As interchangeable lens cameras have evolved, camera sensors have settled into three common sizes: Micro Four Thirds (MFT), APS-C, and Full Frame. Especially for the novice photographer, the sensor sizes can be confusing. Even for advanced photographers, not all the differences are straightforward. Since I am primarily a bird photographer, I have always wanted to do a practical comparison between these three sizes from a wildlife photographer’s perspective. I’m happy to say that my wish came true, and in this article, I will explain the differences between these three sensors from my real-world tests.
Table of Contents
Sensor Size Overview
Micro Four Thirds
This is the smallest of the three most popular sensor sizes for wildlife photography. These sensors measure 17.4 x 13 mm. The biggest manufacturer of these cameras is OM System (formerly Olympus), while Panasonic is their main competitor.
The smaller sensor makes it possible for Micro Four Thirds cameras to be smaller. (Many of their lenses are smaller as well, but that is less true of telephotos.) Another result is that the crop sensor is, quite literally, like cropping an image from a larger camera sensor. This has pros and cons – more on this later – but for wildlife photography, it has the potential to assist with the goal of putting as many pixels as possible on a distant subject. In specific terms, Micro Four Thirds has a 2x crop factor. This means, for example, that a 400mm telephoto lens on Micro Four Thirds will match the framing of an 800mm lens on a Full Frame camera (apart from the slightly different aspect ratio of the sensors).
APS-C
These sensors can be found in cameras from most major camera companies. They are larger than Micro Four Thirds sensors and measure approximately 23 x 15 mm in size. (Canon’s APS-C sensors are a little smaller than this, and most other companies are a little larger, but the disparity is slight.)
As with MFT cameras, the biggest theoretical advantage for wildlife photographers is the smaller size and weight compared to Full Frame cameras (and potentially lower price). However, the weight advantage for APS-C is often smaller than expected, mainly because there aren’t very many dedicated APS-C supertelephoto lenses for wildlife photography. Most APS-C photographers choose to attach Full Frame lenses instead, which tend to be a little heavier.
The crop factor for APS-C cameras compared to Full Frame is about 1.5x. Again, more on that in a moment.
Full Frame
Full Frame has been with us longer than any of us can remember – well over 100 years. It began as the “35mm format” of celluloid film, and today, 36 x 24 mm Full Frame digital sensors can be found in cameras from at least nine brands. In modern photography, Full Frame has always been something of a benchmark and an established gold standard.
But is there a practical reason for the popularity of this format, or is the main reason for its widespread adoption simply inertia and adherence to tradition? The biggest arguments in favor of Full Frame are the high image quality, the control over depth of field, and the huge range of lenses and other accessories. By definition, it has no crop factor apart from 1x.
Is Bigger Always Better?
To introduce the pros and cons of each camera sensor size, it helps to do a short thought experiment. Consider three photographers, all shooting with cameras that have the same resolution and all using lenses with the same nominal focal length and aperture.
This is not just a hypothetical. For example, three well-known cameras representing these three sensor sizes – the OM System OM-1 Mark II, the Nikon D500, and the Nikon D5 – all have a resolution of about 20 megapixels. And for all three cameras, it is possible to purchase a 300mm f/4 lens (the M.Zuiko 300mm f/4.0 IS PRO for Micro Four Thirds, and the Nikon AF-S 300mm f/4E PF for both APS-C and Full Frame). What will be the differences between these systems?
First are weight and size. For these particular cameras and lenses, the weights the photographers must carry are as follows:
- Micro Four Thirds – 2074 grams (4.57 pounds)
- APS-C – 1615 grams (3.64 pounds)
- Full Frame – 2205 grams (4.86 pounds)
Interestingly, it is APS-C and not Micro Four Thirds that is lightest this time! It goes to show the importance of lens selection – the Nikon 300mm f/4 PF was designed to be as lightweight as possible, whereas the OM System 300mm f/4 PRO is a little on the heavy side. However, on average, Micro Four Thirds lenses are smaller and lighter than lenses for APS-C and Full Frame.
But more importantly, what about the photos these three photographers will get? Let’s share these cameras between three photographers and tell them to photograph the same subject with the same camera settings. Say, a bird sitting on a rock in the middle of a stream – and make sure they are the same distance away from the subject. Try to think how these three images will turn out. I will reveal after the photo.
First, the image on Micro Four Thirds will have the bird filling more of the frame. The photo is likely to have more visible noise than the photos from the other two cameras.
Second, the image on APS-C will have a little more environment around the bird. Noise will be less visible by comparison, but there most likely will still be some.
Finally, the photographer with the Full Frame camera. This time, the bird will be by far the smallest in the frame. (If it took up the entire photo on Micro Four Thirds, it will only fill 1/4th of the photo on Full Frame). There will be more environment in the photo. And the photo will have the least noise of all three photos.
What about depth of field? Well, the background will have the same level of blur in all three photos. This is because each smaller sensor’s image is like a crop from the larger sensor, and cropping does not change depth of field.
And what if the photographer with the Full Frame camera decided to crop the image to look the same as the APS-C or Micro Four Thirds photo? It would be possible, but at the expense of losing a lot of pixels! The images would look mostly the same, but cropping to an APS-C level would reduce the resolution from 20 megapixels to about 8.5 megapixels, and cropping to a Micro Four Thirds level would reduce the resolution to about 5 megapixels.
What is the lesson here? With the same sensor resolution, focal length, and distance from the subject, the photo with Micro Four Thirds will place the highest number of pixels on the subject (resulting in the most detail). So much for the larger camera sensor always being better!
In practice, the situation would probably be somewhat different. For example, most Full Frame cameras nowadays have more than 20 megapixels. If you shoot with a 45 megapixel Nikon D850 or Nikon Z8, then you can do some serious cropping and still keep a lot of resolution. Even more so with a 60+ megapixel Full Frame camera like the Sony a7R V. The highest resolution APS-C camera has about 40 megapixels, while the highest resolution Micro Four Thirds cameras has about 25 megapixels.
Also, photographers tend to stand wherever is needed to take their photos. Stand closer with Full Frame, or farther back with Micro Four Thirds, and you can get whatever framing you want. The photographer with the OM-1 (Micro Four Thirds) would probably be several meters back from the photographer with the Nikon D5 (Full Frame). Or perhaps the Full Frame photographer would use a longer lens, like a 600mm, to match the desired composition.
As soon as you introduce different lenses and different camera-to-subject distances, other variables arise between the different sensor sizes. For example, getting closer to your subject results in a shallower depth of field. So does using a longer focal length lens. As a result, if two photos have the same framing despite different camera sensors, the larger sensor will have less depth of field. (This assumes all camera settings are kept identical across cameras, and no cropping is done to match the compositions.)
In fact, you can use the crop factor to find both the equivalent focal length and the equivalent depth of field between two camera sensors. Want to match a Micro Four Thirds camera with a 300mm f/4 lens, and you have a Full Frame camera? Recall that there is a 2x crop factor between these systems. So, as long as you don’t move forward or backward, you can shoot with a 600mm lens at f/8 on Full Frame to get a comparable framing and depth of field.
An important practical difference is which lenses are available for which systems. In theory, it is nice that you could always match the composition and depth of field between two systems – just multiply or divide by the crop factor. But camera companies only make so many lenses. A 200mm f/2 lens on Full Frame could only be matched by a (nonexistent) 100mm f/1.0 lens on Micro Four Thirds, for example.
Generally speaking, Micro Four Thirds offers more choice for lighter-weight supertelephoto lenses. Full Frame offers more telephotos with shallow depth of field and bright apertures. (APS-C photographers usually just use Full Frame lenses, except for Fuji shooters who have more dedicated APS-C options.)
However, “generally speaking” only matters if you’re still not sure which lens to buy. Every company makes some unique lenses. And if you don’t like the native options, it may be possible to adapt a lens or find a third-party lens that suits your needs. You may also be able to use a teleconverter to change the focal length and maximum aperture of a lens, such as turning a 400mm f/2.8 lens into an 800mm f/5.6 with a 2x teleconverter.
Now, what about image quality?
It is true that larger sensors have an advantage here. Especially if we go back to the example of three 20-megapixel cameras, and then imagine shooting all three at a high ISO value and cropping or doing heavy post-processing to the images. The Full Frame photo will be cleaner than the APS-C photo, which will be cleaner than the Micro Four Thirds photo.
However, the image quality advantages to Full Frame go away if you need to crop the photo extensively. If you crop it to match the field of view of an APS-C camera, you will get APS-C image quality (or a little better or worse, depending on how much resolution you started with, and on individual camera sensor differences). And cropping to a Micro Four Thirds field of view gets you Micro Four Thirds image quality at best (in reality, most likely worse, because there are no 80 megapixel Full Frame cameras that would allow you to retain 20 megapixels after cropping so extensively).
Since wildlife photographers often crop their photos, this is a big argument in favor of smaller camera sensors. If you were already going to crop your Full Frame photos so much, then you could have simply used lighter, less expensive equipment and gotten the same results.
In fact, the biggest image quality advantages of Full Frame only occur if you’re prepared to limit how much you crop! And unless you’re mainly shooting animalscapes, this often means a longer focal length lens will be necessary on Full Frame, potentially in combination with getting closer to your subject. This results in a higher expense and a heavier kit, and sometimes a higher chance of scaring away your subject.
Ultimately, Full Frame does have some clear advantages – but you often need to pay more, and you definitely need to optimize your techniques, or you won’t see them. Given that smaller camera sensors still are capable of great image quality, you can see why APS-C and Micro Four Thirds remain popular for wildlife photography.
Small Sensor, Big Noise?
I’ve explained how larger camera sensors have the potential for better image quality. If you don’t crop your images, and you use the same camera settings, the improvements are (very roughly) one stop of noise performance for APS-C over Micro Four Thirds, and one additional stop of noise performance for Full Frame over APS-C. All else equal – which it may not be, depending on the noise performance of each individual camera sensor – a photo at ISO 1600 on Micro Four Thirds will have similar noise as a photo at ISO 6400 on Full Frame (representing two stops of difference: ISO 1600 to ISO 3200 to ISO 6400).
However, noise reduction software has improved greatly over the years. It allows us to use ridiculously high ISOs without dramatically reducing the quality of the photos. So even though larger sensors have a clear advantage in low light on paper, post-processing can make most images taken in reasonable light look good (as well as many images taken in unreasonable light)!
Even with Micro Four Thirds, I found myself able to use ISOs around 5000-6400 and sometimes higher, if the subject required it. And these weren’t “break glass in case of emergency” ISO values; I used them regularly and without fear, knowing that it would be possible to reduce the most objectionable noise in post-processing.
So yes, the advantages still persist (about one stop better noise performance as you jump from Micro Four Thirds to APS-C, and roughly one additional stop when you jump to Full Frame). But if you’re able to stick to ISO 6400 and lower, then you can convincingly get away with any of these three sensor sizes today.
Is the Micro Four Thirds System Lighter?
For most photographers, the immediate answer to this question is “yes, of course.” But is it really the case?
I have hinted at this question already, when I showed that the Micro Four Thirds kit with the OM System 300mm f/4 was heavier than the APS-C kit with the Nikon 300mm f/4 PF. Now, I can find plenty of examples where the Micro Four Thirds kit comes out ahead. But most of the obvious benefits of Micro Four Thirds for size and weight occur with non-telephoto lenses, like a wide-angle or normal prime lens.
The unfortunate fact is that, if your main photographic interest is wildlife, your back and shoulders will suffer similarly, regardless of sensor size. This is because a good supertelephoto lens is often many times heavier than the camera it is attached to. A long focal length with a bright maximum aperture – considered ideal for wildlife photography – is always going to be heavy.
Remember that if you want the same framing and depth of field between camera systems, you need to multiply both the focal length and the maximum aperture by the crop factor. A (hypothetical) 400mm f/5.6 lens on APS-C may be super light and seem like a great choice, but multiply that by the crop factor of 1.5, and you see that you can match it with something like a 600mm f/8.4 on Full Frame. Something like Canon’s 600mm f/8 would be close enough, and that lens is already nice and light, so the hypothetical 400mm f/5.6 on APS-C might not be as appealing as you first thought!
I am still inclined to say that the answer to this question – “Is the Micro Four Thirds system lighter?” – is yes. However, it is a very conditional answer that depends much more on the specific camera and lens you choose.
(For the record, I would say the same thing about mirrorless versus DSLR. Speaking as someone who uses an adapted 500mm f/4 F-mount lens on my Nikon Z9, I am quite confident that my mirrorless kit is heavier than my old DSLR kit!)
Conclusion
I spent three beautiful mornings photographing the White-throated Dipper family, during which I had the opportunity to observe and photograph these exceptional birds (by the way, there are only five species of dippers in the whole world). The pair I photographed had built their nest in one of Prague’s parks, in an unusually busy spot, under a boulder next to a stream. As a result, they were accustomed to human presence and paid no attention to the fact that I was sitting in “their” stream for long hours.
This allowed me to shoot them with not one, or even three cameras, but four. I had two Full Frame cameras (Nikon D850 and Z9), one APS-C model (Nikon D500), and even probably the best Micro Four Thirds combo for wildlife, the OM System OM-1 Mark II with a 150-400mm f/4.5 lens. My goal was to try three different systems on the same subject so that you could compare how the different sensor sizes would affect the resulting photos.
My goal wasn’t to pick a winner, as every photographer has their own specific needs. In fact, my main feeling is that it’s really hard to make a bad choice these days. Regardless of sensor size, all four of the cameras were capable of taking great, detailed photos. With careful processing, even the dreaded Achilles heel of small sensors – noise at high ISOs – was not a substantial problem.
If I had to name one practical benefit of Full Frame, it may not be one that you would expect. My answer isn’t the high ISO performance or even the wider range of lens options. What I found the most beneficial was the greater freedom in cropping photos in post-processing. Yes, I already discussed how too much cropping on Full Frame negates the benefits, and that’s true – but cropping too much on APS-C or Micro Four Thirds is worse. Rather than simply negating the benefits, you could end up with an unusable image if you try to crop too far.
This, however, is something that can be overcome with good technique and discipline in the first place. It simply means that you need to frame your subjects more carefully on smaller sensors so as not to require extensive cropping in post-processing. Perhaps this is even a benefit in the long run; a Full Frame camera lets you be a little lazy with your framing, and that can hurt your photography skills.
It reminded me how much more important it is to know your camera and set it correctly than to chase after a particular sensor size, or even to chase after a particular lens.
A Final Exercise
At the very end, I have 10 sample photos taken with three different sensor sizes. Can you tell them apart?
I hope you enjoyed this article! Camera sensor sizes and equivalence can be controversial topics, so I request that if you leave a comment, let us be civil and remember that there is no reason to talk badly about a photographer’s choice of gear.
Great article, thanks Libor! Is there any difference among the three formats regarding dynamic range?
Example comparison of photographic dynamic range:
Nikon Z9 vs Olympus OM-D E-M1 Mark II
photonstophotos.net/Chart…0Mark%20II
Great article, and one that really brings up some good points. One other thing to consider is a lot of photographers aren’t lugging (or owning) around multiple bodies, and need their cameras to perform multiple types of photography. I use a R7 with the 200-800 for birds, and the reach is fantastic, and the results have been great – to the point I question if I want to get into FF (spending 50% more to just get to the 24mp R6II). As you pointed out about using NR software now to help “clean up” an image, that coupled with the detail the R7s 32mp sensor gets results in very usable photos past ISO 6400 – way beyond what many of us would do with even FF ten years ago never mind APSC (or MFT). And if I need to shoot a wedding, hockey or portrait, the IQ is still fantastic…same for landscapes. The biggest difference that keeps me with APSC is when I travel. Leaving behind my 200-800, and 70-200 and grabbing my Sigma lenses that between the 10-18 and 18-50 weigh about 500g and have a constant F2.8. It leaves enough room in my travel bag to still fit my Tamron 100-400, and fits under an airplane seat if needed! Of course I’m not saying APSC is for everyone, but the multi-discipline, travel and one-body-to-rule-them-all approach is something a lot of articles don’t get into. Yes, if you want to use MTFs, and geek out on light physics and pixel size you’ll convince yourself that FF is always the answer…but in 2025, I think the differences for most are closer than ever in real world results (and I do something that is increasingly rare – I print actual photos, not just look on my phone!). As for weight, I have a friend with the OMII and the 100-400 (for a 800 equivalent reach), and it is far smaller than a 150-600 lens on APSC while still being a very “high end” lens. Not necessarily light but way more compact. I’m impressed with the photos he can get with it.
Andrew wrote: “Yes, if you want to use MTFs, and geek out of light physics and pixel size you’ll convince yourself that FF is always the answer…”
I’m glad you mentioned that important point. I’ve noticed that some of the commentators on Photography Life articles use the pseudoscientific method to convince themselves.
People who use the pseudoscientific method (intentionally or unintentionally) start with their wanted conclusion, then scratch around to find anything that seems to support this forgone conclusion. Search engines and AI are especially useful tools for the creators of science‑y sounding, often convincing, rhetoric. Peter Lipson explained it succinctly:
“If you don’t understand the basics of a subject, it’s easy to form conclusions that seem logical, but these same conclusions seem silly to those who have a deeper understanding of a subject.”
— Peter Lipson, MD
I think one of the main reasons that you detected this is because, like me, you print your photos.
Thanks for a really interesting and informative article Libor, there’s a lot to think about there. As always your photos are spectacular … I really like your little friends!
Thank you so much, Craig. I’ve spent the last few days by a mountain river in Ecuador, where I came across a close relative — the White-capped Dipper. However, my main target was another fascinating bird. But I won’t spoil the surprise just yet.
A nice article that leads to a lot of (mainly technical) discussion. How did I know when I graduated (garden and landscape architecture) what I could do in practice?! Experience, preparation, talent, perseverance, patience, knowledge (in this case birds and habitat) and a bit of luck are all more important than the camera you are on the road with. A top camera and lenses certainly help you to make it more comfortable and easier. I also started photographing birds, but I did not have suitable tools and budget, so I spent a long time looking for second-hand camera and lens(es). Bought last month in excellent condition: Nikon D500 and Nikon 200-500 mm F5.6 for just under € 1500 total! And now I am going to practice and practice again and go out a lot with my old and heavy stuff……
Beautiful photos Libor …I hope one day…
Many greetings, Danny
Hi Danny, you bought a fantastic combo for great money. An equally (if not more) important component behind good photos is time in the field and knowledge of the birds. In my opinion these are far more important things than talent. I wish you many happy moments discovering the secrets of bird life and may you enjoy your photos.
Mft became too expensive and even heavy for what it was. But nice photos, my favourite is the fourth from the end. Why are the birds marked?
Thank you, Florin. You are right that the weight advantage of MFT applies more to shorter focal length lenses. With telephoto lenses, the differences between sensor sizes become quite blurred. Take the Fuji as an example. They have the same lens (optically) for both their systems – medium format and APS-C. The birds have a ring on their feet because Prague, where I photographed them, is full of enthusiastic ornithologists. The rings serve as information about the bird’s age and migration during (possible) recapture.
Well, my experience has been that the FF works better on subjects that move erratically. I know that clipped wings and tails can be added in post, but that is not something that I am willing or able to do. Assuming that the pixel density is the same, ie, 20 meg on the APC and 45 on the FF. If you are filling the frame with an APC camera, on a hummingbird (no, I am not talking about multi-flash) you may miss shots for anything other than a perched bird. I have used both, and I would not go back to the crop cameras.
I agree, Carl. When it comes to Nikon, if I photograph a bird from the same spot using two different cameras (one APS-C and one full-frame) with the same lens, and the bird fills the entire frame on the APS-C camera, there will still be a decent (and safe) amount of space around it on the full-frame. Yet the main subject is covered by almost the same number of pixels. It’s a different story with Canon or Fuji, where their APS-C sensors tend to have significantly higher resolution. In those cases, factors like lens resolving power, our shooting skills, and even air temperature can play a huge role.
That said, even though my full-frame sensor allows for heavy cropping, I still try to compose as precisely as possible. Compared to APS-C, it means I have to get a bit closer — and just like with APS-C, I sometimes end up clipping a wing, a head, or some other part of the bird. Old habits die hard.
I think this is a really nice article – what is missing somehow is the discussion of diffraction and pixel size. The Airy disk as a result of lens diffraction has to be put into relation of pixel size. The pixel size of a 20 MP MFT sensor results in pixel sizes that start to feel diffraction beyond F/4.8, whereas a 20 MP crop of a Z9/Z8 has a critical aperture of F/6.3. In short 300 f/4 is fine for MFT, but much beyond that softer images will emerge as a result of diffraction. KI algorithms will be of limited use to compensate for this.
I agree with your overall point but question the specifics. The tests performed by Spencer & crew show that for the sharpest lenses, central sharpness starts going downhill already at f/4 on a 45 MP FX sensor.
Well take the 600 F/6.3 …. it is super sharp at 6.3. The 400 2.8 is peaking at F/4 simply because the optical design gets more complicated when going to very wide apertures…
A lens can be diffraction limited and very sharp at the same time. The 600 PF is an example for that (this is even stated in the review itself). But looking at the results of lenses like the Plena, the Noct, and the 70-200/2.8, it is clear that diffraction effects start at wider apertures than f/6.3. There are some that plateau at f/4 (e.g. 50/1.8 S), but even for those, f/5.6 already shows a loss in centre resolution.
There is simply a difference between when it starts to dominate your resolution and when it starts to affect it. All contributions to resolution (geometric image distortions (there are many), chromatic aberrations, diffraction, and pixel size) will be convoluted to result in the effective resolution you can obtain from your optical system. The intensity distribution of a circular aperture is given by the Bessel function. We typically plot this intensity on a log not on linear scale. de.wikipedia.org/wiki/…scheibchen. This means diffraction will creep into your image rapidly and will affect lenses that are optically very well corrected sooner as compared to less well corrected optics due to the convolution mentioned above (even though on a still much higher resolution level). Once the resolution goes drastically down and all lenses show the same level of resolution say at F/16 – I would call that diffraction dominated. But it is still there before that happens and smaller pixels will “observe” the effect sooner than bigger pixels. Having said that even heavily diffracting lenses can be fun. I am using an AstrHori Probe lens at F/13 and large magnifications for getting amazing video shots. This system is effectively super diffraction limited (due to its magnification in combination with its aperture) and you can call me crazy mounting it on a Z9 and filming in 8K as the resolution is barely working out for 4K – but there are still reasons for doing it.
In practice, I think it’s better to think of diffraction in terms of sensor size rather than pixel size. (Mainly because it’s possible to *notice* diffraction sooner on a high-pixel-density sensor, but you’ll still capture more detail on those sensors anyway. A hypothetical 1-megapixel camera may not reveal diffraction until f/22, but still better to shoot with a 45 megapixel camera!)
As long as you think of it in terms of sensor sizes instead, things get a lot easier. Multiply by the crop factor to see the equivalent aperture between two sensors — this equivalent will be accurate both for depth of field and diffraction. So f/4 on M4/3 has the same diffraction as f/8 on full frame, for a given print size. That’s also why I wouldn’t usually try to shoot at narrower apertures than f/8 or f/11 on M4/3.
An F/8 lens of course can be made very light and small. They are rarely used as the lens manufacturers optimize their lens designs typically for their smallest pixel sizes. For Nikon the 4.2/4.3 um pixels (Z8/Z9/Z50) ask for an F/6.3 aperture to match the Airy disk size with the pixel size. Which is exactly what Nikon is doing. Again the exellent OM system 150-400 Pro lens features “only” a 1.25 TC build in as diffraction would limit the resolution on the pixel level for a 1.4 TC. Clearly, since many pictures are heavily cropped this matters to many people and this is why we probably won’t see 45 MP MFT sensors very soon as the current lens designs for that system would be limited by diffraction (i.e.no further information would be obtainable from that sensor). The main advantage in lens design for the MFT system is the small image circle that is needed for the small sensor. But of course this comes at a cost.
Michael, Regarding your comments in this thread…
You must’ve obtained your information from authors who have no formal education in physical optics; who don’t properly understand the essential difference between sharpness and resolution.
Using perfect diffraction‑limited optics with green light of 550 nm, the extinction spatial frequency resolution ξₑ at 𝑓/16 is approximately:
* 228 line widths/mm
* 114 cycles/mm
* 114 line pairs/mm
* 114 lp/mm.
Using a (135 format) full‑frame image, which has a picture height (PH) of 24 mm, ξₑ translates to 5472 LW/PH: line widths (LW) per picture height (PH).
MTF LW/PH lp/mm at 𝑓/16, 550 nm
50% 2208 46 ξ₅₀
9% 4464 93 ξ₉ Rayleigh criterion
0% 5472 114 ξₑ
ξ₅₀ is used by Imatest, hence Photography Life, lens tests to indicate sharpness.
ξₑ and ξ₉ are used in physical optics to indicate resolution.
QUOTE Acutance, Wikipedia
In photography, acutance describes a subjective perception of sharpness that is related to the edge contrast of an image. Acutance is related to the amplitude of the derivative of brightness with respect to space. Due to the nature of the human visual system, an image with higher acutance appears sharper even though an increase in acutance does not increase real resolution.
Sharpness
Perceived sharpness is a combination of both resolution and acutance: it is thus a combination of the captured resolution, which cannot be changed in processing, and of acutance, which can be so changed.
en.m.wikipedia.org/wiki/Acutance
END OF QUOTE
Conclusion
Using 𝑓/16 on full‑frame, ξₑ requires at least 5472 sensels vertically and 1½×5472 sensels horizontally ≈45 megasensels. However, a 45 MP Bayer CFA (e.g. RGGB) sensor has only 22.5 million green sensels, which cannot fully resolve the image.
Using 𝑓/16 and the less stringent Rayleigh criterion ξ₉ requires at least 4464 sensels vertically and 1½×4464 sensels horizontally ≈30 megasensels, which again cannot be fully resolved with the above sensor.
Equivalently, a Micro Four Thirds system with a superlative lens set to 𝑓/8: ξ₉ again requires at least 30 megasensels. A 45 MP Bayer CFA sensor would certainly not be overkill.
Dear Pete, I think your monochromatic approximation is quite a stretch.
www.researchgate.net/publi…microscopy
Nobody would use a 550 nm bandpass filter to take conventional photos. To use your pathway estimating diffraction you would need to use the IR-cut limit, i.e. the longest wavelength our sensors would see (around 700 nm) as these wavelength will dominate diffraction. This would correct your estimates by about one stop already. From the article above you see that all pixels see all photons despite with a different weight. From the spectral response of the respective filters at the given pixel the colors are then interpolated. This is typically the color science manufacturers apply. This way pixels are not lost. And the pixel resolution is not affected. And most importantly we see that pixels do not represent pure colors (as often suggested when many people talk about Bayer Patterns).
The MTF will be affected by diffraction once the Airy disc exceeds the pixel size. The MTF, however, is also affected by other optical aberrations (see comments above). The Airy disk has a diameter of 2.4392 * wavelengths * Fstop = 8.45 um (550 nm) or 10.7 um (700nm) at an F-Stop of 6.3. These values correspond to zero intensity. If you would accept a 50 % intensity cut off, these values change to 4.5 um at 700 nm (this means that the MTF is already affected by diffraction). These values correspond to 5333 LW/PH (FWHM) at a picture height of 24000 um. If we measure 3300 LW/PH this simply means that the convolution with geometric image aberrations still results in a FWHM of about 7,4 um. If we for the sake of simplicity assume a Gaussian convolution of the two contributions (diffraction and say geometric) we can calculate the change of resolution as a function of aperture (on a computer you can of course model the convolution correctly as the Bessel functions do not have a Gaussian distribution- but still to keep things simple). At an aperture of F/9 this results in a LW/PH 2900 (which is what the 600 PF is doing going from 3300 LW/PH to 2900 LW/PH). It is possible to model this way many of Spencers measurements on the Nikon prime telephoto lenses as a function of aperture from F/4 on. (600 PF, 400 2.8) Some lenses show drops at their widest apertures (800 PF, 400 4.5, 400 2.8 at small Fstops), which is a consequence of enhanced geometric aberrations at the widest aperture.
You can then ask yourself the question how smaller pixel sizes now challenge the lens design – and it surely does – even though the smaller image circle helps to accomplish really good results. The still enhanced complexity in lens design results in a bit heavier lenses as you might have expected.
Based on this I would think that with the current lens designs a 45 MP MFT sensor would be a challenge. I hope this makes clear why I think this way and why it is not problematic to think intensity distribution of point sources as compared to MTFs. Both can be easily connected.
I wrote “You must’ve obtained your information from authors who have no formal education in physical optics…”
Thank you for proving me correct😂
Dear Pete, very deep comment indeed …
interesting article!- beautiful photos ( whatever the sensor) and a lot of reactions.
No – I cannot tell these images apart: why not? they are too small…
That takes me to an other aspect of photography: the result.
Most photos are shown small on internet sites like these. In that case you cannot see any difference; That is a problem with photography in these times: the quality of the cameras and lenses have become better than ever, but we look at photos on a mobile phone, making the full quality never visible. The AI noise reduction also made it possible to work with higher iso than ever, a big plus for the smaller sensor.
I have an 8K screen and a 44 inch printer – well then you will see the difference.
Since hardly anyone prints big these days we have to wait for large 8K screens becoming the new normal to really see the difference.
But at some point enough information is enough, depending on the subject.
Honestly, Pieter, considering it’s been over a year since I photographed the dippers, I’d probably have a hard time telling which camera I used for which shot myself. Of course, I clearly remember some of them, but if I had to judge purely based on the visual quality of the images in web resolution, I’d be guessing. And to be honest, I don’t think it would be much different even if I printed them. I’d have to make really large prints to be able to tell the difference with any certainty. I’ve seen some of Petr Bambousek’s large exhibition prints (he’s an OM System ambassador) and they’re absolutely top-notch — both technically and artistically. I completely agree with you that chasing technical perfection only to present your photos on Instagram doesn’t make much sense.
When I was picking up my Z50II to add to the stable (alongside the D500 and a Z6II which has since been replaced with a Z5II) the employee at the camera store was *surprised* I was specifically looking to get an APS-C camera given I clearly have some experience, work with a 500PF primarily, and already have a full-frame. Basically what this article is about is what I outlined about that choice along with wanting to try the EXPEED7 AF system, and not really wanting to lug around a Z8 due to its size and weight. It has ended up being absolutely the correct choice for me since I can either use the 500PF bare to mostly fill the frame or get a composition closer to what I would crop to without sticking the 1.4X TC on the 500PF on a FF 24mp body. Heck, a lot of the time I ended up riding with the 1.4X TC even on the Z50II since a lot of the best birding locations near me require I stay on or near the trails and walkways while my little friends I’m photographing don’t have such restrictions. I’d need to invest in the heavier, larger, and much more expensive 800PF Z to really get a benefit from full frame which refer back to why I didn’t opt to invest in a Z8 – size and weight.
Glad to read this!
I’m thinking of replacing my Z5 with a Z50II.
I mainly use my Z8 and 500 PF. I also have a 100-400 and 300 PF.
I think the Z50II will make a better back-up.
I was photographing large birds of prey from a hide where the Z8 and 300mm was ideal. But a Z50II on the zoom would’ve provided versatility to grab for small birds and occasional larger mammal.
I don’t really want a 180-600 because I think I’d only use it as a ‘hide’ lens. I take the 100-400 on walkabout very happily.
In a Z7, Z7ii, Z8, Z9, you have a Z50, Z50ii ;-)
Hi Libor,
very nice pictures!
I use the OM-1 with the 4.0/300 and mostly the MC14 for my bird photography. I also have Nikon FF equipment and tested the Nikon Z8 for bird photography.
This is great, but the advantage to the mFt-Combo is small, means in some point is the the full frame better, in others the mFt.
I decided not to change to full frame for wildlife. Reason for me is, that I´m not only doing wildlife, I also like travelling and for this I need a system which is easy to transport. In summary with other lenses the mFt-System has a significantly smaller weight.
Another point is that the system is cheaper if I not take the fantastic, but very expensive, 150-400 OM lens.
If you take the 100-400 lens you can get very good results or you can buy the 4.0/300 used (what I did).
On the end it is very individual and depends more from the photographer.
Regards Reinhard