It's weird how phones went to 100M with their tiny sensors, but APS-C cameras stayed at 20M.
Anyway with used FF cameras now well under $1000, I have no idea why anybody would buy an APS-C camera. Even if you love some APS-C lens, you can just mount it on a FF camera and crop. Usually the camera will show you the cropped view in the viewfinder, but raw photos are taken at full resolution for you to manually crop later.
The tiny sensors are a marvel of technology but have absurd levels of noise though. They're essentially unusable as traditional single-shot readout sensors in anything but exceptional light conditions. Internally phones take multiple shots and do an enormous amount of postprocessing for each shot. It's a completely different technique.
You can get a feel by how much post-processing is done by installing something like "opencamera" on a flagship phone, disable all filters and look at the raw file (if your phone allows it) and compare the results.
OpenCamera is great if you want natural looking photos.
I went out with my android shitphone and someone brought their iphone 12 pro max. Here's a comparison (opencamera + rawtherapee vs iphone camera jpeg):
I mean, you can take raw photos on iPhone too, if you disagree with their heif/jpeg engine. The default camera app will generate raws with some interesting multi-frame fusion, and 3rd party apps can take direct, single frame raw photos. Plenty of choice to go around.
But, most people are happy with the default output from iPhone in most circumstances.
There is a lot more to image quality than just resolution, and often increasing resolution will hurt sensor performance in other areas like dynamic range, QE, and noise.
The Arri Alexa's Alev III sensor, which has won basically every Best Cinematography Oscar for the last decade, shoots at about 3k resolution (~7MP) yet holds up perfectly fine on huge cinema screens.
Anything at 1080p holds up fine on screens already, and that's only 2 megapixels, and it's been around for 15 years.
Majority benefit from shooting at a higher resolution is the ability to crop/zoom during processing. Sometimes, it's the ability to actually reduce the resolution to get rid of noise/grain.
Phones went to 100Mpx because it’s an easy number to sell. Dedicated cameras have been hovering around 25Mpx for mainstream bodies, and somewhere around 40-60 for high-res bodies, because there’s not much benefit past that. Most full-frame lenses aren’t sharp enough to take advantage of higher-res sensors anyway.
I have an A3 print in front of me, from a photo taken with 24Mpx a7iii, and cropped a little in post. You’d never look at it and think “it needs more resolution”.
This is a common misconception. Even a piece of plastic benefits from a higher resolution sensor.
It’s not very hard to get moiré on a 45mpx sensor with a modern lens, hence we most definitely need higher resolution cameras. But even with a lower resolving power than that there’s an advantage.
True, the dials are nice. And I just noticed that the Fuji camera has a LCD on top, which is a big plus for me. I used to have a Pentax K20D and found that to be very useful.
Although I tend to just shoot on auto-exposure and bracket 3 shots, 0EV, -2EV, +2EV. One of those will usually give me what I want, without any messing around with dials.
I test drove a variety of cameras renting them from Lensrental to find the perfect travel camera.
I took a XT-3 with me to Tokyo. While it’s a nice camera, I still found it too bulky but without the benefits of FF.
I ended up going with a A7R3 combined with a RX100. I leave the hotel room with the former gets taken when I know there’s something important I want to capture, if it’s at night, or when I know bulk isn’t an issue. The latter is taken when bulk is of concern.
High MP rapidly shows the flaws / limitations of lenses and the photographer’s technique. Phone cameras use a ton of image processing to hide these and the limitations of the small sensor. That’s not even mentioning the rapidly finishing returns; 100MP only gives images twice as large as 24mp crop cameras for 4x the disk space needed to store and processing power needed to edit the pictures.
Anyone on this thread is probably into these kinds of cameras and knows, but just in case (it took me a few seconds)
FF = full frame, refers to sensor size. They are about 1.5x - 1.6x[0] in surface area compared to APS-C sensors.
Sensor size has various benefits in how you frame your photos, and can have larger sensor pixels at the same resolution, which can result in less noisy photos.
[0] EDIT: See below, this was a mistake; this is the crop factor, not the difference in surface area. It's more like 2.5x (depending on the exact camera/sensor.)
In theory, the only benefit of FF over APS-C is when using very wide apertures.
For example, you might using a FF camera with a 52mm f/1.2 lens, in order to get the very shallow depth of field this gives and/or the very high light-gathering ability. A good 52mm f/1.2 lens is expensive, but quite feasible (they've existed for many decades).
To get the equivalent effect with an APS-C camera, you would need a 35mm f/0.8 lens. As far as I know, no such lens exists (though it's theoretically possible to construct a lens as wide as f/0.5).
In practice, FF may have other advantages, due to engineering considerations. For example (though I don't really know), it might be that electronic noise from the rest of the camera has more effect on noise during pixel readout when the pixels are smaller.
Why would you put APSC lens on FF body (which is bigger) then crop?
Just put on APSC body, which is smaller. Done.
For some, APSC is still big, and they are happy enough with MFT.
Now I wonder, why would people buy FF cameras (especially if they don't shoot 35mm film cameras)? They are still bulky.
Pick APSC or MFT which is smaller. If you want superb image quality without compromise, then skip FF and join the medium format club.
I have both, a used Nikon D700 FX and a used D300 DX with 12 MP each. Why? Because FX is just nice to work with, it feels a lot like film. DX on the other hand is the best teleconverter you can think of, turning a 300mm FX lens into a 450mm one.
the reverse is also true - with adaptor you can mount any old FF lens to aps-c, there is a slight advantage there that the old lenses tend to be shit in corners which might be visible on FF but not on APS-C...
A D750 does, not that I would do it. I'd rather have FX lenses on a DX body to get the additional reach. Heck, why pay prime money for a FX body to use DX lenses on?
Anyway with used FF cameras now well under $1000, I have no idea why anybody would buy an APS-C camera. Even if you love some APS-C lens, you can just mount it on a FF camera and crop. Usually the camera will show you the cropped view in the viewfinder, but raw photos are taken at full resolution for you to manually crop later.