Web Analytics RiceHigh's Pentax Blog: November 2021

Friday, November 26, 2021

Pentax Online Event on November 27 (at Japan)

The event will be held tomorrow at Tokyo (in Japanese):

https://www.ricoh-imaging.co.jp/japan/event/2021/pentax_meeting_online2021/

(in Japanese)

Here is the tentative programme and rundown for the event:

- Development stories of the D-FA 21mm F2.4 Limited including interview with the developers who will talk more about the design and application of the lens.

- The evolution of K-3 Mark III will continue. New features are to come, via new firmware and other - But what does "other" means? What's the mean to do it?

- About future PENTAX products. The person in charge of product planning will reveal something.

- Q&As - Questions are to be submitted to Pentax in advance via form.

Let's see what will be told by then.

Tuesday, November 02, 2021

The K-3 III Image Corner Blur Issue Strikes Again

Camera-gear YouTuber Kobie M-C tested the K-3 and K-3 III side by side and here is his report:

https://www.youtube.com/watch?v=pH2eQD6fpA0

And, his quick textual comment follows, quoted:

"Some interesting things occurred during the shooting for this test. It seems the K-3 Mark III sensor out resolves some lenses including the DA 50 1.8 which surprised me. It's a good lens, nice and sharp, but just not on the K-3 Mark III. I tried live view, electronic shutter, Focus fine adjustments from -10 to +10 and it was still soft. F/1.8, 2.8, 4 (when the lens is sharpest) and still the same result. This might be what some professional reviewers are experiencing when they mention soft images."

The below quick snapshot refers for easy reference:

(Click to Enlarge)

In fact, Kobie's finding is exactly the same as what I found last time with my new K-3 III when it was tested against my KP side by side.

As the increase in the total number of pixels of the K-3 III against the K-3 and KP is really marginal, I think there exists another factor to cause the decrease in resolution in image corners for images produced by the K-3 III, even for the same old lenses, which used to be optically good. 

I suspect the (different) design of the micro-lenses and (different) assumed incident angle of light should come into play. Indeed, the new 26MP Sony sensor was first used in the Fujifilm X-T4 which has a much short back focal distance. Later on, Ricoh got this sensor and put it into the K-3 III. However, the new sensor is not that highly compatible with many of the old glass in optical sense, especially at the image corners and edges, and that wide angle lenses suffer more than standard and tele ones.

I have verified this with the latest glass marketed by Pentax, in particular, like the D-FA* 16-50 PLM, which shows a much lesser problem for the aforesaid issue and phenomenon. 

Related Article:

When the Sensor Outresolves the Lens