# How do I get the whole picture sharp?



## Jack56 (Apr 29, 2014)

This morning I took this photo with the 100mm L. 
Iso 160 - f/13 - 0,5 sec.
Distance about 30 centimetres. 
I used a tripod and cable release. 
I didn't crop the photo and shot it in raw. Yes, the colour is about that green, that's why I like it.
How is it possible to get everything sharp with this lens even in the corners?


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## neuroanatomist (Apr 29, 2014)

Lenses are always sharper in the center, that's just a basic fact of optics.

Here's the MTF curve from Canon for the 100L Macro:






Sharpness is the thin lines, the blue lines represent percromance stopped down to f/8. The center of the image is the left of the plot and the the corners of the image are at the right – note the fall off in sharpness.

Looking at your image, it appears (altough it's hard to tell for sure with the subject) that the lower right corner is not as sharp as the other three corners. The sharpness fall-off should be symmetrical, if it's not there may be a problem with the lens (e.g. decentering of an element).


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## Jack56 (Apr 29, 2014)

Thank you for your reply. What is the best way to test this?


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## neuroanatomist (Apr 29, 2014)

http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover


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## surapon (Apr 29, 2014)

neuroanatomist said:


> Lenses are always sharper in the center, that's just a basic fact of optics.
> 
> Here's the MTF curve from Canon for the 100L Macro:
> 
> ...



Thank you, Sir, Dear Teacher, Mr. neuroanatomist.
Thanks for your Great Information.
Surapon


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## surapon (Apr 29, 2014)

neuroanatomist said:


> http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover



Thank you, Sir, Dear Teacher, Mr. neuroanatomist.
Thanks for your Great Information of great Link.
Surapon


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## Jack56 (Apr 29, 2014)

Thanks for your help. That's very kind of you.
I made two other images just to check. Because, when I make other photos, long distance f.e., there is no problem in sharpness. On this flat objects the corners look allright to me.
Is a leaf, because it's not totally flat, different?
Are my settings allright?
I didn't sharpen the next images.


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## mackguyver (Apr 29, 2014)

Your test shot looks okay to me, so here's another possibility. It looks to me like the lens was tilted at a slight angle to the leaf because the top left and bottom right corners look a tiny bit softer than the others. With this kind of magnification, even very slight angles affect depth of field and (even) f/13 in the macro world is about like f/2 when shooting portraits  Macro, unless focus stacking, is often about creative choices in terms of what's sharp vs. what's blurred.

Personally I don't find the "softness" to be concerning at all and would be happy with this shot had I taken it.


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## CarlTN (Apr 29, 2014)

Jack56 said:


> This morning I took this photo with the 100mm L.
> Iso 160 - f/13 - 0,5 sec.
> Distance about 30 centimetres.
> I used a tripod and cable release.
> ...



I would have tried closing aperture to f/16 to f/20. (Also, with this subject and lighting, ISO 50 would be useful.) The center might get very slightly softer, but the borders and corners get a bit sharper. Then apply some sharpening in post processing. Experiment with the radius of the sharpening...and also balance the application of it, with the "detail" slider. Many times you can have the detail slider above 50 (out of 100), while keeping the sharpening lower. Other times, not. To make full use of the detail slider, it's necessary to bring the luminance noise that gets captured, to an absolute minimum...hence my suggestion for using ISO 50. If you can't go below ISO 100, then use 100.


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## Jack56 (Apr 29, 2014)

Thank you all. I've learned something and will try to practice tomorrow again. Thanks again!!


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## wtlloyd (Apr 29, 2014)

What camera are you using? Depth of field with a 7D is only .3cm (1/10th of an inch) at your settings. Much more depth of field at greater distances, as you stated...


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## Jack56 (Apr 29, 2014)

Mark5dIII. Thanks.


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## Keem (Apr 29, 2014)

I agree with Mackguyver. In order to comment on corner softness or misalingment of a lens element you should be 100% sure about the following:

i) the subject should be flat (in your case the leaf does not seem to be flat)
ii) the sensor should be perfectly parallel to the flat subject

The other test pictures shows no significant variation among the corners; so if I were you I would not worry about the lens!

For the best results i think you should also consider diffraction limits (before going to a setting like f20):
http://www.luminous-landscape.com/tutorials/understanding-series/u-diffraction.shtml

If you go beyond f11 the image loose sharpness due to diffraction effects!

As a rule of thumb f8 (maybe f11) is the optimum setting you should use. If you use a smaller aperture you may increase the depth of field but the image sharpness will degrade. 

In macro photography, if you want to get your subject completely in focus you should try focus stacking:
http://en.wikipedia.org/wiki/Focus_stacking
(here you can find some software solutions to stack the images)

You may need a macro-focus rail (and patience!) to get good results;

Good luck and happy shooting (you have a nice lens)


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## Canon1 (Apr 30, 2014)

mackguyver said:


> Your test shot looks okay to me, so here's another possibility. It looks to me like the lens was tilted at a slight angle to the leaf because the top left and bottom right corners look a tiny bit softer than the others. With this kind of magnification, even very slight angles affect depth of field and (even) f/13 in the macro world is about like f/2 when shooting portraits  Macro, unless focus stacking, is often about creative choices in terms of what's sharp vs. what's blurred.
> 
> Personally I don't find the "softness" to be concerning at all and would be happy with this shot had I taken it.



This is what I was going to suggest.


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## neal1029 (Apr 30, 2014)

Perpendicular to the plane of focus.


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## CarlTN (Apr 30, 2014)

Keem said:


> In macro photography, if you want to get your subject completely in focus you should try focus stacking:



Focus stacking is both time consuming, and consumes more storage space, and more processing power. Using apertures smaller than f/11 can be perfectly acceptable, in practice...especially for shooting an object that is mostly flat, and parallel with the sensor. If the subject has more depth in the third dimension, that is when focus stacking really makes more sense, and can come into its own. The question really should be, at what point does the image justify the effort spent for focus stacking? Is it really required, or is it more an academic exercise?

For example, magazines such as "Nature Photographer", rarely even include landscape images that were shot at wider than f/14 aperture (whether that is always the right philosophy, might be up for debate...but the editor certainly voices their opinion in favor of it, and very often includes it in the text with the image). In those cases focus distance is not only not in the macro realm, but is usually more than 10 feet from the camera, and on a wider angle lens to boot. Yet at f/14, the lens is yielding noticeable softening at the pixel level, due to diffraction. But the 8.5 x 11 full page (or sometimes smaller) prints in the magazine, do not appear soft. And in most cases, there was no focus stacking.

As photographers, it's our judgment call, based on our experience and our willingness to commit time...as to which technique we use.


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## privatebydesign (Apr 30, 2014)

CarlTN said:


> For example, magazines such as "Nature Photographer", rarely even include landscape images that were shot at wider than f/14 aperture (whether that is always the right philosophy, might be up for debate...but the editor certainly voices their opinion in favor of it, and very often includes it in the text with the image). In those cases focus distance is not only not in the macro realm, but is usually more than 10 feet from the camera, and on a wider angle lens to boot. Yet at f/14, the lens is yielding noticeable softening at the pixel level, due to diffraction. But the 8.5 x 11 full page (or sometimes smaller) prints in the magazine, do not appear soft. And in most cases, there was no focus stacking.
> 
> As photographers, it's our judgment call, based on our experience and our willingness to commit time...as to which technique we use.



Clearly the editor doesn't know what they are talking about, had the same problem when they all insisted we had to have 360dpi for magazines. F14 on what format size?

A 135 format f14 gives the same diffraction as f8.75 on an APS-C and f96 on an 8"x10".


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## CarlTN (Apr 30, 2014)

privatebydesign said:


> CarlTN said:
> 
> 
> > For example, magazines such as "Nature Photographer", rarely even include landscape images that were shot at wider than f/14 aperture (whether that is always the right philosophy, might be up for debate...but the editor certainly voices their opinion in favor of it, and very often includes it in the text with the image). In those cases focus distance is not only not in the macro realm, but is usually more than 10 feet from the camera, and on a wider angle lens to boot. Yet at f/14, the lens is yielding noticeable softening at the pixel level, due to diffraction. But the 8.5 x 11 full page (or sometimes smaller) prints in the magazine, do not appear soft. And in most cases, there was no focus stacking.
> ...



I suggest you write the magazine a notarized letter of complaint. I'm sure the editor will realize they are wrong and you are right, and will issue a front page apology in the next issue, for the error in judgment over the years. This should fix the problem. If not perhaps organize a protest rally around their headquarters, that will teach them a lesson they will never forget! Those always work exactly as intended...and are never a waste of time.


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## privatebydesign (Apr 30, 2014)

CarlTN said:


> privatebydesign said:
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> > CarlTN said:
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Well am I wrong?


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## Menace (Apr 30, 2014)

mackguyver said:


> Your test shot looks okay to me, so here's another possibility. It looks to me like the lens was tilted at a slight angle to the leaf because the top left and bottom right corners look a tiny bit softer than the others. With this kind of magnification, even very slight angles affect depth of field and (even) f/13 in the macro world is about like f/2 when shooting portraits  Macro, unless focus stacking, is often about creative choices in terms of what's sharp vs. what's blurred.
> 
> Personally I don't find the "softness" to be concerning at all and would be happy with this shot had I taken it.



+1


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## CarlTN (Apr 30, 2014)

privatebydesign said:


> CarlTN said:
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> > privatebydesign said:
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About their philosophy? No, but my point was, it's their magazine. People with power tend to have things their way. Why don't you start a magazine? I wonder if that is even possible now. They all lose money. But I do prefer to look at one that is printed well, rather than a screen. Call me old fashioned, but there it is.


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## Keem (Apr 30, 2014)

CarlTN said:


> Keem said:
> 
> 
> > In macro photography, if you want to get your subject completely in focus you should try focus stacking:
> ...



The herewith discussed example is an example of macro-photography; and if you follow the link I have provided you can clearly see the effect of diffraction on sharpness. At closer focusing distances even if you go to a setting like f22 or f32 the DOF is on the order of milimeters. Therefore, if your subject is not perfectly flat (like a leaf having water droplets) and a setting like f13 does not help to have both center and corners sharp, taking a few more pictures (for this examplea stack of 5or8 pictures) and stacking them will not take that much space or need higher processing power. Of course if you go to extreme cases, stacking can be very time consuming.

Whether you should go to stacking or just use a smaller aperture, the decision will depend on the specific purpose of the photograher, and there may not be one true answer...

For landscapes I have not used stacking, using apertures like f16 (for APS-C) or f22(for full-frame), and setting the focusing distance to hyperfocal distance yields very good results; however the example we have discussed here was about a close-focus distance (macro) subject. In landscaped the subject can be meters/or even kilometer away from the sensor !

Happy shooting,


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## danski0224 (Apr 30, 2014)

Jack56 said:


> This morning I took this photo with the 100mm L.
> Iso 160 - f/13 - 0,5 sec.
> Distance about 30 centimetres.
> I used a tripod and cable release.
> ...



What did you focus on: the beads of water or the leaf?

I'd guess that your leaf is not perfectly flat.

The picture, as a picture, looks fine as it is.


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## Marsu42 (Apr 30, 2014)

Jack56 said:


> This morning I took this photo with the 100mm L.



Magic Lantern. Focus Stacking (= Tripod, no wind, stable lighting).


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## Badger (Apr 30, 2014)

You guys are so deep!

My rookie self looked at that picture and wondered if the leaf was perfectly flat, and what the focus was on, the leaf or the water. A few posts later, he posts a picture of a flat sheet of paper that didn't look so bad. 

You all are so smart, you crack me up. I did learn one thing here, what those charts that are assigned to lenses actually represent  Thanks.

Have a great day everybody!


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## Marsu42 (Apr 30, 2014)

Keem said:


> and stacking them will not take that much space or need higher processing power.



The general overhead of stacking cannot be discussed away, it doesn't depend on the number of shots (unless 100+) but the general workflow ... but it's well worth it and imho makes the difference between good macro shots and Joe Sixpack with a "macro" setting on the p&s.


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## dawgfanjeff (Apr 30, 2014)

Focus wise, I'd say the picture is fine; I think you have a really nice shot there, but if it really bothered me, I'd consider a few things:

1. Back up a tiny bit, take the shot again and crop to this size. The slight loss of resolution from cropping might be an acceptable tradeoff for uniform sharpness.

2. Embrace it. Add some vignetting or even soften the edges even more to make the center pop. Add contrast to taste. Example:


Autumn Leaves by dawgfanjeff, on Flickr
3. Crop the less sharp edges it if it will still accommodate the framing you're looking for.


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## privatebydesign (Apr 30, 2014)

CarlTN said:


> privatebydesign said:
> 
> 
> > Well am I wrong?
> ...



My point wasn't about their philosophy, or ownership, I just stated that your editors opinion is incomplete, it is like saying the answer is 42, well yes as we all know it is. But what is the question that arrives at the answer? 

Stating diffraction at f14 as a limit displays a fundamental lack of understanding of what diffraction is and how aperture interacts with it, without knowing the sensor size/crop/reproduction ratio, f14 is a meaningless number. If they said f14 on a 135 format camera we wpould know that for consistency we could submit f8 images from an APS-C and f96 images from an 8"x10".


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## wopbv4 (Apr 30, 2014)

As mentioned before, focus stacking or using a tilt shift lens will help

Check the website from helicon:

http://www.heliconsoft.com/heliconsoft-products/helicon-focus/

I use it a lot for my macro work and it works!

Not cheap though


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## CarlTN (May 1, 2014)

Keem said:


> CarlTN said:
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> > Keem said:
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I never said your subject was not about macro. But even with macro, it depends on the actual focus distance, and the focal length used...but most especially, whether the subject is flat or not. Again, for a flat leaf that is perpendicular to the sensor, I see no need for focus stacking.


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## CarlTN (May 1, 2014)

privatebydesign said:


> CarlTN said:
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> > privatebydesign said:
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Thankfully they are not _my_ editor...


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## Shoot123 (Jun 11, 2014)

Other than using a tripod, having no wind, small aperture, focusing on the same plane as the subject, etc. there IS another thing you can do -- use a camera with a smaller sensor. That's heresy in today's world, I know!!

Here's a couple examples of HANDHELD macro shots taken with a 2MP Nikon Coolpix (vintage 1999 Point and Shoot camera)


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## Marsu42 (Jun 11, 2014)

Shoot123 said:


> use a camera with a smaller sensor



You have to be wrong - on CR, the heavy guys have established that bigger sensors are always better. You just have to crop enough, and what are a few thousand $$$ for lenses and camera between friends 

Also note that time travel is impossible according to the Vulcan Science Directorate - though this didn't stop the Enterprise crew doing it :-> http://en.memory-alpha.org/wiki/Vulcan_Science_Directorate


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## mackguyver (Jun 11, 2014)

Marsu42 said:


> Shoot123 said:
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> > use a camera with a smaller sensor
> ...


LOL and this was the first thing that annoyed me going from compacts to a DSLR. In the film days, it was easier in some ways to get sharp photos so when I moved to digital compacts, landscape shots seemed easy and really sharp. Then I got a crop DSLR and eventually full frame and got really annoyed with DOF. In time I adjusted, but ultimately I bought the TS-E 17 & 24II and now I'm Scheimpflug(ing) my way to full DOF ;D


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## neuroanatomist (Jun 11, 2014)

mackguyver said:


> ...ultimately I bought the TS-E 17 & 24II and now I'm Scheimpflug(ing) my way to full DOF



I trust you realize you're not actually getting any _more_ DoF…you're just getting same amount of DoF somewhere you find it more useful.


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## chauncey (Jun 11, 2014)

IMHO, stacking is the greatest thing since sliced bread for those that wish to avoid any hint of distortion...why tighten that lens down when you can open that lens and stack the images. This was a 300mm at f/2.8, about 20 some image stack.


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## mackguyver (Jun 12, 2014)

neuroanatomist said:


> mackguyver said:
> 
> 
> > ...ultimately I bought the TS-E 17 & 24II and now I'm Scheimpflug(ing) my way to full DOF
> ...


You would have to rain on my parade - but yes, you're right. Love those TS-Es, though!


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