Need more knowledge on exposure

[MiFleur]

I have combined 2 shots of my green tea cup
the image to the left with my Nikon D90 and the Nikon AF 60mm, F2.8 Macro lens
the image to the right with the Nikon D600 and the same lens.
My goal was to try to understand how the camera will record the light, if one was more sensitive to light than the other.
The light source was the same even though the angle of the capture is slightly different.
I have reduced the size of the image from the D600 to have similar sizes

I wrote down below each image the exposure value changed in camera raw, brightness was at zero
How do you explain that the D600 at ISO 100 needed less exposure adjustment than the D90 at ISO 200 ?

 

[The_Traveler]

the internal light meters are calibrated differently.

 

[KmH]

And they are different sensors.

The D90 metering sensor is a 420 segment RGB sensor, while the D600's is a 2,016 pixel RGB sensor.

 

[MiFleur]

And they are different sensors.

The D90 metering sensor is a 420 segment RGB sensor, while the D600's is a 2,016 pixel RGB sensor.

Thanks I read more on the characteristic of the sensors, and it explains quite will what I was looking for.

Much appreciated!

 

[Vautrin]

the interesting question is if you can adjust color profile so they produce exactly the same colors... or if the colors of the d600 is simply out of gamut of the colors of the d90 (my guess)

 

[amolitor]

Honestly I think the differences are more in the colors than the values. The backgrounds, and the table appear to be identically exposed. The whites on the cups are pretty darn similar too. There might be a slight difference in the rendering curve here, giving the middle and/or whiter tones a tiny lift.

It's hard to be sure, though, since the color renditions are quite different. The more yellow rendition on the right will certainly appear brighter, even if it is not.

 

[Patrice]

Am I missing something here?

If you wanted see how the two cameras compared at a given exposure, why did you not take both photos at the same exposure?

The d90: ISO 200, f/3.2, 1/60 sec
The d600: ISO 100, f/3.2, 1/60 sec

There is a one stop difference in the exposures, maybe that is one of the reasons you did not get the same value of exposure adjustment required. The two photos you show are also not equivalent. After your adjustments, the d90 image is still darker.

 

[amolitor]

Oh, the exposures are different? Totally missed that, oops.

I suppose it's less of a puzzle, now. You seem to have adjusted the images to have similar apparent exposures, and you matched up the backgrounds pretty darn close? But the color rendition is different. Well, that's gonna happen. Try it with just one camera at ISO 100 and ISO 200 and do the same thing, I bet you see some color shift. Maybe not as much as when you do it with two completely different sensors, but some.

Also, did you have the white balance settings the same on the two cameras?

I'm no longer sure what the aim of this experiment is.

 

[MiFleur]

Honestly I think the differences are more in the colors than the values. The backgrounds, and the table appear to be identically exposed. The whites on the cups are pretty darn similar too. There might be a slight difference in the rendering curve here, giving the middle and/or whiter tones a tiny lift.

It's hard to be sure, though, since the color renditions are quite different. The more yellow rendition on the right will certainly appear brighter, even if it is not.

I guess that to be able to make everything exactly the same, I would need to check the settings of the cameras, I think the D600 is set to Srgb and the D90 is set to Adobe 1998. I did not think to check that part and I am not sure if Camera raw reads default settings according to the camera or only a general default. I know that on the D-90 it does default lens correction when I use the 18-200 lens. I probably need to check these setting as well.

Thanks for sharing the info. I will certainly do more test, it helps me to understand exposure better.

 

[MiFleur]

Am I missing something here?

If you wanted see how the two cameras compared at a given exposure, why did you not take both photos at the same exposure?

The d90: ISO 200, f/3.2, 1/60 sec
The d600: ISO 100, f/3.2, 1/60 sec

There is a one stop difference in the exposures, maybe that is one of the reasons you did not get the same value of exposure adjustment required. The two photos you show are also not equivalent. After your adjustments, the d90 image is still darker.

I should have, thanks for noticing, but what is weird is that the D90 gives a noticibly darker image.

 

[Vautrin]

google color management and color gamuts

 

[MiFleur]

Oh, the exposures are different? Totally missed that, oops.

I suppose it's less of a puzzle, now. You seem to have adjusted the images to have similar apparent exposures, and you matched up the backgrounds pretty darn close? But the color rendition is different. Well, that's gonna happen. Try it with just one camera at ISO 100 and ISO 200 and do the same thing, I bet you see some color shift. Maybe not as much as when you do it with two completely different sensors, but some.

Also, did you have the white balance settings the same on the two cameras?

I'm no longer sure what the aim of this experiment is.[/QUOTE
The exposures were given by the auto adjustment in camera raw, I have leveled everything except the exposure slider
I am surprised too by the difference in color, but the white balance was both on automatic.

Two purpose to my test
1) To understand exposure better, as you see there are a few things I forgot to check, I may have gray hair but I am still learning, I think it's an non-ending process...
2) I had a weird hissing noise with one of my lens after working in the cold, and I have started to check and compare both cameras performances to see if there is anything that is malfunctioning.

Thank you so much for sharing your knowledge!

 

[MiFleur]

google color management and color gamuts

I know it is quite complex, thanks for the recommendation, will do!