In the months after last summer's solar eclipse, a lot of great imagery and video was posted on the web. I posted a "web roundup" full of links to the best pictures and videos I'd found, as of late October 2017.
Now that a few more months have gone by, a French astro-imager named Nicolas Lefaudeux has posted some wonderful images whose praises I have to sing. One of his images was the Astronomy Picture of the Day for April 30, 2018. Run, don't walk, to visit his webpage with even more great pictures from his eclipse trip to eastern Oregon.
In my opinion, M. Lefaudeux has done a few really noteworthy things:
1) He has figured out how to do the incredible high-dynamic-range image processing that we've previously only seen from Miroslav Druckmuller and his collaborators. Prof. Druckmuller and those associated with him appear to have spent many years developing their own software and workflows, which allow them to produce the absolutely incredible images of the solar corona and chromosphere that we've been treated to for many years now. Seeing someone else shoot for - and achieve - the same kind of result is really neat.
If I understand Nicolas Lefaudeux's webpages correctly, he seems to have been determined to accomplish the same thing himself, even if he had to write his own software, too. He has a background in optics and physics that allowed him to, among other things, design and build his own field flattener for his imaging refractor! How many of us amateur astronomers can claim to have done something like that?
It's clear that his preparations for the 2017 eclipse were a long-time labor of love, which is part of what I enjoyed so much about his eclipse-related webpages. It was so heartbreaking to hear that he'd been clouded out in Europe in 1999! But also very heartwarming to know that things worked out so well for him in 2017, with a clear sky and such perfect seeing. He was seeing the eclipse in the same marvelously clear sky that my friends and I were blessed with in Smith's Ferry, Idaho (about 100 miles / 60 km to the east), and that also adds to my enjoyment of his images. 😊
2) He spent considerable time and effort making images that show what the eclipse really looked like with the naked eye, as well as through small optical instruments (like his spotting scope). This impressed me as much as his HDR, "Druckmuller-like" image, and I think he did a great job.
In my long writeup about visually observing the eclipse, I went on and on about what it looked like to me with the naked eye. I was very taken aback by the brightness of the innermost corona, and how it made a distinctive, bright, circular ring around the limb of the Moon. I was also very surprised by how much "Druckmuller-like" detail I didn't see with the unaided eye. Within seconds after third contact, I thought "the corona looks like some image-processing enthusiast enhanced some of the details, such as the edges of the major streamers, but smoothed out most of the finer-scale details".
(My endless logorrhea about this can be found under "Unexpected appearance of the corona", about halfway down my Eclipse Day post.)
In my opinion, Nicolas Lefaudeux's "Naked-Eye View" image captures this appearance brilliantly. I don't know if he did anything like deliberately suppressing details of a certain size, while enhancing contrasts at another size scale, but whatever he did, I think he has recreated what the eclipse really looked like better than anyone else ever has.
I strongly suspect that he gave a lot of very deliberate attention to this. I sense, from his work, that he stored up some very detailed mental impressions during those two minutes of totality, and then thought about them very hard during the days, weeks, and months after the eclipse. And, while thinking very hard about what it looked like, he made a very determined effort to create images that really, genuinely looked like what he saw. He sweated the details, he worked the problem, and I think it paid off! I know I'm kind of going nuts, gushing about these images, but I think he deserves praise for such fine work.
Like it says on his webpage - download the naked-eye image, put it on your monitor with a good brightness setting, and see what the eclipse really looked like!
I'd add one extra instruction- make sure you sit at the right distance from your monitor, so that the Sun looks the right size. This, however, could be a trickier thing to do than one might imagine. The simple thing to do, of course, is to put the image at native resolution on a good monitor, and then move back until the Sun looks 1/2 of a degree across in your field of view. Imagine holding a green pea between your fingers, at arm's length, and you'll know big the Sun should look. However... you might want to experiment with looking at the image from a slightly closer distance, too. Not so that the Sun looks golf-ball sized or tennis-ball size, nothing like that. But maybe a little bigger than a pea at arm's length. Maybe like a grape.
Why? I make this suggestion because when people see images of the Moon at a realistic apparent scale, it looks too small. It's like taking a picture of a distant mountain with a non-telephoto lens, and then being surprised at how tiny it looks when you view the image on your computer. Even though our eyes can't actually "zoom in" on things, our ability to concentrate on them and search for details works a little like a "mental zoom", in my opinion. So maybe it's worth looking at M. Lefaudeux's images from a range of distances, as long as the Sun doesn't look too big.
3) He has also demonstrated what the Sun looked like through a telescope, and how different parts of the corona were emphasized at different magnification levels.
On the same webpage as the naked-eye image, he has posted images that convey what he saw through a 65mm spotting scope at various zoom levels (15x, 25x, 50x). The 50x image gives an excellent impression of what I saw at essentially the same magnification through my 6" f/10 Maksutov-Cassegrain telescope, using a 31mm Nagler eyepiece.
The parameters of my optical system weren't quite the same as his, since my telescope had a larger aperture and a larger exit pupil, but his 50x image is still looks a very great deal like what I saw through the eyepiece. I think the 50x image quite accurately shows the emphasis on the inner corona and prominences, without the large-scale streamers being as visible.
The 15x image makes me weep for my 15x50 image-stabilized binoculars that didn't work during the eclipse! 😞 Now I think I have a good idea what I would have seen if the stabilizer had worked - it would have been cool! But, with all of the good fortune I had, I can't complain. I saw the eclipse pretty darn well, and I'll shoot for a binocular view in some future eclipse. Probably Texas 2024 if we get lucky with the weather, or, much less likely, Argentina 2020 if a pile of cash magically drops into my lap somehow.
(Ironically, I now have an idea how I could have kept the binos working. One month after the eclipse, their stabilizer worked fine during Calstar 2017, when we were treated to the mind-blowing sight of the NROL-42 launch from a distance of slightly less than 100 miles (60km) at night. That was an unbelievable sight, second only to the eclipse itself. I think the key is keeping the binoculars cool. If I'd just let them get cool on the night before the eclipse, and stuck them in an insulating cooler on eclipse morning, without even any ice, I think they'd have worked. Keep the batteries warm, though. The binos just needed to be kept cool, I think. Oh well, live and learn.)
4) Those mechanically automated solar filters, though! Oh my goodness! 😮 His video showing those filters swinging up, all simultaneously and on command, just makes me want to fall down and beat my fists against the floor in amazement! 😆 I was so very glad that friends of mine who were at Smith's Ferry, like Carl and Wes, had their automation work properly. That's so great. But those mechanized filters - wow! What a neat setup. I don't know if he used Xavier Jubier's software to control them and his cameras, but I'm guessing maybe he did. Vive La France, raise Le Tricolor, sing the Marseillaise! So cool!
I've probably gushed enough, but I just wanted to send folks to Nicolas Lefaudeux's amazing collection of images. I think he's succeeded brilliantly at showing people not only the incredible HDR images of the corona, but realistic views of what the eclipse really looked like. Bravo!