Why Is This Jacaranda Off-Colour??

[Colin B]

DSCN3136.JPGDSCN3136 colour corrected .jpg


A little bit of weirdness here:

I shot this picture of a bunch of Jacaranda flowers against a bright blue sky with the 3pm light behind me and, strangely, the flowers came out pink, as in the first pic. The blue sky was rendered pretty accurately. I punched up the blue in Photoshop and the second image is pretty well what my eye saw apart from the sky being a bit oversaturated..

Can anyone guess why the colour was so wildly off as this is a nearly new camera and I have never seen it do this before:

Camera: Nikon Coolpix B7500 with Nikkor 60x zoom lens.
Mode - shot on auto
Sensor 1/2.3"
ISO 200
Shutter 1/250
Aperture F5.6
Focal length 161mm

[Mark L]

My first thought is something to do with White Balance. What is the WB setting in the camera? This may or may not effect flower color.
Second thought is it's over exposed. Reduce highlights heaps instead of reducing exposure. Do try reducing exposure if this doesn't work.
These thoughts may not offer any solution at all though.

[Colin B]

Nope, I just tried reducing the highlights and adjusting brightness and neither made any difference to the colour. I am not too clued up about "levels" in Photoshop but I experimented with it and found that reducing the red channel and increasing the blue achieved a pretty good result.

My white balance is set to "auto" as this is another adjustment I am not fully across - usually the camera is smarter than me at making these choices but it seems to have got it wrong this time.

That particular tree is a long way from home but I may try a similar shot with a local tree and see if I can find the magic formula.

[ameerat42]

Colin. Is your camera capable of shooting in raw? Is this an in-camera jpeg?
Normally, Auto WB does a good job. However, it may have been "fooled" this
time by the predominance of "blues" in the scene. The first sky would appear
fairly normal still, but not other hues.

When you try the shot again with a local subject, take a shot as close as possible
to this first, then try a shot with other coloured subjects included. Keep the WB
set to Auto throughout.

[Bax]

As others have said, I’d be putting this down to a White Balance jump. It looks like a slightly different colour temperature. Bit odd that it’d throw it so much, but if you shoot in RAW you can always adjust afterwards in post.

[Colin B]

Thanks Baz and Ameerat. Yes, both are in-camera J-Pegs and there was nothing remarkable about the lght that I recall and the sky was pretty close to that mid-blue you see.

I did find another jacaranda this morning and shot three bunches of flowers at the same range and under similar lighting conditions and, would you believe it? all came out perfectly

As a "real man" it pains me to say that I will probably have to take the desperate measure of trawling through the manual section on "white balance" to find an answer to this mystery.

[ameerat42]

...take the desperate measure of trawling through the manual section on "white balance" to find an answer to this mystery...

Have a read, by all means, but I think it'll just happen occasionally when the conditions are right/wrong/on Friday afternoons after four-fifteen
Had you taken a few more, chances are it would have "fixed itself". As Bax said, shoot in raw when you can.
Then you can set it as you think/want/like as you convert to jpeg.

[J.davis]

What metering have you got set, could be spot and you have missed the bloom and got the sky?

[ricktas]

When white balance is in auto, the camera tries to determine what the white balance should be and selects what it 'thinks' is the appropriate setting. Just like hoomans, it can make mistakes. This is one of the benefits of shooting RAW, as you can then adjust the white balance in editing.

Now as to why. There is a shade of purpleish/blue that camera sensors are notorious for not being able to capture correctly. This is just because of the RGB sensor types, it applies to all sensors. My guess is that your camera got confused and tried to deal with the situation how it thought it should. My thoughts are that the anomoly occurs due to the ultraviolet (purplish) end of the spectrum causing an error. Sensors can be modified to 'see' infrared and we see IR photos on AP regularly, but not much is talked about in the ultra-violet end.

[Geoff79]

More or less in line with what’s been said, Colin, but I wouldn’t worry too much about it.

I only ever use auto WB and with some type of very infrequent regularity, I’ll get a result like this from time to time. I never really think about the hows and whys because it really doesn’t happen often and like Rick says, I just accept that the camera gets it wrong every now and then but I forgive it.

[Colin B]

Thanks for all the replies. It was a rather surprising result and Riktas's explanation comes pretty close to what I was thinking may be the cause.

I usually use the automatic metering and focus and the viewfinder highlights the focus area which, I would guess, is where the metering takes place?

Anyway, One off-colour shot out of a couple of thousand is not a bad batting average so as Geoff has said I will forgive Ms Nikon for this one and make sure that, in future, I check my pics on the rear screen a bit more carefully.