My first picture, It's awful!!!

[Moonshed]

This is my first picture using a DSLR through the scope. An 8" Celestron on an EQ5 mount using a Lumicon Easy Guider and a Canon 1100D. I only took 15 x 60 secs subs. The idea was just to make sure I had got everything right and could actually get a picture, a "proof of concept" if you will. I am very surprised at the number of stars that are stretched, I suppose some of it could be due to tracking error but I don't really think so as some of them are perfectly round and I would have thought my gear could have coped with tracking for just 60 secs? I can only assume this is due to coma? Your thoughts would be appreciated as always. I was almost too ashamed to post this rubbish pic but I have to learn. This is it.

image.tiff

[Kropster]

That doesn't look bad for a first image.

The stretching towards the edge does look like coma.

Maybe a coma corrector is available for your scope?

[Stu]

Never be ashamed to put anything like this on SGL, you will get plenty of helpful comments I'm sure. I don't think the star shapes are due to coma, which tends to radiate out from the centre, but I'm sure someone will know.

[Moonshed]

I suppose what I am trying to discover is if the distorted star shapes are caused by spherical aberration or coma aberration and what to do about it. Having looked it up it would appear to me to be coma aberration, but I'm no expert. If it is I believe it is a simple matter of purchasing a coma corrector? What do others think?

[MARS1960]

I don't know what it is (i'm still a novice myself) but i can tell you this,  that is a darn good first effort, if you want to see awful you should have seen my first attempts.

[cjdawson]

Looks like a good shot to me.  If there's coma or aberations in the image, I can't see them so it can't be too bad.  Even at 60 second exposures, you might benefit from guiding.  Anyway, for now don't change anything, except the target of your camera.   Go on, try for a DSO.  I think you'll be pleasantly surprised.

[belfieldi]

I'm not sure that the 'stretching' is caused by coma. With coma, you would expect that tails would point towards the edge, so a star towards the top right corner would have a tail pointing towards the top right, one in the bottom left, would point towards the bottom left etc. That isn't the case here. It could be down to having a bit of tilt in the camera connection.

The other thing is, this is your first astro image and we all could recognise that it was an image of stars, so it was a good image and you should be proud of it

 Clear skies

Ian

[Moonshed]

Thanks for all your replies. I shall carry on with the gear I have for now, if the problem persists I will have to look at it again. In the meantime I am tempted to have a go at M31. The only problem is I was not able to actually see it in the camera viewer, although the photos did show it was there, I had to trust my GOTO on this one, it was hopelessly overexposed! I will have another go. 

Thanks again. Keith.

[wornish]

I agree with the other comments here.  It isn't bad at all for a first attempt, you should see mine.  Looks like a little coma but nothing that can't be fixed in post processing with PS or PixInsight.

 

[Moonshed]

48 minutes ago, wornish said:

I agree with the other comments here.  It isn't bad at all for a first attempt, you should see mine.  Looks like a little coma but nothing that can't be fixed in post processing with PS or PixInsight.

 

That sounds interesting. I have PS and ATAS so will have another go and see if I can reduce those teardrop stars. Thanks.

[bottletopburly]

Think of it as a bench mark,create a flickr account and upload your results as you make progress you will be able to see and compare your results over time 

[spillage]

6 hours ago, Moonshed said:

Thanks for all your replies. I shall carry on with the gear I have for now, if the problem persists I will have to look at it again. In the meantime I am tempted to have a go at M31. The only problem is I was not able to actually see it in the camera viewer, although the photos did show it was there, I had to trust my GOTO on this one, it was hopelessly overexposed! I will have another go. 

Thanks again. Keith.

As everyone has already said this is a good first attempt. You have the same mount and camera as I do and all I can say is the images I get blow me away. Yes many may say there issues with my attempts and there are but we all have to start somewhere and practice makes perfect (at least a bit better).

Do not bother with the camera view finder. Connect it to a laptop if you can and use live view. Take a couple of 15-20 seconds exposure shots and you will see the image on screen.

Adjust your scope if needed so you image is bang in the middle and then I would start out with as many 90 second exposure shoots as you can do in the session as I find this at the moment a good middle ground. I do not use a guide scope yet.

M31 is a good start as this can seen very easily. I found m51 amazing. Not a hope of seeing it through my scope but with the camera you can just make it out and after processing I found it jaw dropping.

Most of all just enjoy it.

 

cheers

Spill.

[Moonshed]

1 hour ago, spillage said:

 

Do not bother with the camera view finder. Connect it to a laptop if you can and use live view. Take a couple of 15-20 seconds exposure shots and you will see the image on screen.

 

Thank you for that, that is so good to know. It's amazing the tid bits of info that can be picked up in just a casual aside. I have problems with my back and looking through the viewer can be a real pain, pun intended? I have already downloaded Live View when trying to download DSS so will give it a go straight away, indoors that is as its raining. Thanks again!

[Owmuchonomy]

Your combination is not ideal for deep sky objects, stars included. A long focal length, large chip and slow f/ratio will give you significant challenges, even guided. Your set up is better suited to Solar System imaging particularly if you have video mode.

[Moonshed]

38 minutes ago, Owmuchonomy said:

Your combination is not ideal for deep sky objects, stars included. A long focal length, large chip and slow f/ratio will give you significant challenges, even guided. Your set up is better suited to Solar System imaging particularly if you have video mode.

Okay, thanks for that, I'll just give up on DSO then and take up stamp collecting.

[spillage]

30 minutes ago, Owmuchonomy said:

Your combination is not ideal for deep sky objects, stars included. A long focal length, large chip and slow f/ratio will give you significant challenges, even guided. Your set up is better suited to Solar System imaging particularly if you have video mode.

I have a celestron 127 mak scope that is F11 and have managed some decent dso images from it. Don't get me wrong you will never see them in a copy of national geographic but its good enough to impress family and friends. I also have a C6-N that was fairly cheap and thats performs okay too.

Just depends on how much you are prepared to spend out but for a small budget you can do okay.

When you have finished using live view to centre and focus your scope you will need to turn it off so that you can change the exposure time to "bulb" and then set up your exposure time and amount of frames to take using the timer button on the lower right hand side.

 

[Moonshed]

Thanks spillage, that's good to know. I don't expect to be taking world class photos either, it's just a bit of fun for me and something I can share with friends and family. I'll just do the best I can and be happy with that, Anyway, I like a challenge, don't tell me I can't do something. Thanks.

[cjdawson]

Don't listen to the people that make you think that you can't take good photos with an 8" SCT.  That is an attitude that I've only come across in the last year, mainly by people on forums.  Whilst it is easier to get an image with a scope with a faster f ratio, all is not lost.      Firstly, you can get a focal reducer that will will help to bring down the exposure time.  This does have the side effect of reducing the magnification - i.e. your camera frame will take a picture of a larger part of the sky.

I'm lucky to have 2 focal reducers.

F6.3 - These are available readily from places like FLO.

F3.3 - This one is ment for CCD imaging.  I'd be willing to give it a go with my DSLR, and crop the vignetting off if the results prove excellent (Not actually used this one yet)

 

As for using a DSLR to capture DSO's, here's a couple from my collection.

 

M42 - This is a stacked image of 3min subs (20 of them iirc, plus dark, bias and flats)

 

Here's M57, this time with the F6.3 Focal reducer in place.   This is a section cropped, so it's not zoomed. 

 

With my kit, I've got a ability to take images in F10, F6.3 and F3.3.  The F3.3 focal reducer is hard to get hold of, but they do exist (Meade used to make them)

Both of the above images are stacks of long exposures.  You'll need to take loads of photos, so maybe 120 frames at 30 seconds each to get similar results.

 

[goose35]

Hi

First up there is nothing wrong with your first image and you are not far away

I have the exos 2 mount and had these very issues you have, it is one of or a combination of the following

Collimation,coma and or guiding

Im still struggling a little with collimation but improving

I got a suitable coma corrector

I had great dificulty guiding the exos untill my last image where i used phd 2 and did a drift align before my image run and found the polar scope to be quite off the mark.

Once the drift was done i found the guiding to be so much smoother and accurate giving round stars all round the image.

So as said in an earlier post get both your dslr and guide cam hooked to the laptop and persever and keep picking up snippets of info and it will get better. 

[Moonshed]

Quote

Thanks cjdawsom I appreciate your supportive comments. Your pics are great I would love to get images like that. I have only just started using a DSLR and have a lot to learn. I am stuck with the gear I have, perfect or not, and can't afford to throw it all away and buy a faster scope, a bigger better mount, star tracker and a cooled CCD. I am sure however that with practice and help from this forum I will be able to produce DSO images that I will be proud of. That will do me.

 

[cjdawson]

Course you'll be able to take great images in time.

I'm guessing that over time, you'll end up getting a focal reducer, although, I'm not really sure that this is a must have item.

Guiding is something that would be worth investing in.   If your scope has an st-4 port (Autoguiding) you could look at getting a stand alone auto guider.  I've been trying out the Skywatcher Synscan attached to a SkyWatcher St-80 (it's a great little scope on it's own) and I've got the whole lot mounted on my LX-90.

Instead of the synscan, you can get cameras with an st-4 guider built in.   These cameras would also be great for planetary imaging.

Another option is going down the PHD2 route, which I know is very popular.

 

It is a big investment, and you can built something like that up over time.   The result is that you'll have a much better tracking ability and can extend your exposure time.  This in turn will mean that you can capture more data in each frame.

 

In the meantime, keep going with the kit that you have and enjoying what you can do.

[Moonshed]

Thanks cjdawsom, but what is a PHD2? 

[Moonshed]

3 hours ago, cjdawson said:

Don't listen to the people that make you think that you can't take good photos with an 8" SCT.  That is an attitude that I've only come across in the last year, mainly by people on forums.  Whilst it is easier to get an image with a scope with a faster f ratio, all is not lost.     

 

I have met people like that at astronomy associations, they think that because they have the biggest and best scopes and mounts that anything less is a waste of time. Telling me that I need better more expensive gear is a bit like a Lamborghini owner telling the guy with a Mondeo that he will never be able to take it at 200mph round a test track. Mondeo man knows this, but only uses his car to go to Tesco once a week and while there buy a lottery ticket and dream... No point in telling him that the odds of winning the jackpot are around 50,000,000 - 1, better to say good luck, you have to be in it to win it, and meanwhile that  Mondeo is a nice economical car. Just a matter of how you look at things isn't it? I just want to take DSO pictures that will please ME.

[happy-kat]

You have equipment already to use great to use it and see how far you can push it reaching the corners of its capability. Your tripod you could also use with just a dslr and camera lens, you might even have lenses to pick from already. There are plenty stunning images posted regularily using cheap vintage lenses in anything from 50mm to 210mm and can be fast like f2 - f4. The dslr and lens only gives a really light payload for your mount. Just sharing as options aren't limited to only being attached to a telescope.

Absolutely keep going with the kit you have, I'm told I can't image because I don't have an EQ mount but it doesn't stop me trying and enjoying what I can do with what I have.

 

[Moonshed]

Thanks happy-kat, appreciate your comments. I intend trying to get some wider shots of the Milky Way by piggy backing and tracking to get longer subs. I have some nice lenses from my Nikon film camera that I no longer use and can use them on my Canon with adapters, saves a lot of money and saves wasting expensive lenses. Like you I think it fun to see how much you can get out of your equipment. Thanks.