SpeedBooster makes lenses wider and faster?!?

kevwilfoto · #1 January 13th, 2013, 08:39 PM

An adaptor claims to make your lens, faster, wider and better!! This is NOT an April Fool’s! | Philip Bloom

If this is true, it could be a BIG deal. Kinda makes me want to track down a Samyang 85mm f/1.4. :)

drewbot · #2 January 13th, 2013, 08:50 PM

$599? Ouch

Promit · #3 January 13th, 2013, 08:53 PM

Metabones aren't nobodies, and Philip Bloom certainly isn't a nobody. But this is firmly in the too good to be true category. I guess they'll be releasing it though, so we'll see...

dhazeghi · #4 January 13th, 2013, 08:59 PM

Quote:

Originally Posted by Promit

Metabones aren't nobodies, and Philip Bloom certainly isn't a nobody. But this is firmly in the too good to be true category. I guess they'll be releasing it though, so we'll see...

It's a focal reducer. Sort of the opposite of a teleconverter. It essentially reprojects the image onto a smaller circle, making the AoV narrower and the image brighter.

IIRC Kodak patented something like this some years back. There's also some evidence that Olympus used this approach with their 14-35/2 and 35-100/2 by taking full-frame designs (28-70/2.8 and 70-200/2.8) and modifying them to incorporate a 2x focal reducer.

The main question is optical quality, but I suppose for video it doesn't matter as much.

Amin Sabet · #5 January 13th, 2013, 09:12 PM

This concept has been done before. For example, the very early Nikon E series DSLR, co-developed with Fuji, used a 4X focal reducer to get the full angle of view and light collecting power of full frame lenses condensed to a 2/3" sensor: Nikon E series - Wikipedia, the free encyclopedia

Adapters serving this purpose are also used in astronomy, where they may be referred to as focal reducers or telecompressors.

Kodak has a 1994 patent which describes a device similar to the one Metabones is introducing: United States Patent: 5499069

pxpaulx · #6 January 13th, 2013, 09:14 PM

It sounds to me like they are saying they are increasing the amount of light hitting the sensor because they are increasing the physical image size, and therefore are creating an increase in aperture? I might have to call zombie BS on that one - glass is glass is glass. There is a reason nobody recommends buying cheap front element lens adapters, even the best made degrade IQ, not increase it.

I think I've read philip bloom a few times...I noticed he passed the buck on this review to his 'right hand man' - who heartily recommends it - Phiilp pops back in to say he'll chime in later, and by the way check out his upcoming workshop. Way too much an advertising piece for my taste, rather than an unbiased review.

Edit: Dhazeghi, it would really make the image brighter? I suppose if you're changing the optical formula it could (and if a teleconverter takes away stops, then a wide converter adds them...is that the basic logic to be applied?).

usayit · #7 January 13th, 2013, 09:18 PM

Speed is in the loosest sense a very common but fairly inaccurate way to describe aperture. Its really a ratio between area and focal length. Area = pi ( f/2 N) ^2 where f is focal length and N is aperture and in this case area is constant given the same lens. So its marketing really stretching the meaning of the math behind the numbers. Its like similar to saying that f/0.95 lenses actually magically intensify the light coming in the front element producing a brighter image out the rear element... and f/1 produce zero light loss. Pure B.S.

Furthermore, like teleconverters there is an extra element in that "speed booster"... which is no way magically able to beat the laws of optics and physics. I can definitely see its uses though.... if a crop sensor camera is a backup to a full frame, it makes the lenses a bit more usable assuming there is no loss in IQ or light... which is highly unlikely.

So in a practical sense... I'll pass on that idea.

Also reading the US patent (I haven't finished) the intent was specifically for larger format to smaller format adaptation.... it doesn't look like their intention was to play fuzzy with aperture for the marketing department.

dwig · #8 January 13th, 2013, 09:41 PM

Quote:

Originally Posted by Amin Sabet

This concept has been done before. For example, the very early Nikon E series DSLR, co-developed with Fuji, used a 4X focal reducer to get the full angle of view and light collecting power of full frame lenses condensed to a 2/3" sensor: Nikon E series - Wikipedia, the free encyclopedia

Adapters serving this purpose are also used in astronomy, where they may be referred to as focal reducers or telecompressors.

Kodak has a 1994 patent which describes a device similar to the one Metabones is introducing: United States Patent: 5499069

Also, way back in the late 19th century and early 20th lenses were sold to increase (negative lenses) and decrease the FL of primary lenses and were used with bellows cameras that could adjust to accomidate the change in FL. A simple closeup lens will reduce the FL of any lens and if you can move the lens closer to the film/sensor you can restore infinity focus. If not, you get a closer focus. With adapted lenses its a simple matter of mounting the lens in a thinner than normal adapter. The principle is the same a teleextenders, where the extender's tube provided the needed extension, except instead of a negative lens and increased extension there is a positive lens and a reduced adapter length.

Just like with teleextenders, you are changing the FL but not the absolute size of the aperture. Since f/stops are relative apertures (FL / aperture diamenter) an extender reduces the f/stop and a reducer increases it (new reduced FL / same old diameter).

Vivalo · #9 January 13th, 2013, 09:59 PM

Quote:

Originally Posted by pxpaulx

It sounds to me like they are saying they are increasing the amount of light hitting the sensor because they are increasing the physical image size, and therefore are creating an increase in aperture?

More like decreasing the physical image size. I think it works like magnifying glass when you try to set fire with it from the sunlight. It sort of intensifies the light on a smaller area, I think....

Ned · #10 January 13th, 2013, 11:12 PM

Quote:

Originally Posted by dhazeghi

It's a focal reducer. Sort of the opposite of a teleconverter. It essentially reprojects the image onto a smaller circle, making the AoV narrower and the image brighter.

IIRC Kodak patented something like this some years back. There's also some evidence that Olympus used this approach with their 14-35/2 and 35-100/2 by taking full-frame designs (28-70/2.8 and 70-200/2.8) and modifying them to incorporate a 2x focal reducer.

The main question is optical quality, but I suppose for video it doesn't matter as much.

If it really is true that Olympus used a focal reducer in their 14-35mm/2 and 35-100mm/2, then how could there possibly be any question about optical quality? ;)