Color in camera not same as viewed

[MikeAdams]

I have found that with some flowers, when I observe the fluorescence directly (wearing safety glasses) there is a strong very deep red color. When I photograph the same flower, the red doesn’t show up. Any ideas of what causes this, and how to correct it.

 

Thanks

[OlDoinyo]

It is possible that part of the red emission is at a wavelength too long for the camera to see, but not so long that you cannot see it, assuming that viewing and photography are under identical lighting conditions. If you have any filter on the camera which interferes with red light, this could add to the issue. Another possibility would be that your glasses themselves are fluorescing, but that would look more like a general red haze and not centered on the flower.

[Andy Perrin]

Possibly also a white balance issue? It is very hard to figure out what white balance should be used for fluorescence.

[Cadmium]

Are you using a stock camera?

Are you using any filters on the lens?

[Alaun]

Stay away from automatic WB. Just try something like 6500K for starting.

[dabateman]

I have found that with some flowers, when I observe the fluorescence directly (wearing safety glasses) there is a strong very deep red color. When I photograph the same flower, the red doesn’t show up. Any ideas of what causes this, and how to correct it.

 

Thanks

 

Yes I have seen this in different ways. Most common is the red you are seeing is close to 700nm. Many stock cameras cut that wavelength out. Also using a S8612 2mm or BG39 will trim too much in higher 600nm range. So I use a sigma SD15 internal filter, which is similar to a Baader UV/IR cut filter. A cheaper alternative is a BW 486 filter with harder edge near 700nm.

The second way you may be cutting it is in your white balance setting and you may need to dial in a kelvin in the 10000 to 14000 range.

[Andrea B.]

To summarize, incorrect colour in visible fluorescence can be caused by:

• Incorrect white balance setting.
  
• Visible fluorescence which is out-of-gamut for the camera. (Try setting the slightly wider aRGB rather than sRGB.)
  
• Filtration cut-offs.
  
• Contamination from unfiltered, ambient visible light. (Shoot visible fluorescence in the dark!)
  

It is possible that the correct visible colour might be recovered in your converter/processor by testing various white balance settings for the raw file.

 

We have had many, many discussions about white balance settings when recording visible fluorescence. You can read more about that here: Sticky :: UV Induced Visible Fluorescence