Requesting a couple of Quattro shots . .

[xpatUSA]

. . looking for two daylight outside shots (pref. fully sunlit or fully overcast) of the 24-patch color checker card, one shot full res, the other shot low res.

Both shots very slightly out of focus and exposed such that the mid-gray patch #22 is close to RGB 121,121,121 when color-picked in SPP and in sRGB working space. White-balanced in SPP on the mid-gray patch #22.

Both posted here as max quality JPEGs.

To keep file sizes down, it's OK to shoot so that the card fills 1/4 - 1/3 of the frame height and crop before posting.

I'm comparing some Sigma camera models for color accuracy using the existing card L*a*b* values against the L*a*b* values color-picked in card shots.

So far, SD1M, SD14 and DP2s are on-going subjects . . .

 

[TN Args]

Would it help to specify SPP6.3.3 and current firmware on the camera?

 

[TN Args]

Do you need them both taken in one session, or can they be from separate sessions?

 

[xpatUSA]

Do you need them both taken in one session, or can they be from separate sessions?

Either one, although similar light would be nice.

Thanks,

 

[TN Args]

Here is one for full res. I didn't shoot low res at the same time.


sRGB, max JPEG quality , dp0Q with up-to-date firmware, SPP6.3.3, sunlit

SPP settings are all default except WB set on patch 22, and EXP+0.1 to bring patch 22 from 114,114,114 to 119,119,119.

--
Arg

 

[xpatUSA]

Here is one for full res. I didn't shoot low res at the same time.


sRGB, max JPEG quality , dp0Q with up-to-date firmware, SPP6.3.3, sunlit

SPP settings are all default except WB set on patch 22, and EXP+0.1 to bring patch 22 from 114,114,114 to 119,119,119.

Greatly appreciated, Arg.

Sunlit is good - gets it a bit closer to CIELAB's D50.

Thanks!

--
Ted

 

[xpatUSA]

Here is one for full res.

SPP settings are all default except WB set on patch 22, and EXP+0.1 to bring patch 22 from 114,114,114 to 119,119,119.

Thanks for the image, Arg.

Here we are:


Lab color circle at left, can't guarantee the bars are color-perfect on your monitor . .



On the basis of color accuracy, the Quattro shows the very best result so far in my series of tests. It is excellent, when compared with my SD1M - both in chroma and in hue. Only the red patch is slightly off, being a little more saturated and tending slightly towards orange.

I am tempted to speculate that Sigma, perhaps influenced by their Foveon guys, have put a lot of work into getting the colors right for the Quattro technology.

--
Ted

 

[TN Args]

Here is one for full res.

SPP settings are all default except WB set on patch 22, and EXP+0.1 to bring patch 22 from 114,114,114 to 119,119,119.

Thanks for the image, Arg.

Here we are:


Lab color circle at left, can't guarantee the bars are color-perfect on your monitor . .

On the basis of color accuracy, the Quattro shows the very best result so far in my series of tests. It is excellent, when compared with my SD1M - both in chroma and in hue. Only the red patch is slightly off, being a little more saturated and tending slightly towards orange.

I am tempted to speculate that Sigma, perhaps influenced by their Foveon guys, have put a lot of work into getting the colors right for the Quattro technology.

--
Ted

Well, that is pleasing. I doubt if you would have had such an excellent result prior to 21 Feb 2016, when Sigma released SPP v6.3.2 and a camera firmware update, with the words "It is now compatible with the RAW data (X3F file) of the latest firmware which improves color reproduction of the dp Quattro series cameras."

--
Arg

 

[TN Args]

Low res dp0, otherwise identical to earlier example that was high res

Hope this one is usable too.

--
Arg

 

[xpatUSA]

Low res dp0, otherwise identical to earlier example that was high res

Hope this one is usable too.

A well-executed shot, Arg!

Results are quite interesting, pedantically speaking.

Low vs. High:


Lo res at left



Overall, low res is just slightly less colorful than high. The low res tends toward the Merrill Standard but is much more accurate in hue than the Merrill, with respect to the Card, IMHO:


both low and high res compared with the x-Rite card data.



If ever I get a sd Quattro, I'll be a mainly low res shooter - like Tom Schum.

Thanks again for your samples . . .

--
Ted

 

[TN Args]

Here is one for full res.

SPP settings are all default except WB set on patch 22, and EXP+0.1 to bring patch 22 from 114,114,114 to 119,119,119.

Thanks for the image, Arg.

Here we are:


Lab color circle at left, can't guarantee the bars are color-perfect on your monitor . .

On the basis of color accuracy, the Quattro shows the very best result so far in my series of tests. It is excellent, when compared with my SD1M - both in chroma and in hue. Only the red patch is slightly off, being a little more saturated and tending slightly towards orange.

I am tempted to speculate that Sigma, perhaps influenced by their Foveon guys, have put a lot of work into getting the colors right for the Quattro technology.

--
Ted

Hi Ted,

regarding your comment on red above, I see the changes listed for SPP Ver.6.4.0 include the following: "It improves the rendering performance of red colored and highlighted parts of the image when the sd Quattro and dp Quattro’s RAW data is developed."

Potentially good news. (Except for the capitalised 'RAW' ;-) )

--
Arg