Thanks for the input. I have gone with a couple of blacklight fluorescent tubes for the moment mainly because I don't seem to be able to get much else near home. LEDs could work but it seems many are more violet than ultraviolet and I don't want to spend an age wiring something up that might not...
Hello all,
Long time no see.
I am hoping to find someone with knowledge of light output (in particular UVA output) of fluorescent tube lights. I have 2 questions:
-Should I expect the light output of a 20 watt CFL bulb and a 20 watt 2 foot long fluorescent tube to be the same, or...
Excellent! I love cross polarisation. I used petrological microscopes a lot a few years ago and rocks look very very pretty massively magnified. I wish we'd had a decent microscope camera and I wish I'd had chance to use the one we had more often.
Here's some of the rock I'd studied for my...
Not yet. 13 stops might be a bit much for sunset. I've worked out exposure times could be over an hour (assuming the light doesn't fade, which it would)
Nice pictures Borek!
For 90 seconds that's not too bad. 5 minutes with the clone tool would sort it out but if you'd rather not go to the trouble then long exposure noise reduction would sort it out for you.
Failed step leader was my first thought but I'm not sure. A few years back my dad was gardening right before a storm hit. The air around him took on a glowing appearance and there was an audible hiss right before lightning hit somewhere very close by. My mum and I saw and heard it too, and a...
An absolute age ago I remember someone saying they wanted a really strong Neutral Density filter but were put off by the price. For anyone who is interested, here is the cheap option: welding glass.
You can pick it up off ebay for very little money. I paid a couple of pounds for mine from...
Blur is good. I like blur. I got a piece of glass from a welding mask and got it cut down to fit a filter mount so that I could do some really long exposures during the day to get some serious motion blur on the sea and the clouds.
It may not be as nice as the £80-100 filters you can buy...
Don't know, but it's worth keeping in mind that the map shows temperature anomaly, not temperature. It shows how much colder or warmer an area was on the 5th of june compared to the average (what average I don't know...)
It could be as simple as an area of unusually persistent cloud cover...
As I understand it hurricane strength is in part due to the amount of water evaporation that occurs which is largely determined by water temperature. It has been hypothesised that spreading a film of biodegradable oil over the sea's surface could prevent or at least weaken hurricanes as it will...