For most of my life listening to music and playing around with cameras and lenses have been my principle hobbies.
This means I have inevitable supplementary hobbies of HiFi and Photography.
Recent posts about equalisation and preference in audio remind me of the similar equivalents I have been looking into in optics for years.
My particular interest has been lenses, and I have studied them for over 50 years.
Whilst sharpness, field flatness, chromatic aberration, vignetting and distortion are easily measured their importance is application dependant.
Distortion is very important in architectural photography, and shortcomings obvious on subjects with straight lines but is non-obvious on most subjects and perspective distortion an inevitable result of wide angle shots so not correctable as such anyway but distortion, in general, is easily corrected in digital photography.
Flatness of field is important for copying but probably never noticed photographing 3D subjects, even with fast lenses, since most of the field won't be sharp anyway.
There are a couple of, IMO, crucial aspects of lens performance that I have never seen a convincing way of measuring.
One is known as boke, the rendition of the out-of-focus (oof) part of the field. With fast lenses this is very important to the look of the picture since almost the whole field will be oof. The Canon Lens Work books state that having both sagittal and radial MTF graphs running close together is an indication of good boke, but no technical explanation is given and almost zoom lenses achieve this though several of their excellent tele lenses do.
The other lens feature that is super critical IME is flare sensitivity, both to in frame and out of frame light sources. I have never seen a measurement parameter for this yet IME it is the shortcoming most likely to completely ruin a photograph.
When the four-thirds standard was agreed for digital photography since it was a new, post digital standard, digital correction of lens aberrations, mainly distortion, was incorporated. This meant lenses could be optimised much smaller and lighter than they could otherwise have been.
Legacy lenses could not do this since they would be fitted to cameras with film or no standard for digital correction.
My guess is now that almost nobody uses film and all camera makers have correction files for their lenses to supply to Adobe etc. maybe all lenses are more compromised in some areas to make the more extreme ones feasible.
AFAIK distortion, vignetting and chromatic aberrations are correctable to a certain degree.
Flare certainly isn't, nor is flatness of field. Poor boke probably isn't either, two of these are crucial to photography.
So it seems to me that optics which are so often discussed simply in terms of sharpness, when this is only one of many important lens characteristics, are much less "correctable" than audio, which is much simpler to measure everything audible.
This means I have inevitable supplementary hobbies of HiFi and Photography.
Recent posts about equalisation and preference in audio remind me of the similar equivalents I have been looking into in optics for years.
My particular interest has been lenses, and I have studied them for over 50 years.
Whilst sharpness, field flatness, chromatic aberration, vignetting and distortion are easily measured their importance is application dependant.
Distortion is very important in architectural photography, and shortcomings obvious on subjects with straight lines but is non-obvious on most subjects and perspective distortion an inevitable result of wide angle shots so not correctable as such anyway but distortion, in general, is easily corrected in digital photography.
Flatness of field is important for copying but probably never noticed photographing 3D subjects, even with fast lenses, since most of the field won't be sharp anyway.
There are a couple of, IMO, crucial aspects of lens performance that I have never seen a convincing way of measuring.
One is known as boke, the rendition of the out-of-focus (oof) part of the field. With fast lenses this is very important to the look of the picture since almost the whole field will be oof. The Canon Lens Work books state that having both sagittal and radial MTF graphs running close together is an indication of good boke, but no technical explanation is given and almost zoom lenses achieve this though several of their excellent tele lenses do.
The other lens feature that is super critical IME is flare sensitivity, both to in frame and out of frame light sources. I have never seen a measurement parameter for this yet IME it is the shortcoming most likely to completely ruin a photograph.
When the four-thirds standard was agreed for digital photography since it was a new, post digital standard, digital correction of lens aberrations, mainly distortion, was incorporated. This meant lenses could be optimised much smaller and lighter than they could otherwise have been.
Legacy lenses could not do this since they would be fitted to cameras with film or no standard for digital correction.
My guess is now that almost nobody uses film and all camera makers have correction files for their lenses to supply to Adobe etc. maybe all lenses are more compromised in some areas to make the more extreme ones feasible.
AFAIK distortion, vignetting and chromatic aberrations are correctable to a certain degree.
Flare certainly isn't, nor is flatness of field. Poor boke probably isn't either, two of these are crucial to photography.
So it seems to me that optics which are so often discussed simply in terms of sharpness, when this is only one of many important lens characteristics, are much less "correctable" than audio, which is much simpler to measure everything audible.