Wednesday, 7 April 2021

Galaxy time

M101 M51 and the Needle Galaxy from the last few weeks. It's been difficult at times with strong winds and snow showers to contend with but having got my guiding sorted out it is now much easier to get longer exposures and gain more data for the final images. M101 was done with my 450d ISO 1600 4 minute subs about 4 hours worth. M51 5 minute subs one hour's worth and last night the Needle Galaxy two-minute subs about 30 of them. One of the most useful discoveries of late is using dithering with my images something I never really tried before but it really makes a big difference to the final stacked image so well worth trying it out.







 

Saturday, 13 March 2021

Leo Triplets

Lots of issues to contend with when doing astrophotography but if you persevere and keep at it you can be rewarded for your efforts. This shot of the Leo Triplets is only 13 shots each 2 min long and an ISO of 1600 it was quite windy tonight so I had to throw out quite a few of my shots that were ruined by gusts of wind knocking the telescope about. I now have a guide camera set up so can get longer exposure which is great. 
My guide camera is a ZWOI120 and I have attached it to my skywatcher finder scope to use as the guide scope which works very well.



 

Thursday, 4 February 2021

Thors Helmet and Galaxy's galore

 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 


M81 M82


The UFO Galaxy



Sunday, 24 January 2021

Rosette Nebula M3 and M51

 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


M3 50sec ISO 16000 x 65 with 30 darks flats and bias Canon 450d


M51 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

Mosaic madness part 2

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


Images lined up and processed further


Image cropped down to size but the problem of the edges and gradients which is normal in single images becomes much more of a problem when stitched together.


So in conclusion
 You can do it but if your single frames are not very clean and gradients are large on your edges it is going to be very hard to get a good final image even with a large overlap on your frames.

I have done this before on several subjects but it has never been easy to do but with guiding in place and longer exposure times the frames are a bit better with more detail and this helps to match them up.
But for now, I think I will stick with single images or invest in another telescope for a wider field.








Tuesday, 19 January 2021

Mosaic madness

Taking a picture of something big in the night sky like the Andromeda galaxy or the Rosette nebula can be very challenging. If your telescope can’t fit it all in, then your options are to get another telescope or try doing a mosaic that will cover the whole subject. It’s not easy and you will run into many issues so I hope this article will help those of you who are willing to give it a try.

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.

FIRST ATTEMPT.



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.



Once it is in the middle of the cross-hair slew the telescope east or west and watch the star. If it goes off the centerline you will need to rotate your camera on your mount to correct this until it follows the horizontal line exactly the same applies to the vertical line in North and South. Once it follows them dead straight then your camera is correctly aligned on your telescope and will match the field of view FOV rectangle in CDC showing where your telescope is pointed.



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.


So what is an EPOCH and J2000?
(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:[4]

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.[5]

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

Eq5 upgrade is here and its awesome.

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.


The hand controller ports



Cable for the hand controller and holder


The RA motor


The Dec Motor


The main control box you plug the eqdirect cable into the hand controller socket on the 
bottom left.


The side covers for the Ra Motor and the two cables that plug
into the RA motor


The cables for RA and DEC and the power cable if you're using a portable battery pack 
fine if you're going to lug it about but I got a power adapter to plug straight into the main control box



You also have the brass cogs that go on your mount and the bolts that hold the Ra and Dec motors and 
there washers.


Instructions to fit them are pretty much nonexistent so 

your first job is to put the motors in place and get them lined up correctly with the cogs so there is no slack or backlash that is very important or you will get tracking errors. If you have fitted the dual-axis motors to the eq5 before this will be easy if not follow this link on the stargazer lounge which has some great tips for getting it set up.

Once it was all put on the mount I plugged in the eqdirect cable and fired up my laptop and it all worked great. I am using the following software to control the mount
Astrophotography tool- Cartes du Ciel- Stellarium- backyard eos and eq mod with the Ascom platform.

Now to test it all out with my Canon 450d and see how it performs.
Here are some images I have captured using the eq5 mount with the synscan upgrade and my Canon 450d to show you what it is capable of doing.

Casper the friendly Ghost Nebula


The Orion Nebula


The Rosette nebula


All of these were taken with the unmodded Canon 450d and are unguided images 
exposure time was 50 sec each and an ISO of 1600. 30 lights 20 darks flats and bias were used stacked in deep-sky stacker and processed in PS.

Once I get a guide camera set up longer subs will be easily achievable.
So is the upgrade worth it YES absolutely worth it, in my opinion, it makes a big difference to the tracking, and being able to control everything with the computer is excellent no more struggling to find targets just get the computer to do it all for you. I will do some more section on the complete set up as I go along but if your thinking of getting this upgrade for your eq5 mount its got the thumbs up from me and I have been using the eq5 for a long time for astrophotography.