Neuro: Do not try to talk away your mistakes and that you dont know its needs a head room to create HTP
Do we really need to go over this again? I have already pointed out your
mistake, the incorrect extrapolation of the case of setting the camera to ISO 100 then enabling HTP while in an autoexposure mode (Av/Tv/P), where the camera will then change the exposure by adjusting the shutter speed or aperture one stop, to be a general
explanation that the mechanism of HTP is for the camera to adjust the shutter speed or aperture by one stop, when if fact, that only occurs at ISO 100. That's something that TheSuede clearly understood and explained very well, but you still seem unable to grasp.
Of course, headroom is needed to preserve the highlights. We agreed on the 'what' - your error concerned the 'how'. My point was that HTP achieves the additional headroom by exposing at a one-stop lower ISO than is actually selected, not
by reducing the exposure so that 'half the photons' hit the sensor as you repeatedly stated.
All of that was hashed out to the nth
degree in the other thread, there's no point in restating those arguments - if you want to continue to argue your points, please go back to that thread
As for MTF - read carefully what you wrote:
Page2 I wrote:
we dont know if this is estimated MTF, Canon and Nikon has a predilection to exhibit estimated MTF results to impress
and then I wrote:
MTF tests from Nikon, Canon, Leitz, Zeiss , Hasselblad are real MTF tests and of the lens only
First, you state that Canon shows estimated MTF results. Then you state that Canon's MTF curves are "real MTF tests". Do you understand that your statements conflict with each other? Canon shows MTF plots for their lenses (one for primes, two for zooms) - those data are either
they are real/empirical. First you state it's the former (correct) then you state it's the latter (wrong). Your statement about Canon having the equipment to actually measure MTF is irrelevant - fine, they can measure real MTF, but they do not show those data for their lenses, they show only theoretical data.
It's obvious that we could go around and around about this just like we did with your 'half the photons' argument, and it's equally obvious that there's no point in doing so. You know as well as I that Canon's published MTF curves are theoretical/calculated, and not 'real MTF tests' resulting from actual measurement of real lenses. There is really no point in discussing it further, and therefore, I will not.