Depth of Field & Sensor Sizes

LensReflex

Member
Messages
36
Reaction score
5
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?

It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
 
Yes, it's true. An APS sensor has about a stop more depth of field than a full frame sensor. So the DOF at f/8 on an APS sensor is about the same as f/11 on a full frame sensor, all else being equal. That's according to the standard model of DOF. There are others but

But there are advantages to the full frame sensor for landscapes. As you go up in sensor size you usually get more dynamic range and less noise.

Another factor to consider is just how far you want to stop down. At some point diffraction effects can limit resolution.
 
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?
No, that’s not true, as you can usually stop lenses down to the point where depth of field is huge. Most of my full frame lenses can be stopped down to f/22, which gives me greater DoF than what I can get on my smartphone, which has an equivalent f/stop of f/11.
It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
As mentioned, depth of field isn’t an issue. However. In dim lighting, stopping down a lot either requires heightened ISO or the use of a tripod with a longer shutter time. Larger sensors typically are able to use higher ISOs than smaller, and the effects cancel each other, leading to equivalent photos. But if you do use a tripod, then the larger sensor typically wins.

Depth of field only has three factors: the lens diameter, the distance to the subject, and a subjective factor for how tolerant your eyes are to blur. Sensor size isn’t a part of it, though of course it can be included in the formula at the expense of greater complexity:

 
It is true.

In terms of DoF, crop factor has to be taken into account.

The basic is simple but usually might confuse some people.

E.g. a 2x crop factor M43 system (the diagonal of Fourth Third sensor is roughly 2X smaller than a Full Frame sensor), has Field of View roughly twice of a FF system. i .e., 50mm focal length FF lens will give a FoV equivalent to 100mm on M43 camera.

The DoF of such lens does not change on either a FF body or M43 body.

But when people wish to shoot for same FoV, usually a 25mm lenses would be used on M43 (to match the FoV of 50mm lens on FF). The DoF of M43 under such FoV would be deeper than a FF system.

The above is under the assumption on using same f/stop.

But other factors e.g. resolution, DR etc might also have to be considered. Therefore there is no winner on this.

--
Albert
** Please forgive my typo error.
** Please feel free to download my image and edit it as you like :-) **
About my
G85: https://www.dpreview.com/forums/post/63025800
GX850/GF9: https://www.dpreview.com/forums/post/65326127
GX9: https://www.dpreview.com/forums/post/67648667
 
Last edited:
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?

It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
Smaller sensors do not inherently have a depth of field advantage (or disadvantage). The size of the sensor is only one of the factors that come into play when determining the depth of field of an image. The effect of the sensor size on depth of field depends on what you change or hold constant among the other settings.

For instance, if you use a smaller sensor but keep the focal length, subject distance and f-number the same as used with the larger sensor, the image with the smaller sensor will have less depth of field.

On the other hand, if you want to keep the field of view constant between the larger and smaller sensors, you will use a lens with a shorter focal length with the smaller sensor. If you keep the f-number and subject distance the same, then the shorter focal length will indeed deliver greater depth of field. But if you adjust the f-number by the same ratio you adjusted the focal length (that is, the crop factors between the two sensors), then the depth of field will be the same between the two sensor sizes.

So claims about the effect of sensor size on depth of field are, at best, oversimplifications. You need to account for and be clear about what changes, if any, are being made to the other factors. You can have a lot of fun trying this out with apps such as DOFMaster. Using that you can decide which variables to change (or hold constant) and see the effect on depth of field instantly.

Dave

--
http://www.pbase.com/dsjtecserv
 
Last edited:
It is true.

In terms of DoF, crop factor has to be taken into account.

The basic is simple but usually might confuse some people.

E.g. a 2x crop factor M43 system (the diagonal of Fourth Third sensor is roughly 2X smaller than a Full Frame sensor), has Field of View roughly twice of a FF system. i .e., 50mm focal length FF lens will give a FoV equivalent to 100mm on M43 camera.

The DoF of such lens does not change on either a FF body or M43 body.
Actually if a 100 mm lens is used on both a full frame and M43 system (and everything else is held constant), the M43 image will have less depth of field. The CoC factor, which represents the degree of enlargement needed to produce a standard print from a given sensor size, would be different in the two cases.
But when people wish to shoot for same FoV, usually a 25mm lenses would be used on M43 (to match the FoV of 50mm lens on FF). The DoF of M43 under such FoV would be deeper than a FF system.
This is correct, because the effect of focal length is greater the the effect of the CoC.
The above is under the assumption on using same f/stop.

But other factors e.g. resolution, DR etc might also have to be considered. Therefore there is no winner on this.
Well, resolution is not a factor in depth of field, but you are correct the a generalization about the effect of sensor size can't be made without accounting for the other factors that affect DoF.

Dave

--
http://www.pbase.com/dsjtecserv
 
Last edited:
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?
No, that’s not true, as you can usually stop lenses down to the point where depth of field is huge. Most of my full frame lenses can be stopped down to f/22, which gives me greater DoF than what I can get on my smartphone, which has an equivalent f/stop of f/11.
It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
As mentioned, depth of field isn’t an issue. However. In dim lighting, stopping down a lot either requires heightened ISO or the use of a tripod with a longer shutter time. Larger sensors typically are able to use higher ISOs than smaller, and the effects cancel each other, leading to equivalent photos. But if you do use a tripod, then the larger sensor typically wins.

Depth of field only has three factors: the lens diameter, the distance to the subject, and a subjective factor for how tolerant your eyes are to blur. Sensor size isn’t a part of it, though of course it can be included in the formula at the expense of greater complexity:

https://en.wikipedia.org/wiki/Depth_of_field
Well that "subjective factor" includes and must account for sensor size, since that directly affects the size of the blur that will be rendered in the final print, as a function of the degree of enlargement from the sensor size to the print size. And while it is "subjective" in the sense that it represents the perception of the viewer, it is not arbitrary, and is based on measurable limits of human vision.

Dave

--
http://www.pbase.com/dsjtecserv
 
Last edited:
It is true.

In terms of DoF, crop factor has to be taken into account.

The basic is simple but usually might confuse some people.

E.g. a 2x crop factor M43 system (the diagonal of Fourth Third sensor is roughly 2X smaller than a Full Frame sensor), has Field of View roughly twice of a FF system. i .e., 50mm focal length FF lens will give a FoV equivalent to 100mm on M43 camera.

The DoF of such lens does not change on either a FF body or M43 body.
Actually if a 100 mm lens is used on both a full frame and M43 system (and everything else is held constant), the M43 image will have less depth of field.
Can't say that since if simply on sensor size, as a generalization, 100mm lens on M43 has twice deeper DoF than a 100mm lens on FF.


e.g. Nikon D800 (FF) vs Olympus EPM1 (M43), 100mm lens, f/2.8 at a shooting distance of 10", the DoF would be:

FF = 0.24"in front of the focus point / 0.26" behind the focus point; whereas

M43 = 0.12"/ 0.13".


The CoC factor, which represents the degree of enlargement needed to produce a standard print form a given sensor size would be different in the two cases.
I am afraid it would be difficult if not impossible to know the exact CoC of a particular sensor... :-(
But when people wish to shoot for same FoV, usually a 25mm lenses would be used on M43 (to match the FoV of 50mm lens on FF). The DoF of M43 under such FoV would be deeper than a FF system.
This is correct, because the effect of focal length is greater the the effect of the CoC.
The above is under the assumption on using same f/stop.

But other factors e.g. resolution, DR etc might also have to be considered. Therefore there is no winner on this.
Well, resolution is not a factor in depth of field, but you are correct the a generalization about the effect of sensor size can be made without accounting for the other factors that affect DoF.

Dave
Resolution or DR etc do not relate to DoF. What I want to say is besides DoF, these are also other factors that would have to consider for landscape shooting :-) . Hence I said the4re is no absolute winner in this matter.
 
It is true.

In terms of DoF, crop factor has to be taken into account.

The basic is simple but usually might confuse some people.

E.g. a 2x crop factor M43 system (the diagonal of Fourth Third sensor is roughly 2X smaller than a Full Frame sensor), has Field of View roughly twice of a FF system. i .e., 50mm focal length FF lens will give a FoV equivalent to 100mm on M43 camera.

The DoF of such lens does not change on either a FF body or M43 body.
Actually if a 100 mm lens is used on both a full frame and M43 system (and everything else is held constant), the M43 image will have less depth of field.
Can't say that since if simply on sensor size, as a generalization, 100mm lens on M43 has twice deeper DoF than a 100mm lens on FF.

https://www.dofmaster.com/dofjs.html

e.g. Nikon D800 (FF) vs Olympus EPM1 (M43), 100mm lens, f/2.8 at a shooting distance of 10", the DoF would be:

FF = 0.24"in front of the focus point / 0.26" behind the focus point; whereas

M43 = 0.12"/ 0.13".
Yes, the Nikon has a total depth of field of 0.5, while the Olympus is 0.25. Twice as much, in favor of the larger sensor.

Here is the result for f/8, to produce easier to use numbers:

Nikon:

ffc23a9cfad941cda1676f0f2b92b60c.jpg

Olympus:

5149e939f2a84bbf9fbd2266c589ecd7.jpg

Notice the Total depth of field for each.
The CoC factor, which represents the degree of enlargement needed to produce a standard print form a given sensor size would be different in the two cases.
I am afraid it would be difficult if not impossible to know the exact CoC of a particular sensor... :-(
Not difficult all since it is a direct function of the dimension of the sensors. There are different approaches to determining what the CoC is, but when the same method is applied to all sensor sizes, the relative result is the same.

Dave

--
http://www.pbase.com/dsjtecserv
 
Last edited:
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?

It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
That is not a simple question to answer as there are a number of factors involved.

The depth of field increases as the aperture decreases, i.e. as the f-number increases. The f-numbers are usually marked:

1.0, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64

In theory, f/64 would give about 64 times as much depth of field as f/1 on a particular sensor.

However, there is a big fly in the ointment: diffraction. Diffraction causes the image to become more blurred at larger f-numbers (smaller apertures).

To make matters even more complicated, the blurring effects of diffraction are more noticeable on smaller sensors. So, a compact camera with a crop factor of, say, 4 will suffer the same amount of diffraction blurring at f/4 as a full frame camera suffers at f/16.

The effect of diffraction is to stop you using the much greater depth of field that is theoretically possible with small sensor cameras (because the result is more blurred on the smaller sensor camera than on the larger sensor camera).
 
Some examples of how diffraction blurs the image when you increase the f-number:

These images are small crops from a much larger image, but they illustrate the effect. The subject is black text on a white background.

f/16
f/16



f/8
f/8



f/4
f/4

The colours that appear in some of these images are moire artefacts caused by the Bayer pattern sensor.
 
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?
Smaller sensor have broader depth of field, but you can easily set eg. f16 on fullframe and set your focus point properly. So for me, it's not true. Better dynamic range and usually high quality lenses help FF to be better for landscapes.
It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
Yes, you need to be more carefull with your setting on FF camera.
 
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?

It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
The point being made in the video -- that smaller sensor cameras are better suited to landscape photography due to more depth of field -- is not true. You can get the same depth of field with a larger sensor by simply stopping down the aperture.
 
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?

It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
The point being made in the video -- that smaller sensor cameras are better suited to landscape photography due to more depth of field -- is not true. You can get the same depth of field with a larger sensor by simply stopping down
(sorry, couldn’t remove post)
 
Last edited:
I was watching a video course on the foundations of Photography, and course material says that a smaller sensor camera is better suited to landscapes because it has a broader depth of field vs. a larger (i.e. Full Frame) sensor. Is this true?

It seems to me that full frame cameras are used quite a lot in landscape photography as well. Does it become difficult to get a broader depth of field (that is, no blurriness in the photo) with a full frame camera under certain conditions, or does this assertion have no basis in reality?
The question is whether smaller sensors have broader depth of field than larger sensors, and the answer is that sensors do not have depth of field.



But I think that what you’re really trying to understand is this: If I stand at the rim of the Grand Canyon with a full frame and a crop sensor camera, both on tripods, which camera will deliver a photo with greater depth of field? (This assumes you are using equivalent focal length lenses on each camera, making field of view the same).

But maybe what you want to know is this: Which camera will deliver a superior result for, say, a 36”x24” print? Or which camera will deliver an adequate result? Or is the full frame camera with the added weight and expense?



So the answer to which camera delivers greater depth of field is, both can deliver equal depth of field. But depth of field is all about “acceptable blur”, right? So digging deeper, the overall better image comes from the camera with the largest sensor, the best lens, and perhaps the best sensor quality. Because, when you’re looking at the tiny flower in the foreground, the higher res sensor is going to deliver a sharper flower.



Landscape photography has different requirements from genres such as sports or portraiture. And part of the requirement is what your output requirements are. If you want to create massive murals, perhaps a medium format Fuji or Hassleblad is absolutely the best, but these can be very costly. You may want the absolutely highest, cleanest full frame sensor, like a 45 or 60 megapixel, and premium prime lenses. But this is costly, and you have to weight the cost against your requirements. Above all, understand that, just because a full frame system is better, it doesn’t mean that a crop sensor camera is a poor choice.
 
If you stand in the same spot, use the same f stop, shutter speed and iso and use the appropriate lens to frame the same desired area, you will be using a lens with 1.5 times the focal length with the FF camera which will always result in a shallower. depth of field. Look up any dof calculator and compare a 100mm lens at f5.6, at 100 feet and compare that with a 150mm lens at f5.6, at 100 feet and you will see the difference. And feel free to pick any f stop or focal length when you compare. Or if you want to go to the effort, go out and. photograph something with your FF with a 150mm lens at. any specific aperture, and then take the same photograph from the same distance with a 100mm lens from the same distance with the same f stop on a dx sensor and compare the results. That's how smart phones get almost infinite dof with a f1.8 lens as they require a much shorter focal length to achieve the same field of view due to their small sensor sizes.
 
But to produce an image with the same field of view, the M43 will use a 50mm lens resulting in greater dof at the same f stop.
 
If you stand in the same spot, use the same f stop, shutter speed and iso and use the appropriate lens to frame the same desired area, you will be using a lens with 1.5 times the focal length with the FF camera which will always result in a shallower. depth of field. Look up any dof calculator and compare a 100mm lens at f5.6, at 100 feet and compare that with a 150mm lens at f5.6, at 100 feet and you will see the difference. And feel free to pick any f stop or focal length when you compare. Or if you want to go to the effort, go out and. photograph something with your FF with a 150mm lens at. any specific aperture, and then take the same photograph from the same distance with a 100mm lens from the same distance with the same f stop on a dx sensor and compare the results. That's how smart phones get almost infinite dof with a f1.8 lens as they require a much shorter focal length to achieve the same field of view due to their small sensor sizes.
True, but only because you’ve added an unnecessary and unrealistic constraint, which is making the aperture the same.

If we do the math, it shows that we can reduce aperture on the FF camera and correspondingly increase the ISO… and we would obtain equivalent quality. But in reality, that is not what we would do. We would just close the aperture to what we want and use all the shutter speed in the world, because landscapes don’t move. Either use a tripod or rely on IBIS and you can have a long enough shutter speed.

There is not a case where the crop sensor camera delivers more depth of field with the same quality as the full frame, unless it’s an old full frame at high ISO. This doesn’t mean the full frame is perfect for everyone or that the added quality of full frame is necessary for everyone, but it does mean that the crop sensor camera is not superior to the full frame.
 
Last edited:
But to produce an image with the same field of view, the M43 will use a 50mm lens resulting in greater dof at the same f stop.
As I explained below, you’re manipulating the comparison by holding aperture constant.
 
Last edited:

Keyboard shortcuts

Back
Top