Astrophotography Opportunity

[astroman]

Below are photos from a daytime occultation of Venus that occurred last summer. A similar event will occur as darkness falls on the evening of the 1st December.
http://i271.photobucket.com/albums/jj138/astroman_caithness/VenusOccultation.jpg
The sky will be darker during the event on Monday making it easier to see/ photograph.

The long range forcast doesn't look great, but for those that are interested there is a good opportunity (weather dependent of course) for some astrophotography capturing a celestial gathering of the crescent moon and the two bright planets Jupiter & Venus.
Look for the moon due south, low above the horizon as sunset approaches. Even in the daylight sky it should be possible to pick out the planet Venus shining just beside the Moon. At around 1545 the Moon will pass in front of Venus causing it to temporarily disappear, only to reappear at around 1705. By this time the sky will have darkened somewhat, making Venus and Jupiter above it much easier to see.

[whitecloud]

Thank you thats very interesting hope its clear fingers crossed eh.I have not long moved to caithness so Im quite new to this site but love the night sky and all its wonders, since you are experienced in this feild you would be the best person to ask, do you see the northern lights here and if so when is the best time to see them.
love light and laughter
whitecloud x

[wifie]

Thank you for the info Astroman! :)

[astroman]

Thank you thats very interesting hope its clear fingers crossed eh.I have not long moved to caithness so Im quite new to this site but love the night sky and all its wonders, since you are experienced in this feild you would be the best person to ask, do you see the northern lights here and if so when is the best time to see them.
love light and laughter
whitecloud x

During periods of high solar activity Caithness & Sutherland are excellent places to see the Aurorae. Here's a photo taken from my garden in Thurso during the autumn of 2002 (the time of the last peak in solar activity)
http://i271.photobucket.com/albums/jj138/astroman_caithness/AURORAE2002B.jpg

Peaks in solar activity occur roughly every 11 years, but unfortunately we're currently in a period of minimum activity. This means you'll have to be patient for a few years or take a trip further north to have a good chance of seeing them.
Check out www.spaceweather.com (http://www.spaceweather.com/) and http://www.swpc.noaa.gov/pmap/pmapN.html (http://www.swpc.noaa.gov/pmap/pmapN.html) for news on solar activity and the chances of seeing aurorae.

[Mystical Potato Head]

Excellent images Astroman,just a shame the weather is so poor and when there has been a clear night its been blowing a Zephyr.Havn't had my scope out for about a month.

A couple more Aurora but the Aurora oval was way above the Arctic circle when i took these so are low down and not the spectacular"overhead" type
Scrabster to the left and Flotta flame to the right of all three.
These were taken in March 08

http://i374.photobucket.com/albums/oo189/sat5_photos/009_5.jpg

http://i374.photobucket.com/albums/oo189/sat5_photos/IMG_3041.jpg

http://i374.photobucket.com/albums/oo189/sat5_photos/IMG_3162-1.jpg

[astroman]

Nice pics MPH. Sky looks really clear in the last one - lots of stars, and the Andromeda Galaxy is visible even though its close to the horizon.

Hope the weather improves to allow us to enjoy similar views :)

[Deemac]

Great stuff chaps. I've still got a starfield long-exposure on my "to-do-list" Living out in the sticks I hope not to have so many light pollution issues!!

[tjc]

Thanks for the info... really into the stars etc but never tried star photography.

I have one of those long exposures on my list too.

Nice sky/aurora pics.

:)

[Mystical Potato Head]

You mean light pollution like this Deemac?

http://i374.photobucket.com/albums/oo189/sat5_photos/IMG_4201.jpg

Thankfully with the powers of PS it turns into this.

http://i374.photobucket.com/albums/oo189/sat5_photos/M45_filtered.jpg

Just shows how much LP there is when taking 4/5 min exposures in Thurso
Deemac,you should be able to get a beautiful Orion widefield from your wonderful location.

[Mystical Potato Head]

In case anyone is interested as to how to remove Light Pollution heres how i do it.

Create a new layer, called 'LPR'
Apply Gaussion blur to new layer
Invert new layer, change opacity
Contrast change

Ater selecting your image

1. Create new layer

Easy: menu: Layer > New > Layer...

Call the new layer 'LPR' (actually the name doesn't matter).

Now select back the background layer: click on Background in the layers tab

Press Ctrl-A (to select the whole background layer image), then Ctrl-C (to copy the whole image)
Now select the LPR layer (as you selected the background layer) and press Ctrl-V (paste the whole image in the LPR layer).

Now we've got two layers, with in each layer the same, original photograph.


2. Gaussian blur

This is to remove all the stars from the LPR layer image, so you don't see any detail in it anymore.
Menu: Filter > Blur > Gaussian Blur...
Experiment with settings so you just don't see the stars anymore, I set the radius to 95 pixels
3. Inverting the layer, set opacity

Now you should invert the LPR layer: Menu: Image > Adjustments > Invert
You should now see the LPR layer in negative colors:

Now set the opacity for the LPR layer:

Experiment with the value, but it should be around 50%. Look at your photograph, you should get an even greyish image.

you should then join the 2 layers: Menu: Layer > Flatten Image


Finally adjust contrast,curves,levels,colour balance or whatever you think think brings out the best in your image,there are no hard and fast rules, although levels adjustment is important,other than the more you adjust the more your image degrades.

For those of you who know how to do this,apologies for boring you.If you dont know i hope this helps.

[Deemac]

Great images MPH. I assume also heat haze will play a part in distorting the general clarity on a very long exposure. (Chimneys, central heating heat loss, vehicles etc.)

One of the first things I noticed when I moved out of Thurso to a single track road (with very little traffic) was the absence of very low frequency vibration (from road noise) except when there is a big swell from the sea (about 2 miles away!!)

I'll let you know how I get on, but it will need to be a clear ,windfree, mild night before I will be tempted to venture out with the gear. I'm just not that dedicated (though I can see why it could be addictive stuff).

[Mystical Potato Head]

The heat from the houses is the worst,the image at the eyepiece wobbles all over the place.The nearer the horizon you look then the more the image "boils"Best time is actually after midnight,less heating on,less thermals and also less lights on.

It is very addictive,i only got my DSLR this year and now i,ve got my setup to my liking i just need good weather to get out(fat chance).My previous camera was a Minolta Dimage Z1,i took a lot of astro images with it but it really wasn't up to the task,and i probably wasn't either.
An example of what i got with it below,this was a 25sec exposure of Orion ,the red dots at the bottom are from an RAF jet.Its the only reason i kept it.

Another one pointing out the Orion Nebula,probably the most photographed object in the sky.
http://i374.photobucket.com/albums/oo189/sat5_photos/IMG_2764.jpg

http://i374.photobucket.com/albums/oo189/sat5_photos/IMG_2765cpy.jpg

[astroman]

.... I'll let you know how I get on, but it will need to be a clear ,windfree, mild night before I will be tempted to venture out with the gear.

Could be waiting a while then Deemac :lol:

MPH, I can't wait for the chance of photographing the Orion Nebula with a DSLR. Previous photos using a compact camera really didn't do it justice.

Other than a few Moon photos all I've managed recently is this one of the Milky Way. It shows the bright patches and darker dust lanes passing through the constellation of Cygnus...
http://i271.photobucket.com/albums/jj138/astroman_caithness/CygnusCepheusMilkyWay29thOct.jpg
To get this I popped out into the country (no light polution here!), got setup took this 2 minute exposure and then promptly had to run for cover as heavy rain come on :mad:. I'd love to have got a few longer exposures.

There's little in the way of image processing here (or in my other photos) as trying to do anything more complex than tweak levels causes a headache. I must try your LPR technique though MPH - it certainly worked wonders with your photo.

[Mystical Potato Head]

Nice photo Astroman,i love widefield views and you've caught the Milky Way really well.
I got the light pollution removal technique from an astro-imiging site ages ago but i'm darned if i can find now but the most common advice i was given was when altering the levels make sure not to go too far when darkening your image,just take it to point where your black point starts to rise steeply,go too far and you lose all the fainter detail and is not easy to recover,sounds obvious i know but the temptation is always to make the sky too black at the expense of losing a few faint stars or nebula whisps.
Practice makes perfect or so i've heard.I am getting better at it but a long way to go.

BTW....just noticed the sky is clear.

[Mystical Potato Head]

Astroman,any luck with the occultation?Had it been tonight it would have been superb.
Out at Harpsdale tonight(working) Jupiter and Venus looked like a couple of diamonds stuck on the darkening sky and the beautiful new moon looking over them,great photographic opportunity with the orange glow low on the horizon.(no camera with me)
If i take my camera to work tomorrow it will be cloudy guaranteed so i wont take it and it will stay crystal clear.....there's logic for you.....aye fuzzy logic.

[dessie]

Astroman..i always thought it was a 7yr cycle....for the sun spots to go active.....and why dont you try and start a new ( forum ) for the sky at night...plus astrophotography...would be great...keep up the good photo.s just love to see them as i,m not in a position tp take photo,s like that.................:Razz

[Deemac]

What lenses do you guys recommend for this type of work?

I wondered about a 30mm prime for optical "pureness!!" (on a x1.6 pickup) Any experience with this?

[astroman]

Astroman..i always thought it was a 7yr cycle....for the sun spots to go active.....and why dont you try and start a new ( forum ) for the sky at night...plus astrophotography...would be great...keep up the good photo.s just love to see them as i,m not in a position tp take photo,s like that.................:Razz

re the solar cycle, have a look here - http://www.windows.ucar.edu/tour/link=/sun/activity/solar_cycle.html&edu=high
We might currently be in a solar minimum, but a friend of mine advised that he saw what he believed to be aurorae last week, so it's always worth keeping a lookout for them.

Regarding setting up an astronomy forum - sounds like an idea if there's enough interest out there, but I wouldn't know how to do it.

[Mystical Potato Head]

There was one last week but it was very faint and i only noticed it because i was walking along the beach with the lights at my back,no chance of seeing it from in the town.

[astroman]

Astroman,any luck with the occultation?Had it been tonight it would have been superb.
Out at Harpsdale tonight(working) Jupiter and Venus looked like a couple of diamonds stuck on the darkening sky and the beautiful new moon looking over them,great photographic opportunity with the orange glow low on the horizon.(no camera with me)
If i take my camera to work tomorrow it will be cloudy guaranteed so i wont take it and it will stay crystal clear.....there's logic for you.....aye fuzzy logic.

Caught a few fleeting glimses of the Moon through breaks in the cloud MPH, but unfortunately the best view captured was when Venus was behind the Moon :~(....
http://i271.photobucket.com/albums/jj138/astroman_caithness/VenusOccultation-1.jpg
Weather last night though was superb. Some photos to follow.

It's cloudy tonight - did you take your camera to work :D

[astroman]

To overcome the disappointment at missing out on the lunar occultation of Venus I felt I had to take advantage of the good weather last night. Here's a couple of shots of the crescent Moon.....
http://i271.photobucket.com/albums/jj138/astroman_caithness/MoonVenusJupiterOverThursoBridge.jpg
Venus and Jupiter can be seen below and to the right of the Moon.

http://i271.photobucket.com/albums/jj138/astroman_caithness/LibraryCrescentMoon.jpg

[whitecloud]

Still its a lovely picture of the moon, I do love the night sky.
love light and laughter
whitecloud

[Mystical Potato Head]

Lovely shots Astroman,help to ease the pain a little.

[astroman]

Travelled out of town to a dark site location to enjoy the clear skies and capture a couple of old favourites. Both were single exposures using a DSLR on a motorised telescope mount (ie no telescope involved). Encountered a new challenge due to the low temperature (-5 deg C) - instead of dew forming on the lens I had to contend with ice crystals :eek:

The Pleiades (M45):
http://i271.photobucket.com/albums/jj138/astroman_caithness/M45_2min_ISO800_300mmequiv.jpg
Compare with MPH's superb photo earlier in this thread.


Orion Nebula (M42):
http://i271.photobucket.com/albums/jj138/astroman_caithness/M42_2min_ISO800_240mmEquiv.jpg

Both were approximately 2 minute exposures at ISO 800 through a moderate zoom lens.

(Wifie, these would be ideal targets for viewing with your binoculars)

[wifie]

Message received astroman! ;)
Loved moon over bridge - looked like it was sittin on the wee cloud! :)

[astroman]

What lenses do you guys recommend for this type of work?

I wondered about a 30mm prime for optical "pureness!!" (on a x1.6 pickup) Any experience with this?

It depends on what you want to photograph. Obviously a fast lens would help with regards light gathering ability. I use standard kit lenses - the zoom lets you adjust the sky coverage to suit the subject. Good quality lenses will obviously help prevent too much in the way of purple fringing around the brighter objects. I suspect that the lenses you currently have would do the trick for starters, but don't let that ruin any excuse for a new Chritmas present ;)

I tend to go for wide angle views (limited to 28mm equiv at the moment) when trying to photograph things like constellations, aurorae, star trails, meteors and the Milky Way. What I'd give though to try out a fisheye, or ultra wide angle lens to photograph a meteor shower or the Milky Way spanning overhead.

For a specific object in the night sky I tend to use a larger zoom to home in on it. Anything needing significant magnification (eg lunar detail) I hook up the camera to a telescope.

Note that for static tripod mounted shots star trailing becomes clearly evident in wide angle shots with exposure times around 50-60 seconds. With a zoom lens the trailing becomes obvious with much shorter exposure times.

Hope this info helps

[Mystical Potato Head]

I use 18-55mm,55-200mm and 75-300mm standard kit jobs,obviously the size of the
target dictates the lens needed and like Astroman,when bigger magnification is needed i couple up to the telescope where it becomes your lens..Only problem i've encountered is blue/violet halos around the brighter stars at around 300mm but unless you have a motorised mount
imageing at that mag would be pointless with star trailing becoming evident in seconds,be ok for the moon though as you treat it as a daylight object so exposures are fractions of a second at full zoom.

Widefields are the easiest way to go,even if your not sure of your way around the sky you can just point your camera up and try pot luck,you'll be surprised at what you can capture.
Stick to ISO800 to keep noise to a minimum,at 1600 images can become very grainy unless you stack multiple images of different settings,also horizontal banding noise sometimes starts to appear and is difficult to remove unless you have the appropriate sofware.

[Deemac]

Thanks for the very detailed info MPH. I'll give this a go. Initially I almost prefer the idea of star trails with a long exposure setting. Soon as the weather conditions are fine I'll give this a go and post some results.

[astroman]

......Stick to ISO800 to keep noise to a minimum,at 1600 images can become very grainy unless you stack multiple images of different settings,also horizontal banding noise sometimes starts to appear and is difficult to remove unless you have the appropriate sofware.

Horizontal banding is quite often visible in my long exposure pics - I presume due to thermal noise. Can you advise the software that can be used to get rid of it? Any other tips eg does stacking of multiple images help make it less obvious?

[Mystical Potato Head]

I've found that stacking of multple images helps reduce the overall noise
but doesn't get rid of horizontal banding.
I use this software from Noel Carboni which you can get as an add on to photoshop
and does a lot of other things as well,some not so good but others are brilliant.
Its a bit like getting the hang of photoshop,the more you use it,the better you get.
Here's the link to it.

http://actions.home.att.net/Astronomy_Tools.html

[astroman]

Many thanks for the info MPH - the image processing side is not an area I'm terribly confident with, but this software looks well worth a closer look.

[North Light]

astroman,

The shot of the moon with venus behind the moon is wonderful, like the bridge too.

[Mystical Potato Head]

Astroman,There is another way to reduce LP and noise.
In Photoshop goto .....Image/Adjustments/Levels.

Bottom right of the levels are 3 eyedroppers.black,grey and white
Click the black one and drag the eyedropper to an area of your image
with no stars and as near to center of your image as possible and left click.

Hey presto,the background should be really black.You can then adjust using brightness/contrast to make it less black because as you know the sky is
not BLACK!!!!!!!!!!!!!!.It also helps to bring back any faint nebulosity in objects
like M45,only problem is if you go to far with the brightness the center of the image
starts to revert back to its original state.

Its a quick and easy way to do it.

If you have Elements its Enhance/Adjust lighting/Levels.

Hope it helps,should have thought of it earlier but i dont use it much myself.
I tend to use it only on an image that is too grey/light .The amount of "blackness"
is really up to each individuals taste and i dont like BLACK!!!!!!!!!!!!!!but black is ok.if you get my drift.

[astroman]

Many thanks for taking the time to pass on the novice friendly tip MPH - and for including the details for how to do it in Photoshop Elements which is what I use.
I'm delighted to be able to say that levels adjustments is one of the very few tools I'm reasonably familiar with and use (I also find Adjust Lighting Shadows/Highlights can be good for bringing out detail on Moon shots). For levels adjustment I always use the sliders as it seems to be a bit more controllable than the droppers - it does take a bit more thought though :eek:.

I agree that making the sky deep black isn't necessarily good - for instance I don't believe the small amount of light pollution in this 4 minute widefield exposure of Orion below detracts from the view...
http://i271.photobucket.com/albums/jj138/astroman_caithness/Orion2ndDec08.jpg
It's amazing how many more stars become visible with the longer exposure :cool:

[Mystical Potato Head]

Those stars are pin sharp,spot on focus and the LP certainly doesn't spoil the image.
Go old M42 really shows up well.Lovely image.

Glad to be of help.

[whitecloud]

hope someone takes a picture of the full moon tonight and tomoz its a cracker.wish I could but my camera is a rather outdated 3mp digital,my moons always look like wee white blurry dots:confused lol.I do love all the lovely pictures in this thread thank you for sharing.
whitecloud x







The real voyage of discovery consists not in seeking new landscapes, but in having new eyes.

[Raven]

hope someone takes a picture of the full moon tonight and tomoz its a cracker

Here you go whitecloud... just for you;)

http://i222.photobucket.com/albums/dd169/Scotland-visions/IMG_5436.jpg

[Mystical Potato Head]

Lovely moon Raven,what was it taken with?

[Raven]

Lovely moon Raven,what was it taken with?

The moon was taken with my OH`s 400D and the 100-400L.... handheld :cool:

[whitecloud]

la luna wow lovely raven thank you, found out that last night and tonight the moon is at its biggest for the year as it comes 30.000 miles nearer earth.Stick your crystal ball out in the moonlight tonight raven for a full charge and cleanse.Got to cleanse them balls.:eek: lol athough the weather said it was going to be raining later, hope not,let the wind blow those cloud away.
love light and moonmadness
whitecloud x

[tjc]

Yeh...

If the clouds stay away it should be a bright night...

:cool:

http://news.yahoo.com/s/space/20081211/sc_space/yearsbiggestfullmoonfridaynight