Comments on: Adam from Mythbusters talks about Speed Booster and NEX cameras.

By: Adrien S

Adrien S — Tue, 12 Feb 2013 00:17:57 +0000

There is a huge mistake made by many people about “aperture”.

In the video they say they will get the feel of a 85/1 with this adapter and a 85/1.4 on a Nex, and that is totally wrong.
You will get the image a 85/1.4 gives you on a full frame. With a f/1 setting for speed, that’s true, but definitely not a 85/1 image look depth-of-field wise.

Just like putting a 50/1.4 on a 1.5 crop sensor won’t make the photographs look like the ones taken by a full frame 75/1.4, but a 75/2 instead, regarding image looks and depth of field. And a 1.4 lense regarding speed, that’s true.

The aperture that gives you the “quantity of light arriving on sensor per surface units” (and so the speed/iso/aperture combination you need in a specific situation) is NOT the same as the aperture that gives you the depth of field you get on a specific setup, if you change sensor.

A x2 teleconverter does change both apertures, because you keep the same sensor. But here, you try to compare things with different sensors, and that’s why the two apertures aren’t linked any more.

By: ChenAlan

ChenAlan — Fri, 08 Feb 2013 11:32:34 +0000

For all his goofyness in Mythbusters, my respect for Adam Savage has just gone up insanely high.

By: Klipsen

Klipsen — Thu, 07 Feb 2013 15:11:35 +0000

Yes, but for use on photo cameras, the technology was apparently patented by Kodak, who never manufactured the product, nor would allow anyone else to do so.

I’ve argued for Sony to start making them for years, because it would turn their APS-C cameras into full frame cameras, increase lens speed and potentially lens resolution.

Front mounted converters reduce image quality, rear mounted converters may actually improve it.

By: Alf

Alf — Thu, 07 Feb 2013 10:27:33 +0000

It gives the same DoF as on FF because you get the same aperture for almost the same focal lenght (x1.08 crop instead of x1.5 crop).
And that’s what defines DoF, not the size of the sensor per se.

Imagine a 100mm f/1 full frame lens.
On an APS-C NEX with speedbooster, this lens will become a 108mm f/1.08
Pretty close isn’t it ?

By: Austin

Austin — Thu, 07 Feb 2013 02:58:48 +0000

The speed booster can’t get faster than 0.9 because of the size of the entrance pupil. So 1.2 lenses will be as fast as a 1 or a 0.95