White/Grey card necessary? (Page 2): You know, you can use green grass or a cloudless sky.

bmike101 Loc: Gainesville, Florida

junglejim1949 wrote:

Is a White card/Grey card necessary with newer DSLR cameras? If so any recommendation?

You know, you can use green grass or a cloudless sky.

rehess Loc: South Bend, Indiana, USA

Ysarex wrote:

I shoot raw and only need one reference shot of th... (show quote)

Unfortunately, the in-camera JPEG is over-exposed. Both the greenery and flower are lighter than they are in the version created from the ‘raw’ variant ..... especially a light flower works much better when slightly under exposed initially.

Ysarex Loc: St. Louis

rehess wrote:

Unfortunately, the in-camera JPEG is over-exposed. Both the greenery and flower are lighter than they are in the version created from the ‘raw’ variant ..... especially a light flower works much better when slightly under exposed initially.

It would only be unfortunate if I wanted the camera JPEG. I hadn't cleared off that card in the camera from yesterday evening and the camera was sitting on my desk. So I grabbed that to create an example knowing that I had used the white card target to take those photos. Like many modern cameras my camera can re-process a raw file to create a new JPEG. I did that in this case in order to get an auto-wb example. Since the camera did the processing it's an SOOC JPEG. All I had to do was change the WB setting to auto. However I also reduced the exposure by 1 stop since I had shot the original raw with a +1 EC and I knew the JPEG would be overexposed. Seemed the thing to do was generate a new JPEG with the camera EC zeroed.

If you think that JPEG is overexposed imagine it with one stop more exposure. In fact below is the JPEG embedded in the raw file. As you can see I obviously don't want camera JPEGs. I keep my cameras' WB set to unity so when my JPEGs are all green and nuked into oblivion I know I got a good exposure.

Joe

selmslie Loc: Fernandina Beach, FL, USA

rehess wrote:

Unfortunately, the in-camera JPEG is over-exposed. Both the greenery and flower are lighter than they are in the version created from the ‘raw’ variant ..... especially a light flower works much better when slightly under exposed initially.

True. Washed out colors do not mean that the white balance is wrong. It looks about the same in all three versions.

For a JPEG SOOC, overexposure leads to less saturation and under exposure can produce dull colors. It takes experience and understanding to get a JPEG to look right.

It's a lot easier to make corrections to the raw file for an over- or under-exposed image so long as you didn't blow the highlights.

selmslie Loc: Fernandina Beach, FL, USA

Ysarex wrote:

It would only be unfortunate if I wanted the camera JPEG. ...

As we can see, the colors in the leaves are correct. The petals of the flower are very much overexposed and washed out - flat. It's even worse than the SOOC JPEG from page one.

Stick to using the raw file. It's a lot easier for you.

rehess Loc: South Bend, Indiana, USA

Ysarex wrote:

It would only be unfortunate if I wanted the camer... (show quote)

There is no point to using an over exposed in-camera JPEG as an example .... the photographer needs to think about what s/he is doing for the effort to be useful for that purpose.

Strodav Loc: Houston, Tx

Yes, it is a very helpful tool whether you shoot raw or jpg. I use a card with 3 1 1/2" squares, white, 18% gray, and black. It is very helpful in setting exposure at the shoot, and extremely helpful setting white point during PP. If you shoot raw, don't think the metadata suggested white point is correct because it probably isn't. If you shoot jpg, the camera decides your white point for you, and it's probably wrong.

https://www.adorama.com/l/?searchinfo=qp+card+101

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

selmslie wrote:

How does the CCP software resolve the two light colors? By splitting the difference? It's not clear how that would work.

Three light sources might be even trickier - direct sunlight, open shade and stuff under a green or autumn tree canopy.

I would expect that a color balance that was right for a part of the scene primarily lit by one of the three light colors would be wrong for the others.

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

At 20:47 Lazell explains how the CCP software can create a "dual illuminant" profile which resolves two light sources with different colors. I've used it and it works.

User ID

junglejim1949 wrote:

Is a White card/Grey card necessary with newer DSLR
cameras? If so any recommendation?

Completely unnecessary and often misleading/misused.
You have in your hand a million hours of R&D specifically
engineers to free you from averaging methods.

Ysarex Loc: St. Louis

rehess wrote:

There is no point to using an over exposed in-camera JPEG as an example .... the photographer needs to think about what s/he is doing for the effort to be useful for that purpose.

The whole point of the illustration was about WB not exposure. The WB difference shows and that's all I intended to show.

Joe

rehess Loc: South Bend, Indiana, USA

Ysarex wrote:

The whole point of the illustration was about WB not exposure. The WB difference shows and that's all I intended to show.

Joe

You cannot show WB difference accurately unless you are careful in the entire process.

Strodav Loc: Houston, Tx

User ID wrote:

Completely unnecessary and often misleading/misused.
You have in your hand a million hours of R&D specifically
engineers to free you from averaging methods.

This is worth the read: https://www.cambridgeincolour.com/tutorials/white-balance.htm

selmslie Loc: Fernandina Beach, FL, USA

Gene51 wrote:

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

At 20:47 Lazell explains how the CCP software can create a "dual illuminant" profile which resolves two light sources with different colors. I've used it and it works.

That sounds pretty much what I described earlier. You record one pair of color balance values (color temperature and tint) for each light source alone and then somehow magically apply them both to the same image. It's the "magic" part that defies logic.

But the proportion of light from each source will change depending on the direction of the two light sources and the shape of the subject. It's different for a flat sheet or table than it is for a round ball or other solid object. It's also different if one light is coming from a window or the sun (almost a point source) and another is coming from a broader source like the sky.

I'm not convinced that it isn't just something that X-Rite didn't just come up with to promote their product. I would have to see something more convincing, maybe some results.

selmslie Loc: Fernandina Beach, FL, USA

Strodav wrote:

This is worth the read: https://www.cambridgeincolour.com/tutorials/white-balance.htm

Now that's a much better explanation. In particular, note the last section:

IN MIXED LIGHTING

Multiple illuminants with different color temperatures can further complicate performing a white balance. Some lighting situations may not even have a truly "correct" white balance, and will depend upon where color accuracy is most important. ...

Ysarex Loc: St. Louis

rehess wrote:

You cannot show WB difference accurately unless you are careful in the entire process.

Well if I ever decide I want to show WB differences accurately I'll remember that. Did I say that's what I was doing? I just wanted to show how I use a WB reference card and the difference that does show (auto-WB is bluer) satisfies my intent. I wasn't conducting a science experiment.

Joe