The time has come to put final closure to all the arguments and speculation about autofocus systems.
I have spent the last few days in contact with all the relevant top level technical personnel at PhaseOne and Leica. To make sure you all understand this, I have been in contact with the people that actually designed the current autofocus systems, with the people that manufacture them, with the Technical Directors in charge of the product lines and with the Chief Technical Officers. This is what I call "the horse's mouth".
In my conversations with these companies, they have verified that the statements in my article are factually and technically correct:
- Autofocus systems work in small steps and not continuously.
- They have verified that my prior posts on this forum are technically correct.
- Finally, they have also verified that distant objects are the most likely to cause autofocus failures. As mentioned in my article, this is exactly what I have observed in the field, and the explanation given in my prior post about this is technically correct.
The Technical Director in charge of the S2 at Leica put it most eloquently. I am always sensitive about not disclosing information that might be considered confidential by a company, so I apologize to the curious members of the forum who would like to know the exact numbers. I will leave it up to Leica as to whether they wish to publicly disclose those numbers.
Here is the quote:
"Reliability is not only one of the major features of the complete S-system but is also a very important point with respect to AF operation. That the S2 AF performance (reliability, speed and precision) is so high has many reasons. It is an advantage to have very small focus steps at distances approaching infinity (where you have the least depth of field), and where the lens has to focus very precisely. The Leica Summarit-S 70mm has a focus resolution of ___ micron (=1 focus step). Furthermore there is a f-stop correction depending on the focus distance. The operating temperature, which also has a big impact on AF precision, is considered as well. But most important is that all lenses and cameras are checked very carefully (and if necessary corrected) by our QA department before they are delivered to our customers. The AF and image sensor planes (CCD) are aligned most precisely. These smallest tolerances are only possible with an integrated digital system! "
While I knew at the time that I wrote the article that all the information in it was thoroughly researched, and factually and technically correct, having done the exercise a second time with the folks mentioned above, I once again stand 100% behind everything written in my article about the S2
Best regards and good luck to all.
1) Refreshing! it results that when the information is asked at the right sources we may once for a while give up the forum erasmus scientist speculations, but I'm afraid it won't happen anyway and "good" (and scientific of course) arguments against will fall very soon on the battle field. Ok, at least another perspective has emerged.
And I would like to have some confirmations from the same sources about that DR stuff that always puts the forum into flammes, when everybody see 1 stop or when I see 4 in practise. As I'm human, I'd like to know where I'm failing or if this just 1 stop is just a collective illusion...
Anyway, maybe before asking for the Mark's head like in the French revolution we should think if we are really capable of managing the right information.(and I'm including myself here)
There is a lot of lecture over the internet.
2) About the print/web. This is simply ridiculous IMO.
If you can't judge images on the web I doubt you'll be able to on a print, regardless on the differences in bits and resolution.
3) ............About the last BCooter post............
This one was psychadelic.If there is one person on this forum who can have access to the gear and test in real field and produce top images with it is BCooter.
I can't beleive that one of the world's most influent commercial photographer does not have the right key to open these doors.
Or he does not have the time because of his agenda to do the testings to his standards, or he likes teasing.
I always find the BC posts very informatives and frankly "above the crowd", except when he comes over and over again on how bad are those testings.
I join the Guy's Mancuso post here on that matter.
Don't get me wrong, BC is right in essence. I'm also fed up to see the happy familly kind of pictures that are generally spread over the internet in gear testing.
And it is true that very little if no information is deliver regarding the PP, the tech issues, the tether task etc...
But the problem is exactly what you see here: Even if people would do those testing in BC's minimum standards, they are poorly rewarded.
Immediatly the "expert's forums" will jump agressivly on the scenery with any arguments against the lightning, that this or that mistake was done with the software,
that the writter has done a big semantic error, that they did not tether with the right cable, that the computer was not maintained properlly, that he should have use this other lens that focus faster,
etc...and in the best cases with manners but generally agressive and cynical reactions.
that anyway we can't judge the pics over internet etc...
So you have all the moderators suddenly busy, and I imagine they will like to use their time better, in order to keep the forum elegance and manners. No surprise if people who could do the testing
in the most professional way say no thanks
If Raw files where deliver it would just be the same story.
So, even if someone was tempted to do those testings in a real pro environment it would generally not happen because of those reasons.
Zacuto have done some good stuff because their structure allow them to do so and there is a commercial reason behind also.
Remember the James Russell article on the Leica M9 and the reactions? Completly crazy.
Remember the reactions when Michael said that famous word about the K7 calling it just "competent"? I was absolutly amazed by the forum's reactions.(and I also shoot Pentax and
I saw the same things as Michael saw in his article and did not feel offended because a brand I own does not convince...Pentaxes forums where all in flammes after that, simply hilarious)
The problem with photography, is that there is a quasi mystic and sexual connection between gear and user. That is why we never see women in those kind of battlefields.
Brands are like the football team we supports so obviously there is an against
necessity. It is competition and who's got the biggest one.
This is the tennage age. The differences between women and men, is that in men the teenage age lasts much longuer...
But yes, American girls are easy.