Lens Sharpness - The Never-Ending
But How Sharp Is it Really!? One of the most common questions that I'm asked is,
Is the ...
lens sharper than
A variation on this theme is...
What do you think of the ...
lens? Is it sharp?
Or there's the more generic...
zoom lens as sharp as a prime lens?
镜头锐度（解像力） － 一个永恒的追求
That's enough! I'm about to answer your questions, (as well as a few that you didn't ask), and from
here on, until the end
of time, you need ask them no more.
And, if anyone asks you these questions,
you'll now know where to refer them. Right here.
类问题了。如果再有人问你，你知道该让他们上哪儿找答案 － 这里。
What's All This About Sharpness Anyhow?
There are photographers who love to test and compare things. When they make prints or examine
slides under a loupe,
they are not looking to see if they have properly
captured a special location, light or subject. They are first
and foremost concerned with technical quality rather than image quality.
Consequently they fret and fuss. They choose primes over zooms. They buy the
most expensive brands
and lenses. But then when they have them, what do they do? Do they settle down to
No, they fuss and fret some more, worrying that if only they had a sharper lens
their photography would somehow
improve. Sound familiar?
There isn't a photographer alive who doesn't care about how sharp his or her lenses are. It's one
of the primary manias
of anyone playing this game. We buy and sell different brands of cameras in
search of the holy grail of sharpness.
Should I trade in my Nikon gear for Canon? Should I trade in my Canon outfit for Nikon glass?
maybe I should buy
a Leica system.
I hear Leica lenses are fantastic.
But, how about Contax?
have great reputations. But boy, are those lenses ever expensive. Are they worth it?
I know you've never had these thoughts, but you have heard from lots of
other photographers who have.
Go to any
of the on-line discussion boards. You will find that talk about lens sharpness
represents probably half the discussions
— most of it filled with unsubstantiated opinions and
After 40 years as a professional photographer as well as an ardent amateur, as a teacher and as a
journalist, I've learned
certain things about photography and photographic equipment, and specific
to this topic — about lens sharpness, its
importance as well as, frequently,
its lack of importance.
Here then is what I know about the subject, shorn of as much baffle
gab and BS as I know how to make it.
Some Cosmic Truths
I'm now going to let you in on the great truths. The ones that all true cognoscenti know, but that are
newcomers and the otherwise uninitiated. If you're
really observant you may notice that
this piece has some scattered evidence of the
use of irony, (some would call it sarcasm.) Ignore the man behind the curtain.
I stand behind every
Finally, note before you enter the inner sanctum that I have occasionally
used the word "Usually".
That's because to
a universal truth, there
must be an exception that makes it so. Otherwise, what would we have to argue about?
Prime Lenses are Sharper than Zooms Lenses (Usually)
The title says it all. There is no free lunch! If you want the utmost in sharpness, don't buy a zoom
lens. But, if you want
versatility by all means do buy a zoom. You'd be a fool not to.
Why are primes sharper? A number of reasons. Zooms lenses by necessity
have more elements than primes.
them more difficult to design, increases the risk of various forms of optical aberration,
and can reduce
contrast and increase
Prime lenses usually have larger apertures than zooms, and the laws of
optics say that all other things
(which they often aren't)
a wider aperture lens will be sharper than one with a smaller
aperture — the issue being
Having made the case for prime lenses, let me say that three of the sharpest lenses I own, the
Canon 70~200 f/2.8L IS
zoom, Leica's M series 28-35-50mm Tri-Elmar, and the
Pentax 67's 55~100mm f/4.5 zoom, are as good
as any primes
in their formats that I've ever used.
As I said — "usually" sometimes defines the rule.
莱卡M系列的三段式变焦镜头 Tri-Elmar 28-35-50mm；宾得67的55-100mm
Camera Manufacturer's Lenses are Sharper than Third Party Lenses
Camera manufacturers want you to buy their lenses. They don't want
you to buy a lens from a third
party. If you do they
don't make as much money, and making money is why they're in
Therefore they have to make some
lenses as inexpensive as possible.
want the finest lenses possible,
which are expensive to make.
What to do?
major brands therefore make two lens lines, sometimes so
indicated (like Canon's "L" series
glass), and sometimes just differentiated by
price. This allows them to cater to both markets.
Third party lens makers usually aren't interested in selling camera bodies. They
want to sell you
lenses. And since most amateur photographers make
their buying decision based pretty much on
price alone, it isn't hard for these
companies to figure out what
to do to get this business.
If you want the finest lens of a given type, buy the manufacturer's top-line
lens. If your priority
is to save money,
then buy the third party lens. No
matter how hard you try and imagine it to be so, that $200 lens (including a
free skylight filter)
from Sigma, Tamron or their brethren just isn't
going to be as sharp, free from flare and optical
aberrations, well designed and
sturdily constructed as a $900 optic from Canon, Nikon or one of the
Are there exceptions to this. Yes, maybe, sometimes. Some types of lenses are easier to design than
others, so low-cost
third-party lenses can be quite decent. But, this brings us to our next cosmic truth.
You Get What You Pay For
Test drive a BMW or a Lexus. Now test drive a Chevy or Nissan. Notice any differences? Of course
you do. Compare
the prices. Now you understand why better costs more.
What applies to cars applies to lenses as well. Quality costs money. When is "good enough", good
enough? Only you can
answer that. If you can afford a Mercedes, good for you. If a Leica prime lens
is within your reach,
go for it. But if you
can't afford one don't delude yourself that a lens that costs 2-3 times as much as another isn't worth the money.
It is. For
those that can afford it! For those
that can't — get over it, and live happily with what you can afford.
Please read my parable on coveting high-end equipment
for further thoughts on this topic.
Good Technique Trumps Sharp
Now for one of the biggest truths of all.
You can fret all you want about how sharp a
photographic technique isn't first rate, having
a lens capable of
resolution and high
worth a damn.
To get the best from any lens here are some things that you should be doing:
Use a solid tripod
For 95% of the landscape, nature and wildlife work that I
do I use a tripod. Religiously.
I own three; big, bigger and biggest. Just
about the only time I hand-hold a camera is when
I'm doing documentary-style street shooting.
Hand-holding usually leads to inferior images,
particularly in landscape and nature photography.
Use mirror lock-up and a cable release.
Vibration; any vibration, is a sharpness killer. Don't hand-hold a lens at a
slow shutter speed and
a wide aperture and then worry about
whether the lenses sharp or not. What are you
Whether it's Canon's IS or Nikon's VR, this is one of the greatest innovations
in lens design of the
last quarter century.
It works, and it works damn well.
for serious long lens work, even when working on a tripod, Canon's family of
Stabilized "L" series lenses are worth their weight in gold
(which partially explains their price).
Use the lens' optimum aperture.
This is typically not with the lens wide open, and never when stopped all the
way down. Only the finest
lenses are as
sharp wide-open as when closed down
somewhat, and no lens is at its best when stopped down to f/22 or f/32, due
to diffraction effects. Most lenses have their optimum aperture at 2-3 stops
down from wide open.
Use fine-grain, high-resolution film
You want to be able to see what you've paid all that money for, don't you? Of course using such film
means ISO speeds
of under 100, which means that a tripod, cable release and mirror lock-up are a necessity when combined with the use of
the lens' optimum aperture.
的胶卷（如ISO50的 FUJI VELVIA － 译者注），相机的反光板锁定功能，三角架，以及快门线。
Your image processing technique and equipment must be as good as your photographic technique and your
Whether in the chemical or the digital darkroom; whether using an enlarger or a computer, anything
less than the finest
and techniques will obviate whatever investment you've made i
n fine lenses.
Can you honestly say that your prints match your hopes for a given image? It may not be your lens
that's at fault. It may
be what you're doing and the tools that you're using after the photograph was taken that's limiting your
If all of the above are not part of your everyday shooting technique then you're likely not getting the
most from your
expensive lenses. Only when you've given a lens every chance to show its best do you
have the right to
determine if its
performing at its best.
Think about the variables standing between a scene in front of the camera and a print hanging on the
wall. A large number
of factors determine whether or not the print will be sharp.
The lens' resolution capabilities;
The film's resolution capabilities;
Camera and/or subject motion;
Aperture used and
consequent depth of field as well as use of optimum aperture.
Film flatness — is the pressure-plate doing its job properly? Film thickness — are all layers in the film (color) bringing the
image into focus.胶卷厚度
Film grain — sometimes grain makes images look sharper — sometimes the opposite! 胶卷颗粒－
Enlarger parallelism — many aren't, and sharpness suffers 放大机的平衡度－
Negative carrier precision and film flatness 底片输送机的精确度和胶卷的平度；
Enlarging lens quality and aperture used 放大机的镜头质量和所用光圈；
Resolution of the printing paper used
Of course digital post-processing has its own issues, including...
The film flatness capabilities of the scanner's carrier;
The native resolution of the scanner chip and
Sharpening level applied in post-processing ; The native resolution of the printer;
For digital cameras many of the same issues as for film cameras apply, as well as those for digital image
See what I mean? The sharpness of a given lens is just one of a myriad of factors, and usually not the
most important one,
in determining if a print will look "sharp".
The Bottom Line
Are you ready for this? Here's the big one. The one big truth that
I've learned about this subject after
a photographer, and which summarizes the points above.
"Most Lenses are Better Than Most Photographers"
Does this idea make you uncomfortable? Good. That's what it's meant
to do. Think about it.
Yes, there is a difference between brands. There definitely is something special about many Leica lenses,
and Zeiss lenses
are generally superb. Top Nikon and Canon glass can be as good as it gets. On the other side of the coin, some
Sigma-Tamron -Tokina lenses are
indeed so much junk. Some though are pretty good.
All of these statements are based on personal experience. None though are
universal truths. But it's my unquestionable experience that it is rare indeed
that I ever see photographs taken by folks that fret about these issues that
even come close to matching the capabilities of even the least pretentious of
This is why there are those folks that makes the claims that they
some lenses or brands, or countries of origin, while there are others who
say that they don't see the differences. This isn't a case of "the emperor's
new clothes". It's often just a matter of experience and skill, each of which
can be acquired if one has
So, unless you are utilizing all of your photographic skills and know what to
look for and how to achieve it, stop worrying so much about sharpness. Buy
the lens that fits within your budget and that meets
the needs of the type
of shooting that you do. Most of all, stop worrying and just enjoy doing your
Once Upon a Time....
Once upon a time there was a young career photographer. He was talented, but he
didn't have much money.
because it was the mid-'60's and he was reacting to his depression/war era parents, he thought that money
wasn't important ?
art always came first.
Consequently while as his peers, who were developing their
his, bought Nikon Fs, M series Leicas and
Hasselblads, our hero had to satisfy himself
along with inexpensive third-party lenses from
Tamron, Tokina and the like. He reveled in the simplicity of his ways.
And, our hero succeeded. His photographs, made with cheap cameras on even cheaper lenses were widely
major magazines, his better work was collected by major galleries and national institutions,
and he was
living as a freelance photojournalist.
Meanwhile his colleagues and competitors continued to tease and distress him about his not using "the best".
Then the illness struck. He started to believe that they might be right. As quickly as he could he started
to buy top rated
cameras and lenses. Nikons, Leicas, Contax, Hasselblads ?all the top brands. His family's
life-style suffered as he plowed
more and more money into the finest camera bodies and lenses available.
Finally his career as well as his personal life were in jeopardy as his spending exceeded his financial
abilities. Years later he reviewed this period of his life. With hindsight he saw how in fact his best work from
that time of his life
was done when he was poor and using so-called "amateur equipment". There was a freshness and a clarity of vision that became
veiled by the later obsession with lines/mm, titanium bodies, exotic lens elements and the like.
Today he can afford to buy whatever equipment he wishes,
and he does, and enjoys every one of them. But, he always
remembers the lesson that that difficult period of his life taught him.