Originally Posted by ddt0725
Unless you have a 1-series body, the AF will not work with the extenders on this lens.
I guess most of the people who love the rumors are bummed that there isn't a 24-70 f2.8L IS for the 3rd or 4th year in row [:P] Especially since rumors were getting much more "truthful" and "reliable" [A]
Certainly it's not intended to compete with 500mm and 600mm supertele primes. But, given that 400mm is the longest Canon lens obtainable for less than $4K, and given the new 70-300mm L's price, I'd say it is intended for a market with a high degree of overlap with the 100-400mm.
Good point. But then, I paid little enough for it that I can sell it with no loss and probably a profit. That, plus the fact that I've got around $2K in cash just waiting for the right lens to come along, means if I wanted to buy this new lens that really wouldn't stop me.
Sure, the DO lens extends ~2.25" for a fully-extneded length of ~6.25". But as I stated previously, it's not the extended length that matters to me - it's the length of the lens in the bag when not in use - just 4" for the DO - that matters.
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Yes, looking at the MTF charts, this new 70-300mm L is very sharp, and seems to compare favorably to the 70-200mm II.
It's not that extenders don't work at certain apertures - it's that autofocus doesn't work at certain apertures. The AF system in most Canon dSLR bodies requires a maximum lens aperture of f/5.6 for AF to work (except the 1-series, which can AF with an f/8 aperture). If you use a 1.4x extender with an f/5.6 lens, the maximum aperture becomes f/8 and AF doesn't work. The camera will 'know' that the aperture drops below f/5.6 at the long end and will thus not autofocus with an extender in place (unless certain pins on the extender are 'taped over' to trick the camera).
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Tom, Jan - where are you getting the information that this lens doesn't extend with zooming? Physically, it's 143mm in length - only 0.2mm different than the 70-300mm non-L/non-DO lens, which extends over 2" with zooming. The new 70-300mm is over an inch shorter than the non-extending 70-200mm f/4 lenses, and yet it has a 100mm longer focal length? I hope you're right and I'm wrong, but I just don't buy that this new lens doesn't extend with zooming. It's internal focusing, yes. But I think it has to extend with zooming.
Has Canon stated that the extenders will work with this lens, at all?
I don't believe that I read anywhere that this new 70-300mm f/4-5.6L is compatible with the extenders. Doesn't mean it won't be - currently as Bryan states, "As a rule, but subject to change, the compatible lenses include fixed focal length L lenses 135mm and longer, zoom L lenses at least 70mm on their wide end and Canon TS-E Tilt-Shift lenses." It depends on the physical configuration of the mount end of the lens, and whether or not there's room for the protruding optical element of the extender to fit into the back of the lens. I'll point out that the extenders do not fit into the back of the 70-300mm non-L lenses, and that the new 70-300mm L lens is the same physical length as the old 70-300mm non-DO, meaning a pretty compact design. Canon might have designed in room for the extender to fit, but since they'll know the new lens+1.4x won't AF on non-pro bodies, and the new lens+2x won't AF on any body, they might not have bothered (but conversely, they do specifically indicate that the 100-400mm is compatible with the extenders (albeit it has the same limitations on AF).
<div>Just like the zoom extension, we may be making a lot of unwarranted assumptions.</div>
You're right, my imagination and drooling played a big role in saying this I think [:P] If I would look at the picture I would be tempted to say it as well, but indeed I'm not sure.
I hope so too! I would love internal zooming on this lens. Perhaps extended zooming looks horrible on this one hihi [:P]
General question: Do you need to look at the absolute maximum aperture of a lens in this case? In other words, the 70-300 has f4 maximum so you could theoretically use it with an 1.4x extender on a non 1D series body? Or do you work with the f5.6 aperture?
Has Canon stated that the extenders will work with this lens, at all?
Man you're sharp this evening! [Y] Well Canon extenders perhaps not, but some of the third party extenders might work? Of course it's a question if you'd really want it.
We'll see John, but as you might have noticed, I'm very looking forward to see/hear more about this lens[]
Seeing that the 70-200 f2.8IS II already downed like 500 euros on the original price. I'm looking forward to this 1500 dollar beast.
Looking at the specs and the 143mm physical length makes me very doubtful that it's internal zoom. It's a rotating zoom, not a push-pull, but I think it's still going to extend.
Now, a black extension from a white barrel...I'm not sure about that... [:S]
I, too, would like to see a $2500 500 f/5.6. But I'm gonna say some stuff you probably already have thought of, Daniel.
As a telescope guy, I'm always thinking a slow lens with a given aperture should be cheaper than a fast one. But often with camera lenses, the reverse is true. I used to think this was just marketing or some other kind of silliness, but there may be more to it than that.
For telescopes, we expect resolution to be proportional to aperture (as it will be with roughly fixed rms error or strhel ratio etc, other things being equal). For camera lenses, we expect resolution to be proportional to focal length. Thus, an 800 f/5.6 is expected to have double the angular resolution of an 400 f/2.8 (ie, it must have far higher optical quality according to the kinds of metrics telescope people use).
In short, a 500 f/5.6 will be a very high quality lens with 90mm of aperture. If canon made one, it might cost more than $2500.
(Or maybe this is all hogwash, and Canon doesn't make a 500 f/5.6 because their marketresearchshows that no one but you and me would buy one [])
...and me makes three. Heck, I'd settle for a 400mm f/5.6 with 4-stop IS - they've already got a pretty sharp but aging 400mm f/5.6, so that's a low bar, right? Canon, are you listening?
Dibs!
Now that you mention it, I think my position on this was wrong all along.
Good point. There are a few exceptions, but they're not very heartening. For example, the 600mm f/4 costs only 8% more than the 400mm f/2.8 and has 10% more aperture area. So on the surface it seems like this is a case where longer/slower equals shorter/faster (I was clinging to it as a beacon of hope []). But if you dig deeper, I don't think it is, becausethe 400mm is noticeably sharper at f/2.8 than the 600mm is at f/4 (in image space, not angular resolution, of course), at least according to Bryan's tests and Canon's MTF.
Maybe the reason is overall length. Telescopes can be much longer than photography lenses because they only have to sit in one place. You don't need to lug them around on a monopod or handheld. The length of the 800mm f/5.6 is only 120mm longer than the 400mm f/2.8, despite a difference of 400mm in focal length.
So maybe the sharpness/cost benefit of the slower f-number is entirely lost on all the extra effort (cost/aberration) required to reduce physical length. Or stated another way, the natural shortening benefit of faster f-numbers more than offsets it's sharpness/cost disadvantage.
I'll have to ask my lensmakeracquaintanceif this theory is true.
This is me, backpedaling a little after spending some time looking at the new 70-300mm L's MTF charts. [:$]
Got me thinking...it's not going to replace my 100-400mm, certainly. But, it's only 1.5" longer than the 70-300mm DO...my main issues with the old 70-300mm non-DO were build quality, and the L is a huge improvement there, with FTM and internal focusing, and of course weather-sealing.
Hmmm....
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