I am not a vision or camera expert, but I know that my eyes perceive colors differently depending on the illumination. My only camera is in my smartphone (iPhone), which is also affected by the lighting source.
The color temperature of a cloudless summer noon is said to be 5600K, which is a bluish white, to our eyes, while earlier in the morning or later in the evening the color temperature becomes warmer/redder (lower K numbers). Photography at clear noon outdoors is difficult because of shadows. Some experts recommend outdoor flower photography in the middle of an overcast day – I am not sure what color temperature that might be. Then, there are folks who like direct sun at 45 degrees to the flower.
Living in Minnesota, I don’t have the luxury of being able to photograph all of my blooms outside at a particular time of day to achieve optimal or consistent lighting. I need to be able to take pictures in my indoor plant room. The only way I can have a black background for the pictures is with black velvet on a wall behind one of my LED lighting panels. I found that the black background usually works better than a white background.
The LED panel by my black velvet is 2 feet x 2 feet and comes from LEDone corporation. It has variable wattage input settings (I use the highest 29W setting) and three different color temperature settings (3500K/4000K, and 5000K). I did a test with Cattleya Triumphans and the 3500K and 5000K light settings of the panel and compared these to two different outdoor lighting situations.
I used the automatic iPhone settings without activating adjustments with a screen tap. I didn’t zoom but I did modestly crop each photo afterwards to about the same size flower. I did no other photo adjustment.
This first photo was taken outside about 9:00 am on a clear day in the middle of May 2021 with the sun behind me at about a 45 degree angle. The light was bright and some shadowing is present. I didn’t measure the light intensity but at this time of year full sunlight at noon is about 2,000 micromoles/m2/sec in the PAR spectrum range so the intensity at the time of the photo must have been at least 1,000.
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Next is a photo taken outdoors at 2:00 pm on fully overcast May 19, 2021. The light intensity in the PAR range measured 380 micromoles/m2/sec with my Apogee full spectrum quantum meter.
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Next is an indoor photo on May 19 with the 5000K LED panel setting. The light intensity measured 190 micromoles/m2/sec at the top of the dorsal sepal.
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Finally, here is the 3500K setting. The light intensity remained 190.
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The flowers looked different to my eyes under each of the illumination conditions and I think the photos show this. I have no idea how the iPhone adjusts to the different light spectra and intensities. What is the true color of Triumphans? There probably isn’t one because it all depends on the light. If I wanted Triumphans to appear the most yellow I would pick the 3500K setting or early morning direct sun outdoors. The 5000K light setting indoors is sort of in between the outdoor overcast sky and morning direct sun results.
I think any photo of an orchid flower, including award photos, are influenced by the illumination. Making comparisons between different orchid photos is likely unreliable. I think I will standardize things and use the indoor black background/5000K panel setting for my pictures. I will know that the photo is only an approximation.
