Does image sharpness come down to the lens or camera?

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blong10

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Assuming everything else is correct like Shutter, aperture, and low ISO. Does it matter more on the lenses or camera body? I'm also assuming Megapixels help with sharpness like 24MP compared to say 50 MP with a sharp lens as it can extract more detail.
 
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blong10 said:
Assuming everything else is correct like Shutter, aperture, and low ISO. Does it matter more on the lenses or camera body?
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All else being equal, it comes down to the lens.

But all else is rarely equal and technique is far more important than equipment.

[edit]...I'd also add that it's not really a simple question as things like presence or absence of an anti aliasing filter in a camera can impact sharpness as can higher vs lower sensor resolution and not always in obvious ways. For instance a very high resolution sensor can reveal slight problems in technique (e.g. subtle motion blur) or shortcomings in the resolving power of a lens more than lower resolution cameras but that doesn't really make the camera 'less sharp' as much as it can reveal other issues. Also things like sensor noise can indirectly impact sharpness if you're willing to shoot at a higher ISO with one camera and thus can use faster shutter speeds or can stop down for a bit more DoF relative to a camera that must be capped to a lower ISO for noise reasons.

All that said, generally lenses have more to do with sharpness than camera bodies but again technique and settings appropriate for the conditions matter a lot more than specific lens or camera choices assuming relatively good gear.
 
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IMHO, in descending order:

1) your technique
2) your chosen AF settings on your camera body
3) camera body AF algorithm accuracy & consistency
4) camera body AF speed (if moving subject)
5) lens focusing speed (if moving subject)
6) lens sharpness

Despite this order, any one of these items can still cause significant sharpness issues if they are exceptionally bad.

Megapixels help with resolution, not sharpness, assuming viewing conditions are equalized. For example, when comparing a 24MP vs 50MP image of the same scene, viewed fullscreen on the same display, or printed at the same size (assuming neither print falls below an acceptable DPI), you will see no difference.

So while a higher megapixel camera can print larger or be cropped further than a lower resolution camera can, there's nothing inherently sharper about those extra megapixels (again, assuming viewing conditions are equal when comparing images).
 
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This question is like asking "Which came first; the chicken or the chicken."

Either component can become the limiting factor in production of a sharp image.

W
 
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Still a good question.

A simple addition to the list is distance from the camera to the subject. It's impossible to detect much detail in a subject that's very small in the frame hence it won't look sharp. The significant cropping that would be needed wouldn't help either.
 
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gbodave said:
Still a good question.

A simple addition to the list is distance from the camera to the subject. It's impossible to detect much detail in a subject that's very small in the frame hence it won't look sharp. The significant cropping that would be needed wouldn't help either.
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Great point!
 
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Let's look at two identical cameras and put the same lens alternatively on both, mount both cameras on a stable tripod, set both to exactly the same settings for shutter speed, aperture, ISO and autofocus settings, and take two pictures with both cameras of exactly the same target under the same controlled conditions. The one way in which one image may be sharper than the other would be if one camera needs its autofocus fine tuned with that lens while the other camera may need less fine tuning. So there are factors that affect the sharpness of the image that can be controlled by the photographer: AF fine-tuning, ISO settings, shutter and aperture settings, and a stable shooting platform.

One thing that cannot be controlled by the photographer is the sharpness of the lens. Just like there is sample variation between camera bodies, there is also variation between lenses. I know of numerous photographers who returned lenses that they bought, two or perhaps even three times before they got one that they were satisfied with. Not all lenses, even if the same model, are created equal. Some are sharper, others less so.

So to answer your original question, unless there is something wrong with the body the lens is the most important part of the kit to ensure sharpness of a picture. When I started getting rid of my old kit lenses and replacing them with more serious pro glass it was like my camera had been rejuvenated as well. Suddenly my old Nikon D7000 was making images that could compare with the best in terms of sharpness. Prior to that I felt like a wannabe because my old lenses were just less sharp.
 
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Two biggest factors are the lens and the technique of the photographer. The higher the resolution of the camera the more apparent will be any shortcomings of the lens and any shortcomings in technique on the part of the photographer. When I first started shooting with the 36MP D800e I soon learned I needed to exercise more care to get sharp images than with my prior cameras.
 
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Sharpness is measured in line pairs / mm (lpm), i.e., the number of line pairs / mm your camera and lens can potentially resolve. The higher the sensor mp, the more line pairs / mm it is capable of resolving. Glass is not perfect so sharpness varies in any given lens, usually dropping off the further you get away from the center of the frame. Lens sharpness also varies by fstop. Most glass is "softer" wide open and performs best stopped down a bit. Most lens manufacturers will show the Modulus Transfer Function (MTF) of their products by distance from the center and by fstop in the specifications section. So the MTF of the camera with lens shows the potential sharpness you can get, but when photographers say sharpness, they really mean perceived sharpness or accutance.

Accutance has more factors than MTF. Some of the factors happen at the time the image is captured, others in PP, and some when viewing the final image. Things like light, heat distortion, haze, fog, camera shake, focus, exposure / noise happen up front. You can improve some things in PP like increase contrast, dehaze, sharpen edges and even stabilize and deblur (Topaz sharpen AI), reduce or increase noise (yes a bit of random noise in an image can make it look sharper), but you can only decrease, not increase detail in post. When viewing, things like viewing distance, lighting on a reflective print, brightness, color space, and gamma of a monitor, resolution of the printer or monitor are all factors.

Accutance is not as simple as many photographers make it out to be. Again, camera and lens give you the potental for accutance, but you have to look at the process end to end. If most monitors are only capable of displaying around 90ppi at about 6 or 7 bits per pixel, why do I need a higher resolution camera at 12 bits / color / pixel with expensive glass?
 
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DRwyoming said:
All else being equal, it comes down to the lens.

But all else is rarely equal and technique is far more important than equipment.

[edit]...I'd also add that it's not really a simple question as things like presence or absence of an anti aliasing filter in a camera can impact sharpness as can higher vs lower sensor resolution and not always in obvious ways. For instance a very high resolution sensor can reveal slight problems in technique (e.g. subtle motion blur) or shortcomings in the resolving power of a lens more than lower resolution cameras but that doesn't really make the camera 'less sharp' as much as it can reveal other issues. Also things like sensor noise can indirectly impact sharpness if you're willing to shoot at a higher ISO with one camera and thus can use faster shutter speeds or can stop down for a bit more DoF relative to a camera that must be capped to a lower ISO for noise reasons.

All that said, generally lenses have more to do with sharpness than camera bodies but again technique and settings appropriate for the conditions matter a lot more than specific lens or camera choices assuming relatively good gear.
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You mention motion blur can be more apparent (more of a noticeable problem) in higher resolution cameras. Can you elaborate on that? I'm interested since I use a Z7 (as you may know from prior posts). Thanks!
 
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pfinfante said:
You mention motion blur can be more apparent (more of a noticeable problem) in higher resolution cameras. Can you elaborate on that? I'm interested since I use a Z7 (as you may know from prior posts). Thanks!
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I can elaborate verbally, but Steve discusses this with a good example in his D850 review video here:

The discussion of how higher resolution can reveal issues like motion blur is at roughly the 18 minute point in the video.
 
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