The headache of lens selection

I have been trying to decide on a good wide angle lens for my Pentax after being rather disappointed by my initial choice. But after weeks of research I’m none the wiser and actually rather frustrated. Here is a list of issues.

I have looked at lens choice requests made on forums only to find that by the time everyone has had their say virtually every lens out there has been put forward by someone and the poster is none the wiser.

Multiple reviews come to different conclusions.

There are image examples posted that are not useful in many areas. Centre sharpness is always covered, but bokeh with specular highlights may not have been. Edge/Corner performance can’t be judged because they are out of the depth of field anyway. Even respected review websites fall down here.

Charts are a good empirical method of stating performance but how many people would know exactly what they are going to see in a real photo. There are plenty of charts that suggest a lens is good but example images tell a different story.

I find empirical systems questionable. The DXO marks would have you believe Pentax glass is half as good as others makes, which is clearly silly.

There are people who post example images that are reduced in size and therefore tell you very little.

Posted images and websites like Pixel Peeper or not very useful as the images are often processed and so they are not on a level playing field. Raw images also have an unknown level of processing. I think images should be default, out of camera, full size, fine jpegs, that way you can properly compare.

Some lenses perform better at different distances. A lens may be sharp close up photographing a test target but soft at more normal photographic distances and vice versa.

A commenter may say some aspect is good but how do you know if you agree on what good is, without a full size image to prove it.

Scientific understanding is an issue. If I see blurring on the edges, is it the best you can expect given the laws of physics or is it just a bit poor.

Finally there is a complete lack of useful example photos when gambling on an older lens from ebay.

I would be interested to hear what others think about these issues but I will take a guess at one type of reply and answer it now. Yes, I know I should just go out and take pictures and believe me I have thousands. But I print large and often find it is lens performance which holds me back, not pixel count.