Pleiades

Deep sky photography quickly became my  main goal when I started photographing the sky. It turned out there were many pitfalls and the road was going to be bumpy and hard.

 

I will tell you how I shot one of my favourite constellations

Reading blogs about astrophotography told me there were two main problems: 

1. Falling down the rabbit hole.

2. The steep learning curve (which I will get to in this episode) 

 

1. Falling down the rabbit hole.

Basically it boils down to this: this hobby is not cheap. In the beginning the results are iffy at best. (I have seen people who claim they got into astrophotography 'only four months before' deliver excellent photos, but I am doubtfull if they are for real.) When researching what could go better, there are many possible aids that can improve your pictures, all of which cost money. 

I was lucky enough to make some extra money the year I started, but my advice is this:

- Wait before you buy: Ask yourself repeatedly: 'Do I really need this or do I just want this?' many times it will be the first.

- Research the hell out of it: You do not want extra stuff lying around that you don't need.

- Buy second hand stuff: Most amateur astronomers take good care of their stuff and want new toys every now and then. keep an eye on specialty websites for this. Because this is a relatively small world, people who fail to deliver get found out real easily.

 

2. The steep learning curve

Is it hard to learn? Yes it is at times. 

You need an equatorial mount, to follow the rotation of the earth and avoid star trailing. Once you have this, you have to learn how to use it: aligning it properly, balancing is important,... Second hand material does not always help this (I do think my AVX may need some tuning for instance). What helps is a QHY Polemaster: this really helps in aligning the mount to get it perfectly on Polaris. But even then your balance can be off.

Once all this is done the work can begin.

 

Pleiades

In winter, one of my favourite DSO's is the Pleiades or the 'Seven Sisters'. It is small to behold, but even as a child I was fascinated by those beautiful little sparkles of light far away (about 140 Parsecs).

When trying to photograph it, it seemed I could not get the nebulae that surround the stars in the picture. Turns out, I needed more time on subject.

This means you need more exposure time than you would like. Thie picture accompanying this blogpost has about sixty 120 second shots stitched together. The reason for this is that the longer you expose, the more noise you get. By taking multiple equally long exposures, the signal to noise ratio can be balanced out and improved. 

You need to add flats to remove small remnants of dust on the lens and thus 'flatten' the image and darks to callibrate the image and remove even more noise from the image. You can also do Bias frames

 

After doing all this (this is two nights work as I try to get some sleep at a decent time as well) it is time to do the processing.

Darks, Flats,  Bias and light frames can be merged using Deep Sky Stacker (DSS). This is free stacking software that combines all the images and produces a final image, taking into account all the previous steps. 

As I live in a city and do most my photography from there, I use a CLS-filter, which removes part of the light pollution, but still the image is usually somewhat overexposed. This means the final image needs some stretching in DSS, is improved somewhat in Photoshop (I could be a lot better at that) and colours can be enhanced in Photoshop or Lightroom (which I prefer).

 

This final result is one of the pictures I have been most proud of this year, allthough much can be improved.

 

Hope you like it!

 

You can Always comment, so I know if anyone actually reads this.

 

Merry Christmas!