Canon EF 135mm f/2 L - Test-Shots (Qs)

[YoungRebel]

Hey all,

For a while I am owner of Canon's 135mm f/2 L lens.
I usually take it out for street-photography and at f-stops around f/4.

Today I thought I compare different f-stops of that lens on the same object.
What came out really surprised me and I am a little worried...
---------
The lens definitely shows it's sharpest at f/4-f/5!
f/2 is way too soft and even f/9, f/14, f/22 it's just really soft and that shouldn't be like that IMO....

Maybe you can give me some advice or comments on following test-shots:

ALL SHOTS WERE FIRED USING TRIPOD AND SELF-TIMER IN AV-MODE / FOCUS ON PALM-TREES
First Scenario
1/160 - f/5 - ISO200

100% crop1+2 @ 1/1000 - f/2 - ISO200

100% crop1+2 @ 1/160 - f/5 - ISO200

100% crop1+2 @ 1/40 - f/9 - ISO200

100% crop1+2 @ 1/15 - f/14 - ISO200

100% crop1+2 @ 1/6 - f/22 - ISO20

I have a second scenario that I will upload soon, but for now that should be enough....

What I am wondering about is, that everything looks so soft at above f/9.
Ok, shot at 1/40 and slower but used really sturdy tripod.
I usually dont shoot landscape but high f-stops like 18+ are usually used for landscape right, to have full sharpness...HOW IS THAT POSSIBLE, cause in my pictures it is obviously really soft....

OR is my lens just a bad copy?
Looking at my pictures I should use this lens definitely just at f-stops around f/5

Thanks for taking the time!!!

Patrick

 

[Garbz]

Diffraction through the aperture causes problems above f/8 on APS sized cameras. I try not to ever go to f/22 because of it. You will find they will be tac sharp all the way past f/11 on a full frame camera.

Your opinion doesn't count either, because "You canna change the laws of physics capn" regardless of how much money you spend. Wide open apertures are never as sharp as stopping down 1 or 2 stops, and the only way to defeat diffraction is to get a larger sensor and larger optics to go with it.

Advice: Don't crop to 100%, and add a slight touch of sharpening in post.

 

[YoungRebel]

Yeah, I know - dont wanna change physics but that was my first test on something like that and I just a little surprised 'cause I expected to get sharper images out of the camera without post-sharpening at f-stops above f/9...

So, if I understand you right:
ON APS sized cameras it's normal that above f/8 the quality or especially sharpness lacks?

So when shooting a landscape, EVERYBODY says to get settings like:
ISO100 - fast shutter - f/18 +

This is to get most details and the best sharpness in the landscape shot.

With an APS-sized camera now the best option would be to stay under f/8 for a landscape shot 'cause above it automatically loses quality/sharpness out of physical rules???

Thanks for your time!!!

 

[Antithesis]

People don't shoot at f22 because it's the sharpest point of the lens, they do it to get everything in focus (larger DOF). If you want the sharpest possible image "F8 and stay there" is probably your best bet with any lens. It looks like f14 is still pretty sharp on that lens, and your DOF seems broad enough for landscapes as long as you don't have anything of interest in the foreground.

 

[YoungRebel]

Thanks!

That's I think was what I misunderstood in the first place! I never really shot any landscape so I didn't look too much into it...
The 135mm wouldn't be used for it anyway

 

[kobayashi]

also, since it is lens primary intended for portraits on FF, try it on some closer objects and see if photos are sharp enough, since not many lens can provide sharp details with distant objects, especially on APS-C camera.
You can even take the best L lens, it won't be spectacularly sharp on APS-C, because it is not the same thing to watch 100% crop of a close objekt and a distan object on your monitor, because the bigger mm(real life)/pixel ratio the worse the details are.
Also, some people claim that, since camera does interpolation due to Bayer sensor, every photo neds a bit of software sharpening.

One of the great ways to sharpen photo can be found here: http://www.luminous-landscape.com/tutorials/high-pass-sharpening.shtml

 

[Antithesis]

Thanks!

That's I think was what I misunderstood in the first place! I never really shot any landscape so I didn't look too much into it...
The 135mm wouldn't be used for it anyway

I think it was primarily designed as a portrait lens like Kobayashi said, but you could certainly use it as a landscape lens if the need arose.

 

[Garbz]

The formula for calculating the loss of detail due to diffraction is complicated. But yeah basically diffraction is the limiting factor on any lens, just that when you start getting below f/8 other things become and even greater problems due to imperfections towards the edge of the lens.

So you have a typical bell curve for sharpness of every lens. They'll be poorest wide open and at f/22 the former because of CA and other such problems, the latter because of diffraction. And sharpest somewhere in the middle of the range.

If used on a full frame camera the diffraction equation changes because of the pixel size and the sharpness graph skews itself a bit further to the right.