« on: December 19, 2013, 10:36:58 PM »
At this point! I will believe it when I see it.
This roller coaster ride has ended for me.
This roller coaster ride has ended for me.
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Looking at the MTF charts for my two Canon lenses it follows what you say to a tee. I have to agree also with what I have found with my two lenses.
The bare lens is reet. Beautiful flat field wide open. Stopped down with a 1.4 T.C = a flat field, and a sharp enough image. For me the 2.0x is a no fly zone.
My two Canon lenses perform so good with out a t.c. I don't worry about my settings other than correct exposure. All the pressure is off. And I just enjoy the hobby.
Just to demonstrate how a 600mm f/4 with a 2x TC can and does produce stellar IQ. Here is Art Morris discussing his IQ with the 1200mm combo:
Half way down, under the section "The Power of Twelve Hundred Millimeters":Quote from: Art Morris"To create the relatively large-in-the-frame vertical image above I went with the 600II/2X III combo. Though many state openly that it is not possible to create critically sharp images with a 2X teleconverter I do just that consistently. "
By "I do just that consistently", he means he creates "critically sharp images" with a 2x TC on a consistent basis. His work truly demonstrates that fact. It is ALWAYS "critically sharp", as he would never accept anything less. For many people, they simply cannot accept that fact, and will only use lenses without teleconverters, at any cost. That is certainly an OK personal choice, I understand the desire for maximizing IQ. Real world results speak for themselves, though...and a good lens with a 2x TC IS indeed capable of producing critical sharpness.
The wide aperture affects AF speed and AF point precision and capability. Remember, particularly in the 61pt AF system, there are f/2.8 double cross type points, f/4 cross type points, f/5.6 line points, and the center expansion f/8 points. With an f/4 lens, you ALWAYS AF at f/4, no matter what you stop down to for actual shooting. The extra stop of light allows the AF system to operate more quickly and more accurately. When f/4 AF points are used, they tend to be more precise than f/5.6 points, which need larger pixels in order to sense as well as f/4 pixels.
The point of an f/4 lens isn't that you always shoot wide open (although in the evening, it isn't uncommon...I tend to be around f/8 aperture for shooting during daytime, and f/4-5.6 for shooting around sunset, for wildlife.) It's that you ALWAYS AF wide open (by design.) And yes, with an f/4 lens, when you slap on a 1.4x TC, you still AF at f/5.6, which is still better than AF at f/8, no question.
Jrista, thank you.
I actually completely forgot about the difference between f4 AF points and f5.6 ones. The high precision f2.8 AF points are referenced so much I guess I clumped all the others into the same group. (After reading multiple articles detailing all the AF points, and watching the entire B&H Canon AF seminar [ ww.youtube.com/watch?v=iAx86nblZ2g ][great video BTW], you would think that someone would remember something like that. I guess a guy can only fill his head with so much.)
That changes my perception of the TCs quite a bit. I've been assuming that you get "worse AF" when using a TC because of a combination of optical performance and some kind of interference in the circuitry, if on the other hand it's actually just due to the change in the type of AF points used, then the 600f4+1.4xTC is actually going to AF exactly the same as the 800f5.6. I was assuming the latter would have an advantage.
Indeed that does make a very good case for the 600f4, and makes the 300f2.8 more appealing now that I know it's not some mystical interference from the teleconverter making AF worse at 600mm.
The point was that it's possible to shoot BIF handheld with the 600 II + 2xIII. Hit rate was ~50%, due to the difficulty of keeping the center + 4 AF points on the bird, but it can be done.I agree that it is possible, but AF is too limited. Keeper rate is low and 1200mm is difficult on anything that moves, regardless of AF functionality.
The bittern shot is cropped by about a third,...it was a gray, ugly day at the end of October, 2012. This shot from 40 minutes later that day (also with the 600 II + 2xIII) shows the rain that started falling on us, being blown nearly sideways by the strong winds…it was the outskirts of Hurricane Sandy.
You guys must not pay much attention to professional bird photographers. Many of them use the 600II + 2xTC III. Some of them rarely ever use anything else! Most of them used the 800/5.6 before, many never removed their 1.4x TC's from it. One of the primary reasons professional bird photographers buy 1D series is for the f/8 AF, because they use it CONSTANTLY.
Keep in mind, the 1D officially supports f/8 AF. It isn't like the makeshift f/8 AF you can get with a Kenko slapped onto a 400mm f/5.6 on a 7D, where your luck is basically a roll of the dice, and AF performance is excruciating. Nor is it even like the 5D III, which supports f/8 AF, but isn't as fast as the 1D series. I am guessing, at best, most of you calling f/8 AF slow have only used the 5D III. Try rending a 1D IV sometime, or if you know a friend with one, see if you can borrow it. When it is officially supported, especially these days with support for expansion mode (where a total of five central AF points are used in the 1D X/5D III), it is fast, accurate, and very usable.
Now, granted, f/8 lenses aren't ideal for tracking birds in flight. Usually, if a bird is flying towards you or angled across your field of view, f/8 lenses, which are usually over 800mm in length, are just too long...you need something wider anyway to compose properly and leave a little room for some of that necessary cropping and straitening. So it isn't like anyone expects f/8 AF to be used to track one of the most complex and difficult subjects that you can track. That's the reason f/4 supertelephotos exist...LOT of light, FAST af...you track BIF with a 500mm or 600mm f/4. The f/8 is most frequently used for perching birds, shorebirds, waders like herons, waterfowl, distant wildlife, etc. where you don't have to bother tracking...you just point, focus, and shoot. Both the 5D III and 1D X are MORE than capable of doing that with an f/8 lens.
I wonder if Canon would decide to not develop an 800mm f/5.6 IS II and instead just release a 600 f/4 IS with 1.4TC instead?? Already the 600II with external 1.4 TC has equal IQ and AF to the 800 IS I. So a built in TC that could be even better optically paired to the lens may make a 800 II a useless proposition.
According to a majority of white lens owners here in Japan, you apparently cannot be recognized past amateur level unless you use a giant tripod, from "big white" to a 70-300 with IS, even if what you're shooting absolutely doesn't need any such support, but you're willing to lug around an F/2.8 zoom all day but shoot at F/16 only... err....
Seriously it's insane, was just at a nice place for autumn leaves viewing and I lost count past 50 of people with the 70-200 series of lenses, mostly 70-200LII too, and few of them are any sort of pro, just part of a photo group/club. It was interesting to see that a majority of users are Canon here, and more Olympus/Panasonic mFT users than even Nikon.
So high megapixel? For Canon that means what? 24MP Might be pushing it... Prob closer to 23.8MP
From past rumors about Canon high-mp cameras in testing, probably 40mp+.
People are studying what appears to be a CG marketing image way too closely.I think that is a handkerchief to cry into when we find out that the 7D2 will not be released until 2015
Who here thinks they really placed a cloth across the new body and photographed it to make this image? Raise your hands...