Variables of MTF lens testing

[eclarke]

Yeah, way too much thinkig..

You're correct. I think the OP wants a quantifiable way of comparing two lenses, which is fair enough.
But, comparing MTF reminds me of the audiophools, who sit around comparing unquantifiable qualities to the extent of forgetting that the gear was meant as a way to hear music.

[Prof_Pixel]

The idea of measuring MTF by shooting charts is somehow flawed at its root.

What you will end up with is the cascaded lens and film MTFs.

[Dan Fromm]

Folks, read post #5 in this thread. In it the OP explained what he really wants to accomplish.

I've been on the fence about the OP for years. On the one hand, he often seems completely insane and his recent posts have been more incoherent than usual. On the other, he isn't a native speaker of English; given how hard it is for native speakers of English to express themselves clearly in their own language, I can only respect him for making the effort and trying to communicate with us in ours.

This thread is a lovely example of one of the reasons why I denigrate bulletin boards. Posters, after the first couple, have responded either to the OP's original post and ignored his second (and so far latest) post, #5, or they're responded to a post after #5. The entire thread, with the exception of the original poster's two posts and one other, is completely off-target and is getting farther from what I think the OP wants to learn. Its appalling.

[Prof_Pixel]

The OP (in his first posting) brought up the subject of MTF. Even the subject line of this thread mentions MTF.

[Diapositivo]

The OP asked a question about how to perform some MTF tests to a FED lens he has and how the admittedly imperfect method he would use would affect the results.

He received answers stating that MTF tests are useless and a user inferred the OP thinks the FED lens was superior to his Leica (which the OP never stated).

A discussion about MTF or resolution tests and their relative scarce utility in measuring the quality of a lens would be a welcome discussion but in this thread is OT just like a comparison between Leica and FED lens could be interesting but OT.

Dan is right that, for the most, this forum ignored the OP question and just begun questioning his motives to ask it, which just lowers the noise/signal ratio. This post does not raise it either but can be taken as a remainder to be more disciplined in forum behaviour

[Dan Fromm]

Oh, my. I spent most of my career working as a consultant. Consultant in the old sense of outside expert, no in the modern sense of contract laborer who needs close supervision. It sometimes looked as though I spent most of my time on data processing, applied statistics, computer science, but all that was in the interest of solving clients' problems. I like to think that I wasn't quite the worst that ever was.

In the earliest stages of a project a good consultant hears the client out and probes to find out what the client actually wants to accomplish. The real problem, or what the client wants to accomplish, often has little to do with the problem as initially presented. Fixating on the problem as originally presented can lead to disaster. I've seen it happen.

The OP started this discussion by asking a question about something he wanted to do. In post #5 he explained why. His goal, as revealed in post #5, is to find out whether his new treasure will take a particular kind of picture. Answering this question has nothing to do with what he first said he wanted to do. More evidence of unclear thinking.

Prof_Pixel, if you'd worked for me and consistently been as inflexible as you were in post #14 in this thread I'd have fired you.