imaginary_number
Senior Member
oeyvind said:
I think we have to be thankful for the fact that he uses paragraphs. ;p
Why the EFS 10-22 is likely an optical gem
- Thread starter Jonathan_Kwok
- Start date
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I think we have to be thankful for the fact that he uses paragraphs. ;p
Jonathan_Kwok
New Member
Apparently, there's an unspoken rule here that messages to this forum have to be very concise. I sincerely apologise for imposing my lengthy analysis upon you people.
Take care,
Jonathan
Take care,
Jonathan
imaginary_number
Senior Member
Jonathan_Kwok said:
Jon,
there're no such rules around - no worries; the comments were made in jest. It's just that it's a little uncommon to see such detailed, lengthy posts over a lens (incidentally, when there's a flame war going on, it becomes more common though... don't ask me why).
Belle&Sebastain
Senior Member
Jonathan_Kwok said:
cool man, i love to read, so write, there are no rules.
the spoken rule is not to be rude or vulgar.
aaronng said:
Where did you get that from? Does Canon publish a white paper on how they arrive at their published MTF graphs?
If not, your guess is as good as mine, and i'm more inclined to think it's a weighted average of different subject distances.
In any case, for wide angle lenses, infinity focus is reached after about 3-5m and infinity focus would be 'regular working distance' for most landscapers. FWIW.
It's in the glossary for MTF at www.canoneos.com, the last paragraph for MTF.
Here is the link
http://consumer.usa.canon.com/ir/controller?act=GlossaryAct&fcategoryid=216&alpha=MNO
Canon USA doesn't have the MTF up for the 10-22mm yet, but the MTF for 16-35mm L is the same as the one on Canon Japan's site.
As far as I know, most of the MTF readings are done at infinity. Same as for the ones at photodo.
Aaron
Here is the link
http://consumer.usa.canon.com/ir/controller?act=GlossaryAct&fcategoryid=216&alpha=MNO
Canon USA doesn't have the MTF up for the 10-22mm yet, but the MTF for 16-35mm L is the same as the one on Canon Japan's site.
As far as I know, most of the MTF readings are done at infinity. Same as for the ones at photodo.
Aaron
Jonathan_Kwok
New Member
Not sure if this is on topic, but here are some interesting links to better understand MTF charts as well as lens design theories.
http://www.photodo.com/nav/artindex.html (Photodo.com site)
http://www.imx.nl/photosite/leica/leicahome.html (The Leica Papers)
http://www.imx.nl/photosite/leica/technics/optics01/lensdesign01.html (Lens design; Criteria and Considerations by Erwin Puts)
http://www.imx.nl/photosite/technical/resolution/resolution.html (Understanding resolution and debunking myths around Leica Lenses by Erwin Puts)
When I started using the Eos system 14 years ago, I presumed that if a lens had more elements, it should be better. After reading the book "The Leica Lens Compendium" by Erwin Puts and using Leica lenses on my Eos cameras, my paradigms completely changed.
Take a quick look at some of the best lens designs from Leica and you'll realise that they often manage to design and manufacture lenses of superlative quality, while generally utilising fewer lens elements than their Japanese counterparts. That takes superior art and science. Puts argues that computers merely help the designer to optimise a lens but it doesn't automatically guarantee a good design. Designers who have not mastered the finer art of lens design often keep adding lens elements to combat certain abberations, but that in itself, introduces new problems in the optical path. Light is energy, and the more lens elements stand in its path, the more "resistance" there is to that flow of energy.
The situation with Canon is that while they undoubtedly make many outstanding lenses (especially their L telephotos) some of their lenses are truly less than stellar. The EF17-35L for instance suffered from terrible chromatic abberation in the edges. The EF70-200 f/2.8L IS while a fine lens, because it uses so many elements (23 elements), is often prone to veiled glare. I'm speaking from experience as I've own these lenses. Also, due to economic reasons, budget EF lenses are often just mediocre as design and material compromises are made.
Perhaps that's why lens design interests me. It often gets entertaining when one can almost start to predict a lens' performance by examining its design and heritage. That's why when I saw the EFS10-22's optical layout, I was excited as the indications were good that this lens would be an optical gem. I cannot say the same for the EFS17-85 IS USM though.
My gratitude to those of you who explained things to me about the length of posts. Truly appreciate your clarification. Anyway I'd better stop before my verbosity becomes an issue.
http://www.photodo.com/nav/artindex.html (Photodo.com site)
http://www.imx.nl/photosite/leica/leicahome.html (The Leica Papers)
http://www.imx.nl/photosite/leica/technics/optics01/lensdesign01.html (Lens design; Criteria and Considerations by Erwin Puts)
http://www.imx.nl/photosite/technical/resolution/resolution.html (Understanding resolution and debunking myths around Leica Lenses by Erwin Puts)
When I started using the Eos system 14 years ago, I presumed that if a lens had more elements, it should be better. After reading the book "The Leica Lens Compendium" by Erwin Puts and using Leica lenses on my Eos cameras, my paradigms completely changed.
Take a quick look at some of the best lens designs from Leica and you'll realise that they often manage to design and manufacture lenses of superlative quality, while generally utilising fewer lens elements than their Japanese counterparts. That takes superior art and science. Puts argues that computers merely help the designer to optimise a lens but it doesn't automatically guarantee a good design. Designers who have not mastered the finer art of lens design often keep adding lens elements to combat certain abberations, but that in itself, introduces new problems in the optical path. Light is energy, and the more lens elements stand in its path, the more "resistance" there is to that flow of energy.
The situation with Canon is that while they undoubtedly make many outstanding lenses (especially their L telephotos) some of their lenses are truly less than stellar. The EF17-35L for instance suffered from terrible chromatic abberation in the edges. The EF70-200 f/2.8L IS while a fine lens, because it uses so many elements (23 elements), is often prone to veiled glare. I'm speaking from experience as I've own these lenses. Also, due to economic reasons, budget EF lenses are often just mediocre as design and material compromises are made.
Perhaps that's why lens design interests me. It often gets entertaining when one can almost start to predict a lens' performance by examining its design and heritage. That's why when I saw the EFS10-22's optical layout, I was excited as the indications were good that this lens would be an optical gem. I cannot say the same for the EFS17-85 IS USM though.
My gratitude to those of you who explained things to me about the length of posts. Truly appreciate your clarification. Anyway I'd better stop before my verbosity becomes an issue.
Long informative posts like yours are always welcome - Status
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