Fast sensors have made fast lenses obsolete Locked

Started Jul 31, 2013 | Discussions thread
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Anders W
Forum ProPosts: 17,543Gear list
Re: "Preconceived ideas"?
In reply to amalric, Aug 4, 2013

amalric wrote:

Interesting to open you from time to time, just to see how far your pseudo science carries you into the absurd.

What is truly absurd is that you think you have the wits to tell the difference between science and pseudo science.

1. Everybody knows how short distance to flange creates problems to even resolution across the frame in m4/3,

On the contrary, noone who knows anything about optics thinks so.

therefore comparing lenses that have 2 or three times the distance to flange, and which don't have this problem is particularly stupid.

Particularly stupid is not to understand, especially in view of the content of my previous post, a) that the MFT flange distance isn't particularly short (in the sense that counts, i.e., relative to the diagonal of the sensor format) and b) that a short flange distance is never a disadvantage from the point of view of optical design (since it allows the rearmost element to be placed closer to the sensor without forcing it to be placed closer).

2. Roger Cicala was the first to remark on the poor performance of the PL 25/1.4 at full aperture:

"The Panasonic/Leica 25mm disappointed a bit: it was good but I had expected it to be THE best of the bunch and it’s not."

http://www.lensrentals.com/blog/2012/05/wide-angle-micro-43-imatest-results

and

"We also did some confirmation testing at 25mm. First retesting the Panasonic – Leica 25mm f/1.4 because it just didn’t seem as great as we expected on the initial set of tests. Then we did some comparison testing, testing the same lenses on both the Panasonic GX1 and the Olympus OM-D E-M5. I won’t bore you with all the numbers, but testing 6 copies of the Panasonic-Leica f/1.4 didn’t change our initial results much. (The results have been updated on the previous article.)"

http://www.lensrentals.com/blog/2012/05/standard-range-micro-43-imatest-results

Those are in fact Imatest data, and he found that the PL 25/1.4 has HALF THE RESOLUTION at 1.4 compared to 2.8.

No Roger Cicala didn't find that. He found that the center resolution at f/1.4 is 72 percent of the resolution at f/2.8. Let me know if you need help with the math.

So you and Bustard are just clowns manipulating arbitrarily data for the noobs.

Conversely Roger's data prove very well my point: that it is better to use a fast sensor and a moderate aperture, than the opposite, in terms of resolution. The two CV at f/0.95 prove the same.

The best is to use a good sensor and a fast lens with good MTF already wide open, such as those exemplified in my previous post.

Possibly because of the short distance to flange, they are a waste of money in terms of resolution, well below Lenstip's 'level of decency' at full aperture.

Instead, in terms of Price/ Performance the Sigmas are a fantastic buy, if you have a fast sensor like the E-M5.

QED

Now please go back to the obscurity where the quack doctors and ragged devils are condemned

Particularly stupid is also not to realize that a single counter-example (I was generous enough to provide no less than three) refutes your general claim and that regurgitating what we all already knew about the PL 25/1.4 doesn't help you one bit.

Why, by the way, do you think Roger Cicala was slightly disappointed at the 25/1.4 if not for the fact that fast lenses can do better than it did? Consequently, it wasn't a particularly bright idea to base your general claim on that particular example in the first place.

 Anders W's gear list:Anders W's gear list
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