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Olympus M.Zuiko ED 300mm f/4 IS PRO announced
#31
It's not entirely impossible to take some photos with those beasts.  ^_^

 

I assume, if one goes the comfortable path and get a zoom instead of primes, this one might find it difficult to understand why a zoom should need manual focus theses days? Which is Zeiss' credo, "manual focused lenses are better" (at least they don't loose their expensive resolution because of weak / unreliable AF).

#32
Quote:Regarding the ability of the various consumer optics firms, I would rate them something like the following:

 

1.  Zeiss - EUV litho and medical division for their aggressive utilization of freeform and aspheric optics

 

2.  ARRI - same reasons

 

3.  Canon - they seem to be miracle workers re: price/performance (10-18 stm etc) and also capable of very radical designs (11-24)

 

4.  Leica - Excellent use of aspheres, very good to excellent performance in extremely small sizes

 

5/6. Zeiss (ZE/Milvus/FE/etc) - not as good as they used to be but still offering top-notch lenses

 

5/6. Sigma - very good lenses of late

 

7.  Nikon - They're this far down for by and large being too conservative in the last decade+.  Simple lenses, average/good performance, expensive, not particularly small.

 

8.  Schneider - very good lenses, but extremely long development times.  Give a man 4 years to design a lens and almost anyone could produce something great by chance.

 

9.  Tamron - I may be being overly punitive because of sloppy construction on many/most lenses, but they have some excellent models like the new 35 and 45mm lenses in that regard.

 

10-xx Sony, Olympus, Panasonic, Fuji et al - I would never purchase a lens from any of these companies.  16% distortion in some models is simply inexcusable, very bad assembly quality, poor mechanics, and not particularly great performance out of any of them.
 

Interesting, thanks.  Where does Voigtländer and Pentax fit in that list?


This ranking of lens design, or design+execution?    
#33
re: compact zooms.  I have minimal data from them, but some.

 

28-80 @ 28mm/T2.8 -  http://i.imgur.com/LvdOFDs.png

 

28-80 @ 50mm/T2.8 - http://i.imgur.com/Yme82tC.png

 

28-80 @ 70mm/T2.8 - http://i.imgur.com/3skLkQs.png


70-200 @ 70/T2.8 - http://i.imgur.com/u0TrTyX.png

 

70-200 @ 135/T2.8- http://i.imgur.com/XhsYvJL.png

 

70-200 @ 200/T2.8- http://i.imgur.com/APlZ40j.png

 

The performance is... competitive, but the consistency/assembly quality is a notch above (though not as good as the 11-24).  All 3 samples of the 28-80 look like that, and both of the 70-200 look like that.  The distortion of the compact zooms is much much better than the photographic lenses.  The fact that they are extremely rotationally symmetric is also very good, especially for a zoom.  To give you an idea of what most photographic zooms look like, here are two 70-200 IS IIs @ 200mm

 

http://i.imgur.com/m1xF3I6.png

 

http://i.imgur.com/LZzTQyI.png

 

A mixed bag.

 

Dave, without seeing CAD files I can't really separate design from the manufactured product.  It is mostly design, but I do consider quality of manufacture as well.  I did not rank voigtlander because I do know enough about their lenses to really rank them, but I would probably put them somewhere around Nikon.  Pentax would go around #9 or so.

#34
Quote:The lens is very large because the lens designers of the mirrorless companies are less skilled, and the companies perform serious price gouging because the market for the non-kit lenses is mostly wealthier amateur users.  They charge such a crazy amount for a mere 300/4 because people will buy it for that.
 

I assume you have some highly specialist knowledge about lens design to make that statement. However form what I can gather you are Brendan form Lens Rentals - a young 2nd year optical engineering student. No offence intended, but perhaps the more senior designers who work in the industry may have some experience and knowledge which should not be so easily dismissed. 

#35
Quote: I see what you mean there Klaus, everything seems to be turned into round nervous spheres.....

 

   ............in this case soso = So no thanks!
This reminds me of my nikon 300 PF that I had before. The said nikon had some serious contrast problems when trying to shoot backlit subjects. http://g3.img-dpreview.com/BD81FCB672644...359D38.jpg I faintly remember that I had to take lots of care with this picture , as the background was much much worse than in this final image.

 

I'm optimistic that the olympus will be better, holding higher contrast, but maybe a bit too expensive even so? I'll prolly grab a pl 100-400 if its AF is faster than oly 75-300 ii

#36
Quote:I assume you have some highly specialist knowledge about lens design to make that statement. However form what I can gather you are Brendan form Lens Rentals - a young 2nd year optical engineering student. No offence intended, but perhaps the more senior designers who work in the industry may have some experience and knowledge which should not be so easily dismissed. 
The only offensive parts are an inability to spell my name and not knowing what companies I work for Smile 


Age has never been a factor in how good an optical designer is.  There is some degree of artistic talent needed to find what we call a "solution space" and the rest is being good at making the software work its magic.  Gone are the days of Mandler at Leica and Merte at zeiss where intuition and talent alone made you the best. 

 

Only a few months ago one of the best optical designers in the world passed, Dr. Kevin P. Rolland-Thompson.  He was responsible for the design of many very famous systems, including CONSTAR, the first service mission for hubble, but he developed what is known as Nodal Aberration Theory and its in-use tool, Full-Field Displays.  NAT is necessary for freeform optical systems because they lack symmetry.  The magic of freeform, and the last 4 years of our research in field dependence of different configurations, is being able to take an existing system and fold it into any nearly shape that is desired while maintaining the original level of performance or providing an improvement. 

 

It is effective utilization of technologies like freeforms, aspheres, gradient index optics, diffractive optics, and others that truly sets designers apart.  Most senior-in-age designers are completely unfamiliar with aspheres and simply unable to design with them, or unable to design with them effectively.  If they use them at all the rely on the "Asphere Expert" tool in Code V or its equivalent in Zemax that suggests suitable locations in the design to implement an asphere.  Asphere expert uses NAT to evaluate the effects of inserting an asphere at any surface and is only possible because of the work done by Dr. Thompson. 

 

Simply adding aspheres to fix performance is not so special, though using them creatively is.  For example, the Nikon 24/1.4G has a conical asphere in the wide angle attachment portion of the lens.  Without the addition of its aspheric profile, no light at all makes it through the lens.  Quite special.  But that implementation is quite unique from Nikon and by and large they do many "special" things of late.

 

It is perhaps similar to the situation if you have someone very good at programming in DOS today.  That's great and all, but the best are using better and more powerful tools.  Many of the world's best optical designers are quite young.  For example, the top freeform designer at zeiss, responsible for the design of the world's highest resolution lens, is only 28.
#37
Quote:The only offensive parts are an inability to spell my name and not knowing what companies I work for Smile 


Age has never been a factor in how good an optical designer is.  There is some degree of artistic talent needed to find what we call a "solution space" and the rest is being good at making the software work its magic.  Gone are the days of Mandler at Leica and Merte at zeiss where intuition and talent alone made you the best. 

....

 

Simply adding aspheres to fix performance is not so special, though using them creatively is.  For example, the Nikon 24/1.4G has a conical asphere in the wide angle attachment portion of the lens.  Without the addition of its aspheric profile, no light at all makes it through the lens.  Quite special.  But that implementation is quite unique from Nikon and by and large they do many "special" things of late.

 

It is perhaps similar to the situation if you have someone very good at programming in DOS today.  That's great and all, but the best are using better and more powerful tools.  Many of the world's best optical designers are quite young.  For example, the top freeform designer at zeiss, responsible for the design of the world's highest resolution lens, is only 28.
 

Well, Brandon, a couple of things in your post deserve another point of view. To me, some of your posts I simply don't understand because you're talking laboratory instead of shop Wink That makes you sound cocky from time to time (and I use the verb "sound" on purpose, as I don't know if you are cocky). Not that I understand "shop" much better than "laboratory"  Smile I'm only one of those consumers spending the money to make lens designer's salary.

 

Putting the old guys more or less completely into the science trash bin is another thing taking some sympathies - but quite normal for well educated dudes in your age. At first, the 28 year old pioneer at Zeiss might be young but benefits of all the experience and knowledge of hundreds of old guys, the persons who learnt a life long simply because there were no internet researches possible when Zeiss started to make his microscopes better by try and error, no programs available. The guy might be a genius by designing freeform elements, but change his computer against a chalkboard or notepad and see what happens. That works the other way around, too - give the old guys the modern computer and see what happens. Not very much, I assume.

 

All the today less cool people were necessary to make the cool work of few possible - and even if they only were working against them, resistance is also a motivator. It's not a crime to remember this from time to time, it's also no weakness to be humble. No offense meant, I guess you get it the right way.

 

Also, lens design is not just optical design and I suspect you're talking more about the optics, the mathematical miracles  delivering all this contrast and resolution record numbers. However, what happens if the mechanics can't stand the environment those lenses are used in? If it's so obviously simple to design outstanding stuff, why don't we see more of it at affordable prices?

 

I totally agree with your statement about Nikon although I'm not entirely sure if it's grammatically flawless Wink : Too late and not daring enough. But please put against a more daring and more up-to-date design: they mess up with some things and apparently don't run a good prototype testing lab. They get some great photog names, give them the lens and show what it can do. The VR fault of the 300PF is telling something how much optical designers talk with electronical and mechanical design colleagues. Not testing a lens with all available bodies and at all shutter speeds is inexcusable. There were other callbacks as well and I'm afraid, not everything can be fixed in Nikon's repair shops.

#38
Quote:Well, Brandon, a couple of things in your post deserve another point of view. To me, some of your posts I simply don't understand because you're talking laboratory instead of shop Wink That makes you sound cocky from time to time (and I use the verb "sound" on purpose, as I don't know if you are cocky). Not that I understand "shop" much better than "laboratory"  Smile I'm only one of those consumers spending the money to make lens designer's salary.

 

Putting the old guys more or less completely into the science trash bin is another thing taking some sympathies - but quite normal for well educated dudes in your age. At first, the 28 year old pioneer at Zeiss might be young but benefits of all the experience and knowledge of hundreds of old guys, the persons who learnt a life long simply because there were no internet researches possible when Zeiss started to make his microscopes better by try and error, no programs available. The guy might be a genius by designing freeform elements, but change his computer against a chalkboard or notepad and see what happens. That works the other way around, too - give the old guys the modern computer and see what happens. Not very much, I assume.

 

All the today less cool people were necessary to make the cool work of few possible - and even if they only were working against them, resistance is also a motivator. It's not a crime to remember this from time to time, it's also no weakness to be humble. No offense meant, I guess you get it the right way.

 

Also, lens design is not just optical design and I suspect you're talking more about the optics, the mathematical miracles  delivering all this contrast and resolution record numbers. However, what happens if the mechanics can't stand the environment those lenses are used in? If it's so obviously simple to design outstanding stuff, why don't we see more of it at affordable prices?

 

I totally agree with your statement about Nikon although I'm not entirely sure if it's grammatically flawless Wink : Too late and not daring enough. But please put against a more daring and more up-to-date design: they mess up with some things and apparently don't run a good prototype testing lab. They get some great photog names, give them the lens and show what it can do. The VR fault of the 300PF is telling something how much optical designers talk with electronical and mechanical design colleagues. Not testing a lens with all available bodies and at all shutter speeds is inexcusable. There were other callbacks as well and I'm afraid, not everything can be fixed in Nikon's repair shops.
Any of the technologies I'm talking about are "industry-ready" and utilized.  Freeform has been around since the 1980s (polaroid SX-70) commercially.  Older-generation designers unable to utilize advanced technologies aren't trash, but they also are not the best designers around and I have no intention of mincing my words.

 

Freeforms aren't really designed by hitting "go" in the software either.  In producing a tilted and decentered (folded) system the performance immediately dies.  A 50/1.8 like the 1.8 STM has about 1.5-2 waves rms wavefront error at full aperture.  A freshly titled system has about 20-40 waves rms wavefront error.  To recover performance you need to do a very detailed study of the new aberration fields of the system - some geometries are uncorrectable (e.g. those in which the coma is in the wrong orientation) while others can be more than recovered and outdo the original symmetric form.  An example would be a recent TMA telescope we designed - nominal was 1/5 wave worst point in the field, after folding it up and turning it into a freeform the performance was 1/100 wave worst point in the field.

 

As of yet the tools for this aren't totally supported in the design software, so the math is done in Matlab in our case, someone else might use python or something.  Code V has been around since the 80s though, and the first optical design codes (FLAIR, etc) were designed in the 1950s and 1960s by Robert. E Hopkins.  I think Zemax was started in the 90s, but I don't use it so I am not sure. 

 

3rd order aberrations can be corrected by hand calculation - the maths is not so brutal.  They are sufficient up to about a 5 degree full field of view at f/10.  The higher order aberrations are 'impossible' by hand (for a 6-element double gauss each coefficient would require over 10 pages of math, the probability of making no errors in the calculation is ~0).  This is where CAD comes in - perfect calculation of the formulas, and since the 90s or so real ray tracing instead of paraxial approximations.

 

The mechanics of consumer lenses are interesting.  They offer many more features than your average industrial lens, so they are a small miracle.  On the other hand, they offer much less precise construction, are less robust, etc. 

 

Here's an industrial projection lens [url=http://i.imgur.com/SqRoGEc.jpg.%C2][/url] The mount is 1/8" steel, as are many of the barrel pieces.  Not even a supertelephoto has this level of build quality.

 

Regarding outstanding at good prices - optical manufacturing is extremely expensive.  If you want a single piece of the front element for a double gauss 50/1.4 you will pay $550+ for it.  If you want a hundred pieces you may pay $25/ea for them.  At a hundred thousand pieces, I don't know - perhaps only $15-$10/ea.  At that point it depends almost entirely on what glass it is - the most common is $7.20/lb, but the most expensive ones are several hundred dollars per pound. 

 

A full-frame sensor is also actually extremely large.  Most designs are made for perhaps a 5mm detector, 10mm at the largest.  distortion and petzval become very difficult to sufficiently control on such a large image area; they are also the most difficult aberrations to work with in general, as there is no zero condition for them where an aplanatic surface produces 0 spherical, 0 coma, and 0 astigmatism.  Clever tricks can be used for the other aberrations, but to fix petzval and distortion the solution is pretty much make it bigger.  Miracles of price can be worked on smaller chips (see: 10-18 for $300, the brevy of f/0.95 and faster lenses for m4/3, etc) but full-frame is difficult. 
  


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