/p/ Posted August 27, 2013 Share Posted August 27, 2013 Does anyone know specifically what the crop factor would be for Speed Booster + Nikkor DX lenses on a BMCC? Quote Link to comment Share on other sites More sharing options...
rsquires Posted August 28, 2013 Share Posted August 28, 2013 I know it's probably a stupid question, but what is to stop you buying an FD to Nikon G adapter so you can use FD lenses with the Nikon to Micro 4/3rds Speedbooster. I have loads of old FD lenses so a native adapter would be absolutely superb but is this an option. Quote Link to comment Share on other sites More sharing options...
Brian Caldwell Posted August 28, 2013 Share Posted August 28, 2013 Does anyone know specifically what the crop factor would be for Speed Booster + Nikkor DX lenses on a BMCC? The horizontal dimension of DX and BMCC frames is 23.6mm and 15.81mm, respectively. So the horizontal crop factor would be: (23.6)(.71)/15.81 = 1.06 If you calculate it based on the diagonals (28.4mm and 18.133mm, respectively for DX and BMCC) you get: (28.4)(0.71)/18.133 = 1.11 Either way, you wind up cropping just a small portion of the DX format image circle. On the other hand, if you mean crop factor relative to full-frame (24mm x 36mm) format based on the horizontal you would get: (36/15.81)(0.71) = 1.62 Quote Link to comment Share on other sites More sharing options...
Jacek Posted August 28, 2013 Share Posted August 28, 2013 I know it's probably a stupid question, but what is to stop you buying an FD to Nikon G adapter so you can use FD lenses with the Nikon to Micro 4/3rds Speedbooster. I have loads of old FD lenses so a native adapter would be absolutely superb but is this an option. FD lenses are closer to camera sensor than Nikon lenses. - so there is no FD (lens) -> Nikon (camera) adapter. - there is only Nikon (lens) -> FD (camera) adapter. FD -> m43 SpeedBooster would be the ultimate one (to accept FD, FE, Nikon...), but not sure if it's gonna be build. Quote Link to comment Share on other sites More sharing options...
soundimageplus Posted August 31, 2013 Share Posted August 31, 2013 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? Quote Link to comment Share on other sites More sharing options...
Brian Caldwell Posted September 1, 2013 Share Posted September 1, 2013 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? Using a DX lens on m43 via the 0.71x Speed Booster shows about 7% more image circle diameter than using the non-boosted lens on a DX camera. In most cases this has little or no effect on image quality - you just get a little wider field than normal. Note that if you shoot video the top and bottom of the image are cropped, so this effect goes away. Did you use a hood with your 30/1.4? The only time I've seen such pronounced vignetting with a DX lens on m43 is with ultra-wide lenses having fixed hoods. FWIW, I've tried the new version of the Sigma 30/1.4 on the Speed Booster, and it doesn't behave this way at all, even with the hood attached and stopped-down to minimum aperture. Quote Link to comment Share on other sites More sharing options...
soundimageplus Posted September 2, 2013 Share Posted September 2, 2013 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. Quote Link to comment Share on other sites More sharing options...
Brian Caldwell Posted September 2, 2013 Share Posted September 2, 2013 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. I co-authored that Metabones document, so I'm familiar with the figure :) It makes no sense at all to me that your Sigma lens could vignette for video. That is, assuming that the width of the sensor's active area remains 17.3mm when in 16:9 mode. The Sigma has to cover a 28.4mm image circle for DX format, meaning that its image circle with the Speed Booster will be at least 28.4 x 0.71 = 20.16mm. A 16:9 rectangle that is 17.3mm wide has a diagonal of only 19.85, so something is definitely odd here. Does your m4/3 body have a variable active sensor width depending on the aspect ratio? DX lenses we have tried on full micro four thirds format (21.6mm diagonal) with the Speed Booster without any obvious vignetting (at any aperture) include: 1) Sigma 30mm f/1.4 version II 2) Tokina 11- 16 f/2.8 3) Nikon 35mm f/1.8 4) Nikon 10-24mm f/3.5-4.5 The Sigma 8-16mm does have vignetting due primarily to its fixed lens hood shaped for 3:2 instead of 4:3. I've also heard that the Nikon 17-55/2.8 works fine with no vignetting, although I haven't tried it myself Andrew Reid 1 Quote Link to comment Share on other sites More sharing options...
/p/ Posted September 2, 2013 Share Posted September 2, 2013 Mine is on it's way, Nikon G > MFT for my BMCC.. I am very excited. Quote Link to comment Share on other sites More sharing options...
soundimageplus Posted September 3, 2013 Share Posted September 3, 2013 "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. Quote Link to comment Share on other sites More sharing options...
/p/ Posted September 3, 2013 Share Posted September 3, 2013 Don't suppose anyone has tried the Nikkor 12-24 f/4G with a Speed Booster on the BMCC? What would the 35mm FF equivalent focal length be with that combination? (12-24 + Speed Booster + BMCC). Quote Link to comment Share on other sites More sharing options...
Nikkor Posted September 3, 2013 Share Posted September 3, 2013 I have the nikkor and the quality isn't very good on APS-C, when I put it on the d800 and go to 18mm (no vignetting,19-20mm with filters) it really shows how bad it is. Maybe for video (as long as you can find a way to correct CA) it's ok, but for stills its very bad. Quote Link to comment Share on other sites More sharing options...
Brian Caldwell Posted September 4, 2013 Share Posted September 4, 2013 "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. Yes, that's me. I really appreciate your extensive review, and the unexpected behavior with the original version of the Sigma 30/1.4 is certainly something I need to look into. The new version of the 30/1.4 is a really nice lens, BTW, and even though I only bought it for Speed Booster testing I'll definitely keep it since 21mm f/1.0 is really nice on m4/3. soundimageplus 1 Quote Link to comment Share on other sites More sharing options...
Dustin Young Posted September 10, 2013 Share Posted September 10, 2013 "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. I was hoping you could post some links so we could observe for ourselves the vignetting from using the Sigma 18-35mm with metabones attached to the GH3/G6 it would be much appreciated, Quote Link to comment Share on other sites More sharing options...
Dancehall Connect Rasi Posted December 16, 2013 Share Posted December 16, 2013 is there a speed booster that fits 17.5mm f 0.95 voig for micro 4/3 Quote Link to comment Share on other sites More sharing options...
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