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Thank you Keelin! I captured it some years ago with the cloudspotter app on my phone. I remember that the shadows fascinated me. Some spelunking in the archives (I like the way you once described this process) at the moment the shadow issue was addressed by George made me find it again.
I agree George, this thread is a real joy. Unfortunately mr. Crow himself left the forum for a uncertain time, but there must be enough material to keep it interesting and going.
For the practical part of your question: I use a 100 – 400 mm telezoom. And then a picture can also be cropped for even more detail. The circumstances are first of all the right plane. That means one with wingtips that give the kind of vortices needed for Crow instability.
This is a link with some information I once found: Crow instability in contrails.
Another page on the same site:Hybrid Contrails with Crow Instability.
This last page states that the the phenomenon typically occurs at high humidity and low altitude.
I don’t know how high or low low is meant to be here. I live in the proximity (about 10 to 20 km distance) of Schiphol Airport (Amsterdam) so there is a lot of air traffic around, but the planes are luckily for me not low when they pass. When I spotted some interesting trail it wasn’t specifically a low trail or else I would have remembered it for the noise. The planes are mostly that high that only a distant sound can be heard. A typical day with a lot of contrail you can find in Contrail Thread Volume I on the pictures with the higher numbers: enough humidity by cirrus or cirrostratus.
And at last you must have the opportunity (i.e. the time) to look after them. A few days ago it was a cold day with clear blue sky and dry air from the east. That seems not to be favorable, but at a certain moment I spotted a nice trail to capture. I sprinted inside to get my camera, but when back within much less than a minute (my second name is Usain) it was already gone. Maybe they last a bit longer when there is more humidity but the camera must be at hand to capture it.
We had a lot of too heavily clouded gray skies for about a month over here (except for the occasion two days ago). Now I watch out for the circumstances to look after your castellanus issue or for a next one in the Contrail Game or whatever makes a nice picture with contrail.
I hope this helps. I look forward for an example you will spot some day, but beware for the ones that leave your chimney!
Smooth topping Michael. Good occasion to share one out of my series of iridescence for the 2018 calendar shot.
Sadly enough the millstone slows and finally comes to rest. The sky is on fire in England and Arizona as well. In between the cool blues of Night To Day with a diminishing moon.
Great variation again!
Purple Haze
‘Scuse me while I kiss the sky
Thanks Keelin. It could have been in the series of textures of the former volume of this thread. I love your Early Bird for its curly gentle waves. The series of Overhead and Duplicatus by Michael is also wonderful.
Coincidentally I captured one that follows well the ‘shades of light and dark to run your eyes over’ you mentioned. The same aspect must have made us spot it.
And for some reason I did not know whether you were pulling our legs with your announcement some weeks ago, Alec. Well so be it, but the doctor must have a damn good reason to pull you out of our shared project, all be it for maybe a limited time. For some reason I advise you to watch out better next time before signing a contract without reading the fine print defining the legal engagement with the unscrupulous scientist we learned some things about. Yet we know far too little about this mythical researcher and I watch out for new stories the new project will yield. I suppose the Doctor knows very well who to call for, for your track record on the subject of sky symbols must be unmatched.
Many thanks for giving the forum a push with your daily production of wit, advise and pictures. I enjoyed your contributions very much.
I will watch out for the moment you reenter da house. In the meantime the grinding will go on elsewhere on this planet. All sorts of fun and luck with your new project!
Like Keelin a picture in blue mood. I am listening now to “Grind of Blue” by Airmiles Davis.
Haha, my favorites! But oops this reply was meant for a former post with the jazz musicians you mentioned Alec. Very funny!
