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My first 'real' Deep Sky.... so happy!

Stratis

By Stratis
in Imaging - Deep Sky

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Stratis

Stratis

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I've been waiting a very long time to make this post.

My journey into astrophotography started nearly two years ago when I realised that just seeing beautiful objects in the eyepiece wasn't going to cut it.... I needed to show other people these wondrous things, and I couldnt keep waking my girlfriend up at four in the morning :D

Being a total newbie (typical story, owned a Tasco refractor for about five minutes when I was too young to even point the thing) I burned through a half dozen unsuitable scopes on the way to my current imaging rig, a 102ED doublet APO. Even then, my first attempts failed dismally due to a total inability to polar align (house in the way) and no guiding setup. My first attempt was a pretty terrible M42, unguided, I could barely manage 30 second exposures on the HEQ-5, so poor was the alignment... I got something alright out of it with processing, but nowhere near the posters here. I resolved to improve.

Then...I got a new job, all my time was eaten up for a whole year, but finally I am ready to start again. I've waited night after night, checking and rechecking my equipment, and tonight was a whole 10 hours of clear (hazy, moonlit but I'll take it!) sky... I chose the first deep sky object I ever saw, back with my AstroMaster 114 Hall-Newtonian (yes, yes I know, horrible) but it caught my breath even through such a mediocre scope....

Tonight I was back, with Canon 6D and SX Lodestar guiding, although STILL not properly polar-aligned so relying 100% on guiding to correct polar drift... amazingly this setup works very well despite being relatively cheap and low-tech.

It's a lot of preamble for not a lot of result, but I couldn't be happier :)

May I present, with a bare minimum of stretching, no darks, no flats and no bias..... M13.

m13.png

I'm happy with it :D

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Stratis

Stratis

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Good stuff, but you do need flats!

I know, I know.... :D

I'm assuming that I can add the flats at any time provided I keep the optical train the same? I'm using the 102ED with a 0.8 FR and while I think I have the spacing correct (I will post an uncropped image for corners, looks ok to me) the FR really does cause some vignetting. 

This is all with the cheap SkyWatcher LP filter in heavily polluted skies btw :)

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Droogie 2001

Droogie 2001

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Well done Stratis.

A lot of what you describe is how I felt when I took my first acceptable DSO image.

Just take your time in getting all of the technology working at the same time, this is where I struggled to start with. Thankfully I have got past most of the gremlins but they do still pop up every now and then.

Like the M13 image as well as the galaxy (or two)  that has photo bombed the image.

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AndrewG

AndrewG

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Great first image I really like it!!

Fabulous start to your imaging journey. but beware, it's a very slippery slope..........

Steve

Very slippery in deed.........look what happened to me and my bank balance.......... :grin: !

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Stratis

Stratis

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Thank you all for the kind words... it gets a bit lonely with just the laptop and DeepSkyStacker to keep one company so it's good to know I'm on the right lines.

On the topic of flats, clearly the APO + FR combination is in particular need of that... as far as I know, flats are produced by throwing a white t-shirt over the objective? If that is the case, that flats are pretty much taken without the need for the night sky to actually be there, can I just bench the scope with the same optical formula (same focus distance, same filters etc) and take my flats after the fact?

If not, is there a reason why not?

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kalasinman

kalasinman

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Thank you all for the kind words... it gets a bit lonely with just the laptop and DeepSkyStacker to keep one company so it's good to know I'm on the right lines.

On the topic of flats, clearly the APO + FR combination is in particular need of that... as far as I know, flats are produced by throwing a white t-shirt over the objective? If that is the case, that flats are pretty much taken without the need for the night sky to actually be there, can I just bench the scope with the same optical formula (same focus distance, same filters etc) and take my flats after the fact?

If not, is there a reason why not?

There seems to be many ways to take flats. The primary concern being an evenly illuminated source. I leave my scope out usually anyway so 2 thicknesses of T-shirt, a piece of printer paper and the clear sky in the day seem to work fine.

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Stratis

Stratis

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So, I took everyone's advice and looked into flat frames.... it seems the only real way of getting that damn gradient out of the image without compromising elsewhere.

I took my flats in an interesting way; I propped my iPad up against a box, rested the scope on the floor and used a 'Torch' app to show a pure white screen. With the dew shield pressed firmly against the iPad, I just took 10 shots at one orientation, then rotated the pad 90deg and took another 10 shots; ISO100, I dont see a need to corrupt a flat frame with ISO noise.

I am deeply pleased with the result; this is using nothing but the sliders in DeepSkyStacker, I dont own anything more complicated than that so this is as close to the raw data as I can get. 

M13_nicer_smaller.png

A slight increase to saturation really shows the variation in colour.... I can alter the 'cast' to whatever I want but the golden colour seems the most natural-looking without actually modifying the underlying data. Please note the very well-controlled CA in this ED doublet objective :D

For the sake of completeness, I include the full frame image from which these are savagely cropped:

get.jpg

I'm thinking in future I will just use the APO in native f/7 for greater image scale. 

Thank you so much to everyone for their advice and encouragement  :rolleyes: 
 

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Stratis

Stratis

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Another method would be to use DBE in Pixinsight...

Sadly I don't own any processing packages, I'm stuck with basic levels and curves at the moment :) I keep hearing good things about PixInsight, MaximDL and Nebulosity but they are individually expensive and I'm not sure which one to invest in. Any advice?

One final try below (no more updates I promise!), this next one is using Entropy Weighted Average stacking as well as 2x Drizzle... seems to have sharpened things up a bit :). Learning something new every time I try this...

M13_entropy.png

Full resolution:

get.jpg

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Stratis

Stratis

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Apparently PostImg is killing my direct links so:

First processing step:

M13_nicer_smaller.jpg


Second processing step:

M13_entropy.jpg

If an admin wants to delete this post and go back and edit the original posts (I cant any longer) then please feel free.

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