Here is my latest M42 captured with my Canon 1100D thru my Nexstar 4SE at prime. I used an old 3″ Mak to guide but found the usual star guiding apps could not lock on the stars. I then switched on DSSR and used it to guide right thru the 3 hour session. Stacked in SkippyStak and processed in StarTools.
I have always admired the fantastic Milky Way mosaics that you see on the web and here is how to try it for yourself.
I shot this in Scotland in October using only a fixed tripod and a Canon 1100D with the stock 18-55mm lens. At this time of year, the Milky Way passes close to the zenith which makes this method easy to use. You could adapt it for other dates by tilting your tripod head so that it follows the Milky Way as you tilt the camera.
First, get to a dark site with clear views of the Milky Way from horizon to horizon. Set your tripod level and take some test shots to test focus and exposure. I set the lens to 18mm, wide open aperture, ISO 6400 and exposure to manual at 30sec.
Now aim at where the Milky Way crosses one horizon and take your first shot. Tilt the camera up about 15 degrees and take another shot. Repeat until the camera is pointing straight up which should give you a series of 7 shots or thereabouts. (The angle is not too important – you just need a good overlap between shots. Now turn your camera round to the other horizon and repeat for a second series.
Shooting all the images took me about 10 minutes.
Create the Mosaic
I used the amazing and free Microsoft Image Composite Editor (ICE) to stitch the mosaic. Start by loading the first series of images (I used the raw .cr2 files). Then click Stitch and select the Transverse Mercator projection when it has finished stitching. Click Crop and then No crop and then click Export and select the .PNG image file option. Click Export to disk and select where to save your first half of the Milky Way. Repeat for the second series of images which will give you 2 mosaic halves like these.
You can now use ICE to join these 2 halves to make a complete mosaic. Load them in ICE and Clicking Stitch will give you a result like this.
We need to rotate this a little to bring the Milky Way vertical so insert a value of 10 for Roll to give this.
You can now click the Crop button and adjust the crop window to suit like this.
You can now export this image and edit it in your favorite image editor.
You can also load both sets of original images in and let ICE stitch them all together. Below is how this looks using the Fisheye projection and colors tweaked in Gimp.
Not bad for 10 minutes of field work?
I was imaging Orion when I captured this shot. Still trying to work out what it was. It was taken from Inverness, Scotland on 16th February, 2015 at 21.04UT.
Below are some other shots I took the same night.
All images taken with Canon 1100D, stacked in DeepSkyStacker and processed in StarTools and Krita.
I got a book on astrophotography for xmas and one of the things it said was that you can’t do deep sky imaging with an alt-az mount. I thought I would try it out and left my NexStar 4SE tracking M42 un-guided while I watched the football. My Canon 1100D recorded around 50x good 30sec exposures which were stacked in DeepSky Stacker and processed in StarTools and Krita to give the result below.
Here is my first real go at capturing clusters with my Nexstar 4SE OTA and Canon 1100D combo on an unguided HEQ5 Pro. All stacked in DeepSkyStacker and processed in StarTools and Krita. Krita is very cool and easy to use and can handle the 16bit tiffs from StarTool. Lights and darks all 20s and biases 1/4000s, all at ISO 6400.
This is my latest M42 captured on my Canon 1100D thru a Nexstar 4SE OTA mounted on a HEQ5 Pro. Stacking was done in Deep Sky Stacker and Processing in StarTools. I know it looks very gaudy but I like it. To me, it looks like we are peering thru furnace clouds into the blue white heat of the stellar foundry within. There is even a hint of some Pillars of Creation type features around the blue core.
Image was composed of 189 lights, 22 darks and 23 biases. All shot at ISO 6400 with 20s for lights and darks and 1/4000s for biases. Mount was unguided.
StarTools creator Ivo took pity on my processing efforts and produced the image below from my data. Talk about chalk and cheese. You can see his processing workflow here.
I normally keep my mounts poorly aligned to allow testing of DSSR’s autoguiding feature. However, I wanted to take some deep sky shots so thought I better drift align first. Drift aligning is done in 2 steps and you can use the Sun, Moon, planets or stars as drift targets.
First, setup DSSR looking at a target in the South (or North if you are South of the equator) with roughly 0 degrees declination and open the Autoguide window and its Graph window. Right click on the target (I used a sunspot) which will turn on the drift monitoring mode and watch how the mDV line drifts off the horizontal. Stop monitoring, adjust your east-west mount adjustment screws and start monitoring again. If the slope of the mDV line gets steeper you have adjusted in the wrong direction. Repeat this process until the mDV line is horizontal like this screenshot.
Next, choose a target near the eastern or western horizon. Repeat the monitoring process but this time adjust the north-south screws on your mount to get mDV horizontal like below.
You can see above that I over-adjusted and the mDV curve started to climb. I then had to adjust in the other direction to bring the curve horizontal. I am now drift aligned.
ps Make sure you set your scope rate to suit your drift target.
Managed to get this winter’s first shots of M42 last night with my Canon 1100D/Nexstar 4SE OTA/HEQ5 combo. Clouds and poor alignment meant I only got 36 decent shots of 10s at ISO6400 at prime focus. Stacking was done in DeepSkyStacker with post-processing in StarTools.