« on: July 26, 2014, 02:52:53 AM »
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Unlike many Google translations, this one is a bit more readable...
I note the comment that the 16-35 mk2 was good for APS-H ;-)
The multiple aspheric lens surfaces allow them to ease some of the compromise between reducing distortion and field flatness. The two front lens elements make quite a significant contribution to this and will likely be seen again in new ultra wide zoom designs.
I still want a TS-E14 though ;-)
All Sigma lenses have focusing problems! I had two of the a 24-700 and 70-200 last versions - I sent them to be calibrated with my body and then everything was ok.
This is FALSE. I have two Sigma lenses that have had no focusing problems. (I don't consider improving AF accuracy with in-camera AFMA to be part of a "problem.")
But the 50 Art that I received did have erratic, unreliable AF that could not be helped with AFMA.
So, if online chatter can lead to Sigma fixing the problem, we aren't helping by using sweeping, ranting statements such as "All Sigma lenses have focusing problems!"
I stated this before and say this again: I did not and do not have AF problems with my 50Art. And I agree with YuengLinger. It is wrong to make statements like "All Sigma lenses have focusing problems!" - it is not true. Sigma did a great job with the Art series.
But it's annoying to buy a fairly expensive AF lens which you're expected to fiddle around with on a docking station and even then seems best used, in the case of many copies at any rate, in MF mode.
Why do you think AFMA exists on Canon cameras? To address the same problem that the docking station is for.
The problem isn't QC it is engineering tolerances and the fact that neither camera nor lens are all made the same. There is copy variation between each camera and lens. This means that whilst AFMA might be +5 for a given lens on your camera, that same lens might be -5 on my camera and that same lens might be +0 on someone else's camera.
Like we've said soo many times before, it's NOT about afma ... Sigh, it's the inconsistency ! Please print this message and tape it on your fridge.
AFMA is there because there is inconsistency. Canon recognizes that there is inconsistency in camera/lens manufacture and thus introduced that feature to allow people to tune their own camera. If every lens was the same, AFMA wouldn't be needed.
It's difficult for me to imagine a reason I'd ever buy a gopro.
Stupid.You can get most of that right now by combining any of the current generation of waterproof compacts with a gopro
Want a useful underwater hyperzoom?
Full frame fisheye (180° diagonal) to 100mm.
Admittedly I have not looked into Speedboosters but I wonder how they increase stops of lights passing through them? Changing perspective such as what an extender does I get but extenders degrade the amount of light rather than boost it.A teleconverter enlarges the image projected by the lens. This is much like moving a projecter further away from a projector screen - much of the image is missing from the screen, and even though the quantity of light coming out of the projector is no different, what is on the screen is bigger and dimmer.
How about distortion? I really like 0 distortion on the macro lenses. My most used focal lengths are 35,50,70 and 105(which would probably be 135-150 on 70-200 lens).
Maybe it's just saying that this is the body and focal length it's tested at?
There were at least 7-8 so called hidden cameras during Arg-Hol semifinal game. 'Canon' brand name was written on the cover material. A lot of them were the middle part of the pitch rather than corner areas. Testing a crop body from distance may be ? No rain before and during the game and all the Nikon body and lenses used were without cover btw.