Had a go at imaging the M101

[Mark_C]

Hi all,

This is my first serious attempt at astrophotography and thought I'd share what I have been able to achieve. I was having some initial issues with star trailing/field rotation which I think boiled down to less than optimal polar alignment and flexure of the finderscope.

I've managed to get familiar with the DARV polar alignment method and eimlinated most, if not all of the finderscope flexure. Doing this has helped a great deal in getting longer subs.

I'm fairly pleased with this image, however I think it's a little bit on the noisy side. I think some of that may be due to subtracting only a few dark frames and not taking any flat/bias frames (still not sure on either of these).

This is a combination of around 14 x 5 min subs stacked in DSS, with a bit of tweaking in Photoshop.

[bish]

I'm not an imager but would be really chuffed if I had taken that image.

[carastro]

If this is your first serious attempt at AP then you've done exceptionally well.  This is a very faint object and deceivingly tricky.  Flats would improve it, but Rome wasn't built in a day.

Carole 

[Mark_C]

Thanks for the positive comments.

I had done a considerable amount of research prior to attempting to image to avoid making too many mistakes and giving up, doing so has really helped things along.

The crucial step to all of this was managing to set up plate solving with Astrotortilla to centre the M101 in the FOV... without this I think I would have struggled..as you've mentioned Carole it's a very faint object and almost undetectable unless exposed for some time. I didn't think it was there at first until I exposed a 2 minute sub and I could see it right bang in the centre of the image, my immediate reaction was WOW, that looks amazing! I decided to carry on taking subs of it while the going was good and I am pleased with the results. Unfortunately it gets light so early this time of year so there is only a few hours of usable imaging time, bit of a pain really.

I have to say though that Astrotortilla is an amazing piece of software, it has taken a bit of messing to get working but once all of the obstacles overcome its an absolute godsend and is an essential tool for imagers. It essentially removes the need to carry out star alignments and removes any element of second guessing whether the DSO is in the centre of the frame or not.

I have probably dived in the deep end with regards to choice of DSO but it seems to have paid off, I just need to learn how to take flats/bias and I am sure that will help greatly.

Hopefully if the skies clear again I will get more subs to reduce noise further... I may look in to imaging M81/2 or the M106 as my next target. Just need to get my 60D astro modified or buy a cheap modded 1100 as I am sure there is a lot more Ha detail to be picked up and is currently lacking in the above image.

I guess eventually I will end up buying a CCD but for the moment the DSLR seems to be working fine for me.

Mark.

[Astrosurf]

That's a superb first image! You've got some star colour there too. Give yourself a pat on the back.

Alexxx

[lensman57]

That is an excellent first attempt with a tricky target. Nicely done.

A.G

[PeterCPC]

Well done that man - good image.

Peter

[The BFJ]

I have to agree with everyone... I'd be stoked to take get an image like that at the 1st try!

[PhotoGav]

Brilliant, well done! A superb start down (or is it up!) the slippery and expensive slope of AP. That thrill of seeing the first sub pop up on the computer screen and the target object showing where you wanted it and the first hints of detail coming through really is fantastic and stupidly addictive. As for Astrotortilla and plate solving generally, as you say, a total essential to making the very difficult just difficult.

There are several ways to reduce noise; more subs, longer subs, more darks and dithering - that doesn't include cooling, darker skies etc etc etc! Worth trying all four of those.

Bias frames are really easy to do - just take darks, but at the fastest shutter speed your camera can shoot at. Then stack them up and make a master bias file for use in all projects.

Flats are not so easy, but essentially you need a uniform light source (a light panel, a blank computer screen or a t-shirt over the scope pointing at the sky) and expose with the camera in AV mode so that the histogram is about half way along from the left. The optical chain must be identical to when the lights were taken, so just don't move the camera or anything, best to take these at the end of the imaging session. Take lots of frames, stack them up and create the master flat for that set of subs.

Good luck and enjoy!

[Sandancer10]

Well done Mark, a very good capture and image processing.

[Mark_C]

Wow, thanks for all of the positive comments everyone, I really appreciate it! And thanks for those tips Gav, I shall try and obtain some more darks/flats/bias frames over the weekend and improve on what I already have. Unfortunately it's not looking like it will be clear here until Sunday night at the earliest.

[laser_jock99]

Tidy first M101 if you ask me. More subs might get rid of some noise.

[Adamar98]

That's a great first image. Loads of detail coming through to say it's only 14x5mins. Well done.

[Atreta]

Great picture, i always like to see spiral galaxies.

[cockney]

awesome image and well done. thanks for posting i always love looking at people attempts.

[Mark_C]

Thanks. I've just realised there were some other subs I took of the M101 that I didn't realise about so I have stacked these with the ones used to create the image above, doing so appears to have brought out slightly more detail towards near the centre of the galaxy, although I don't really know if it improves on the above image at all really.

I really am gobsmacked at how well these images have turned out considering I have had next to no experience with imaging beforehand, beginners luck perhaps? 

[Astrosurf]

Yes, it has brought out a bit more detail. Do take care with processing not to bring out too much noise, though! You're getting there. Well done!

[simmo39]

V nice, Hopefully my first DSO image will be as good as these.

[todd8137]

Looks good to me and the kit as had a decent work out ,be proud of the image and keep going

Pat

[michaelmorris]

That's a stonking first image - nicely processed to.

[Christopher Davenport]

Everybody above have already said it.

Beginners luck or not, who cares that's a great image.

I struggled for ages to get this target.

Now that you have this one down, what's next?

[The BFJ]

Long may your "beginners luck" continue!

That 2nd image is even more impressive than the 1st... and I LOVE the 1st!

Please keep posting images like that. It gives total noobs like me something to strive towards when I finally get round to having a crack at it myself.

[Mark_C]

Thanks everybody! I really appreciate the compliments. I hope this encourages anyone, especially those with minimal experience to get out and give imaging a try. I was a bit doubtful at first as to whether everything would work as expected but fortunately it did. I think what is most crucial is getting precise polar alignment. Even with autoguiding, if PA is slightly out it will restrict how long your subs can be. I tried a 10 min sub the other night and there was star trailing so there is definitely room for improvement, although I think play in my mount is causing issues there.

Unfortunately I won't be imaging for a while as my AZ-EQ6 isn't well and is in loads of bits at the moment after me being silly stripping one of the RA worm set screw threads, meaning there's now loads of play in my RA axis as the gears are no longer meshed properly. Whilst stripping the mount I also knocked off a white 3 pin connector from the RA indexer PCB which now has to be soldered back. Things aren't going so well for my mount at the moment, I really hope it all works ok after I (hopefully) reassemble it and hopefully eliminate the play that was present.

If my mount returns back to its duties, I think my next target will be the M63! I love it's patterned structure and is quite dim so will be quite a challenge, I'll perhaps give the M51 a try too.