This is something I've been sitting on for a few months. Being rather ignorant about image processing, I've only recently discovered a suite of tools from imagemagick.org which appeal to my nerdy side (like I have another), including command line options to manipulate images precisely, like crop, translate, rotate, reduce, adjust brightness/contrast, set colour mapping, and hundreds of other things. I needed them for this little project and tonight has been cloudy enough for me to learn how.
Most people avoid astrophotography around Full Moon, as the Moon shows less contrast and it illuminates the rest of the sky. Despite this, I think there are still interesting things to be seen. Here is a sequence from the night of Full Moon last September and the nights immediately before and after. These are good times to observe the limbs of the Moon, to detect its subtle libration, and to see its changes in appparent size.
Each of the three shots is simpy a single exposure of about 1/1000th of a second, with my scope operating at prime focus and fitting the Moon's image on the camera sensor just perfectly. There are probably a lot of other things I could have done to the images to improve them, but you have to stop somewhere.
Around Full Moon, September 2013.
Re: What did you see in the sky tonight?
Posted: Sat Jan 11, 2014 12:24 am
by BDanielMayfield
That is interesting Nitpicker. I’m surprised that the apparent size of the moon changed so much in only, what, about 48 hrs?
This series of yours makes me want to see a series of 12 consecutive full moons presented this way. Has anyone produced such a series of moon shots?
Bruce
Re: What did you see in the sky tonight?
Posted: Sat Jan 11, 2014 12:58 am
by Nitpicker
BDanielMayfield wrote:This series of yours makes me want to see a series of 12 consecutive full moons presented this way. Has anyone produced such a series of moon shots?
BDanielMayfield wrote:This series of yours makes me want to see a series of 12 consecutive full moons presented this way. Has anyone produced such a series of moon shots?
Oops, re-read your question and realised I had mis-read it initially. A series of 12 consecutive full moons would be interesting, but the simple elliptical orbit model of the Moon has the line of apsides (i.e. the line joining perigee and apogee) rotating a little over 40° every year, which means that the changes in apparent size of the moon are not quite in phase with the phases of the Moon as seen from Earth. Libration is more complicated again: it is mainly an effect caused by the Moon's elliptical orbit, but also by the inclination of the Moon's orbit to the ecliptic and also slightly by the location of the observer on the Earth, as it rotates. Like most celestial objects, the Moon's orbit is not perfectly elliptical, it is perturbed by many different gravitational forces, which makes things even more complicated.
Re: What did you see in the sky tonight?
Posted: Fri Jan 17, 2014 7:20 pm
by Chris Peterson
I saw some really funky cloud and Moon effects. This was two nights ago, on January 15. I was on the deck, making a timelapse image of the full Moon rising behind the mountains. Afterwards, the Moon passed through a dense band of clouds, blocking its direct light. But the clouds were lit from beneath by orange light pollution from Colorado Springs (60 km away, behind Pikes Peak), and from above by the partly shadowed Moon. (I shot these with a new 14mm f/2.8 lens; I'm very happy with the extremely low distortion seen in the stars.)
Re: What did you see in the sky tonight?
Posted: Fri Jan 17, 2014 8:15 pm
by owlice
Nice shots, Chris!
Re: What did you see in the sky tonight?
Posted: Fri Jan 17, 2014 8:30 pm
by BMAONE23
I'm expecting to see the firey rim of the colossal craft peer out from the cloud at any minute
A LA
Re: What did you see in the sky tonight?
Posted: Fri Jan 17, 2014 9:42 pm
by geckzilla
Chris Peterson wrote:(I shot these with a new 14mm f/2.8 lens; I'm very happy with the extremely low distortion seen in the stars.)
Which one is that?
Re: What did you see in the sky tonight?
Posted: Fri Jan 17, 2014 11:58 pm
by Chris Peterson
geckzilla wrote:
Chris Peterson wrote:(I shot these with a new 14mm f/2.8 lens; I'm very happy with the extremely low distortion seen in the stars.)
Which one is that?
It's a Samyang 2.8/14mm ED AS IF. A 90° FOV with my Canon 7D. This lens has variable reviews on general photography sites, but is very popular with people taking nighttime Earth/sky images. And I can see why. There are some good optics coming out of Korea these days. To get something significantly better I'd have to spend ten times more for Canon glass, which is hard to justify given my casual and occasional nighttime photography.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 12:38 am
by geckzilla
Oh, nice, it's budget. I was wondering if it was expensive. I've only ever had one lens on my 350D but I've been wanting something suitable for macro photography down to, say, ant-size insects. I always get bogged down in reading reviews and never end up buying anything, though.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 1:20 am
by rstevenson
geckzilla wrote:... I've been wanting something suitable for macro photography down to, say, ant-size insects.
The best macro camera/lens I ever owned (sold off long ago, sadly) was my Leica M3 with a Visoflex reflex housing and the 65mm Elmar lens. You could focus just about to the front edge of the lens, and the huge ground glass in the reflex housing gave you a bright view of what you were shooting. It was heavy, but that made it easy to get steady shots hand-held. What a lovely tool it was.
Here's a picture of a similar combo, except mine was the Visoflex II while this one is the Visoflex III.
VisoflexIII.gif (47.16 KiB) Viewed 1624 times
I wonder if this could be attached to one of the modern digital Leica Ms. Best of both worlds. I'll try it next time I win a lottery.
Rob
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 1:39 am
by geckzilla
Retro. You'd think I would know more about photography but aside from reading my own camera's manual my mind is fairly sparse of that sort of knowledge. My grandfather was a professional photographer and left some gear behind when he passed but somehow my cousin ended up with all of it.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 2:02 am
by rstevenson
To get back to (affordable) reality, my current camera is a Canon PowerShot G10, which in macro mode can get down to 1cm from the front of the lens, shooting a scene about 3cm wide. Close enough? And the G10 is quite a good camera for general photography as well, though like most cameras in its price range it yields lots of noise in low-exposure areas. You can get one for about $300 on eBay, or about 1/20 the cost of a Leica M8 with a Visoflex and 65mm Elmar.
Rob
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 4:42 am
by Nitpicker
rstevenson wrote:To get back to (affordable) reality, my current camera is a Canon PowerShot G10, which in macro mode can get down to 1cm from the front of the lens, shooting a scene about 3cm wide. Close enough? And the G10 is quite a good camera for general photography as well, though like most cameras in its price range it yields lots of noise in low-exposure areas. You can get one for about $300 on eBay, or about 1/20 the cost of a Leica M8 with a Visoflex and 65mm Elmar.
Rob
There are some arthropods, especially the poisonous ones, that I would prefer to photograph from a distance with a long, long lens.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 4:53 am
by geckzilla
That's a good idea, even for the harmless ones. If you get close to them they tend to run or fly away. Of course, then you have to deal with not only the movement of the subject and wind blowing whatever it's on but any camera shake will be that much worse. That's why entomologists throw them in jars of poison and then pin them down after they die. So mean.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 5:50 am
by Chris Peterson
geckzilla wrote:That's a good idea, even for the harmless ones. If you get close to them they tend to run or fly away. Of course, then you have to deal with not only the movement of the subject and wind blowing whatever it's on but any camera shake will be that much worse. That's why entomologists throw them in jars of poison and then pin them down after they die. So mean. :)
Not sporting at all. Every one of these was shot very close, and not a one jumped at me, bit me, or otherwise posed much of a threat. And IMO, they look a lot better in the wild than poisoned and pinned to a board.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 5:59 am
by geckzilla
I completely agree. I don't live in Australia, though. I can see it getting tiresome for any of the more energetic ones, too. I haven't had an insect attack me since I was a kid running through some place I probably shouldn't have been when a wasp appeared out of nowhere and lanced me at least three times on my leg. Must have been a nest nearby that I missed.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 6:09 am
by Nitpicker
Awesome photos Chris.
I grew up in an area renowned for Funnel Web spiders, and we would have fairly regular and scary close-encounters with them in dark corners of the house. I am not yet convinced that my continued fear of spiders is irrational.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 6:17 am
by geckzilla
Fear is irrational. There are certain things to respect about certain creatures. Sometimes you respect their beauty, and other times you respect the amount of distance you think they might appreciate you giving to them.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 6:29 am
by Chris Peterson
Nitpicker wrote:Awesome photos Chris.
I grew up in an area renowned for Funnel Web spiders, and we would have fairly regular and scary close-encounters with them in dark corners of the house. I am not yet convinced that my continued fear of spiders is irrational.
A degree of fear when you live around dangerous creatures is probably healthy. But there's a difference between fear that drives a proper degree of caution, and fear that prevents you from approaching potentially hazardous things under controlled, substantially safe conditions.
There is evidence that people have an intrinsic fear of spiders, but even intrinsic fears can be suppressed by intellect. I consider that an effort worth making.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 6:31 am
by Chris Peterson
geckzilla wrote:Fear is irrational. There are certain things to respect about certain creatures. Sometimes you respect their beauty, and other times you respect the amount of distance you think they might appreciate you giving to them. ;)
Fear can be either rational or irrational.
Re: What did you see in the sky tonight?
Posted: Sat Jan 18, 2014 6:32 am
by geckzilla
I should have confined that to fear of insects. There is virtually no rational fear of any insect.