The Best and Worst of 2025

[EricN]

The point of the question is to lead to a discussion of what happens when we process RAW data and the choice of RAW converters. If you are unaware of your software doing correction, then how on earth could that make you a liar? (Lying is deliberately telling an untruth.)

I agree with this, no shame in making a mistake when we admit it. Digging our heals in and doubling down to avoid embarrassment is more shameful.

 

[neuroanatomist]

While optical correction is bending light, you don't disagree with the statement that optical correction doesn't stretch light. Arguing about bending light is a bit pointless because that's the whole point of a lens - to bend light such that it lands on the sensor.

The light that is digitally corrected to fill the corners when required still falls on the sensor.

Some lenses deal with this better than others. Some subjects are impacted by this more than others. Measuring CA is what a lot of lens test websites do when they shoot specific subjects to measure lpmm, etc. Your generalizations here are no better than mine.

The difference is that I’ve provided empirical evidence to support my points. Have you? Has anyone who claims that optical correction of geometric distortion is inherently superior to digital correction.

Let me make your day: I don't use distortion correction when processing images, I can't even remember when I last used CA correction.

So you shoot RAW, and you don’t use a lens profile in your RAW converter? I’m skeptical. Especially after your intentionally evasive reply to @AlanF.

 

[David_B]

The point of the question is to lead to a discussion of what happens when we process RAW data and the choice of RAW converters. If you are unaware of your software doing correction, then how on earth could that make you a liar? (Lying is deliberately telling an untruth.)

Good software that does raw conversion gives you the option of whether or not to do correction based on known lens profiles or CA elmination. I leave those check boxes to the default software position - off.. Maybe DPP turns it all on by default, IDK 'cause I don't use it. As I said above/previously, I don't use lens profiles/CA correction and I said that knowing that the software I use doesn't have those things turned on for images that I process.

 

[David_B]

The light that is digitally corrected to fill the corners when required still falls on the sensor.

But the ability to pull apart some of the individual beams is lost.

To go to an extreme point, why even bother with a full frame lens if all we need to do is put an APS-C lens on the front of a full frame model and then stretch that image such that it "fill the picture".. Afterall, what's a few dark corners/boundary between friends if digital corection is ok? Where's the cutoff point between too much stretching vs acceptable stretching?

Canon's asking people using its equipment to take it on good faiith that the dark corners from various lens is acceptable. Or at least I say that because I haven't see Canon say anything with authority on this subject matter and I'm pretty sure if you had then you'd have quoted it by now.

The detail that gets lost in the squashed iamge (it doesn't fill the srnsor, so I'm using "squash" as the term to refer to it being made small) can't be made to reappear with some magic process. Even if you take into account the blur from the AA, there must be less refined data to work from in an image that's only 19.96mm "high".

The difference is that I’ve provided empirical evidence to support my points. Have you? Has anyone who claims that optical correction of geometric distortion is inherently superior to digital correction.

You've eyeballed some images and made some claims that you're asking us to accept on no better grounds than faith.

I don't trust humans to be a good judge of the evidence because humans are unreliable and all too frequently plagued by biases.

So you shoot RAW, and you don’t use a lens profile in your RAW converter? I’m skeptical. Especially after your intentionally evasive reply to @AlanF.

Correct. Using a lens profile is not a requirement of using a raw converter, nor is using CA correction.

Faith is an interesting word to being up in the discussion of this topic because there is practically no verifiable analysis done on it but we're alll excepted to accept the new lay of the land as being ok. Summary, Canon's asking us all to take a huge leap of faith in it.

 

[EricN]

I don't trust humans to be a good judge of the evidence because humans are unreliable and all too frequently plagued by biases.

LIKE YOURSELF, ERICN IS ALSO NOT A FLAWED HUMAN BAG OF MEAT.

 

[P-visie]

LIKE YOURSELF, ERICN IS ALSO NOT A FLAWED HUMAN BAG OF MEAT.

Your profile picture (and mine) suggests otherwise .

 

[roby17269]

But the ability to pull apart some of the individual beams is lost.

To go to an extreme point, why even bother with a full frame lens if all we need to do is put an APS-C lens on the front of a full frame model and then stretch that image such that it "fill the picture".. Afterall, what's a few dark corners/boundary between friends if digital corection is ok? Where's the cutoff point between too much stretching vs acceptable stretching?

The detail that gets lost in the squashed iamge (it doesn't fill the srnsor, so I'm using "squash" as the term to refer to it being made small) can't be made to reappear with some magic process. Even if you take into account the blur from the AA, there must be less refined data to work from in an image that's only 19.96mm "high".

This is how I look at it:

• If the image circle of a lens covers the entire sensor then there is no a priori pixel loss, but the lens that requires the most geometric correction will result in a (slightly) less image quality since more pixels will be "stretched" / extrapolated.
• If it doesn't then there is an additional (small) loss of quality: an optically corrected lens may still require stretching, but the data used to create the corrected image is based on the full mp count of the sensor, while with digitally corrected lens whose image circle does not cover the full sensor, the stretching will be done using less data (less pixels), therefore more pixels are "created" with digitally corrected lenses.

This is based on my own reasoning that, essentially, the less data you interpolate and / or the more data you start from, the better.
I do not have a scientific proof of this. It makes sense to me. But no one has given me reasons to reject my reasoning so far.
So I will continue to believe that optical corrections, all else being equal, are better IQ-wise, and obviously worse size- and weight-wise. Maybe marginally, but better. And therefore I will continue to have a slight preference for optically corrected lenses... the good ones at least

You've eyeballed some images and made some claims that you're asking us to accept on no better grounds than faith.

I don't trust humans to be a good judge of the evidence because humans are unreliable and all too frequently plagued by biases.

@neuroanatomist has freely admitted that his evidence is empirical and therefore potentially imprecise. And it is entirely possible that the differences, while present (imho), are not meaningful enough to make a difference in real life shooting scenarios. But I do not believe that Neuro has an agenda here.

 

[scyrene]

But the ability to pull apart some of the individual beams is lost.

I think your conception of optics is a bit idealistic tbh.

To go to an extreme point, why even bother with a full frame lens if all we need to do is put an APS-C lens on the front of a full frame model and then stretch that image such that it "fill the picture".. Afterall, what's a few dark corners/boundary between friends if digital corection is ok? Where's the cutoff point between too much stretching vs acceptable stretching?

Is your argument here that because an extreme and somewhat contrived situation is unacceptable, that every gradation between that and your ideal setup must also be rejected? If it is a continuum, why is zero the only acceptable position?

Canon's asking people using its equipment to take it on good faiith that the dark corners from various lens is acceptable.

I don't trust humans to be a good judge of the evidence because humans are unreliable and all too frequently plagued by biases.

Faith is an interesting word to being up in the discussion of this topic because there is practically no verifiable analysis done on it but we're alll excepted to accept the new lay of the land as being ok. Summary, Canon's asking us all to take a huge leap of faith in it.

Canon is producing novel lenses with new compromises that weren't possible before. You don't have to buy them. I suspect the alternative, especially in a much smaller market than 20 years ago is that these lenses simply wouldn't exist. More choice is better, no?

As for faith/evidence, you clearly have an entrenched view but haven't presented anything to support it except high-minded principles (such as your comment on "separating beams of light" above), Neuro has asked for evidence. And somehow you are turning that into, he is blinded by faith in the new optics?