Help with focusing/sharpness

Howdy,

I'm not a total newbie, but still have a lot to learn. I know I have too much camera/lens for my purposes, but bear with me. I'm trying to understand why it's so difficult to take a sharp portrait (and landscape) picture where I don't want the background to be blurred. I thought that the way to accomplish this would be to max out the focal length of my zoom lens, but I'm finding that even at the max focal length, I can't get both the near object and far away scenery to be nice and sharp. Whereas my iPhone seems to do that all the time by default. Is it a limitation of the lens I am using, or am I doing something wrong?

For the 2 photos attached, I'm using a Canon 5DmkIV with a 24-70mm 2.8L II USM lens. The one with the woman in profile is zoomed out at 30mm, 1/60sec, f/22. The other with just the landscape is at 24mm, 1/30sec, f/22. As you can see, the near elements (the woman, the railing) is relatively sharp, but the Golden Gate bridge and SF cityscape is fairly unfocused. I'd like to be able to take a photo where everything on the photo is nice and sharp. Any hints would be appreciated. Thanks in advance.

henrus said:

Howdy,

I'm not a total newbie, but still have a lot to learn. I know I have too much camera/lens for my purposes, but bear with me. I'm trying to understand why it's so difficult to take a sharp portrait (and landscape) picture where I don't want the background to be blurred. I thought that the way to accomplish this would be to max out the focal length of my zoom lens, but I'm finding that even at the max focal length, I can't get both the near object and far away scenery to be nice and sharp. Whereas my iPhone seems to do that all the time by default. Is it a limitation of the lens I am using, or am I doing something wrong?

For the 2 photos attached, I'm using a Canon 5DmkIV with a 24-70mm 2.8L II USM lens. The one with the woman in profile is zoomed out at 30mm, 1/60sec, f/22. The other with just the landscape is at 24mm, 1/30sec, f/22. As you can see, the near elements (the woman, the railing) is relatively sharp, but the Golden Gate bridge and SF cityscape is fairly unfocused. I'd like to be able to take a photo where everything on the photo is nice and sharp. Any hints would be appreciated. Thanks in advance.

Click to expand...

Hi Henrus,

You chose a good aperture and have a wide angle on your lens, and even if the autofocus selected the person as the subject, there should be sufficient depth-of-field to cover all the way to infinity. Two possible explanations of softer-than-desired focus come to mind; first that there is atmospheric haze over the bay and bridge, and second that f/22 on a zoom lens might introduce aberrations to the sharpness.

Are you sure that the lens was switched to autofocus, not manual? I ask because in the second image, without a close subject, the focus appears to be on the railing. Ideally you want the focus to be further out, on the first lit cliff, for example. In that way, you maximise the depth-of-field. Look up Hyperfocal Distance if you are unfamiliar with it - it is a way of getting the most out of DoF at any aperture and with most focal lengths.

henrus said:

I'm not a total newbie, but still have a lot to learn. I know I have too much camera/lens for my purposes, but bear with me. I'm trying to understand why it's so difficult to take a sharp portrait (and landscape) picture where I don't want the background to be blurred. I thought that the way to accomplish this would be to max out the focal length of my zoom lens,

Click to expand...

Depth of field (DOF) is deeper at short focal lengths not long one. But that's not really your problem.

henrus said:

but I'm finding that even at the max focal length, I can't get both the near object and far away scenery to be nice and sharp. Whereas my iPhone seems to do that all the time by default. Is it a limitation of the lens I am using, or am I doing something wrong?

Click to expand...

Your phone as a very short focal length so its DOF is huge; also, the smaller yo view a picture the sharper I looks.

henrus said:

For the 2 photos attached, I'm using a Canon 5DmkIV with a 24-70mm 2.8L II USM lens. The one with the woman in profile is zoomed out at 30mm, 1/60sec, f/22.

Click to expand...

Here's a screenshot of your lens tested a Photozone http://www.opticallimits.com/canon_eos_ff/773-canon2470f28mk2ff?start=1. Notice how the resolution falls away form f/5.6 to f/8 to f/11. This is caused by a phenomenon called diffraction; it affects all light passing through an opening and gets more severe as the opening gets smaller. By f/22 the effect is severe.



If you use a DOF calculator such as DOFMaster http://www.dofmaster.com/dofjs.html it shows DOF increasing as you stop down but these calculators ignore diffraction.

henrus said:

The other with just the landscape is at 24mm, 1/30sec, f/22. As you can see, the near elements (the woman, the railing) is relatively sharp, but the Golden Gate bridge and SF cityscape is fairly unfocused. I'd like to be able to take a photo where everything on the photo is nice and sharp. Any hints would be appreciated. Thanks in advance.

Click to expand...

Try using about f/8 where your lens is generally much sharper than t f/22 and focus (manually if necessary) juts beyond the near subject.

henrus said:

Click to expand...

--
---
Gerry
___________________________________________
First camera 1953, first Pentax 1985, first DSLR 2006
[email protected]

Lenshoodie said:

Hi Henrus,

You chose a good aperture and have a wide angle on your lens, and even if the autofocus selected the person as the subject, there should be sufficient depth-of-field to cover all the way to infinity. Two possible explanations of softer-than-desired focus come to mind; first that there is atmospheric haze over the bay and bridge, and second that f/22 on a zoom lens might introduce aberrations to the sharpness.

Are you sure that the lens was switched to autofocus, not manual? I ask because in the second image, without a close subject, the focus appears to be on the railing. Ideally you want the focus to be further out, on the first lit cliff, for example. In that way, you maximise the depth-of-field. Look up Hyperfocal Distance if you are unfamiliar with it - it is a way of getting the most out of DoF at any aperture and with most focal lengths.

Click to expand...

Thanks for the helpful response, Lenshoodie. I'm fairly certain it was on autofocus at the time. In looking at some other photos of the day, there was some haze that day for sure, so that may be a big part of it. I'll check out Hyperfocal Distance. Thanks again!

You have a good start, but this is a challenging type of photograph, especially for larger formats.

Larger sensors will give a shallower dof than small ones. This is why the focus looks different than the tiny sensor on your phone. This can be an advantage for portraits or separating subjects from their background, but a challenge in your situation. Ansel Adam's group f/64 was called this because they used larger format film and had to stop down to extreme apertures to get everything in focus. Wide angle lenses will put more in focus and small apertures will do the same at the cost of diffraction softening. This means that you will have more kind of sharp, but you will have a slightly softer image across the frame.

One thing that will help you out here would be using hyperfocal technique. Basically, instead of focusing on the foreground or background, you focus somewhere in between, often at the hyperfocal point. What this does is hopefully put both objects in reasonably sharp, if not perfect focus. Depending upon your focal length and aperture, you will have a focus area of a certain depth. The edges of this aren't defined by a hard line, just what is "acceptablly sharp". Knowing the depth of this zone, you can try to place both objects within it to be in "acceptably sharp" focus. If this doesn't make any sense, google hyperfocal distance or technique for a better explanation.

If you are using a tripod, you can also try focus stacking, a technique where you capture the same scene at different focus points and digitally merge the resulting images together later.

Hope this helps, good luck!

Gerry Winterbourne said:

henrus said:

I'm not a total newbie, but still have a lot to learn. I know I have too much camera/lens for my purposes, but bear with me. I'm trying to understand why it's so difficult to take a sharp portrait (and landscape) picture where I don't want the background to be blurred. I thought that the way to accomplish this would be to max out the focal length of my zoom lens,

Click to expand...

Depth of field (DOF) is deeper at short focal lengths not long one. But that's not really your problem.

Click to expand...

Thanks for the correction. I keep getting my terminology wrong. I should have said "maxing out the f/stop" (to f/22) or, probably more accurately, minimizing aperture. But your points later are even more informative.

Gerry Winterbourne said:

Your phone as a very short focal length so its DOF is huge; also, the smaller yo view a picture the sharper I looks.

Click to expand...

Ok, I finally get this now.

Gerry Winterbourne said:

Here's a screenshot of your lens tested a Photozone http://www.opticallimits.com/canon_eos_ff/773-canon2470f28mk2ff?start=1. Notice how the resolution falls away form f/5.6 to f/8 to f/11. This is caused by a phenomenon called diffraction; it affects all light passing through an opening and gets more severe as the opening gets smaller. By f/22 the effect is severe.

Click to expand...

Thanks for this!

Gerry Winterbourne said:

If you use a DOF calculator such as DOFMaster http://www.dofmaster.com/dofjs.html it shows DOF increasing as you stop down but these calculators ignore diffraction.

Click to expand...

Got it.

Gerry Winterbourne said:

Try using about f/8 where your lens is generally much sharper than t f/22 and focus (manually if necessary) juts beyond the near subject.

Click to expand...

Ok, I'll try this next time around. Thanks a bunch, Gerry!

Wonderful tips. Thanks, tamaraw35!

Larger aperture like f/22 would work if you're close to the subject. Don't worry about diffraction because sharpness is not really a factor when you can edit in clarity.

In your case of lady in front and horizon in back, shooting a wide shot on the horizon leaves one thin line of detail and 80% dead space. This causes out of balance composition. Thus, the location was not ideal for a good composition with lady and bridge. If you wanted to get the lady in the photo with the bridge, the best locations would be near the entrance so you can compress the shot and give it depth using the bridge as a perspective tool. On this shot the tiny bridge/horizon splits the shot in two leaving 50% empty sky, and the foreground with little to create dynamics.

Thus, for the Lady shot, you could have just filled the frame with the head shot, and blurred out the background for a better composition.


For the horizon shot a telephoto compressing the scene and taking out the sky in the composition would create more depth, or at least make the bridge larger so that there is a object of interest in the scene. Cropping out dead space can help you gain better composition.

The noise reduction is so heavy there that some portions of the photo look like an impressionist painting (the area behind the model's neck, for one.) Figure out how to turn off that noise reduction, bring a flash, and focus stack below f/11.

Something extra happened to the photo with the lady. Looks like heavy duty noise reduction, maybe skin smoothing was applied to entire photo. The focus is fine.

Edit: Yep, that's it. Digging deep into EXIF shows the follow tags only in the smoothed photo:

• Luminous Noise Reduction Detail = 50
• Luminous Smoothing = 99

Sounds like a Lightroom or ACR setting


No lady in this shot. 100% crop of the stony hillside looks just dandy. Handrail looks fine too.


That stony hillside is not out of focus, the handrail is not out of focus. All details have been smeared or smoothed. An extra processing step has been applied to this photograph.

--
Lance H

henrus said:

Lenshoodie said:

Hi Henrus,

You chose a good aperture and have a wide angle on your lens, and even if the autofocus selected the person as the subject, there should be sufficient depth-of-field to cover all the way to infinity. Two possible explanations of softer-than-desired focus come to mind; first that there is atmospheric haze over the bay and bridge, and second that f/22 on a zoom lens might introduce aberrations to the sharpness.

Are you sure that the lens was switched to autofocus, not manual? I ask because in the second image, without a close subject, the focus appears to be on the railing. Ideally you want the focus to be further out, on the first lit cliff, for example. In that way, you maximise the depth-of-field. Look up Hyperfocal Distance if you are unfamiliar with it - it is a way of getting the most out of DoF at any aperture and with most focal lengths.

Click to expand...

Thanks for the helpful response, Lenshoodie. I'm fairly certain it was on autofocus at the time.

Click to expand...

What part of the image that the camera indicated it was autofocused on?

henrus said:

In looking at some other photos of the day, there was some haze that day for sure, so that may be a big part of it. I'll check out Hyperfocal Distance. Thanks again!

Click to expand...

I originally replied to this thread on my phone. When viewing your pictures on my desktop, I agree with SoCalWill and lehill. Focus looks fine, but there is some very heavy noise reduction going on that is destroying detail, especially visible on your model's face and white sweatshirt. See how everything looks waxy and smooth? This smoothing and over-aggressive noise reduction is the loss of detail that you are seeing, not a focus issue. Diffraction is also hurting detail, but not nearly as much as the noise reduction/sharpening. The buildings in the first pic also look to be a bit overexposed, but nothing a little highlight recovery couldn't fix. Take noise reduction way down and you will see a drastic improvement in detail. Sharpness/detail in landscape may also be affected by atmospheric haze or just UV light over distance. A high quality UV filter or polarizer may help reduce visibility of haze or smog if this is an issue, but we can't see this until you fix the noise reduction first. Also, white balance is too warm in the first pic and too cool in the second, btw.

Here's a example of a picture that I took a while back with objects very close to the camera and very far away all with a reasonable amount of detail. Obviously, you don't look at these images 100% and my example could have been executed a lot better, but it's what I had on-hand to show what can be done. My shot was taken handheld while it was snowing at f/22 on aps-c (well past the diffraction limit), so sharpness isn't the greatest, but most everything is in decent focus.



Take noise reduction and sharpening down a bit and you will see a big improvement in detail. Learn hyperfocal technique while using the largest aperture (smaller numbers) you can get away with, and you will see an improvement in sharpness. Good luck and have fun!

henrus said:

[...] I can't get both the near object and far away scenery to be nice and sharp. Whereas my iPhone seems to do that all the time by default. Is it a limitation of the lens I am using, or am I doing something wrong?

Click to expand...

As others have already explained, noise reduction seems to be destroying distant detail in one of the shots posted and atmospheric conditions are visible in the other.

I'm another big fan of using hyperfocal distance for landscape scenes - if you learn a few basic numbers and apply these, it will work every time. For example, for your 5D, at 24mm, you have infinite DOF if you focus about 10 feet away (i.e. from 5' to infinity), even using f8 - you really do not need tiny apertures to get that amount of a scene in focus. My go to aperture for landscapes is f11 where light is good enough, open a smidge if not. You took those shots at 1/60 and 1/30 - which with landscapes can be too slow as trees, flags, flowers etc. can move about in a breeze; opening the aperture and improving the shutter speed will freeze action within the scene better, so you get an additional benefit.

But a little tip to help you test this - it's something I do when setting focus especially for multi-frame panoramas, where I set everything manually and take all frames with the same exposure and focus.

Focus on the scene where you think will give you that infinite DOF using autofocus and then switch to manual focus. Scan over the scene at the horizon or further distances and just touch the shutter button gently as if pre-focusing and the focus point will flash red if that spot under it would be in focus. This allows you to test the DOF before taking a shot.

henrus said:

Gerry Winterbourne said:

henrus said:

I'm not a total newbie, but still have a lot to learn. I know I have too much camera/lens for my purposes, but bear with me. I'm trying to understand why it's so difficult to take a sharp portrait (and landscape) picture where I don't want the background to be blurred. I thought that the way to accomplish this would be to max out the focal length of my zoom lens,

Click to expand...

Depth of field (DOF) is deeper at short focal lengths not long one. But that's not really your problem.

Click to expand...

Thanks for the correction. I keep getting my terminology wrong. I should have said "maxing out the f/stop" (to f/22) or, probably more accurately, minimizing aperture. But your points later are even more informative.

henrus said:

Your phone as a very short focal length so its DOF is huge; also, the smaller yo view a picture the sharper I looks.

Click to expand...

Ok, I finally get this now.

henrus said:

Here's a screenshot of your lens tested a Photozone http://www.opticallimits.com/canon_eos_ff/773-canon2470f28mk2ff?start=1. Notice how the resolution falls away form f/5.6 to f/8 to f/11. This is caused by a phenomenon called diffraction; it affects all light passing through an opening and gets more severe as the opening gets smaller. By f/22 the effect is severe.

Click to expand...

Thanks for this!

henrus said:

If you use a DOF calculator such as DOFMaster http://www.dofmaster.com/dofjs.html it shows DOF increasing as you stop down but these calculators ignore diffraction.

Click to expand...

Got it.

henrus said:

Try using about f/8 where your lens is generally much sharper than t f/22 and focus (manually if necessary) juts beyond the near subject.

Click to expand...

Ok, I'll try this next time around. Thanks a bunch, Gerry!

Click to expand...

I should have added that while theory cam help so far, you can't beat trying things out for yourself. My suggestion of f/8 is based on theory plus my experience with my cameras. But you might find something between f/8 and f/22 works best; or even as wide as f/5.6. Put your camera on a tripod and run through the various apertures.

Also, DOF depends on exactly where you focus. Find the best f-stop as above using autofocus on your near subject; then try focusing manually a little further away (look at where AF gets you on the focus ring then switch to manual and move it round a bit).

____________________________________________________________________________________________

Other people have mentioned noise reduction, which I didn't notice. That doesn't mean that what I said is wrong - every factor adds its own influence.

As someone else says, using a wider aperture allows a faster shutter speed. That's nothing at all to do with diffraction but opening up carries both benefits - faster shutter and less diffraction.