The Lenski and Star Adventurer deliver an image at last

Posted by Rob Leonard

Back in April this year I was reading up on how simple prime lenses from the 70’s and 80’s can be excellent for wide field astrophotography and had for a pittance. I started browsing ebay to see what was available late one evening and ‘accidently’ acquired a 1976 Soviet made f4 135mm prime lens for the princely sum of £25 (I know there are a few other club members who have similar ‘accidents’ whilst idly browsing second hand sites!). This is clearly a bargain so long as you ignore the price of tracking mount to put it on… (in my case a Star Adventurer).

To cut a long story short, the lens appeared to be more or less sound- but through a combination of human error and other factors I didn’t manage to get a decent image out of it before the short summer nights rolled in.

Roll forward to yesterday, and coming home from our summer holidays in France found I had a clearish night. After a long day of driving the sensible thing would have been to go to bed, but where’s the fun in that?

See below for a 2 frame mosaic (my first- yay!) acquired over 55 minutes (45 mins on Deneb and 10 mins on Sadr when the clouds rolled in) plus calibration frames. Transparency wasn’t great and the tracking was pretty awful (I didn’t polar aligned very well, making the image quite soft) so I think this can be quite a lot better, but I’m still quite excited about the potential of this little rig to use alongside my main kit.

 

 

 

My reaction to having successfully taken my first ever deep sky images

Posted by Andrew Thornett

On a roll after successfully taking my first ever image of both a deep sky object and of a galaxy last night, I downloaded DeepSkyStacker and stacked 7 images of M101 that I took at the time to give total equivalent exposure 40 minutes and then looked up on YouTube some great videos on processing to remove light pollution. I am very excited about the resulting photo as it showed star forming regions in spiral arms of the galaxy. Now I can see why so many amateurs find astrophotography so addictive! A bit more processing leads to new discoveries – it is like someone has massively increased the size of my telescope! Aperture fever here I come! Each new process in GIMP2 is like buying a new eyepiece giving new revelations! For those who have never done astrophotography you don’t know what you are missing!

Andy

Stacking and processing image of M101 to remove light pollution in GIMP

Posted by Andrew Thornett

It is amazing what instructions you can find on YouTube and Google! I downloaded DeepSkyStacker and stacked 7 images of M101 I took last night to create single image with equivalent exposure of 40 minutes and then carried out the instructions at https://www.youtube.com/watch?v=FsvX48S807Q to remove light pollution – results were amazing as you can see below!

This post follows from my previous post & is using images from that session:

First deep sky images with QHY10 camera

Andy

I had taken 7 images of M101 “subs” last night – in my previous post I only presented a single frame. Today I stacked all 7 in DeepSkyStacker (http://deepskystacker.free.fr/english/index.html) to create single image equivalent total 40 minutes exposure (below):

The following image is my first iteration of applying curves in GIMP:

I then applied curves again to above image each time narrowing down the top and bottom so that it bridged the data seen on the histogram:

Another iteration of curves:

Now when I looked at the histogram the edges of the curves touched the data both sides:

I used despeckle with standard settings in GIMP on above image to get following image:

I now followed the instructions at https://www.youtube.com/watch?v=FsvX48S807Q to remove light pollution.

The first step was to create a copy of the layer and on this copy I used despeckle with largest radius and maximum black and white points to remove stars, then used the clone tool to remove the two galaxies as best I could to create a layer showing image of the background light pollution.

I then used subtract on the layers to remove this light pollution layer from the original image to give following incredible image (seems incredible to me that this can be done so easily):

First deep sky images with QHY10 camera

Posted by Andrew Thornett

I know that the following photos are not very good but they do show real deep sky objects – M57 (Ring Nebula in Lyra) and M101 (spiral galaxy in Ursa Major). I took these photos tonight using my QHY10 camera on my Sky Watcher Equinox Pro 80mm scope on HEQ5 Pro mount. I spend a long time polar aligning the scope and then did three star alignment. The sky was poor with a lot of moisture but I still managed to get my first successful deep sky photos after 4 weeks of hard work.

These images are certainly not works of art and I have long way to go on my astro-imaging journey but I am excited about the start I made today. I have already achieved my objective of being able to photograph a galaxy and show its spiral arms – my next objectives are now to show star formation regions in a galaxy in one of my photos and detail in the wall of a planetary nebula and to successfully image the North Americal Nebula and Horse Head Nebulae. My objectives are predomently observational rather than to create artistic renderings of the night sky. To me, the camera is a tool to help improve my observations of the night sky.

Andy

M57 240819@2247 60s.png – original image (single frame, 60 second exposure):

Applying some curves to above image in GIMP:

Cropping the above image and scaling up the image:

M101 240819@2340 300s.png (original image – single frame, 300 second exposure):

Applying curves in GIMP to above image brings out M101:

Greyscale and further curves and a little playing around with contrast and brightness and I was able to bring out the spiral arms in M101 – I felt this was quite an achievement!

I took 7 images of M101 tonight & the following post describes what happened when I stacked those images:

Stacking and processing image of M101 to remove light pollution in GIMP

Quiet Sun? – – – 23/08/2019

Posted by Roger Samworth
And then – –  –
Despite my forebodings the other day, look what turned up after being out all day today – – -!
Later (21:10 UT) :
From the images on the GONG web-site, it seems that this prominence was rapidly evolving, and reached its peak intensity at around 17:00 UT – just about the time I caught it. The beauty of solar observing and having a scope at instant readiness! I have to admit, however, that due to the Sun’s position, I had to forsake the window-sill in favour in the garage floor, pointing it through the open door!