Massa 86 MM UV Adapter (1 Viewer)

[Hughv]

I bought the above device for my Sigma 150-500 and all images are blurry/out of focus with it attached.
I RMA'd the original and get the same results with the new one.

The lens works perfectly without this adapter attached.

Is this just a low quality device, or is something else going on?

 

[seaspirit]

I bought the above device for my Sigma 150-500 and all images are blurry/out of focus with it attached.
I RMA'd the original and get the same results with the new one.

The lens works perfectly without this adapter attached.

Is this just a low quality device, or is something else going on?

Wasn't sure what you mean with UV Adapter and googled it.
If you use a 86mm Massa UV filter then the filter is likely the reason for the blurry images.
Good quality UV filters of this size (i.e. Tiffen, BH, Sigma) will cost more than 10x what the Massa filter is listed for (found it listed for < $10).
All filters in front of the lens will compromise image quality. However, good (expensive) filters will have a barely noticeable effect and cheap ones can be catastrophic. With increasing filter size, and 86mm filters are huge, cheap filters get worse as they are often wrapped and not plane. I got some cheap polarizers from ebay with the 49mm working OKish and a 77mm one visibly wrapped and unusable (no AF possible, in MF blurry results.
Like with all optics you get what you pay for ......

Ulli