lens reviewers

[bluekorn]

Photozone reviews the Nikkor 17-35 2.8 as a little better than average. Bjorn Rorslett reviews the same lens as stellar. When looking for reviews for Nikon and Canon lenses is there a general consensus about where to look for reliable opinions?

[The View]

A good lens is not only sharp and has a lot of lines of resolution.

It is also about color reproduction. It's also possible that the combination lens/sensor is also of influence.

Judging a lens is also largely an esthetic judgement, which cannot be boiled down to numbers.

Generally, I'd read the review, and if it's all about pixel peeping, I'd trust it less.

[Tony Beach]

You must have read the wrong review at Photozone, because nowhere does it say the Nikkor 17-35/2.8 is "a little better than average".  I do not see a discrepancy between Bjorn's review and Photozone's review on this lens.

[Chris_Brown]

When looking for reviews for Nikon and Canon lenses is there a general consensus about where to look for reliable opinions?

What do you consider reliable? Charts or actual scenes?

[Ray]

What do you consider reliable? Charts or actual scenes?

Charts are generally more reliable because they are standardised. Where they fall down is in respect of QC variability between different copies of the same lens. However, if someone is able to standardise a scene, as they do at Imaging Resource in their Comparator, then an actual scene can be as useful as a set of MTF charts, provided the scene chosen contains a variety of different subjects which can reveal subtle differences in resolution and noise etc.

What is not particularly useful is an example of a single scene without reference to the identical scene shot with another camera or lens, unless one is comparing edge resolution with centre resolution.

One should always bear in mind that test results at Photozone show 'system' performance rather than lens performance. The Canon tests use an 8mp cropped format camera (the 350D). I believe the Nikkor 17-35 was tested using the 10mp D200. This is why comparing lens tests across different systems is not recommended by Photozone.

[ErikKaffehr]

Hi,

Much depends on the tests and also on the user. Photozone is pretty much on the technical side and there are other aspects to lenses then what can be easily measured. Depending on motive different characteristics of the lenses are tested. In many cases corner sharpness may not matter, essentially in cases where depth of field is short and the point of focus is well centered. I architecture photography corner to corner sharpness may be an absolute requirement. Sensors do matter, regarding Nikon a 12.5 MPixel APS-C sensor will have very different demands than a 12.5 Mpixel FX-sensor. Reason is pixel density in the APS-C sensor is much higher but over much narrower area. A high resolving lens would easily outresolve the sensor in the 3D, so a lens that is "so so" on the APS-C may really shine on FX.

Lens flare is another aspect in real life. It is difficult to test for flare as it is very much dependent on the kind and direction of light.

Another area is focusing. When testing lenses there is normally some focus bracketing done, in real life focusing may be of. A combination of lens and camera body with better focusing may give better results than a sharper lens which is slightly defocused.

Erik

Photozone reviews the Nikkor 17-35 2.8 as a little better than average. Bjorn Rorslett reviews the same lens as stellar. When looking for reviews for Nikon and Canon lenses is there a general consensus about where to look for reliable opinions?

[bluekorn]

Thanks very much to those who responded. I finally learned something very useful that in the past has refused to sink in. Post processing notwithstanding, a lens is part of an image making system that includes a world of micro electronics, the function of which I'm not particularly interested in learning about, except to note the complexity of the process from sensor to storage. The lens is just the first step. I imagine, without any claim to authority, that the process in a camera/lens combination in digital photography is much like the process in film photography including camera and lens and negative development.
Peter