Consistency and care is always paramount in all experimentation, including the humble lens test.

I agree, and that is what I have been using. After all, there's no hurry. However, also a manual check as well for each shot.

Unfortunately they are all different lens samples as well as different testers - a direct comparison can never be made. However, comparisions can be made between different lenses tested by the same tester, provided of course that the testing situation has not changed.

I would point out that as focusing is done on the centre of the chart, if anything this would favour a high performance at centre. If there was a focus error this would mean that the edges were even more creditable.

What is possible is some curvature of field, but that is not covered in the testing regime.

Yes indeed. I've just speculated on EPZ (potentially very confusing having this conversation split over two areas!) that perhaps the AL component is to blame, if blame is the correct term for something that clearly has evened out the performance so well across the field.

No, there's a star focus point on the chart and focus is done very carefully. In addition, the chart is absolutely huge so there's no real issue with working distance.

Just accept it is what it is - the computer does the chart automatically. Magic, it has to watched doing it to be believed. The thing about scientific results is that we accept our observations, rather than not accepting them if they don't fit a preconceived idea.

You're welcome! It looks like it was quite a holiday...

As regards the MTF curves, they are what they are and it's not unknown.

Another example is the Voigtlander 50mm f1.8 Ultron of the 1970s, where the edges were corrected more than the centre.

However, the upshot is for the 35mm f2.4 that it's an excellent lens, tremendous value for money and although it's not as good as the 31mm it's more than good enough for critical use.

The sentence reads OK to me, simply saying that it's a pity there's no aperture ring as then we could take more advantage of its full frame coverage, should we wish to.

As for the graphs, they exhibit the normal rise and fall pattern of a high quality lens. You are maybe reading the third (CA) graph in reverse, where the higher the result the more CA is present. Needless to say, the centre shows much lower (better) results than the corners.

The first set of questions regarding comparisons now have some answers as the 35mm f2.4 review is now up on EPZ:

http://www.ephotozine.com/article/smc-pentax-da-35mm-f-2-4-al-lens-review-16804

No doubt a link on PU will follow soon.

If the OP hoped to get this for a reasonable price I'm not sure that asking about it was a good option. It's a mixed blessing really, getting the answer but alerting a lot of people if it happens to be a bargain.

Then we end up bidding aginst each other...potentially.

And no, I wasn't bidding....