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First attempt at capturing The Heart Nebula & Soul Nebula.


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I used my Sky-Watcher Star Adventurer Pro, Canon 600D, Canon EF 75-300mm Lens f/4-5.6 (135mm focal length in this session in manual focus) to photograph this image, at a 16 minute exposure unfortunately, I did polar align the mount but the problem was that I used a ballhead at first attempt since it was hard trying to aim to the target the RA and Dec clamps. I left it out doing it's job for over an hour but it didn't go as planned as the camera dewed over and the camera slewed slowly out of place overtime. I used 50 lights and 45 darks, this is my first attempt of photographing this.

You can definitely tell the shape of the Soul nebula and Heart nebula, if I had an hour exposure it could have showed better results.

Hopefully this progress will improve as I have more experience in this each session.

Result.thumb.png.0246bfbb60990bdc2bf324081f9f6112.png

Please help me and give suggestions which is key for future improvement.

Cheers and clear skies.

William

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Great start!

My best advice would be to keep trying to refine the basics. When it comes to unguided subs, its getting the basics spot on that make a good image.

(1) Polar alignment + Sharp focus = Good images

You want to be able to consistently produce 30 - 60 second images that have no trail and are sharp. I am not familiar with the SA (I used a SGP) but I am sure they are pretty similar. PA, take some test shots, zoom in on the 600D and check the stars. With a decent PA, there should be no trail in most of your images at your focal length.

Again, not familiar with focusing using a DSLR lens (outside of a 14mm i set at infinity), are you able to use a bahtinov mask with it? Will help you focus. You can always do it by eye, but getting good focus like that is hit and miss. Even with a B mask I am not happy with my focus sometimes :D 

(2) Polar alignment + Sharp focus + dithering = Great images

You are not going to be able to leave your rig unattended for more than a couple of minutes if you want to drastically improve the quality of your images as you will need to dither between images to fend of walking noise. In short, you need to move the subject of your image within the frame ever so slightly between images to prevent the image becoming swamped with noise. On a SGP, this involved adjusting the RA a SMALL amount by the tapping one of the keys, and adjusting the DEC by adjusting the DEC screw, loosening/tightening (be very careful here, do not over loosen it, you're aiming to 'feel' the screw ease up, not completely remove it!) this will be enough to shift the dec by small amounts.

Is your 600D modded? Heart and Soul are surprisingly faint Ha objects, tough going for any unmodded dslr. You will need many hours of good quality data to bring them out.

You should find pretty cheap USB dew heaters on amazon along with a portable USB power bank, that should keep the lens clear

If you are really struggling to navigate the night sky and find targets, have a look at red dot finders, pretty sure you can attach them to the 'horseshoe'(?) thingy m'bob on the dslr. It was a game changer when using my SGP. trying to find Andromeda without one of those things with a 430mm scope + DSLR was embarrassingly tough when I first started :D  

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On 09/05/2022 at 12:01, WilliamAstro said:

You can definitely tell the shape of the Soul nebula and Heart nebula, if I had an hour exposure it could have showed better results.

Great first attempt. What software did you use to stack and post process?

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Posted (edited)

Hi William, I started off with a similar setup and hopefully can add a few pointers.

After polar alignment, balance is of the utmost importance. I would not use the ball-head for anything other than wide-field imaging with a moderately light setup. Polar alignment and balance are much more critical the further that you zoom. This video includes a good setup routine and shows very clearly how to achieve correct balance in the the RA and DEC. You might need a longer dovetail/arca swiss plate or a lens with ring/dovetail combo to be able to achieve this but it won't hurt to try with what you already have at hand. Good balance will take most of the stress off the motor and in fact, some people even balance slightly east heavy so that the rig is already wanting to move in the direction of the sky while reducing the likely hood for backlash.

According to this chart your cameras input read noise starts to level off between 1600 and 6400 iso. I'd probly start with 1600 or go with 3200 as a tradeoff between the two. Make sure any noise reduction functions on your camera are disabled if they exist. If you don't have an intervalometer I would suggest getting one, you could get by if your camera has the software built in but it's just another useful tool to have. Start with say 30s sub exposures at 1600, and try to keep your histogram at least 1/3 to 1/4 of the ways from the left, somewhere in that region means you will have sufficient data to stretch later. As you may already know doubling the ISO has an inverse effect on exposure time, so, the higher you crank it the less exposure time is needed, this invariably introduces noise but that's not too much of an issue as you will be stacking to increase the SNR anyway. It's good to grasp the basics either way. 30s should be enough time to diagnose any issues in your polar alignment or balance routine. Once you have that nailed, you can start to increase further to say 60s and see where you are then, are the stars still nice and round, are you still happy with the quality of the image? You may be able to push things a little further but without guiding at your max focal length that would be a stretch imo.

Inspect your images and throw away any that don't look good, periodic errors in your gears, the wind and who knows what will occasionally throw up some doozies so just toss them as you go, there's no point stacking images that have bad data. You'll have much more success stacking 5-10 good quality images than 20 that introduce anomalies that will affect the quality of your final image.

Once you have all that down, it's time to learn post-processing but I don't think ill jump into that rabbit hole with you! There are plenty of good youtubers out there now that focus on helping people new to astrophotography, nebula photos, kamil pekala, astrobackyard, cuiv the lazy greek, peter zelinka, all those should help you get started on your journey. Someone mentioned dithering above and you should definitely consider dithering at some point. If you have the wifi version of the starwatcher, it has a dithering function with the phone app so you won't be needing to do it manually. Kamil Pekala has a video describing autoguiding and dithering in the linked video. Worth mentioning that when you use the SA app it stores your last used settings into your sidereal (star mode) and needs to be cleared if you intend on using the mount manually in future. 

My 2 cents, or loose change might be better fitting, hope it helps you get on the road to taking pictures you'll be proud of.

PS: A dew heater is a must as you've already well discovered. I'd also consider either making or ordering a bahtinov mask to achieve proper focus. If your lens is not too stiff it could easily move out of focus over the night due to temp variations, gravity etc so.. it might be worth checking you still have good focus every 30mins or so until you know the limits of your gear.

 

Edited by Sien
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A quick time extender is out of card make a shroud for your lens, could just use rubber bands to keep it on, helps keep the dew away. 

DSS if you have 20+ lights then use kappa sigma clipping (helps remove planes etc.). 

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Good start and you've got lots of good pointers there. 

I would stick to that focal length with that lens or not much further, as you will notice the chromatic aberration gets very bad (you can see it when focusing). 

My first (and so far only) attempt at the heart nebula ended up with the nebula in the bottom corner 🙈 so you've done a good job getting it in frame. 

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Posted (edited)

I would say 800 possibly lowest for long exposures but for short subs that won't collect enough data, imo anyway :)

Edited by Sien
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Good early effort. Heart & Soul are available all year so plenty of opportunity to improve. I think noise is your biggest challenge - it was for me. So improvement is about increasing signal and reducing noise. Imaging when the sky is at its darkest, modding the camera (which may be attractive if you bought it cheap and don’t use it outside of Astro) and using a filter (Optolong L-Enhance) will improve signal, especially if you also increase exposure time. To get longer exposures, you need more accurate PA and better mounting on the SA Pro. To reduce noise (ie the grain in the image), leave intervals between captures (to enable the sensor to cool down), lower iso, and dither between subs. A lens with a lower aperture would enable you to offset reduced iso. Noise reduction software in processing (eg Neat Image) will also help but not on its own. Good luck and post your images as you progress!

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Posted (edited)
On 09/05/2022 at 13:01, WilliamAstro said:

Canon 600D

Hi

Good effort.

600D, so ISO800.

Take flat and bias frames but lose the dark frames. Otherwise, just keep adding and stacking. The more frames you have, the better the image will get and the easier it will be to process.

Cheers

Edited by alacant
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  • 2 weeks later...
Posted (edited)
On 09/05/2022 at 12:01, WilliamAstro said:

I used my Sky-Watcher Star Adventurer Pro, Canon 600D, Canon EF 75-300mm Lens f/4-5.6 (135mm focal length in this session in manual focus) to photograph this image, at a 16 minute exposure unfortunately, I did polar align the mount but the problem was that I used a ballhead at first attempt since it was hard trying to aim to the target the RA and Dec clamps. I left it out doing it's job for over an hour but it didn't go as planned as the camera dewed over and the camera slewed slowly out of place overtime. I used 50 lights and 45 darks, this is my first attempt of photographing this.

You can definitely tell the shape of the Soul nebula and Heart nebula, if I had an hour exposure it could have showed better results.

Hopefully this progress will improve as I have more experience in this each session.

Result.thumb.png.0246bfbb60990bdc2bf324081f9f6112.png

Please help me and give suggestions which is key for future improvement.

Cheers and clear skies.

William

I think you may have missed low and got the double cluster instead of the heart and soul. Still a good first effort. 

Adam

Edited by Adam J
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