are blurry. On top of that, I got charged a UPS invoice for "importing" this into Canada, even though it was mailed to my house. Avoid at all costs.

Buen precio