reply to post by ScorpioRising
I always check "my ATS" and log in fairly regularly, so I usually catch any replies left to old posts of mine.
I think you are right to cast doubt on what you saw being noctilucent clouds. Usually they are seen in Summer, up till the end of July, and when the
sun is between 6 and 16 degrees below the horizon. They would also only be seen in the West, and relatively low on the horizon.
Sussex is also a borderline location for observing them since more northerly latitudes are favored.
I'm not sure you can entirely discount ground based lights, although street lighting is unlikely. Did the cloud appear to be stationary? How long did
you observe it for?
Was it perhaps misty or foggy at the time? Under these conditions ground based lights can easily be scattered back towards an observer's eyes.
I think the next step would be to firstly check on google earth in the direction you saw the cloud/s, if there is anything that might be a potential
source of blue-tinted light. A few things that spring to mind as potential sources are : Maintenance crews working on railways, or industrial
sites/construction sites. New business opening up or holding special events/promotions will sometimes shine search-lights upwards. Sports and
recreational grounds/facilities may be another possibility. I'm sure there are lots more potential sources of light out there.
One thing to bear in mind with colour is that it's relative... for example, our brains actually correct the colour of any scene we view without us
consciously realizing this. The corrections are made based on what our brains expect to be seeing under natural lighting.
So if you are standing on a street underneath a sodium vapor street light, which only puts out light in a very narrow band of wavelengths in the
orange part of the spectrum, everything should look one shade or another of orange, but you can still see that plants look green etc (just about)
under the same light. That is because your brain is trying to correct for the "extreme orangeness" of the scene, much like "auto white-balance"
function on your camera does.
The upshot of this, is that if you see a light that would appear to be blue-white under "normal" (ie daylight) circumstances, under these
circumstances, it would appear to be much more blue in colour.
Keep in mind that although your eye may not seem to pick it up, there is artificial light pollution virtually everywhere in the UK now, unless you are
lucky enough to live in a remote glen somewhere in the highlands.
Your eye may not always pick it up, but a good camera can with a relatively long exposure certainly will.
I would also say, try and document and observe the phenomena again if you can. I'm not sure what camera you have, but consumer-grade point n shoot
cameras although great for daylight photography tend to struggle with subjects like clouds at night, so I wouldn't get your hopes up too much as to
what you managed to catch on your camera.
A good camera and tripod if you don't already have one will help a lot. If you are determined to document it properly, a DSLR would be best, but you
don't need to spend an arm and a leg on a new one, when there are plenty of cheap 2nd hand DSLRs out there that will do the job. I'd recommend a
Canon EOS 20D if you don't want to pay too much. It can be bought in good working order, and plenty of life left in it for £150 to £200 on ebay.
Perhaps even less. I haven't checked prices in a while.
For a bit more, the 30D (shares the same sensor as the 20D) would likely give you more longevity (50k more rated shutter life than the 20D, so 100k vs
50k shots before the shutter is expected to wear out), and Canon are more likely to be able to fix it if something does go wrong in the future. Not
that it should - they are very rugged/reliable cameras, but they do wear out eventually.
Anyway, DSLR sensors are better at gathering light than "consumer" digital cameras, which usually have much smaller sensors. Even older DSLRs like
the 20D (or equivalent from Nikon) trump the much smaller sensors of digi-cams. In fact some of the older DSLR sensors out-perform newer (and higher
mega-pixel) sensors in terms of low light performance/noise.
Just as importantly, you have the option to have full manual control over your camera with DSLRs. Just make sure you set your "white balance" to
"daylight". Setting it to "auto" means the camera chooses the right tint of the scene (ie giving you false colors).
One other advantage with buying a Canon EOS mount body is that you can find adapters for lots of other lens mounts, winch gives you access to a vast
array of optics, many of which will work very well on DSLRs for considerably less cost compared to their modern Canon counterparts.
I can't think of anything else to suggest right now, but that should give you a few ideas where to start.
Good luck )