Author Topic: The Pentax K1: True Color per Pixel  (Read 7510 times)

Bjørn Rørslett

  • Fierce Bear of the North
  • Administrator
  • ***
  • Posts: 8252
  • Oslo, Norway
Re: The Pentax K1: True Color per Pixel
« Reply #15 on: May 20, 2016, 10:40:50 »
To clarify: while the label 'Nikongear' reflects the historic roots of the original web forum, members have differentiated over time in their choice of gear to use. Many are now multi-brand users, including most admins of the Core Team. We kept NG as a 'brand name' and at the same time encompass every camera brand in actual use amongst members. This simply is to respect members' choices. For the very same reason, any bashing of products based on brand or flame wars will not be tolerated.

I for one really welcome Michael's experiences with the Pentax K-1 and the pixel-shift technology. It is a bonus for NG to be able to have such technical discussions running in our forum.

Michael Erlewine

  • Close-Up Photographer
  • NG Supporter
  • **
  • Posts: 2067
  • Close-Up with APO
    • Spirit Grooves
Re: The Pentax K1: True Color per Pixel
« Reply #16 on: May 20, 2016, 11:03:19 »

I for one really welcome Michael's experiences with the Pentax K-1 and the pixel-shift technology. It is a bonus for NG to be able to have such technical discussions running in our forum.

Yes, I am experimenting with (first the Pentax K3II, which I bought to presage the coming of the K1) and now the Pentax K1, and I have been corresponding with Lloyd Chambers, who is really the great pioneer to my knowledge here with the Pentax K1 (and many other areas). Over the years, there have been a few great testers, of which our own Bjørn Rørslett has been key in educating me. Then there was Thom Hogan, but he does not test and report on lenses, etc. as much as he used to. He now more reports on the overall camera scene. But aside from Bjørn Rørslett, Lloyd Chambers continues to power-on, looking at a lot of new equipment and reporting on it in his columns. It must be very expensive to keep up with all that Chamber's reports on. His column work has saved me a small fortune. 

I am glad we kept the original title "Nikongear," because that name captured and (continues to capture) a certain spirit, not only in name, but in the particular eclectic collection of those who post here. I am a child of the Sixties, so the kind of sharing and freedom I find here is just what my life has been all about anyway.

MichaelErlewine.smugmug.com, Daily Blog at https://www.facebook.com/MichaelErlewine. main site: SpiritGrooves.net, https://www.youtube.com/user/merlewine, Founder: MacroStop.com, All-Music Guide, All-Movie Guide, Classic Posters.com, Matrix Software, DharmaGrooves.com

Erik Lund

  • Global Moderator
  • **
  • Posts: 6529
  • Copenhagen
    • ErikLund.com
Re: The Pentax K1: True Color per Pixel
« Reply #17 on: May 20, 2016, 11:09:57 »
Thanks Michael! Nice of you to comment on my humble images.

I still think the whole idea behind any APO lens is to correct color, but newer mind - Fell free to continue your journey ;) No problem!

Very interesting findings on what might be the future standard on tripod/studio cameras
Erik Lund

Michael Erlewine

  • Close-Up Photographer
  • NG Supporter
  • **
  • Posts: 2067
  • Close-Up with APO
    • Spirit Grooves
Re: The Pentax K1: True Color per Pixel
« Reply #18 on: May 20, 2016, 11:24:43 »
I still think the whole idea behind any APO lens is to correct color, but newer mind - Fell free to continue your journey ;) No problem!

Very interesting findings on what might be the future standard on tripod/studio cameras

Over these last years, I too, as you must know, have championed APO lenses for what they brought to color by removing the various aberrations (fringing, etc.). This lets the color be seen. However, I did not pay enough attention to the disadvantages of the Bayer interpolation method, per se, and the fact that it is an impure approach. It can never be definitive because it is, by definition, an approximation. No amount of fiddling will make it represent each pixel/site in a unique way.

Pixel-shifting is just in its infancy as far as products we can use, but the concept of true color for each pixel/site (however they do it) makes sense. As mentioned, I saw this in the Sony A7s, as far as dynamic range and luminosity is concerned by just allocating a deeper “well” for each site. Pixel-shifting is doing something similar by removing the approximation achieved with the Bayer system and replacing it with unique pixel/sites, with no smearing of adjacent sites together.

As a close-up photographer who shoots still subjects, this is like going to heaven. Of course I felt the same way when the D810 came out, etc. Anyway, I see progress and light at the end of the tunnel, where Canon and Nikon have done little for me lately.
MichaelErlewine.smugmug.com, Daily Blog at https://www.facebook.com/MichaelErlewine. main site: SpiritGrooves.net, https://www.youtube.com/user/merlewine, Founder: MacroStop.com, All-Music Guide, All-Movie Guide, Classic Posters.com, Matrix Software, DharmaGrooves.com

Erik Lund

  • Global Moderator
  • **
  • Posts: 6529
  • Copenhagen
    • ErikLund.com
Re: The Pentax K1: True Color per Pixel
« Reply #19 on: May 20, 2016, 11:37:00 »
Very true! Nikon, Sony and Canon are so far playing safe - Not venturing off their beaten path,,, but we might see some of the medium format boys starting up on this - Imagine a Pentax 6x7 sensor with pixel shift - But the imagine the price for a lens going on such a beast...

I would love to shoot the Leica Monochrom - It's also Bayer-less,,, Although only B&W ;)
Erik Lund

Andrea B.

  • Technical Adviser
  • *
  • Posts: 1671
Re: The Pentax K1: True Color per Pixel
« Reply #20 on: May 20, 2016, 14:45:05 »
I've searched (waded) through patents and chemistry papers looking for info about dyes used in Bayer sensors and how they react to light. It is apparently an interesting & complex process.

But I wonder why each sensor/sensel thing (whatever they are called) can't just directly detect the wavelength of the light and translate that into the RGB colour?? Is it a problem in miniaturization? If we had that kind of wavelength detecting sensor, then a menu setting would let us change our visible cameras easily into an IR cam or a UV cam or a Red channel only cam --- and so forth. That's my dream!!



bjornthun

  • Guest
Re: The Pentax K1: True Color per Pixel
« Reply #21 on: May 20, 2016, 15:15:37 »
I've searched (waded) through patents and chemistry papers looking for info about dyes used in Bayer sensors and how they react to light. It is apparently an interesting & complex process.

But I wonder why each sensor/sensel thing (whatever they are called) can't just directly detect the wavelength of the light and translate that into the RGB colour?? Is it a problem in miniaturization? If we had that kind of wavelength detecting sensor, then a menu setting would let us change our visible cameras easily into an IR cam or a UV cam or a Red channel only cam --- and so forth. That's my dream!!
The photosensitive part in a pixel just creates an electric current when hit by light of a wavelength to which it is sensitive. Unfortunately it has no way of knowing the wavelength of the light that hit it. This is an inherent property of the photosensitive material available to us today. Actually it works like a monochrome or b&w film.

bjornthun

  • Guest
Re: The Pentax K1: True Color per Pixel
« Reply #22 on: May 20, 2016, 15:52:54 »
A Russian photographer made colour photographs with black & white film from Imperial Russia at the beginning of the 20th century by using three cameras, equipped with respectively red, green and blue filters.

Link: https://en.m.wikipedia.org/wiki/Sergey_Prokudin-Gorsky

Probably could be done with three Leica Monochroms as well.  :o