Secondly, we already do correct distortion and chromatic aberration in software, but this doesn't really make up for loss of resolution that you can't fix. Information is being lost.

The error you get out is of the order of the sampling error you put in. That's true of all lenses.

Information is lost when a ray strikes somewhere it shouldn't. Things get blurred and cannot be recovered. You can't fix this with software.

Can't you? If you're dealing with known hardware, then you can apply a deconvolution. Blurring can literally be undone, people do it all the time. It's harder when you have to estimate the kernel, but much easier when you already know the lens's exact properties. Also when you apply it directly to RAW data.

So not exactly sure which information you're referring to you when say information is being lost?

Sure artifacts can be introduced from noise, etc., but that's all just tradeoffs. If a simpler lens is letting in more light, or you put money towards the sensor rather than the lens, the end result may well be better, no?

And there's a variety of sharpening tools that claim to do this! DxO is a company that sells a raw processor for precisely this purpose. People still buy better lenses.

Lens design is about minimizing this.

Even if reconstruction is possible, it might amplify the noise by a substantial amount.

Unfortunately, you don't. You have a sensor that captures only amplitudes, on a spatially quantized grid, with some noise. It loses a lot of information. If your lens has very low aberration and not too much distortion, most of that information is information you don't care about. If your lens has a lot of aberration and distortion, a lot of the information you care about is encoded in exactly the stuff that the sensor is losing.

Canon's M-series was similar, they didn't go all in on "pro" features, instead focussed on a consumer market that was shrinking rapidly.

The problem wasn't the technology, the problem was the fear of cannibalizing their own DSLR sales.

I assume part of this is that the camera companies are Japanese and refuse to pay any engineers more than $20k a year.

For real pretension you have to get a Leica.

It looks like they still don't really plan to add it: https://www.dpreview.com/interviews/9195902169/interview-son...

but at least if they had better bracketing options we could do it ourselves.

Not better tech (better as in takes better photos), rather more convenient tech which is good enough.

that's what phone cameras are...

And a lot of lens aberrations not correctable robustly. LCA is basically impossible to correct, field curvature is impossible to correct, bokeh quality is impossible to correct (within reason), wide depth of field is impossible to correct, dynamic range is impossible to correct (without bracketing), coma is impossible to correct, flaring is impossible to correct and the list goes on.

For example Panasonic has a 25mm f/1.7 lens that is 125 grams and costs $150 brand new.

Of course you can also buy similar focal length lenses that are huge and weigh over a pound, while spending $1500+. But I don't know how much advantage those really give except in specific rare situations.

For 150g on full-frame you can get a 50mm 1.8, at a cost of 150$ brand new. So on full frame at a similar weight and at the same price you get superior optics.

If you really care about the weight, the 40mm 2.8 has the same weight and the same price but superior optics again.

All modern FF cameras do distortion correction too. M4/3 lenses are not especially decided to trade-off distortion for sharpness anymore than full-frame.

Noise is decided by the quality of the sensor, and the solid angle of light that hits each point on the sensor. The solid angle as it happens also decides depth of field.

So it is always true that you should apply crop factor to aperture. ISO is just not the correct factor to describe gain because an inverse crop factor is applied to it in effect.

So at the same exposure and shutter speed, at f/3.4 on FF you will get the same image with the same amount of noise as you would at f/1.7 on M4/3.

I'm interested to learn more about the effect of light angle on noise. Do you have a source that talks about this? I didn't find anything useful in 2 minutes of searching the web.

As for light angle, it's a consequence of the second law of thermodynamics, that translates in optics as the conservation of étendue.

Basically what this means it that the amount of light captured from a light source is equivalent to the solid angle of light from that light source onto the entrance pupil - whose size is the focal length divided by the f number.

So basically, what determines in the same scene how much light is received by the sensor depends on the size of the aperture in milimiters.

So on a sensor of the same efficiency, it's the physical size of the aperture that determines how much light is captured.

> what determines in the same scene how much light is received by the sensor depends on the size of the aperture in milimiters

That's true, but the amount of light is not the intensity of light.

Yes, you will need four times the ISO. But you will get exactly the same amount of noise.

https://en.wikipedia.org/wiki/Light-field_camera

I wouldnt say the camera companies did not see this coming. They did and chose to not do anything about it. I shoot videos with some pretty low end DSLR cameras and they are often lacking the feautures of any modern flagship phone. It's a joke. We once used a whole Iphone shooting at 120fps and made some plain scenes look amazing in post. A revelation since most pro videographers pooh pooh phone cameras without realizing that they are growing with alarming speed.

I believe it’s called the iPhone.

A great example of this is DiffuserCam [1], which uses a diffuser as a “lens”, combined with a carefully measured point spread function (PSF) of a single point for each axial plane to estimate the “true” PSF that actually varies throughout the entire volume. So although in this work they estimate the reconstruction by making a translational invariance assumption, this is done for practical reasons and quality is lost.

To fully recover a lossless image as you suggest, one would have to measure a PSF for each point in the volume.

[1] https://waller-lab.github.io/DiffuserCam/

It's the photography equivalent of "if you were a real audiophile you'd only use pure analogue signals, digital destroys the sound".

Once you are in the 2k$ usd lens space the buyer is looking for ultra premium stuff either as an enthusiast buyer or as some one who makes their living that way.

This is what I thought (it's not really convolution, but yes it is correctable), until I realized darktable/lensfun doesn't have lens profiles for any of my lenses... :(

https://pixls.us/articles/create-lens-calibration-data-for-l...

Such corrections are all but essential for affordable zooms, but I'm still split on the potential for over-use in primes. I'll point to the Sony 16/2.8 E as an example; the use of correction in JPEGs is pretty evident compared to shooting raw, and you can see the correction softening the corners.