Lens IQ

[Johnsoo]

Hi,
As i read reviews on lenses, i find this term pop up now and again regarding IQ of a lens. Could someone elaborate on this?

Some forums do comparison between using a 24-105L lens on lets say a 40D vs a 5d and often enough a fellow CS would mention that the IQ improves when the lens is fitted on a 5D.

Any enlightenment would do. Thank you

 

[Rashkae]

Go read the reviews on DPreview and photozone.de; they explain things well.

Also, learn the difference between full-frame and APS-C.

 

[Rashkae]

Oh, and remember, in this context IQ is not intelligence. It's Image Quality.

 

[Ah Pao]

Interesting...the IQ of a lens changes when fitted on different camera bodies? "Image Quality" may not just refer to the characteristics of the lens (sharpness, contrast, bokeh, etc.), but it can be applied to the output of the image from the camera (noise control, colour, etc.)

You may want to re-read the thread(s) say that the IQ of the lens changes when mounted on a 40D compared to 5D. Perhaps it's a misread or quote out of context.

 

[Octarine]

Some forums do comparison between using a 24-105L lens on lets say a 40D vs a 5d and often enough a fellow CS would mention that the IQ improves when the lens is fitted on a 5D.

Some lenses show quite pronounced vignetting on FF cameras (e.g. 5D) whereas when used on cropped sensor cam (e.g. 40D) the vignetting is less obvious or gone (because of the smaller sensor). The same goes for corner sharpness...
There are many factors contributing to the final image. The characteristics of the lens is only one side of the coin.

 

[Rashkae]

There are many factors contributing to the final image. The characteristics of the lens is only one side of the coin.

Yup. Then there's the microlens array on the sensor, the different bayer filters, pixel density, etc etc etc