Last year, I looked at Hawkweed flowers, a plant in the scientific category of ‘Looks vaguely like dandelions’. It’s time to look at another well-known flower in this category, the dandelion.
… wait, I think I confused myself.
I’d been hoping to do more UV flower photos this year, but it’s been a cool, wet, and most of all CLOUDY summer, so I haven’t had many good days. On the other hand, I also haven’t been choked out by smoke, so it is a fair tradeoff. On the OTHER other hand, I had a lot of smoke experiments planned for this summer, and I might have to wait another year. Why can’t natural disasters happen on my schedule?
The dandelion. In northern BC, they’re mostly a spring flower; they bloom everywhere in May, and are mostly gone by the end of June. a few continue flowering here and there throughout the summer, but in very small numbers. They’re not native to North America, rather brought over during European colonization. Dandelions flower, but they don’t need to be pollinated to reproduce; a flower can clone itself into the seeds. They’re mostly limited to fields and cleared land, not forests. From what I’ve read, they’re invasive, but aren’t too damaging to native plants compared to other weeds… which is good, as I don’t think there’s any way of getting rid of them without burning the continent to ash.
So, Dandelions… Everyone’s seen them, right? Do I really need to show a photo? Well, here it is anyways.
The name is derived from the french name, Dent De Lion, or Lions tooth. This referees to the serrated shape of the leaves, but come on! the yellow flower must have SOMETHING to do with being called a lion! They’re bright yellow, with a slightly darker colour in the centre. Maybe a bit more ‘orangey’, but not enough to call it orange. It’s a good lion colour!
channels are very similar. The green channel best shows the darkening of the centre, so the flower is very slightly skewed to reflecting the longer wavelengths and absorbing the shorter ones in the middle.
The blue channel is a little more different.
The dandelions in the shorter visible wavelength are extremely dark, even compared to other vegetation in the photo. They are slightly darker in the centre, but they absorb so much blue light that they appear black when looking at the unaltered blue channel. you have to mess with the contrast to show this increased absorbtion:
I’m not going to look at infrared photos of dandelions this time around(spoiler: they’re bright white and fairly boring). Instead, I’m looking at the shorter wavelengths.
As always, the short pass filter photo is completely illegible…
… at least until I work at adjusting the white balance. Side note: Is illegible the right word for an image?
Once I fix the white balance, the dandelions are… well, they’re different. The centre remains dark, but the outer ‘petals’ are much brighter than the centre or the other vegetation. Well, I say petals, but each petal is more like its own flower. What seems like a single flower is a tight cluster of thousands of small flowers. I’m going to keep calling them petals, however, as I’m sure I’d slip up and use it anyways, and edditing isn’t my stron suit.
So, if the short pass filter, unlike the blue filter, shows a light outer ring of petals, does that signify that the outer petals are lighter in the true ultraviolet spectrum?
Yes. Yes it does. Combining my Schott BG40 & UG11 filters gives this photo. The outer edges of the photo are much brighter than the rest of the picture.Adding my short pass filter to ‘triple-stack’ my filters, reducing infrared leakage and pushing the spectra slightly to shorter wavelengths, shows the same, but the centre is even darker:
At least, in general. The centre is darker for the opened centre of the flowers, but brighter in the younger flowers, before the inner ‘petals’ open up. The dark centre is much larger than in the hawkweed flowers.
Still, from an artistic standpoint, the short pass filter is easily the prettiest and most colourful, maybe even better than the visible spectrum photo. That’s why I’ll leave off with a photo from that filter.
… umm.. that’s actually kind of boring. Maybe more dandelions?
No. More dandelions!
More Dandelions! ALL THE DANDELIONS!
Okay, that’s enough. Enjoy the photo, and see you next time.
The above photos were taken with a modified Canon Rebel T3i camera.