Photon Junkie

M45 The Pleiades Star Cluster (RGB)

Euan — Sat, 28 Jan 2012 17:01:08 +0000

I tend to be put off RGB most nights due to the really bad gradients I seem to get. No doubt something to do with a lot of LP in my vicinity. I’ve done a lot of work on getting my flat frames better, but this has only made a slight difference. Thankfully I’ve been able to pull something out of this in PixInsight with a modest number of subs.

Camera: Atik 383L+ Mono with Baader 1.25″ RGB CCD Set
Scope: Borg 101EDII with 0.85x Reducer @ F5.3
Mount: EQ6 with EQMOD
Guiding: Orion ST80 with QHY5
Capture Software: CCD Commander, Maxim DL
Processing Software: Deep Sky Stacker, PixInsight
Exposures: 4 x 10 mins per colour
Calibration: 25 x Bias, Flats, Darks

NGC 2237 The Rosette Nebula (Hα/OIII/SII)

Euan — Sat, 28 Jan 2012 12:00:24 +0000

I’ve been tinkering with full narrowband on and off for ages, but never managed to get anything resembling an image. I don’t know if it’s just now that I’ve moved to a 100mm scope, but things seem to be falling into place now.

So here is my first ever full narrowband image, to say I’m chuffed with this would be an understatement. There’s still a lot of bits to figure out mind you, like purple haloing and the purple sky background. I might add another hour each to OIII and SII to see if I can get it a bit smoother. I had to download a trial of Photoshop CS5 to tweak the colour as I couldn’t find a way to do it in PixInsight, so it might be worth buying just for final tweaking. I’ve added the Hα only in as well.

Camera: Atik 383L+ Mono with Baader 1.25″ Hα / OIII / SII
Scope: Borg 101EDII with 0.85x Reducer @ F5.3
Mount: EQ6 with EQMOD
Guiding: Orion ST80 with QHY5
Capture Software: CCD Commander, Maxim DL
Processing Software: Deep Sky Stacker, PixInsight, Photoshop CS5
Exposures: 9 x 10 mins (Hα), 6 x 10 mins (OIII), 9 x 10 mins (SII)
Calibration: 25 x Bias, Flats, Darks

IC1318 The Gamma Cygni Nebula (Hα)

Euan — Thu, 29 Sep 2011 12:46:48 +0000

This is the first proper outing for the new 101EDII. Just a test run of 7 x 15 min subs on this quite dense area of Cygnus. Auto focusing worked really well and pulled in a HFD of 2.15 which is the lowest I’ve seen, it usually gets somewhere between 3 and 4. I’ve also added a S2 filter to the wheel, so will try and get Hα/O3/S2 on this over the next few clear nights (it could take a while!!)

Camera: Atik 383L+ Mono with Baader 1.25″ 7nm Hα Filter
Scope: Borg 101EDII with 0.85x Reducer @ F5.3
Mount: EQ6 with EQMOD
Guiding: Orion ST80 with QHY5
Capture Software: CCD Commander, Maxim DL
Processing Software: Deep Sky Stacker, PixInsight
Exposures: 7 x 15 mins
Calibration: 20 x Darks

Atik 383L+ Flat Frame Exposure Testing

Euan — Thu, 01 Sep 2011 19:17:49 +0000

I’ve never got along well with flat frames, I’ve always had trouble with getting the levels just right. It’s tempting just to fire it all through PixInsight and let the background extraction tools take care of it, but it doesn’t get better than having good calibration already done, espacially when you have light pollution to battle on top of that.

So, I thought it was time to get to grips with this part of imaging, so I bought a Gerd Neumann Aurora Flat Panel.

The first problem when it comes to flat frames and the Atik 383L+ is just what is the exposure length I need to get above to overcome any smearing from the mechanical shutter? I’ve heard 0.5 – 1 secs as a rough guide, but it should be easy to work out and have a measurable effect on the data.

Well, here is a range of exposures through a Red filter using the Aurora. Analysed using CCD Inspector. The resting position of the shutter is obviously on the bottom right looking at the first exposure. With increasing times this gradually decreases the effect on this corner and starts to show the real vignetting in the system on everything above 2 secs, it may be possible to get away with cutting it fine somewhere between 1 and 2 secs, but for the sake of headroom, 2 secs will be my minimum exposure length.

Scope: Borg 101EDII (@ F5.3)
Filter: Baader 1.25″ Red CCD

Mobai (Mobile Observatory Automation Interface)

Euan — Sat, 20 Aug 2011 10:14:57 +0000

When I built my automation system, the one thing that became apparent is how poor the user interface is. Running multiple apps, each with multiple windows of their own, is a bit of a mess and quite hard to keep track on what is happening at any given point. ACP presents a nice user front end in a website, but is priced at the higher end of the market where people can have the open of renting out their Observatory. There seems to be no open source middle ground for hobbyists to explore.

I’ve started to develop an open source solution that can interface with automation applications in different ways. The idea is that if you can have a client that brings all your applications into one standard communication protocol, then this can be used to interface with anything; a web server, database, or external controller. This could simply be displaying information on a website as ACP does, but with touchpanels now being ubiquitous in everyday life, why can’t your remote Observatory have an interface on an iPhone or iPad?

The Mobai Windows Client will run as a console application on your Observatory PC and connect into each of your applications (supported so far are MaximDL, CCD Commander, ASCOM mounts, the Aurora Cloud Sensor and MJPEG IP webcams). It will then send all the stats for these applications over the network to another device. What I plan to develop with the client is that you can pick and choose your configuration. This could mean support for different automation applications, and the choice of how you want your user interface to work, this could be a simple webpage, or an iOS / Android application. So far this information is read only, but it also has the ability to send commands into your applications from the interface and there is a lot of room for development on this front.

The way I am creating a user interface is to send all the client data to an AMX Netlinx controller. This sits inside the house on the same network as the Observatory PC and can also control lots of devices via RS232, relays and digital sensors. These are high-end AV & Industrial controllers, but can be found occasionally on eBay for a few hundred pounds. AMX controllers can also be connected to their own touchpanels, which again are quite expensive, but some cheeky Russians have brought out their own AMX compatible iPhone, iPad and Windows application called iRidium that allows the use of AMX touchpanel files normally meant for proprietary devices. The license for this is a few hundred pounds, but in effect this means quite a high-end automation system for not a lot of money.

For more info and to try the source files visit the Yahoo Tech Group: http://tech.groups.yahoo.com/group/Mobai/

SGL Motorfocus Project

Euan — Sun, 07 Aug 2011 13:29:37 +0000

One thing I noticed with the 77ED was that at least one of the colours in an RGB run would be slightly out of focus, I noticed this on a few images and checked it all with a bahtinov mask. Going between RGB and having to change focus all night is not something that can really be done manually. There is also the problem of compensating for temperature changes over the course of a night. Focusing is the last part of my workflow that is not automated, so it was time to build a full auto focus system.

Accurate auto focusing is not really possible with the helical focuser that original came with the 77ED, so the first step was the upgrade this to the M57 Feathertouch. I’ve always had difficulty with heavy imaging trains and 2″ eyepiece holders, I’ve never found them to be very reliable and can introduce tilt quite easily. The M57 version of the Feathertouch allows the Borg adaptors to screw directly in making it all rock solid. I added in a camera rotator as well, it won’t really work without this as it locks your CCD angle in wherever the threads tighten up.

I then noticed a great thread on Stargazers Lounge by Neil Chase, who had also started his own automation group (SGL Observatory Automation). The idea was to use a combination of Arduino and Motor Driver to build an ASCOM compliant Motor Focuser. The programming side was really straightforward, it just took a wee bit of tweaking some of the variables to match what I was doing. The Feathertouch doesn’t have any fixing points so it took a bit of trial and error and a few bits and pieces from eBay to properly mount a stepper motor on it’s own frame bolted onto the main section of the scope. The result works quite well on a artificial star, now to just get it working with AquireStar to automatically find focus stars during imaging runs.

New Imaging Scope: The Borg 101EDII

Euan — Sun, 07 Aug 2011 12:48:43 +0000

Astronomical darkness returns to 55° North on Tuesday so it’s time to get my finger out and finish a few summer upgrades. The first and the most major is moving from the 77ED to the 101EDII. It is compatible with the same components as the 77ED, so all you have to do to upgrade it is to change the front objective.

It has a focal length of 530mm compared to the 77ED’s 430mm so gives a slightly tighter FOV, and is also slightly faster with the 0.85x reducer giving it F5.3 compared to F5.6. I’ve still to run some flat frame tests but still being under F5 I’m hoping 1.25″ filters will still just about do the job.

Last of the Season: M42 The Orion Nebula, NGC1977 The Running Man (RGB)

Euan — Sun, 10 Apr 2011 12:25:14 +0000

With the clocks moved forward it’s only a few weeks before Astronomical darkness is gone in Scotland until August. I haven’t managed many images in 2011 due to a cracked CCD as well as some other technical issues. Thankfully Atik agreed to replace the cracked 383L+ with a brand new camera, so all is back to normal. This was the last thing I had left to process, it was a pain to sort out the gradients in the image and has finally convinced me to get a Gerd Neumann panel to try and make my flat frames more consistent.

The 77ED front objective is now sold and hopefully next season will see the arrival of a new 101EDII objective, and a few refinements to the automation process including full auto-focus which is being developed at the moment. Part of this is also to build a cloud sensor which I have been testing and will be a really good way to measuring sky quality.

Camera: Atik 383L+ Mono with Baader 1.25″ RGB
Scope: Borg 77ED with 0.85x Reducer @ F5.5
Mount: EQ6 with EQMOD
Guiding: Orion ST80 with QHY5
Capture Software: CCD Commander, Maxim DL
Processing Software: Deep Sky Stacker, PixInsight
Exposures: 4 x 15mins (each colour) = 3 hours
Calibration: 100 Bias, 100 Flats (per colour), 100 Darks

Dug out of the snow: IC5067/70, NGC1499, B33/IC434 (Hα)

Euan — Wed, 08 Dec 2010 13:36:59 +0000

It’s been a month since I used my gear, mainly because of rubbish weather. The clear skies convinced me to spend a few hours digging the obs out from underneath over a foot of snow and ice. It was so bad, that when the obs went to close itself this morning, it failed and woke me up, as it had frozen open as it was -10 outside. Even though there was no moon, RGB was not going well and just far too bright, probably because of LP reflections from all the snow. It was good to get back out again, these will turn into full narrowband projects if the weather keeps up

Camera: Atik 383L+ Mono with Baader 1.25″ 7nm Hα Filter
Scope: Borg 77ED with 0.85x Reducer @ F5.5
Mount: EQ6 with EQMOD
Guiding: Orion ST80 with QHY5
Capture Software: CCD Commander, Maxim DL
Processing Software: Deep Sky Stacker, PixInsight
Exposures: 7 x 20 mins (IC5067/70), 3 x 20 mins (NGC1499), 5 x 20 mins (B33/IC434)
Calibration: None (yet)

New imaging scope: the Borg 77ED

Euan — Sat, 30 Oct 2010 22:53:11 +0000

I’ve wanted one of these ever since seeing the excellent results people were getting with them. Being an Astrograph it is perfectly suited for imaging, giving a nice flat field over up to 35mm full frame sensors. I’m 0.8mm off the 55mm spacing requirement but even with that the curvature is extremely low, if my guiding is up to scratch this should result in much sharper images.

The major advantage of the Borg system is it is completely modular. Each component can be broken down and re-arranged. It can even be upgraded to the 101mm version just by changing the front lens. I’m running it with a 0.85x reducer at the moment, so will at native F6.5 this brings it down to F5.5. It has a super reducer that can bring it down to F4. I will eventually buy this and then switch from 1.25″ to 2″ filters.

I’ve just been giving it first light and been playing with the helical focuser, which being more like a camera lens focuser is completely different to the usual crayford types on most scopes. So far it’s turned out to be excellent, it can take the weight of the imaging train easily and is nice and smooth and can be locked off once set.