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M81 (First EVER Astro Image)


Damo127

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Hi all,

 

I wanted to share this, my first ever astro photograph! I bought myself a dslr literally last week so to say i'm new at this is an understatement. It's a pretty rubbish result by others standards but i'm still kind of proud of it and the experience has already taught me a lot. I would however appreciate any pointers on how i might squeeze more out of my existing set up (Yes i know if i had better xyz but having just spent £300 on a new camera i'm not shopping for any new kit just yet)

 

My set up for the image:

Sykmax 127 telescope on Alt Az mount (Goto)

Canon 700d camera attached with T ring

Intervalometer to auto control shutter. 

 

I took 150 subs @ ISO 800 on 20 second exposure, 50 bias, 25 flats and 25 darks. All were done at time of capture to ensure same temp (Although the bias could have been done whenever). To shoot the flats i put camera into aperture priority. Darks were shot at same 20 second exposure. Question: How do you know how many of these to take? Is there some kind of ratio or is it driven by other parameters? 

 

To process I used SiriL as i'm on a MacBook pro (an old one - see lessons learnt below). 

 

What i've learned:

1) I'm out of frame - i should have cranked up the ISO and taken another test shot. Question - once the synscan mount is tracking, is it possible to adjust it's position, to better frame up, and the scope continue's to track or will it simply move back to where it thinks the object is? I did a 2 star alignment and then asked it to find M81. When i double checked the precision of the alignment by driving back to the reference stars i could see one of them looked low in the frame the same as the final picture.

 

2) I started too early. I began shooting at about 11pm. M81 happened to be in the North East where there was still quite a bit of sunlight in the hemisphere compared to when i looked more West where the sky visually appeared darker. Maybe i should have gone after a different target - i only picked M81 since it's Magnitude was around 6.5ish where as other messier targets were around 8. Or i could have simply waited another hour and half but i was too excited! 

 

3) Buy a better T ring adapter. I got a cheap job off eBay (Was about £7) however there's quite a bit of play when inserted into the scope causing it to sag under the weight of the camera. This might explain (partially) why the framing was bad but i noticed it more when i looked at one of the flats, you can see the edge of the telescope tube cutting off the left hand corners!!!

 

4) Using a 10 year old MacBook which i think has 4GB RAM was a BAD idea. Stacking alone took 28 HOURS!! and this was after it had rejected around 50 of my lights due to being unable to detect enough stars. Anything less than about 23 and it said no. Fortunately i looks like i can upgrade the RAM for around £20 so that needs sorting asap. It also took me days and numerous failed attempts to get the darn thing to actually run or to stop the happy auto logging out and closing the program. I finally cracked it last night (Wednesday) and have been trying to process the image since Monday morning.

 

I think they're the main take aways from this first attempt. If anyone know's how i might be able to extract more from the image in post then i'd love to hear. So far i've basically been following a few youtube tutorials without really understanding what i'm doing. It would have been nice to see more of the galaxies arms in the image but perhaps i just don't have enough data 😞 So far i've cropped the image a bit, stretched it, used something called background neutralisation by selecting a sample of dark sky, and removed Green noise. 

 

I have to say though that while the result isn't brilliant I kind of half expected that and the fact that i've got anything at all feels like a win. Just having all the gear rigged up and siting back and realising that i'm doing something that i'd thought about for years was a really great feeling. 

Look forward to all the comments on top of the great advice i've already had - remember, i'm very new to this so be gentle2021-06-17T11_10_07.png.dd00e05bc952a8a32050ffe1e9c8fc03.png

  

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3 hours ago, Damo127 said:

Hi all,

 

I wanted to share this, my first ever astro photograph! I bought myself a dslr literally last week so to say i'm new at this is an understatement. It's a pretty rubbish result by others standards but i'm still kind of proud of it and the experience has already taught me a lot. I would however appreciate any pointers on how i might squeeze more out of my existing set up (Yes i know if i had better xyz but having just spent £300 on a new camera i'm not shopping for any new kit just yet)

 

My set up for the image:

Sykmax 127 telescope on Alt Az mount (Goto)

Canon 700d camera attached with T ring

Intervalometer to auto control shutter. 

 

I took 150 subs @ ISO 800 on 20 second exposure, 50 bias, 25 flats and 25 darks. All were done at time of capture to ensure same temp (Although the bias could have been done whenever). To shoot the flats i put camera into aperture priority. Darks were shot at same 20 second exposure. Question: How do you know how many of these to take? Is there some kind of ratio or is it driven by other parameters? 

 

To process I used SiriL as i'm on a MacBook pro (an old one - see lessons learnt below). 

 

What i've learned:

1) I'm out of frame - i should have cranked up the ISO and taken another test shot. Question - once the synscan mount is tracking, is it possible to adjust it's position, to better frame up, and the scope continue's to track or will it simply move back to where it thinks the object is? I did a 2 star alignment and then asked it to find M81. When i double checked the precision of the alignment by driving back to the reference stars i could see one of them looked low in the frame the same as the final picture.

 

2) I started too early. I began shooting at about 11pm. M81 happened to be in the North East where there was still quite a bit of sunlight in the hemisphere compared to when i looked more West where the sky visually appeared darker. Maybe i should have gone after a different target - i only picked M81 since it's Magnitude was around 6.5ish where as other messier targets were around 8. Or i could have simply waited another hour and half but i was too excited! 

 

3) Buy a better T ring adapter. I got a cheap job off eBay (Was about £7) however there's quite a bit of play when inserted into the scope causing it to sag under the weight of the camera. This might explain (partially) why the framing was bad but i noticed it more when i looked at one of the flats, you can see the edge of the telescope tube cutting off the left hand corners!!!

 

4) Using a 10 year old MacBook which i think has 4GB RAM was a BAD idea. Stacking alone took 28 HOURS!! and this was after it had rejected around 50 of my lights due to being unable to detect enough stars. Anything less than about 23 and it said no. Fortunately i looks like i can upgrade the RAM for around £20 so that needs sorting asap. It also took me days and numerous failed attempts to get the darn thing to actually run or to stop the happy auto logging out and closing the program. I finally cracked it last night (Wednesday) and have been trying to process the image since Monday morning.

 

I think they're the main take aways from this first attempt. If anyone know's how i might be able to extract more from the image in post then i'd love to hear. So far i've basically been following a few youtube tutorials without really understanding what i'm doing. It would have been nice to see more of the galaxies arms in the image but perhaps i just don't have enough data 😞 So far i've cropped the image a bit, stretched it, used something called background neutralisation by selecting a sample of dark sky, and removed Green noise. 

 

I have to say though that while the result isn't brilliant I kind of half expected that and the fact that i've got anything at all feels like a win. Just having all the gear rigged up and siting back and realising that i'm doing something that i'd thought about for years was a really great feeling. 

Look forward to all the comments on top of the great advice i've already had - remember, i'm very new to this so be gentle

 

For a first image you did very well. Your stars look round, but you can stretch the image a little more, there is more of the galaxy hiding in the background.

 

There is no substitute for taking as many images as possible. 150 might sound like a lot, but at 20s each, it's only 50 minutes. I would suggest 4 times the amount, at least. When taking calibration frames, don't adjust anything regarding the camera settings except the length of exposure. Take darks, bias and flats with the same settings as your light frames. Flats and bias are not temperature related, but darks preferably need the same temperature as lights. You will probably find your camera will get very warm in hot weather, which can affect the noise in your images. One trick is to wrap your camera in a plastic bag, and place it in the fridge for an hour or two before your imaging session.

 

You don't mention which capture software you are using, I would recommend APT, it is a free astro capture software and works great with DSLR's. There is no limit to the amount of calibration frames. I limit myself to 50 of each. The bias and daks can be combined into master darks and master bias, and can be used for many months. Flats need taking every time you change anything in your imaging setup.

 

Regarding tracking and being out of frame, this is where platesolving comes into it's own. Any astro software will have some kind of platesolving in it's arsenal. Platesolving will find your target very precisely once you have a reference to work from.

 

M13 is a good object to go for at the moment. It's close to the zenith around 11pm, and the sky will be much darker. It's mag 5.8, so it's quite a bright object.

 

 

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Hi Damo

I am only an observer so can’t comment on the technical stuff. However, I can say that you have my admiration going down the AP road as there seems a lot to learn.

I think your first image is great and you deserve a pat on the back🙂

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@Damo127 that's a hell of a lot better than my first shot! Celebrate the wins:

- You actually got a DSO in the frame (ok not actually in the centre but a crop will sort that out)

- Your focus is spot on as far as I can make out

- Your star shape is good, so no star trails or beans. It's what you would expect for 20 seconds, but implies that you could possibly push the exposure time a little more?

- There is definitely more in what you have, but as @AstronomyUkraine says, much more data will give better results.

 

I downloaded the png and did a very crude stretch in Gimp and you can see that there's more detail in there. Granted, the sensor noise is starting to show but it's a very good start.

image.thumb.png.5cf6133ea7169d5140ad51855b02313e.png

 

+1 for APT, but it does mean connecting a PC, and I'm not sure it supports MAC. You should be able to adjust framing after doing a goto if you think you're slightly off; the mount will continue to track from wherever you point it. Mounts track 'in the blind' unless you're guiding - tracking just means that it tries to move the RA axis at a constant rate. 

 

Isn't it amazing to point your scope at an object that you know is there but can't see, and take a photograph to prove it!

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2 hours ago, AstronomyUkraine said:

 

For a first image you did very well. Your stars look round, but you can stretch the image a little more, there is more of the galaxy hiding in the background.

 

There is no substitute for taking as many images as possible. 150 might sound like a lot, but at 20s each, it's only 50 minutes. I would suggest 4 times the amount, at least. When taking calibration frames, don't adjust anything regarding the camera settings except the length of exposure. Take darks, bias and flats with the same settings as your light frames. Flats and bias are not temperature related, but darks preferably need the same temperature as lights. You will probably find your camera will get very warm in hot weather, which can affect the noise in your images. One trick is to wrap your camera in a plastic bag, and place it in the fridge for an hour or two before your imaging session.

 

You don't mention which capture software you are using, I would recommend APT, it is a free astro capture software and works great with DSLR's. There is no limit to the amount of calibration frames. I limit myself to 50 of each. The bias and daks can be combined into master darks and master bias, and can be used for many months. Flats need taking every time you change anything in your imaging setup.

 

Regarding tracking and being out of frame, this is where platesolving comes into it's own. Any astro software will have some kind of platesolving in it's arsenal. Platesolving will find your target very precisely once you have a reference to work from.

 

M13 is a good object to go for at the moment. It's close to the zenith around 11pm, and the sky will be much darker. It's mag 5.8, so it's quite a bright object.

 

 

That’s great advice. I wasn’t using any capture software. It was a very basic setup. Just mount, scope and dslr. Some capture software sounds worth looking into though. 
SiriL did have plate solving which aligned everything really well. I was more bothered that my target appears almost out of frame towards the bottom of the image where I also have some distortion, probably from the rotation. Some images were rotated up to 10 deg even over my relatively short time frame. 
Can’t wait to have another go and put this advise into good use. Love the tip about camera in fridge. It was 22 deg just before I started shooting, probably dropped to about 17 if that so not idea but doubt I’ll have that issue often in the UK 🙂

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1 hour ago, Marmot said:

Hi Damo

I am only an observer so can’t comment on the technical stuff. However, I can say that you have my admiration going down the AP road as there seems a lot to learn.

I think your first image is great and you deserve a pat on the back🙂

Thanks Marmot, much appreciated. Maybe I can be one of the backyardastro apprentices haha

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3 minutes ago, Damo127 said:

Thanks Marmot, much appreciated. Maybe I can be one of the backyardastro apprentices haha

Apprentice is a good word. I very much feel like I am an apprentice observer, but the guys and girls of the yard are great mentors and are helping me along the road of learning. I am sure they will do the same for you. 🙂

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16 minutes ago, Damo127 said:

That’s great advice. I wasn’t using any capture software. It was a very basic setup. Just mount, scope and dslr. Some capture software sounds worth looking into though. 
SiriL did have plate solving which aligned everything really well. I was more bothered that my target appears almost out of frame towards the bottom of the image where I also have some distortion, probably from the rotation. Some images were rotated up to 10 deg even over my relatively short time frame. 
Can’t wait to have another go and put this advise into good use. Love the tip about camera in fridge. It was 22 deg just before I started shooting, probably dropped to about 17 if that so not idea but doubt I’ll have that issue often in the UK 🙂

Check out KStars. It is a free software that works on the Linux platform, should work OK on a Mac.

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1 hour ago, Padraic M said:

@Damo127 that's a hell of a lot better than my first shot! Celebrate the wins:

- You actually got a DSO in the frame (ok not actually in the centre but a crop will sort that out)

- Your focus is spot on as far as I can make out

- Your star shape is good, so no star trails or beans. It's what you would expect for 20 seconds, but implies that you could possibly push the exposure time a little more?

- There is definitely more in what you have, but as @AstronomyUkraine says, much more data will give better results.

 

I downloaded the png and did a very crude stretch in Gimp and you can see that there's more detail in there. Granted, the sensor noise is starting to show but it's a very good start.

image.thumb.png.5cf6133ea7169d5140ad51855b02313e.png

 

+1 for APT, but it does mean connecting a PC, and I'm not sure it supports MAC. You should be able to adjust framing after doing a goto if you think you're slightly off; the mount will continue to track from wherever you point it. Mounts track 'in the blind' unless you're guiding - tracking just means that it tries to move the RA axis at a constant rate. 

 

Isn't it amazing to point your scope at an object that you know is there but can't see, and take a photograph to prove it!

Love this. And thanks for the advice on tracking. I’ll make sure I get better centred next time confident that tracking will continue. 
SiriL gave me the option of stretching and I’ve messed about with trying to stretch more but like you say I just get a really grainy image. I think my initial crop was a bit too heavy. I think the original result file was around 350Mb and after I’d cropped it was 143mb. I should have saved the original before messing with it. 
I was going to download GIMP and try more modifications but I’m not sure I can take in much more learning just yet. I’ve crammed so much into the last week feel like my heads going to pop.

Thanks for the encouragement though, much appreciated 

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21 minutes ago, Marmot said:

Apprentice is a good word. I very much feel like I am an apprentice observer, but the guys and girls of the yard are great mentors and are helping me along the road of learning. I am sure they will do the same for you. 🙂

Defo, I’ve only been a member for a week and already have had some brilliant advice. So glad to have a forum like this to assist rather than go it alone. 

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I've used a DSLR attached to my scope and you are absolutely right about the weight of the camera being a problem. They are heavy and their shape doesn't help. Can I suggest you look at the Baader Click-lock range. I've used them and they seem to grip both lenses and my DSLR much more positively than thumb screws. If your polar alignment is good and your tracking working as it should you could try trusting your scope to centre the object using Synscan and then attach your camera. What I found was that if my connections aren't secure and I have any amount of weight at the viewing end, the camera will move slightly as the scope slews into position and can waggle loose. I found out the hard way when a 2" wide angle lens dropped out of the tube and smashed on the floor! I too am a first year apprentice when it comes to A.P. and I've discovered some lessons are more expensive than others. Really like the image by the way.  G.

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Congratulations on your first DSO its definitely there and I agree it can take a little more of a stretch in processing. You'll find a lot of support and advice on the forum which I've found a massive help. I'll throw one more option into the mix which is the ASIAir pro. It does the lot ...... polar alignment, goto, plate solving , image sequencing  , guiding etc etc all on just a tablet or phone. There's a ton of youtube videos on the asiair and I personally found it to be the the best £300 investment I made in astro photography.

Congrats again on your image and good luck in your astro photography journey 

Cheers

Paul 

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That's a good start Damo, definitely more to see in your image. Don't be afraid to stretch it more, you may see some noise and the background won't be as dark but more of your target will show. 

More subs (and longer if possible) is a good idea, 25 to 35 darks, flats and bias should be enough for any number of subs you take.

Software for Mac..... KStars/Ekos for capture and control and Pixinsight for processing.

 

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20 hours ago, AstronomyUkraine said:

It incorporates EKOS which can control all your gear, platesolve, find targets and much more.

Been watching some tutorials on this today and it looks fab albeit a little intimidating although that’s probably because they’re talking through settings that don’t apply to me yet (focuses, guides, filters). The best thing about it is it’s free which suits my wallet for the time being. I still need to buy the leads etc though so I can connect up. Think this is something I’ll have a go with over the next month or so. Thanks for the tip!

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5 hours ago, Sonyme said:

I've used a DSLR attached to my scope and you are absolutely right about the weight of the camera being a problem. They are heavy and their shape doesn't help. Can I suggest you look at the Baader Click-lock range. I've used them and they seem to grip both lenses and my DSLR much more positively than thumb screws. If your polar alignment is good and your tracking working as it should you could try trusting your scope to centre the object using Synscan and then attach your camera. What I found was that if my connections aren't secure and I have any amount of weight at the viewing end, the camera will move slightly as the scope slews into position and can waggle loose. I found out the hard way when a 2" wide angle lens dropped out of the tube and smashed on the floor! I too am a first year apprentice when it comes to A.P. and I've discovered some lessons are more expensive than others. Really like the image by the way.  G.

Ouch, that sounds like a mare! Lucky for me nothing dropped out. I’ll check out those connectors you’ve mentioned. In the short term (saving money) I might just wrap some shim around the cylinder. I bought some .020’’ shim a while back to pack out an RSJ and have loads of it left sat in the garage doing nothing. I prob just need to paint it black though so it doesn’t reflect any light inside the tube. Should keep me going until I can reach back into my pocket again

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2 minutes ago, Damo127 said:

Been watching some tutorials on this today and it looks fab albeit a little intimidating although that’s probably because they’re talking through settings that don’t apply to me yet (focuses, guides, filters). The best thing about it is it’s free which suits my wallet for the time being. I still need to buy the leads etc though so I can connect up. Think this is something I’ll have a go with over the next month or so. Thanks for the tip!

I have it installed on a Raspberry Pi, and will have it hardwired to my internet once I get around to it.It can also be controlled over WiFi, or a direct connection to a laptop.

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5 hours ago, P Holdsworth said:

Congratulations on your first DSO its definitely there and I agree it can take a little more of a stretch in processing. You'll find a lot of support and advice on the forum which I've found a massive help. I'll throw one more option into the mix which is the ASIAir pro. It does the lot ...... polar alignment, goto, plate solving , image sequencing  , guiding etc etc all on just a tablet or phone. There's a ton of youtube videos on the asiair and I personally found it to be the the best £300 investment I made in astro photography.

Congrats again on your image and good luck in your astro photography journey 

Cheers

Paul 

Thanks Paul, much appreciated. I’ll certainly have a look into that software at some point but for now I’m trying to keep costs low/zero. Yes I know - wrong hobby for that haha. 
@AstronomyUkraine has already pointed me towards Kstars which looks pretty comprehensive and is free! And works on a Mac so I’ll prob start there and upgrade in future. 
I think I’ll reprocess that first attempt and try cropping less before the stretching. I’ve just ordered some Ram upgrade for my machine though since processing took a stupid amount of time for 90 subs, + 100 calibration frames. Given that the general consensus is that I’ll need way more subs in future then this seemed like a sensible purchase (£50). 

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Just reprocessed my data after upgrading the RAM on my computer. No improvement to the image of course BUT processing time down from 28 hours to 1 hour 13 mins 🙂 I can't believe that doubling the RAM from 4GB to 8GB would have made such a difference. 

I'm really pleased about this since the advice i've had is to take many more subs than this first attempt so knowing i can now process more without reaching retirement in the process is very exciting - all i need now is some clear skies!

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On 6/17/2021 at 1:05 PM, Damo127 said:

once the synscan mount is tracking, is it possible to adjust it's position, to better frame up

Yes is the answer to that. 

 

On 6/17/2021 at 1:05 PM, Damo127 said:

Question: How do you know how many of these to take? Is there some kind of ratio or is it driven by other parameters? 

I have always done about a dozen of each, seems to work.

 

I'd say that was pretty darn good for a first attempt, you should have seen my early attempts, or perhaps not!!!

 

Nice round stars.  It's all a learning curve and you got a lot of things right already.  

 

Taking a galaxy during Astronomical Twilight is going to be difficult, but as you say you were dying to have a go and have learnt much from it.   Not having a cooling camera will produce noise, the fridge idea is good, but of course that won't last for too long.

 

My main comment is 20 sec exposures is not going to give you detailed images,  but all things in good time.  Ideally you need 300secs but this requires accurate tracking and also guiding when you are ready for this.

 

Carole  

 

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