Is MTF chart reliable ?

[chunkeat]

Eg:

Sigma 24-70mm f3.5-5.6
http://www.sigmaphoto.com/lenses/lenses_all_details.asp?id=3262&navigator=2

Nikon 24mm f2.8D
http://nikonimaging.com/global/products/lens/af/wideangle/af_24mmf_28d/index.htm

The Sigma (much cheaper) is a zoom lens, the Nikon is prime. How come Sigma quality apparently better ? Thanks.

 

[NMSS_2]

should be reliable but funny thing is that they didnt mentioned which F-stop did they took this. and a good MTF chart results should have at least 4-5 F-stops MTF at every lens zoom.

 

[yyD70S]

Default MTF charts are always taken at the max aperture.

 

[zcf]

usually 3rd party mtf review (magazine etc) are more trustable than the own maker one.

but lens also have some variation, who knows whether the one been reviewed is a sharp copy or lemon :sweat:.

Itdoes give you more idea on the sharpness of lens. But mtf chart don't give much info on contrast, colour, flare resistence of the lens.

I thought most mtf chart are taken at wide open and f/8?

 

[billpepsi]

Eg:

Sigma 24-70mm f3.5-5.6
http://www.sigmaphoto.com/lenses/lenses_all_details.asp?id=3262&navigator=2

Nikon 24mm f2.8D
http://nikonimaging.com/global/products/lens/af/wideangle/af_24mmf_28d/index.htm

The Sigma (much cheaper) is a zoom lens, the Nikon is prime. How come Sigma quality apparently better ? Thanks.

Default they are tested at max f/stop. For apple to apple comparison, both lenses should be tested at the same f/stop.