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The speed booster...

Ben Rubinstein

pro member
It isn't just video, not even close. It makes your FF lenses work as FF on a tiny crop camera which incidentally does great image quality. If you wanted a fast normal lens on a Nex you were pretty limited to date. Now you have a huge choice at a fraction of the price. I almost ended up buying a NEX 7 with the speed booster as my 'retirement' camera and only ended up with the 5D3 due to the need for the versatility of AF.
 
Sure thing Ben, it can be very useful for stills too.... The thing is that for stills, there are alternatives using fast AP-c lenses through adapters e.g. the Tokina 11-16 for instance, while in video, where much of the sensor area is inactive, problems like vignetting, corner resolution or edge distortion are much less, if you add the flexibility of the rocker zoom that exists in all recent Nex mount cameras (vg-30/900, eh-50, fs-700) which can double the FL with insignificant loss of quality, the advantage is huge... A Canon 24-105 or a Nikkor 24-120 can cover the entire FF range from 26 to 230mm/265mm (FF equivalent) being of f2.8 without their disadvantages being enhanced further as it happens if the full sensor is used... same thing with the 24-70mm zooms, that will be able to cover 26-155mm at f2.... wow!
 

Jerome Marot

Well-known member
Let me tell you something: if, just by designing a standard converter, one could take a decent lens and make a good quality fast lens, we would have had f/1.0 lenses all over the place long ago.

But we have not. A focal reducer, which is what this converter is, comes with its own set of optical compromises. Astronomers know about these, since focal reducers have been available for telescopes for the past 20 years.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Sure thing Ben, it can be very useful for stills too.... The thing is that for stills, there are alternatives using fast AP-c lenses through adapters e.g. the Tokina 11-16 for instance, while in video, where much of the sensor area is inactive, problems like vignetting, corner resolution or edge distortion are much less, if you add the flexibility of the rocker zoom that exists in all recent Nex mount cameras (vg-30/900, eh-50, fs-700) which can double the FL with insignificant loss of quality, the advantage is huge... A Canon 24-105 or a Nikkor 24-120 can cover the entire FF range from 26 to 230mm/265mm (FF equivalent) being of f2.8 without their disadvantages being enhanced further as it happens if the full sensor is used... same thing with the 24-70mm zooms, that will be able to cover 26-155mm at f2.... wow!

Ben, Theo and Jerome,

Let me remove some misconceptions we might have had. There's never any increase in effective FL! The convertor always makes the lens wider by a factor of 0.7 and puts the entire full frame image on the APS-C sized NEX sensor, increasing the MTF near the center of the lens. So this could be great for landscapes and also for taking pictures in concerts without having to muffle mirror slap with a large clumsy box, such as the very effective Sound Blimp. A 70-200 2.8L IS would now be used as a 49-140mm 1.4 giving an especially welcome advantage in low light shooting in theaters, concert halls and night clubs.



Sound blimp.com: Sound Blimp

While the lens in the center is pretty damn good, the corners are not perfect. A multiplication factor of 0.67 would be needed and that would be too bulky and limit lenses compatible. More information is given in the fascinating White Paper by Brian Caldwell, Caldwell Photographic Inc.
and Wilfried Bittner, WB Design.

@Jerome,

Yes, reducers have been around for a long time in astronomy optics. I think this lens designer has done a pretty good job at shrinking the full frame image on to the APS-C size sensor with essentially no practical loss of detail in the full frame. No miracle but a pretty useful tool for low light and non-intrusive photography.

Asher
 

Jerome Marot

Well-known member
A 70-200 2.8L IS would now be used as a 49-140mm 1.4
2.0, actually.


giving an especially welcome advantage in low light shooting in theaters, concert halls and night clubs.
Not compared to a full frame camera. You get 1 stop advantage between a full frame and an APS-C camera (the sensor is bigger) and 1 stop with this focal reducer. We could have guessed that it would be the same, since in both cases we use a front piece of glass of the same physical size, by which all photons have to pass...


I think this lens designer has done a pretty good job at shrinking the full frame image on to the APS-C size sensor with essentially no practical loss of detail in the full frame. No miracle but a pretty useful tool for low light and non-intrusive photography.
I am not saying that the device is without merit, but that its value is greatly exaggerated. In any cases, you'll get no usable AF, poor corners (especially for wide-angles) and a system that is not very compact. Whether the central part of the picture is reasonably sharp and exempt of aberrations remains to be seen for each primary lens on a case by case basis. I would be surprised if it is really good with a f/1.4 or faster lens as a primary lens.

As to noise, that entirely depends on the camera. Some Nikon and Canon SLRs have a quiet mode which is more silent than most NEX cameras, for example.
 
Undeniably Jerome has a point here... the device seems perfect in theory, but OTOH, no lens is perfect... we should expect the better lenses to be benefited and the poorer ones to have their disadvantages exaggerated. However, the lower analysis (2k) and the smaller frame used in video, undeniably benefits video users more than it does stills shooters... besides, the fact that the image area is squeezed by exactly one stop (i.e. it's root square smaller or 0.71x) still leaves some of the extreme edge and corners out from a FF lens with respect to the APS-c area of NEX (which is 0.65X the FF area), so that some lenses that are problematic only on the very far edges and corners (especially in video frame for the later) will still benefit a lot... What I haven't solve yet, is if the DOF area shrinks by one stop... or if a 24mm lens at (say) f2.8 real used aperture, will become a 26.3mm (image area FF equivalent) of f2.0 with 24mm f2.8 DOF though... DOF will remain the original one ...no? As it will when the rocker zoom is used ...no? Never the less, I will buy the thing for my (recently added - I replaced the 3ccd cameras I was using up to now) NEX mount videocameras...
 

Asher Kelman

OPF Owner/Editor-in-Chief
As to noise, that entirely depends on the camera. Some Nikon and Canon SLRs have a quiet mode which is more silent than most NEX cameras, for example.
I've used the NEX5N but not in a concert. It's claimed that there's an additional synthesized shutter sound in the NEX3 that can't be shut off! The Sony RX100 as in the Ricoh GXR are pretty well undetectable with their sounds switched off. Anyway, the NEX5N Leaf Shutter seemed very much quieter than my 5DII and that's one shot after another. I understand that the NEX7 shutter is even quieter. With the 5DII, AFAIK, one can only delay the loud mirror slap, but not keep on shooting.

Asher
 
Undeniably Jerome has a point here... the device seems perfect in theory, but OTOH, no lens is perfect... we should expect the better lenses to be benefited and the poorer ones to have their disadvantages exaggerated. However, the lower analysis (2k) and the smaller frame used in video, undeniably benefits video users more than it does stills shooters... besides, the fact that the image area is squeezed by exactly one stop (i.e. it's root square smaller or 0.71x) still leaves some of the extreme edge and corners out from a FF lens with respect to the APS-c area of NEX (which is 0.65X the FF area), so that some lenses that are problematic only on the very far edges and corners (especially in video frame for the later) will still benefit a lot... What I haven't solve yet, is if the DOF area shrinks by one stop... or if a 24mm lens at (say) f2.8 real used aperture, will become a 26.3mm (image area FF equivalent) of f2.0 with 24mm f2.8 DOF though... DOF will remain the original one ...no? As it will when the rocker zoom is used ...no? Never the less, I will buy the thing for my (recently added - I replaced the 3ccd cameras I was using up to now) NEX mount videocameras...

Have you checked out BlackMagic's pocketable videocamera yet? I wonder if Metabones will make a mount for that!

http://www.blackmagicdesign.com/products/blackmagicpocketcinemacamera
 

Jerome Marot

Well-known member
What I haven't solved yet, is if the DOF area shrinks by one stop...
The depth of field of a given lens at a given aperture on full frame will be roughly the same as the depth of field of the same lens on an APS-C camera through the adaptor.

Example: Sony A900 and 50mm f/1.4 wide open = Nex7 and adapter and 50mm f/1.4 wide open.
 

Jerome Marot

Well-known member
I've used the NEX5N but not in a concert. It's claimed that there's an additional synthesized shutter sound in the NEX3 that can't be shut off! The Sony RX100 as in the Ricoh GXR are pretty well undetectable with their sounds switched off. Anyway, the NEX5N Leaf Shutter seemed very much quieter than my 5DII and that's one shot after another. I understand that the NEX7 shutter is even quieter. With the 5DII, AFAIK, one can only delay the loud mirror slap, but not keep on shooting.
The RX100 and GXR without M-mount module use leaf shutters and are as silent as can be (mind you, an Hasselblad with the mirror up is also almost silent). The GXR M-module and all NEX use a focal plane shutter which is too noisy for a concert. The NEX-7 is a bit more silent than the older NEX, because it uses a partial electronic shutter, but it is definitely not silent. Some APS-C SLRs have a quiet mode that is surprisingly silent. I have heard a Nikon (don't remember which model, D90 maybe?) that was less silent than a leaf shutter but slightly more than the NEX-7.

If this is a requirement you have, you should definitely check the quiet mode of various SLRs.

(Joke mode on: or get an H4D-40 and use an external viewfinder... ;) )
 
Have you checked out BlackMagic's pocketable videocamera yet? I wonder if Metabones will make a mount for that!

http://www.blackmagicdesign.com/products/blackmagicpocketcinemacamera
Yes, I've checked it... superb IQ alright..., but the "black magic" I have rejected due to sensor size... I think it won't be long before we see affordable 4K raw video on a Nex mount... I believe (personal opinion) that the Nex mount is the most advanced mount in industry and that it may be equaled but cannot be bettered in the future. This is because:
1. It provides S35 image area as standard (the cinema look)
2. It can serve a FF sensor
3. It is the shallower depth from all S35/Aps-c sensors
4. It has the highest compatibility with older lenses (which saves lots of money)... and
5. With the speed booster it makes possible to transfer all the existing lenses that a photographer owns (my case) into filming without having to be used in a different approach of AOV...
In the case of black magic or 4/3rds, if a speed booster will be used, it will still have different AOV than FF... that was the decisive factor, I don't like changing mind with respect to equipment in the future, I like long term solutions that will possibly last me a lifetime.
 
The depth of field of a given lens at a given aperture on full frame will be roughly the same as the depth of field of the same lens on an APS-C camera through the adaptor.

Example: Sony A900 and 50mm f/1.4 wide open = Nex7 and adapter and 50mm f/1.4 wide open.
That's what I thought... in fact it will be A900 and 50mm f1.4 = 54.5mm AOV with f1.0 aperture (only as exposure is concerned) for the same DOF as is on the A900... hence there will be root square of depth of field increase for the actual aperture that is used for exposure (f1.0 in this case). Still there will be 0.6 of shallower DOF than if an APS-c lens was to be used for the same AOV and the same light passing through aperture.
 
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