soundimageplus

"It makes no sense at all to me that your Sigma lens could vignette for video."   Well all I can tell you is that is does. I was shooting in standard 16:9 on a Panasonic G6 (Did the same on a GH3). No hood, not even a UV filter. As I said even wide open there is some shading in the corners, stills and video. I don't have any other DX lenses to compare, as everything else I'm using are 35mm lenses so I can't tell if its just this lens (this example or the model in general.) No problems with any other lens. Basically I really don't have any answers for you.   Personally, its not a problem, I was selling the lens anyway, have now sold it. However I thought that I should post what happens with the lens. By the way its almost brand new and hardly used. I bought it for some low light work, but with the Speed Booster I don't need it now and I have better lenses anyway.   Apart from that, and presuming that you are Brian Caldwell ???, my congratulations on a spectacular piece of kit. The results I'm getting for stills and video are just incredible and your 'magic' (though I do realise it has nothing to do with that!) trick of widening the lens, adding a stop more light and actually improving my lens performance is seriously impressive. I'm using nothing else but my Nikon primes currently and have a Nikon > Fuji X Speed Booster on order, to use them on that camera. So I'll leave the Sigma mystery with you (Perhaps some other users might clarify whether its a problem with my lens or more widespread.)   Anyway thanks for replying and above all thanks for your creation. Best piece of kit I've bought for years.

No I didn't have the hood on, nor even a UV filter. Metabones have a diagram (attached) which shows DX lenses + Speed Booster right on the edge of vignetting or not. It seems it depends on the lens. The Sigma also vignetted for video except for when it was wide open.

You mentioned using the Sigma 18-35mm f/1.8 zoom in your review. I'm testing the Nikon G > m4/3 speed booster at the moment and the only DX lens I have used so far (the only one I've got) - Sigma 30mm f/1.4 (The old one) has severe vignetting. http://soundimageplus.blogspot.co.uk/2013/08/panasonic-g6-metabones-speed-booster_29.html   Its not so bad wide open, but as the speed booster is stopped down it gets worse. I've attached a file showing what happens. No problems with any my Nikon G  35mm lenses and as you say, the edge sharpness, apart from wide open is excellent and better than I was expecting from reviews of other adapters.   I can't say whether this is because of this lens specifically, or all DX APS-C lenses in general. Any ideas on this?