[thibs]

As for Nikon, their S line for the Z-mount is quite affordable and when turning profile corrections of in a raw converter that allows for that, like Capture one, you will see that these prime lenses, like the 50mm f1.8 and the 85mm f1.8 do not rely heavily on software correction, or manipulation as you like to call it.

That proves nothing of what you're implying.
What you states would tend to prove that the embedded corrections metadata can be 'not used' by CaptureOne. Fine by the way, that's good.
Some manufacturers are said to cook the RAW itself, not just embed metadata for corrections by RAW software.
Capture One can't disabled cooked RAW (if it is cooked, I have no idea).

[Mistral75]

(...)
Some manufacturers are said to cook the RAW itself, not just embed metadata for corrections by RAW software.
Capture One can't disabled cooked RAW (if it is cooked, I have no idea).

Lens corrections are applied to image files, after demosaicing, not to unprocessed binary files (RAW files). This is why they are included as correction metadata, not 'RAW cooking'.

[Class A]

There is no such thing as a separate "Bokeh CA". It simply is LoCA.

Incorrect.

The green/magenta in front of behind the focus plane is LoCA. It is precisely green and magenta, because the red/blue light doesnt converge in the focus plane as it should.

When there is a lack of convergence in the focus plane then, yes, it is referred to as LoCA (Longitudinal CA).

However, the green and and magenta in out of focus areas are -- by definition -- not caused by colours not converging the focus plane.

Since you seem to be unable to follow my explanations on your own and perhaps distrust my knowledge on the matter, perhaps it will help you to know that @ProfHank has referred to "Bokeh CA" as a "scientific term", and that @falconeye (Ph.D. in Physics) has written "Bokeh CA isn't an aberration, it isn't Lat. or Long. CA. But it's still cuased by the lens and proportional to aperture and glass dispersion.".

Hope this helps.

[Serkevan]

Incorrect.


When there is a lack of convergence in the focus plane then, yes, it is referred to as LoCA (Longitudinal CA).

However, the green and and magenta in out of focus areas are -- by definition -- not caused by colours not converging the focus plane.

Since you seem to be unable to follow my explanations on your own and perhaps distrust my knowledge on the matter, perhaps it will help you to know that @ProfHank has referred to "Bokeh CA" as a "scientific term", and that @falconeye (Ph.D. in Physics) has written "Bokeh CA isn't an aberration, it isn't Lat. or Long. CA. But it's still cuased by the lens and proportional to aperture and glass dispersion.".

Hope this helps.

But the reason of Bokeh CA existing is that red and green converge at different distances from the focus plane. If it depends on glass dispersion it by definition *is* an optical aberration.
EDIT: I think it would be easier if people posted examples of what they are referring to with the different aberrations. The inconsistent nomenclature is getting confusing .

[Class A]

But the reason of Bokeh CA existing is that red and green converge at different distances from the focus plane.

No.

As I have written a number of times before, it is theoretically possible to design a lens such that all three colours converge in the same focus plane, i.e., a lens that has zero LoCA.

Such a lens will still have Bokeh-CA, though, because due to dispersion the different colours, i.e., wavelengths, have to converge at different distances before or behind the focus planes.

One could tune LoCA in such a way that Bokeh-CA is zero for a certain plane in the out-of-focus region (which would leave non-zero LoCA in the focus plane, of course).
The two concepts are related (both caused by dispersion) but they are not the same.

If one throws them into the same bag, one might as well through LoCA and LaCA into the same bag as well.

If it depends on glass dispersion it by definition *is* an optical aberration.

Again, that's not correct.

Optical aberration: "In an imaging system, it occurs when light from one point of an object does not converge into (or does not diverge from) a single point after transmission through the system. "

This refers to points in focus. Bokeh-CA is formed by points that are not in focus.

One can minimise LoCA aberrations to zero (theoretically, for a number of wavelengths) but one cannot do that with Bokeh-CA using lenses with residual dispersion.

[MMVIII]

It almost looks like the line(not curve anymore) is going past 100% at some point.

The number of this post says it all...

[Kunzite]

No.

As I have written a number of times before, it is theoretically possible to design a lens such that all three colours converge in the same focus plane, i.e., a lens that has zero LoCA.

OK...

Such a lens will still have Bokeh-CA, though, because due to dispersion the different colours, i.e., wavelengths, have to converge at different distances before or behind the focus planes.

So "all" wavelengths would converge in the same focus plane, but at different distances? I'm not sure I get it...

[Class A]

I'm not sure I get it...

Have a look at this image here:



Even if all three colours converged at the same spot on the sensor (behind the lens), which they don't quite do in the above example, then they would diverge after having met in one point.
That's because they come in at slightly different angles.
So, even if you have zero LoCA in the plane of focus (no colour fringes for points in focus), you'll still get coloured bokeh (i.e., Bokeh-CA) around edges.

In the following image (ignore the top part which illustrates the effects of an apodization filter) you can see how a point that isn't in focus converges before the sensor (in this case, because it is too far away) and hence the sensor records the rays that have already started to diverge.



Since the colours diverge at different rates, one doesn't get a colour neutral blur, i.e., one will see a coloured blur (the Bokeh-CA) around edges.

I hope this helps.

[Kunzite]

Thanks. My mind is clouded - it's too late here - and I'll re-read tomorrow, but it seems to make sense

[robbiec]

The number of this post says it all...

It's the Devil's own 85?

"Here is Wisdom. Let him that hath understanding count the number of the beast..."

*or chart I suppose

[monochrome]

It's the Devil's own 85?

"Here is Wisdom. Let him that hath understanding count the number of the beast..."

*or chart I suppose

That's a demon whispering in your ear.

I ain't gonna work on Maggie's farm no more
I ain't gonna work on Maggie's farm no more
Well, I try my best
To be just like I am
But everybody wants you
To be just like them

[thibs]

Didn't see anyone claim that a 24 would also be a Star (or Ltd) lens. Just the focal length was mentioned that I've seen on this specific example.

I'm fairly certain I'm not in need of a lecture on Ltd. vs Star and what the general design goals would be for those two families of lenses.


To Norm's point about web polls, I have doubts that folks voting on a web poll are steering product lineup that directly at Ricoh Imaging, but who knows. Maybe the thought is that a Ltd 21 and Ltd 31 sandwiching a Star 24 has that section of the focal length spectrum covered. A killer 24 seems nice although I fear how large/heavy it would be as a Star family member.

This one wasn't *that* big (considering).
FA* 24/2 AL [IF] | The K-Mount Page

[thibs]

Lens corrections are applied to image files, after demosaicing, not to unprocessed binary files (RAW files). This is why they are included as correction metadata, not 'RAW cooking'.

Well I sincerely hope it is so. Though I still have my doubts.

[clackers]

Technically, what your image shows is "Bokeh CA", not CA (in the technical sense of the latter term).

?

It is exactly Longitudinal Chromatic Aberration, Class A!

And please, 'Bokeh CA' is not an optics term.

[thibs]

edit: I think it would be easier if people posted examples of what they are referring to with the different aberrations. The inconsistent nomenclature is getting confusing :d.

+100000