[Guest]

Hi fellows,



I have a question about the rendering of greens: it seems that often my Canon 5D gets the white balance wrong in scenes (such as woodlands) where there is a lot of green. It seems that the colour range is limited - in low light particularly a lot of the dark greens take on an almost turquoise cast.



When I shoot analogue, I get a beautiful rendering of a multitude of different shades of green, but my DSLR never really matches this.



Am I doing something wrong in the processing, or is this a problem of the sensor technology?



Thanks in advance for any advice.

[Guest]

Do you shoot in RAW or JPEG?

If RAW: Which Converter is used and talk about the settings.

If JPEG: Please tell us your camera settings.



Do you have those issues when watching your pictures on the computer screen or/and with your prints?

If first only: Is your monitor calibrated?



Please check the RGB values of a picture: All below 255 in the area where the problem occurs?





Ciao, Walter

[Guest]

The RGB sensors in digital cameras behave different than film: As soon as you overexpose the green channel only, which may happen when shooting very green subjects, the color mix of green (clipped due to overexposure) with red and blue (which are not clipped in this case) is out of balance and you get weird greens, that have too much blue and red in.

As Walter said, you should check an RGB histogram to be sure no channel is clipped.



Another issue is how the in-camera processing renders greens. This is of course only relevant if you shoot JPEGs. I can't speak for Canon, but Nikon manages to render really ugly greens by default; messing with the in-camera curves or shooting RAW and using a third party converter can be mandatory depending on your taste there.



And of course there is white balance. Just shoot RAW and adjust it afterwards. Even if you don't like post-processing at all, being able to correct white balance is reason enough to shoot RAW.

[Rainer]

- WB: If you work with Jpgs straight from the camera, you are likely better off, if

you do manual WB against a grey-card.



- Exposure: A good idea might be to dial in -2/3Ev to -1Ev exposure compensation

to make sure you don't overexpose the green channel.



Generally, shooting in raw and applying WB in rthe raw-conversion, plus a slight negative

exposure compensation are likely the easiest way to go.



Just my 2cts ... Rainer

[Brightcolours]

Like suggested above, do not use auto-WB (cameras always are just guessing on very limited information). Set the WB yourself on anything neutral in the light you are at (like a white piece of paper, or even t-shirt, or a grey card).

Or just use daylight WB setting.



Also the chosen picture style will influence the colours.

[Guest]

Thanks belatedly for you replies and input, chaps.



I am shooting raw, and therefore I can change the paramerters post-shooting - but I'm still not getting the subtle shades of green I would expect. I'll fiddle around with the processing some more and see what the results are like.

[joachim]

[quote name='Pinhole' timestamp='1287961824' post='3763']

Thanks belatedly for you replies and input, chaps.



I am shooting raw, and therefore I can change the paramerters post-shooting - but I'm still not getting the subtle shades of green I would expect. I'll fiddle around with the processing some more and see what the results are like.

[/quote]



There could be colour space issues involved. Compared to the human eye, many of them are severely restricted when it comes to greens, see e.g. [url="http://www.opticallimits.com/color-spaces"]http://www.opticallimits.com/color-spaces[/url] You could try going for one of the wider ones, but then you also need an output device capable of reproducing those. Another question is how deep into the "green" the camera can go.



I assume when you speak about analogue, you are discussing slides. There is something in slides, which I don't find in digital. Not sure whether this is or isn't a colour space issue. Never saw a colour space map for E100G. So I am not fully sure I am on the right track here.



Unfortunately where I live these days E6 120 processing is hard to get and expensive if you find it <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='' />