Canon announces EF 70-200mm f/2.8L IS II USM

[mongo]

Even though different people think differently about the value of MTF charts, Mongo still would have liked to see one. If it is as good as the manufacturer says, they should not hesitate to include a chart. Handling, compatibility, cosmetics etc aside, the chart can be a reasonable “apples with apples” comparison with its predecessor if done correctly as well as a gauge with other brand lenses.

The use of fluorite is interesting. It is well known for its excellent properties for this purpose but has always suffered from instability; particularly with temperature changes. Perhaps canon may feel they have overcome that problem.

In any event, it appears to pack some technical clout that should produce truly outstanding images. How much better it is than the existing version (if at all) is yet to be seen.

All this from a Nikon user. Mongo is more interested in the engineering of fine optics (from whatever source) than arguments over brand names.

[Xenedis]

The use of fluorite is interesting. It is well known for its excellent properties for this purpose but has always suffered from instability; particularly with temperature changes. Perhaps canon may feel they have overcome that problem.

Canon has been using fluorite elements for well over a decade.

All of the super-teles contain a fluorite element (or two in the case of the 800/5.6L IS). Both of the 70-200mm f/4L zooms contain a fluorite element, as does the 100-400.

Yes, fluorite is sensitive to heat, and unsurprisingly only white-barrelled lenses contain fluorite elements.

[Tannin]

Even though different people think differently about the value of MTF charts, Mongo still would have liked to see one. If it is as good as the manufacturer says, they should not hesitate to include a chart. Handling, compatibility, cosmetics etc aside, the chart can be a reasonable “apples with apples” comparison with its predecessor if done correctly as well as a gauge with other brand lenses.

Yes. That's why they have released MTF charts.

The use of fluorite is interesting. It is well known for its excellent properties for this purpose but has always suffered from instability; particularly with temperature changes. Perhaps canon may feel they have overcome that problem.

Bahh. Fluorite has been used for the finest quality optics for many, many years now. No other material provides the same optical qualities. For long glass of any sort (be it used in camera lenses, spotting scopes, or in binoculars), a fluorite component is nearly always part of the recipe. Not just camera lenses - all three top scope and binocular manufacturers use fluorite as routine in their premium products. Whether you buy Swarovski, Zeiss, or Leica, if you buy top of the line, you get fluorite. These are products that get rough and tumble use for years and decades on end - far rougher use than most camera lenses ever see. Problems? There aren't any problems. Hell, how else could Swarovski provide their extraordinary 30 year warranty? And yes, that's a real warranty - their service is legendary. 30 years.

Meanwhile, over in camera land, Canon have been happily using Fluorite elements in long lenses for ... what ... 20 years now? Fluorite is the best available material, there is no question of that. Although it is very difficult to work with in a manufacturing environment, once embedded in a properly designed and constructed lens barrel, it is perfectly practical and very durable. Really, the only question you should be asking with long lenses is (assuming we are talking top-drawer quality here) why doesn't this lens have it?

[mongo]

Yes. That's why they have released MTF charts.

thanks Tony . There does seem some improvement but whether it's enough to notice or warrant selling a perfectly good current version is very unlikely.

Also , thanks for the general info re fluorite use. Mongo knows Nikon allegedly tried it once or twice in the 70's or early 80's on possibly a 400mm f5.6 but this is hard to verify it seems. Either way, it seems they never have since as far as Mongo knows - at least in their camera lenses. If they do, they do not seem to advertise that point well or at all.