[Serkevan]

I expect Ricoh Imaging will publish yet another apology for not being able to meet the demand.

Most likely, the lens is pretty low volume and there are certainly a bunch of people who kept their jobs while not being able to spend their money outside... that means lens retail therapy! . I'll be happy to see such an apology even before the release date - it will mean that preorders exceeded expectations.

[normhead]

A 24mm lens after the 21 comes to market seems like crowding at one end of the spectrum. Something 26 to 28 would perhaps fit nicer between the 21 and 31 primes.

But their ideas and my ideas seem to rarely coincide.

They go by web poll demand. And if you've ever looked at those, you'd know your chances of aligning with demand is pretty slim. But how great would it be to actually want every lens Pentax's polls tell them to make?

[Class A]

Nikon is cheating with lens corrected manipulated raw data same as Sony, ...

Is there any evidence for that?

[normhead]

Most likely, the lens is pretty low volume and there are certainly a bunch of people who kept their jobs while not being able to spend their money outside... that means lens retail therapy! . I'll be happy to see such an apology even before the release date - it will mean that preorders exceeded expectations.

Exactly, selling out the first run means they exceeded their break even quota for production line set up and R&D and will be in position to reduce the price soon. Especially if it happens before the first production line is shut down, enabling them to just keep on trucking and avoiding new start up costs.

[Kunzite]

Is there any evidence for that?

A quick search:
Disabling Z7 lens corrections for ACR/LR: Nikon Z Mirrorless Talk Forum: Digital Photography Review

[Class A]

Plenty of CA.

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

(Longitudinal) CA is defined as the chromatic aberration in the focus plane, i.e., it describes the level of colour fringing for objects in the focus plane caused by the failure of all colours to be focused on exactly the same plane. (Lateral CA is the failure to focus all colours with the same magnification, but we can ignore this type of aberration for now.)

The greenish and purplish discolouration we see on focus charts or on out of focus twigs is caused by colours not converging on out of focus objects. A good name for this particular aberration is "Bokeh CA" or rather "Toneh CA".

Guess what, here's the Pentax DFA*50, that DPR maligned but didn't actually measure. Why, it's *less* than one pixel.

Well, here you may see an example of why the difference between (Lo)CA and Bokeh-CA can matter.
A lens may measure extremely well for actual LoCA but may show distinct colouration in out of focus areas.

I'm not saying the HD D-FA* 50/1.4 is an example for that.
I'm also not trying to defend DPReview. Most of the time, when reviewing Pentax equipment, they don't know what they are doing, mess up something critical, and blow up any tiny issue to the size of Olympus Mons (Everest won't do it when it comes to Pentax). So no, I'm not giving DPReview any pass.

Just pointing out that it can pay off to be precise about the difference between in-focus CA (that's what "Longitudinal CA" and "Lateral CA" refer to), and "Bokeh-CA".

[Class A]

A quick search:
Disabling Z7 lens corrections for ACR/LR: Nikon Z Mirrorless Talk Forum: Digital Photography Review

Wow!

The amount of default correction is unbelievable!

I bet DPReview kicked up a storm about this.

Or perhaps they didn't...

[Serkevan]

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

(Lo) CA is defined as the chromatic aberration in the focus plane, i.e., it describes the level of colour fringing for objects in the focus plane caused by the failure of all colours to be focused on exactly the same plane.

The greenish and purplish discolouration we see on focus charts or on out of focus twigs is caused by colours not converging on out of focus objects. A good name for this particular aberration is "Bokeh CA" or rather "Toneh CA".


Well, here you may see an example of why the difference between (Lo)CA and Bokeh-CA can matter.
A lens may measure extremely well for actual LoCA but may show distinct colouration in out of focus areas.

I'm not saying the HD D-FA* 50/1.4 is an example for that.
I'm also not trying to defend DPReview. Most of the time, when reviewing Pentax equipment, they don't know what they are doing, mess up something critical, and blow up any tiny issue to the size of Olympus Mons (Everest won't do it when it comes to Pentax). So no, I'm not giving DPReview any pass.

Just pointing out that it can pay off to be precise about the difference between in-focus CA (that's what "Longitudinal CA" and "Lateral CA" refer to), and "Bokeh-CA".

Isn't the longitudinal CA the one that would be called "Bokeh CA" (or spherochromatism if we get technical)? With lateral CA being present in the plane of focus and getting worse at the edges of the image. I'm nitpicking the names, though, because the CA shown in Clackers' image is spherochromatism/Bokeh CA as you said (and exists for the reasons you mentioned).


My question remains, though. Nikon and Sony correct distortion and aberrations automatically, but that's not different from applying the one-click lens profile and purple-fringe-removal in Lightroom. What's interesting to know is if they also remove spherochromatism because that one cannot really be eliminated without losing color information from the picture - it's a pesky thing to have sometimes.

[monochrome]

24 in the future.

Bookmarked

Dont think Many pentaxians Will buy this lense for 2K

Enough will buy it to make it profitable.

I do not wish.
I hope 35，too.

4 DFA* Primes . . . . . .

A 24mm lens after the 21 comes to market seems like crowding at one end of the spectrum. Something 26 to 28 would perhaps fit nicer between the 21 and 31 primes.

But their ideas and my ideas seem to rarely coincide.

Distinguishing DFA Limited from DFA* is a critical element of lens selection.

IMO DFA Limited lenses will remain true to the classic film era rendering that promotes the central figure in the photo - a 3D pop effect - and will be small(er), metal, jewel-like lenses with pixie dust, while DFA* lenses will be sharp across the entire frame, heavily corrected in the design (not software lens profile correction), probably have notably pleasing bokeh and color transmission, will be larger, heavier and more expensive. They’re intentionally designed to resolve higher resolution sensors coming in the future.

Different lens lines for different final output goals, so a DFA Limited 21 and a DFA*24 dies not mean too close a FL. DFA* and DFA Limiteds are not necessarily interchangeable.

[Class A]

Isn't the longitudinal CA the one that would be called "Bokeh CA" (or spherochromatism if we get technical)?

No, technically not.

Apochromatic lenses can achieve next to no Longitudinal CA in the plane of focus but still exhibit Bokeh CA.

The aberration measured with respect to Longitudinal CA is just the amount of colour fringing caused by objects in the focus plane. The same applies to Lateral CA, of course.

Bokeh-CA is different from the two CA measurements above because it applies to objects that are not in the focus plane.

I would always expect some correlation between Longitudinal CA and bokeh CA but they are two different concepts.

[Class A]

24 in the future.

I'll probably prefer this over the 21mm LTD.

I love my three FA LTDs but 21mm seems a bit too wide for me personally.

I look forward to seeing user-created 21mm LTD sample images, but I'm pretty sure I'll find the angles to be too exaggerated.

[Class A]

wow, that is such a poor picture to put there full size

I agree.

The lighting is really poor, with bright spots on her chin and back shoulder.

The red of the lipstick is breaking up into two different hues of red as well.

The model's expression is not quite there either.

The image still communicates that the lens is great, but as an image as such, it is pretty bad, in my view.

[pres589]

Distinguishing DFA Limited from DFA* is a critical element of lens selection.

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.

[Class A]

There's actually 12 full sized sample images....

Thanks, some really nice ones among these.

[Serkevan]

No, technically not.

Apochromatic lenses can achieve next to no Longitudinal CA in the plane of focus but still exhibit Bokeh CA.

The aberration measured with respect to Longitudinal CA is just the amount of colour fringing caused by objects in the focus plane. The same applies to Lateral CA, of course.

Bokeh-CA is different from the two CA measurements above because it applies to objects that are not in the focus plane.

I would always expect some correlation between Longitudinal CA and bokeh CA but they are two different concepts.

Curious, one would expect longitudinal aberrations to be along the optical axis (thus being Bokeh CA): Longitudinal and lateral chromatic aberration

Just for the record my optics knowledge is rustier than a rusty nail, and the Internet is being mighty confusing about the topic