Lens Performance Data

Bengt Nyman

Senior Member
Thanks for trying Wayne. Been there done that. If I want data before I buy I guess I wait, wait, wait.
When you buy a car the manufacturer provides the data you need. It seems the photographic business, especially the lens business, feels no obligation to do that. An occasional MTF chart with 10 and 20 LP/mm when the lens is supposed to deliver between 40 and 50 LP/mm is not an answer. We should demand that the lens manufacturers provide reliable lens performance data.
 

WayneF

Senior Member
Just saying, whatever does turn up, my bet is that it shows up on Google first. :)

I know the DxO testing is... let's generously say suspect, but what makes you think they have stopped?
 

Bengt Nyman

Senior Member
DxOMark used to do a good job of testing image sensors and lenses. However, their philosophy involved testing each lens on a very large number of cameras, which I think turned out to be an unnecessary and costly mistake. DxO has since tried to market lens correction software and they finally launched a head on challenge to Adobe post processing software. It seems that financial survival of DxO in its present form can not be taken for granted. It now takes DxOMark up to a year to test a new, main stream lens, like the Nikon 300 mm f/4 PF VR, essentially taking them out of the business.
I have lately been relying on data from LensTip, though I am not sure they have the resources to test everything coming out.
I believe that we have the right to expect Nikkor and other lens manufacturers to provide us with reliable lens performance data.
 

WayneF

Senior Member
I don't think DxO was testing lenses, seemed to be testing the bodies with the lens. Seems absurd that a lens had many numbers, depending on the sensors resolution.
 

Bengt Nyman

Senior Member
DxOMark tests and scores camera image sensors separately. To test a lens you have to have some kind of image sensor. DxOMark choose to use image sensors for which the lens is intended. As a result they tested Nikon lenses on a very large number of Nikon cameras; an ambitious goal, but unfortunately slow and expensive. This might very well have been the beginning of their downfall. Trying to sell lens correction software, post processing software competing with Adobe, and finally their own camera does not seem to have helped.
The problems with testing lenses with a laboratory quality image sensor are two fold:
1. If you replace the sensor you loose the apples to apples comparison with earlier lenses tested.
2. You still do not know exactly how the lens will perform on a specific camera.
However, since the resolution of camera plus lens is the product (multiplication) of the transfer functions of the two, you can still produce a decent estimate of the image quality.

Anyway, please Nikon, when I buy my next Nikon lens I would like to see a performance specification showing center resolution, DX side resolution and FX side resolution expressed in LP/mm (line pairs per mm) as a function of aperture opening.

Thank You Nikon !
Truly Yours.
 
Top