Depth of field, the range of distance within a photograph that appears acceptably sharp, is a fundamental aspect of photography. It influences the way viewers perceive images, directing their attention and creating a sense of depth and dimension. Understanding how sensor size impacts depth of field is crucial for photographers, allowing them to make informed decisions about the equipment they use and achieve their desired creative vision.
Coming to you from Jay P Morgan with The Slanted Lens, this insightful video delves into the relationship between sensor size and depth of field. Morgan conducts a practical test, comparing four different camera formats: Micro Four Thirds, APS-C, Full Frame, and Medium Format. By analyzing the results, he demonstrates how each format renders depth of field at various apertures, highlighting the distinct characteristics and advantages of each system.
The video emphasizes the importance of considering depth of field when selecting a camera system. For instance, Micro Four Thirds cameras, known for their compact size and portability, offer greater depth of field compared to larger formats. This can be advantageous for landscape or street photography, where keeping both foreground and background elements in focus is often desired. Conversely, full frame and medium format cameras excel at creating shallow depth of field, producing the sought-after "bokeh" effect with beautifully blurred backgrounds, ideal for portraiture or isolating subjects.
Morgan's experiment provides valuable insights into the practical implications of sensor size on depth of field. He demonstrates how the distance between the camera and the subject, along with the chosen aperture, interact with sensor size to influence the final image. This knowledge empowers photographers to make informed decisions about their equipment and settings, ensuring they achieve the desired level of sharpness and background blur in their photographs.
Beyond the technical aspects, the video underscores the artistic value of understanding depth of field. You can use this tool to direct the viewer's gaze, emphasize specific elements within the frame, and evoke emotions through the interplay of sharpness and blur. Whether seeking to capture the vastness of a landscape or the intimacy of a portrait, understanding the relationship between sensor size and depth of field is essential for photographic mastery. Check out the video above for the full rundown from Morgan.
Very interesting of all cameras and the depth of field of each. One thing not really pointed out, Camera focus point used but I did see your focus on the cards was interesting - a great compare! One thing what focus setting was used, I mean yes you MF'ed to the card but when doing the person there are some settings to choose from wide, zone, center fix, Spot small, medium, large, Expand spot. And tracking not for this. When I am wanting a very narrow depth of field I use small spot and place over subject or center fix. the image of the Donkey was taken with the 24-240mm f/3.5-6.3 but in APS-C mode at 360mm (cropping on sensor) using small spot. The bee a crop but with small spot on the bee using 24-70mm f/2.8 at 70mm. Difference between MF and AF using small spot I'll have some playtime with a 50mm.
I’m confused. Are you implying the size of the sensor spot selected influences the dept of field?
Depth of field does not change when you select DX or remain at FX. Think about it... when you first loaded up the image in your editing software, and then cropped it, did the DOF actually change? Of course it didnt.
In my opinion, Micro Four Thirds, while it may have some limitations, performs admirably in many shooting situations. Having both MFT and medium format systems can complement each other well, allowing you to choose the most suitable camera for each project in terms of required portability and image quality.
You can't use all tools in the same way to achieve the same results, but you can get the same depth of field with a micro 4/3 and a medium format. You simply have to understand your how your entire system works together
I wish I could just shoot on an 1" interchangeable system to be honest. I don't like the shallow depth of field of full frame, but I want the IQ. If they could give us a 1" that has all the high ISO performance of the Sony A7SIII while having 20+ megapixels, I'd be sorted.
Even for street and documentary I'd love to just sit at f8 1/320 and let the ISO do whatever it likes but still get a clean image. That would be great ✨
Did you actually watch the video? Its absolutely useless lmao!
Just a quick rundown of the worst parts.
1. Never mentions the lenses being used. But does mention the tripod isnt being moved, so each smaller sensor must be using a subsequently smaller/wider focal length, which focal lengths? No idea, since they never once mention it.
2. Never mentions relative aperture, literally the other side of the small sensors increase the advertised focal length on lenses situation, since virtually all crop/FF lenses are measured at 35mm equivilent. For example MFT lenses are a full 2 stops darker when using a 50mm 2.8 lens than a FF camera using the same, and both are letting less light through, relatively, to a medium format designed 50mm 2.8 lens.
If they were using the exact same fixed focal length lens, adapted to each camera, they would have seen all of these very obvious outcomes and if they had someone there technically adept enough to understand what was happening it could have been a good video. Instead im left wondering why yall are signal boosting them.
--- "Did you actually watch the video?"
--- "1. Never mentions the lenses being used."
The question is, did you? He mentions it at 7:50. Granted, he could have mentioned it earlier so trigger happy trolls don't get so, well, trollish. When he was doing the card test, it was obvious they were equivalent since the framing was similar.
--- "2. Never mentions relative aperture,"
The video is about how sensor size affects depth depth of field, not light transmission. He mentions it in the video, also, it's in the title of the video.
--- "If they were using the exact same fixed focal length lens, adapted to each camera,"
Wrong. Focal lengths would have been all over the place, thus, defeating the purpose of comparing "How Depth Of Field Changes With Sensor Size".
Using the exact lens adapted would show reach and framing, though a valid comparison, is not what this video is about.
The change in aperture is the reason why mft will have different DOF from a FF camera. Its integral to the entire topic. I couldnt care less about the t-stop of the lenses they use (im sure theyre all different, which is a whole different conversation he should have addressed when planning that video though). Its a bad video, done by someone who im almost certain doesnt understand the topic.
So theygrabbed a 24mm 2.8, a 35mm 2.8, 50mm 2.8, and a 75mm 2.8. Want to wager that at least *one* of those lenses is a completely different type of lens formula, which alone changes how DOF values are determined. Then the whole longer the lens, smaller the dof thing. So yeah, a completely worthless video. Go grab 4 lenses in those focal lengths on the same sensor size and dof would be extremely varied.
--- "The change in aperture is the reason why mft will have different DOF from a FF camera."
It's the sensor size given equivalent focal lengths and the same aperture setting. And, they are using practical aperture. Meaning, the actual dial/setting on the camera.
--- "I couldnt care less about the t-stop of the lenses they use"
Yeah you do. You brought it up. Re-read your paragraph "2." point above.
-- "Go grab 4 lenses in those focal lengths on the same sensor size and dof would be extremely varied."
No, duh. And, therein lies the problem. You are comparing dof based on focal lengths on the same sensor size, whereas the video is based off differing sensor size on equivalent focal lengths. I don't think you understand how crop factor works. That may be your issue.
This video is so elementary. Lol, now, there's two of you who don't get it because you are either overcomplicating it, or have very limited scope on camera dynamics.
"For example MFT lenses are a full 2 stops darker when using a 50mm 2.8 lens than a FF camera using the same, and both are letting less light through, relatively, to a medium format designed 50mm 2.8 lens."
This is incorrect. f/2.8 is f/2.8 regardless of the sensor size of the camera the lens is attached to. The same amount of light is being let through, no matter what camera it is attached to.
The sensors, however, may be more or less sensitive to light.
That is *not* true. Has never been true. And the fact that its repeated by both enthusiast photographers AND many writers in the consumer optical business press is one of the wildest things ive cone across in any special interest group. And i spent years in datsun forums watching people throw money and HP away buying expensive kits to replace fuel injection with a 4 barrel carburator on their turbo engines.
So lets start from the top. They are repeating *the same focal length* on every single camera. Which requires them to put shorter lenses on the smaller sensors. Think about that for a second... the aperture diameter for 2.8 on a 28mm lens, is much smaller than the aperture diameter of a 50mm 2.8 lens. Since aperture is just a ratio of length/max aperture diameter.
Do you even own prime lenses? Just the difference in aperture (and therefore lens) diameter between a 50mm 1.8 and a 35mm 1.8 is incredibly obvious. Considering its over 25% smaller.
So tell me again how an aperture of 2.8 lets the same amount of light into the camera, no matter the length of the lens used again... i could use another laugh.
Ill give you a little experiment to run. Take a photo with a full frame camera at a wide aperture, close to the subject. Now crop it at a ratio of 1.6/1. Exactly how a crop sensor would have taken the photo.
Did the depth of field change when you cropped the outside of the image? Of course it didnt, that would be incredibly dumb to think it would... so we can pretty accurately say sensor size has zero influence on depth of field. It is *all* based on the lens (and its aperture setting), the subject, and the location of the subject in relation to the lens.
Like ive said several times in these comments already, all they did was show how wider angle lenses have a deeper depth of field at specific aperture settings compared to telephotos. Which yep, of course they do, but why waste a dozen minutes of everyones time (and a half day of their time) showing us something everyone learned the day they got their first camera with selectable aperture.
This is a garbage video. First off, for any fixed focal distance, and fixed enlargement size, and fixed viewing distance, DoF is not affected by f-number, but by aperture diameter.
For the same horizontal FoV, focal length changes proportionately to sensor width. An 18mm frame with a 50mm lens and a 25mm aperture, (f:2.0), will have to same DoF as a 36mm frame with a 100mm lens and a 25mm aperture, (f:4.0). Likewise, a 67mm lens on a 24mm wide frame and a 670mm lens on a 240mm frame (10×8 view camera), will both have the same DoF with a 25mm aperture, (f:2.7 & f:27 respectively).
Now if one wants to compare a 54mm frame with a 150mm lens and a 18.75mm diameter (f:8.0) with an 18mm frame, 50mm lens and a 6.25mm diameter, then of course the DoF changed, because the aperture diameter has changed. However, at the same diameter, the MFT is now at f:2.7, letting in more light for the same DoF. This is a definite improvement for noise reduction.
That being said, I take the majority of my portraits at about 3-4m from the camera, at about f5.6-f:8.0, on an APS-C system, (varying focal length to set my framing), and still have problems sometimes getting all parts of the subject in acceptable focus, when viewed on my 43" 4k monitor from 1m away. I do not have a problem getting enough DoF in my 8"×12" prints.
This is hardly an issue to consider.
--- "DoF is not affected by f-number, but by aperture diameter."
F-number is directly related to the aperture diameter. It's the measurement. Therego, setting it affects dof. The setting terms F-number, F-stop, and Aperture are interchangeable.
Oh. One more fun fact. Did you know that a fresh out of the box Nikon Z 85mm f/1.2S lens actually has the same Tstop value in lab tests than the 1970s designed nikon 85mm 1.4 ais (back in the day, high end lenses that said 1.4, got 1.4. Or 1.38 i think in the ais case). That brand new $3000 1.2 lens, just about keeps up with my couple hundo dollar relic. And the 1.4 ais tests out better at transmission than the 85mm 1.4 ART lens, the 85mm 1.4 AF-S, AND the zeiss otus 85mm 1.4 (all of them test right around 1.6 t/stop). Anyways!! Since so many people attribute a lenses fstop to its light transferance ability, without once stopping to wonder why the fstop doesnt go up once a lens is full of dirt mold and dust, the number of elements, transmittence values of the lens element material, or surface coatings... its easier to just point out there are many lenses with the same focal length, where the fstop doesnt correlate to transmittance score. Fuji has a mid-50s 1.2 prime with a built in filter to add extra vignetting (for... reasons? Idk, marketing junk im sure) which pushes its tstop while wide open to almost f/2.
So yeah, i hope you dont delete your post saying i dont comprehend the most elementary principles of optical theories. Id love to pop back in once in a while when i want a chuckle.
F-number may be related to the aperture diameter, but it is also related to the focal length. Aperture diameter is NOT related to focal length, and only aperture diameter is related to DoF at any given distance, print size, and viewing distance.
Saying that F-number and aperture are interchangeable, it's like saying that time and distance are interchangeable, when someone asks, “how far is it to the studio?” Distance is constant. Time is dependent on means of travel, traffic, speed, stops, etc al.
F-number is a ratio. Aperture diameter is a distance. f-stop is a construct. (Not getting into that right now). I made it quite clear how an aperture of 25mm gives identical DoF yet varying F-numbers. Understand that, and you will not make simple errors.