Wednesday, 7 April 2021
Saturday, 13 March 2021
Thursday, 4 February 2021
Another nice batch of images from this simple setup all taken at an ISO 16000 50sec each and about 60 or 30 lights depending on the subject stacked with 30 darks flats and bias.
I am using APT and Cartes du Ciel together at the moment to control the mount and camera but I must say I am tempted to try out NINA as it looks very good.
Thors Helmet Nebula
Sunday, 24 January 2021
A few more clear nights and I was able to get out and do a bit more imaging with my current set up still not got a guide camera yet but that will come later on.
All images were taken unguided with a canon 450d on my skywatcher eq5 pro with a skywatcher 200p being controlled by Astrophotography tool and hooked up to my laptop using an EQdirect cable to my mount.
Rosette Nebula 50sec ISO 16000 x 65 with 30 darks flats and bias Canon 450d
Current Equipment for Astrophotography
Telescope and mount: Skywatcher 200p and EQ5 Pro mount Connected to PC with eqdirect cable that bypassed the use of the hand controller and powered by a mains adapter
Camera: A Canon 450d with 10ft long cable that connects to pc and is controlled by software. Software used: Astrophotography Tool APT, Cartes du Ciel Planetarium, Ascom platform & EQmod
Friday, 22 January 2021
Well is it worth it?
Another frustrating session taking a mosaic of the Rosette Nebula. I thought I had solved the issue of the frames not lining up but once it was all connected to my mount nothing lined up again so its back to the drawing board I guess but I decided to line the mosaic frames up manually which at least got me enough frames to stack them and have something to try out.
Only ten images for each of the four frames which were 50 secs long and an ISO 16000. This gave me enough to work with but with no guiding in place, longer exposures are not going to happen. The other big problem you face when doing this with a DSLR is the gradients you get on the edge of your frames and also how to process them all.
When I put them together I got the following which is very hard to process successfully so I must conclude that yes this can be done if you are willing to work hard at your processing and stitching the images together but overall my feeling is its not worth the hassle unless you're using a very good camera that gives you nice clean images with no gradients and noise to deal with.
As for the problem of the mosaic frames not lining up I might try and solve that later on or just stick to single images while using a DSLR for the time being.
Individual frames put side by side then processed as one image
Tuesday, 19 January 2021
First of all, this is the equipment I am using to do this.
A Skywatcher EQ5 mount fitted with the synscan upgrade allows me to connect to a laptop and control everything from there.
A Skywatcher 200p Newtonian telescope
A Canon 450d for imaging
And an EQ direct cable to bypass the handset that comes with the synscan upgrade and connects directly to the computer.
For the software, I am using the Ascom platform and EQMOD along with APT astrophotography tool and CDC Cartes du Ciel planetarium
Getting APT and CDC working together and making sure your camera is correctly aligned on your telescope is the biggest challenge I faced so let’s trace back my steps as I started off and find out how things progressed.
Not what I wanted at all, unfortunately, the images were taken at an exposure of 50 seconds each ISO1600 unguided and I took 9 of them just to test out the setting but when they were stitched together in Photoshop nothing matched up so it was back to the drawing board.
Puzzled by why my frames were not matching up I concluded that my camera was not lined up correctly with the RA and Dec coordinates so to put this right you need to do the following.
First, find a bright star in the sky to focus on using live view in your camera and get it lined up in APT using the cross-hair like this. Then line it up so it’s right in the center.
It also needs to be pointed out that setting your FOV angle in CDC is needed to get your camera correctly aligned using 0 degrees or 90 degrees as shown here in CDCs options for this on number 4 which is my settings for the canon 450d you change it under offset to 0 or 90 this will align your FOV rectangle to lay flat or two be on its side so make sure you match it correctly to what you are seeing when you take a photo of your subject.
So with all that now corrected, I thought all would be well but of course, nothing is easy in this hobby and once again the frames would not match up correctly even though the camera angle had been corrected so it had to be the setting in CDC or APT that were the issue and I was correct. This is how I fixed it and I hope it helps you out if you are having the same problems.
First of all the problem, we had to fix was this.
In CDC the mosaic frames it creates have coordinates that tell APT where to point to in the sky but when I used them APT could not align them to the position of the mosaic panels so it looked like this once the telescope had slewed to there position. Here you can see the area that my telescope has been moved to and in red the actual position of the mosaic frames which is not lining up with my telescope's position.
After much research on this problem I came across the word EPOCH and its associated number J2000? what the hell is that all about I wondered.
Well, it turns out that the EPOCH and its Number J2000 affect the coordinates in APT and CDC and in turn, can mess up your alignment.
(Due to the wobble in the Earth’s orbit the RA and Dec positions of the Stars appears to change. The older star atlases used Epoch 1950 for their positions, newer atlases use Epoch 2000.)
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
For example, orbital elements, especially osculating elements for minor planets, are routinely given with reference to two dates: first, relative to a recent epoch for all of the elements: but some of the data are dependent on a chosen coordinate system, and then it is usual to specify the coordinate system of a standard epoch which often is not the same as the epoch of the data. An example is as follows: For minor planet (5145) Pholus, orbital elements have been given including the following data:
Epoch 2010 Jan. 4.0 TT . . . = JDT 2455200.5
M 72.00071 . . . . . . . .(2000.0)
n. 0.01076162 .. . . . Peri . 354.75938
a 20.3181594 . . . . . Node . 119.42656
e. 0.5715321 . . . . . Incl .. 24.66109
where the epoch is expressed in terms of Terrestrial Time, with an equivalent Julian date. Four of the elements are independent of any particular coordinate system: M is mean anomaly (deg), n: mean daily motion (deg/d), a: size of semi-major axis (AU), e: eccentricity (dimensionless). But the argument of perihelion, longitude of the ascending node and the inclination are all coordinate-dependent, and are specified relative to the reference frame of the equinox and ecliptic of another date "2000.0", otherwise known as J2000, i.e. January 1.5, 2000 (12h on January 1) or JD 2451545.0.
Ok, that's the nerdy stuff out of the way so now we need to tell CDC and APT and EQMOD what are Epoch settings are so that they are both singing from the same hymn sheet!
Correcting the setting in CDC APT and EQMOD
1. Go to the general settings panel and set it to Force J2000 and make sure you are using Alt/Az coordinates in the chart settings.
In APT make sure that the JNow button is not used.
Leave this JNow tab not highlighted so it does not convert J2000 to JNow as you have told CDC to use J200.
And lastly, in EQMOD in the driver set up, you will need to change it to J2000 under Ascom options
Right then that's all the setting put in and in part two of Mosaic Madness, I will continue with my progress and let you know how I get on. PHEW!
Saturday, 16 January 2021
Well, it's time to upgrade the eq5 mount with the new syn scan upgrade from RotherVally Optics who I have to say are first class and a pleasure to deal with well done guys.
So who does it all fit together and is it easy to do? Well yes, actually it was pretty easy to put it all on the mount and get it up and running. Here is what you get with the upgrade
I ordered an eq direct cable as I don't want to use the handset and it works great just plugs straight into your laptop and you use EQMOD and the ASCOM platform to control the mount.