Canon 60D - blue traffic lights

[enaiman]

Last night I've noticed that the green traffic lights show light blue on my pics.
Is anyone else experiencing a similar issue?
Everything looks OK except that.

Any ideas?

[herbert]

Hi Eugene,

Can you post an example? It may be a white balance issue.

Note that light is made up of different wavelengths of light. Think of white light as the colours of the rainbow. If you adjust the different amounts of each colour you get a different mixed white. Our eyes adjust automatically using our expectation of the true colours in the scene. Our cameras have no learned expectation and use a white balance to mix the weighting of colours. It may be that the camera has shifted your green traffic light into a more blue colour when trying to white balance the scene.

Alex

[enaiman]

Thanks Alex for your input.
I did a little bit of research and it turns out that the modern lights have a blue colour component to help people with difficulties seeing the green light.
I do have a pic where the traffic lights are blue but a navigation light is green so, white balance is not the issue.

[DanK]

Eugen,

Are you shooting JPEG?

The "styles" that come with Canon cameras for producing in-camera jpegs differ quite a bit in their color rendition. As an experiment, take a scene with a lot of greens & blues (and reds, if you can find a scene with that also) and take identical photos, switching from one profile to the next. You will see (or at least I saw, with my older Canon) a very large difference in colors, for example, between "standard" and "landscape."

So, if you are shooting JPEG, the first thing you could try is changing the picture style.

Second, to beat an old drum, you could shoot raw, in which case all of this is under your control in postprocessing. I use Lightroom, and shooting with a 50D, I find that the Adobe standard profile usually provides a good starting point for colors, but not always. It's quite easy to change not only white balance, but color balance, using most postprocessing software.

Dan

[Geoff F]

Thanks Alex for your input.
I did a little bit of research and it turns out that the modern lights have a blue colour component to help people with difficulties seeing the green light.
I do have a pic where the traffic lights are blue but a navigation light is green so, white balance is not the issue.

I hadn't heard about green traffic lights also containing blue but I suppose it would make sense for people with red - green colour blindness.

Also, unless you are comparing different lights of the same colour (green) side by side, any results will be questionable due to light angles and the effect of any ambient light. For example, street lights, vehicle lights, etc which could be tending to 'react' with the light in question.

[enaiman]

Thank you Dan and Geoff for your help.

I had the same suspicion that the JPG conversion will alterate some greens but that's not the case.
The pic I am posting is comins straight from the RAW file only with some cropping. You can see the blue traffic lights on top of the bridge (they were all green) and the green navigation light at the base.

[herbert]

Hi Eugen,

The picture may come straight from raw but it will have a white balance applied to it and, if using the camera post processing software, will still apply your picture styles. Have a try updating the white balance and picture styles in the raw converter and see if you can get the lights a bit less blue.

Alex