What is Exposure Magnification

[XenoPhoto]

There are two 1.4x and two 2.0x teleconverters lens in Tamron website.
the "white" colour have the word Exposure Magnification under their specification.

Anyone know what Exposure Magnification is for and differences between the white and black teleconverters?

[ortega]

try this

http://www.tamron.com/about/manuals.asp

[XenoPhoto]

well... they do not explain about it on their lens. I only see it on their white teleconverters

[ortega]

i think it is exposure compensation

[catchlights]

it means the exposure compensation is about two stops for a 2X Exposure Magnification.

the white version SP AF2X Pro Teleconverter is a pro version. more ex.

the black version AF2X Teleconverter is a consumer version. cheaper.

[shaoken]

If I'm not wrong the the light lost through the tele-converter.

In most cases, 2x tele-converter will result in -2 stops of light. 1.4x results in about 1.5x light loss.

[XenoPhoto]

wow! -1.5 stop is a lot for 1.4x teleconverter
i thought it will only be -1 stop for 1.4x

[catchlights]

Originally Posted by shaoken If I'm not wrong the the light lost through the tele-converter. In most cases, 2x tele-converter will result in -2 stops of light. 1.4x results in about 1.5x light loss.

incorrect.

Quote: decreases the effective aperture by one F-stop (with 1.4x Tele Converter) or by two F-stops (with 2x Tele Converter).