07-14-2015, 05:44 AM
Canon EF 11-24mm f/4 USM L
07-14-2015, 05:44 AM
Unless we are talking about the middle range I don't think that you got a bad copy.
Remember that the Canon MTFs show the simulated, naked results - WITHOUT a sensor.
It has to be worse WITH a sensor.
The review MAY be up sometime tomorrow night (or the day thereafter)
07-14-2015, 01:21 PM
Judging from the 70-200, I don't think a "good copy" of the 11-24 exists. They must all be wrong at one end or the other.
Canon's MTF shows a strong astigmatism, so by playing with the focus you should be able to fix the bad corners at 11mm. In real life images anyway - that'd be fudging it for a resolution test.
Regarding MTF; many lenses improve considerably when you add the coverglass of the sensor to the path. If a lens has undercorrected spherical aberration there is a solid chance it will improve. (And almost all do).
The actual sensor itself tends to have shit MTF towards the edges. This is a big issue with digital and requries a telecentric lens design to solve, which the 11-24 is decidedly not. True cine lenses do better in that respect.
Here's the mesaured MTF of the 135L. Agrees quite closely with canon's published chart.
Most lens models are assembled too imperfectly on average to resemble the mfg published charts, but it is possible some copies do resemble them.
07-14-2015, 06:53 PM
Quote:Seems to me that the copy of the 11-24 that i have is not good at or approaching infinity, while closer it appears to be ok (but i suppose i could be wrong)….soLong, I looked at your pictures, they don't appea unsharp to me at all. May be your expectations are too high...
07-14-2015, 07:36 PM
07-15-2015, 02:01 AM
Can you just exchange it, instead of going through warranty process? After all this is expensive lens.
07-15-2015, 05:57 AM
Hmm, with several products I made the experience a good repair is better than an exchange. What AiryDiscus tells in the lens detail thread leads me to the idea either playing good copy - bad copy roulette or let a good tech fix it. But since it's Australia and the lens quite new, I hesitate to believe there are already capable techs available for it.
Btw. in Europe each manufacturer has the right to choose "exchange or repair" for two times in such a case. After that it's money back time. This is generally spoken about consumer products.
07-15-2015, 06:33 AM
Quote:Hmm, with several products I made the experience a good repair is better than an exchange. What AiryDiscus tells in the lens detail thread leads me to the idea either playing good copy - bad copy roulette or let a good tech fix it. But since it's Australia and the lens quite new, I hesitate to believe there are already capable techs available for it.
Well, the usual strategy is to claim that the thing is within specs. Thereafter you are alone. Here, in Europe, everywhere. A joke.
As mentioned before I highly doubt that most lenses are even designed to be serviceable.
07-15-2015, 06:59 AM
Sorry, but that's not my experience so far. But then I never sent in a lens claiming it's decenterred. All of the lenses I sent in had issues:
300/4 PF E was one of the batch with terrible OS. Now it's okay
85/1.4 G was sent in because AF motor was broken within warranty time, service and still working fine with the usual complaints about CA wide open. Hardly a service issue.
24/1.4 G fell down a stair and had a little bump go the filter thread (inside it, I don't know). Serviced a reasonable price.
If a kit lens is made as a throw-away at that price, I won't blame the manufacturer. If a 2000$ lens is designed that way, I hope to find out before buying crap. Canon lenses are designed very well, I learnt from lensrentals. Pity, their cameras use sensors which can't reach Sony quality.
To put things in perspective: Although I do sometimes paid jobs with my gear, most of the time I use it for my pleasure and sometimes for the pleasure of others as well. In 95% of my "average" shots it's the guy behind the lens, not the lens itself responsible for sort of an average result. Although I have to say, my average improved I'm still far away of delivering top quality all the time. What use is the best, most repairable lens for if I don't have a story to tell with? ^_^
07-15-2015, 09:53 AM
Quote:Sorry, but that's not my experience so far. But then I never sent in a lens claiming it's decenterred. All of the lenses I sent in had issues:
Yes, of course, professional grade lenses are designed to be serviceable.
However, I have often received replacements for lenses around the 800$ mark.
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