Today i'm going to show you what the bortle scale is and how it can help your Astrophotography!
(Rockin' Music!)
The bortle scale is a nine level numeric scale that measures the night sky's
brightness of a particular location it quantifies the astronomical
observability of celestial objects and the
interference caused by light pollution so basically it's a scale where the
lower the number is the more stars you'll be able to see if
you're at a portal 9 location you won't be able to see many stars at
all you might be able to see the odd planet
and at the right time of the month the moon but nothing more than that this
tends to be the rating given to city locations and places where there is a
lot of light being emitted bleaching out those stars on the other
hand if you're at a portal one location you can get some pretty amazing night
skies on those clear days if the milky way is out you should be
able to see it clearly with the naked eye
and you'll be able to see all of the constellations and planets and
everything that's in the night sky for the location that
you're at each level between nine and one gives you a progressively
better chance of seeing the stars so the darker the location the lower the
number a sky with a portal level of nine to
eight is a city sky it will be properly bleached out and you
won't be able to see much apart from the planets and the moon like i've already
said this is why it's so important to get
away from those cities with all of their lights
if you want to see those stars with a portal rating of seven to six this is
where you've come away from that city centre a little bit
and it's more what you'd see above suburbia there are still
very few objects in the sky and you'll be able to see the planets and the moon
again at the right time of the month for the
moon you will be able to see more stars than in a nine or an eight
portal location but not many more when it is cloudy any
of these ratings between nine and six will tend to reflect
a lot of that light pollution off the bottom of the clouds
the problem with this is those clouds will seem brighter and this will
again reduce the amount of things you'll be able to see in the night sky
now if you can get to a location with a four or a five portal rating
this is where you'll start to see more stars they will still be quite bleached
out but you will see more stars than in the city
you might just be able to see the milky way as well but it'll be quite pale and
white with no color or detail and it's easy to
mistake it for high clouds in these locations at a portal 3 location
you'll start to see more stars and if the milky way is out
you'll see much more detail in it this is when it gets really good
and if you're photographing the stars in the milky way you'll start to get some
color and detail in that milky way now when you get to a
baltimore two location the skies will look fantastic you'll be
able to see all of the constellations and if the milky way is out in the sky
that's above you you should be able to see it clearly
when you take a long exposure shot of the milky way in one of these locations
if the core is in the sky you'll start to get the yellows and the browns
in the dust clouds around the core also you'll start to see the sort of darker
tendrils coming out from the core as well and these are
the shadowy parts of the milky way at a bottle one
location this is as good as you're going to get
the milky way should be clearly visible with the naked eye
if it's in the sky and even with the winter side of the milky way
you should be able to see this as a white streak
across the sky there will be millions of stars to see
and you should be able to make out all of the constellations that are in the
sky at your location for the given time so
you can see if you're planning on heading out to a
location check the portal rating at that location before you go there i
use light pollution map dot info for this
and once you find the location you have in mind click on it and it will give you
a lot of info including this portal rating in the
pop-up box if i click on where i live this is a
city location and it gives me a portal rating of nine
but if i go out to kudra it's down to a level five
bortle rating and then down in leewa it drops to a
bortle level three so you can see by looking for locations
around you you can find some really dark skies
now as well as all of this you do need to work out the direction in which
you're going to be looking or taking a photograph
if there is a city in that direction that you intend on looking or taking a
photograph you might get a lot more light pollution
from this city especially if there's dust in the atmosphere
so as well as knowing the portal scale at that location
you need to work out which way you're going to be taking your photograph
i use photopills for this and it'll give me all of the information that i need
and when i use it in conjunction with light pollution map dot info
i can work out where the best location will be for the sky that i want to
photograph so when working out the portal scale
at that location finding where the object you want to photograph will be in
the sky and which direction you're going to be
pointing your camera you can find good locations near you
or you should be able to see how long it will take to drive to a good location
or even if you have a vacation planned you can work out where you'd like to go
or you might even plan to go to a different location
and when it's darker when there's a new moon so you can get some great
night sky shots as well as having a good holiday
now i've been to a portal 3 location but struggled to get a good shot
as there was a city in the direction that the milky way rose that night
but i've been at a portal 5 location and because i was looking out to sea where
there was no light pollution i was able to get a
shot of the milky way so when planning your location properly
you can tip the odds in your favor so when the skies do clear you'll know
exactly where to go and how to take the shot now if you want
to learn about astrophotography click on this next tutorial here and if
you want to learn about photo pills click on this one down here and if you
haven't already be sure to subscribe for weekly tutorials in photography
i'll see you next time you