Whirlpool Galaxy

I have finally managed to photograph a recognisable galaxy. I used a Canon 700D (which I am borrowing) set to ISO 6400 and 23 second exposures. Unfortunately, I was only able to take 30 photos before it went out of my field of view. DeepSkyStacker allowed me to stack 26 photos. I also took flats, darks and bias frames. I used ISO 6400 because I have a Skywatcher EQ3-2 tripod which gives me errors after 90 seconds or so, although it sometimes messes up at 1 minute.

This is something that I never thought would be possible by me. So, it feels wonderful to be able to photograph it. I know that I need to take more lights to reduce the noise produced by using such a high ISO.

Skywatcher Explorer 150P

Thanks for looking.

Naddie

Fantastic work! Grerat capture and composition!!!

When you say the tracking messes up, what do you mean? Are you using PHD and it starts beeping and flashing red? I used to only be able to track for 60-90 seconds myself. Turned out my balance was way off and lop sided.

When I swapped out the mounting plate for a longer one and balanced it perfectly I then managed 10min plus subs! Longer if it weren't for light pollution.

- Daniel

Good job, i hope i will capture galaxies sooner or later from my light polluted area too, i am not in rush, but i feel if i set everything properly then i will be able to do DSO astrophotography.

Thank you Daniel, I am sorry, I was busy with university and other things. Unfortunately, I only have an EQ-3 mount as it was the only thing that I could afford. I didn't know that I would get into astrophotography properly when I was buying it.

I do have a problem with balancing it on the Declination axis, so if I let the bolt slacken, it will spin round. I have tried to move the telescope up and down the rings, but that wasn't much help. Balancing on the RA axis with the weights has no problem. As I only have an EQ-3 mount and a single axis drive I didn't realise that would have any effect on the output.

Thanks

Naddie

legoman_iac wrote in post #18584315
Fantastic work! Grerat capture and composition!!!

When you say the tracking messes up, what do you mean? Are you using PHD and it starts beeping and flashing red? I used to only be able to track for 60-90 seconds myself. Turned out my balance was way off and lop sided.

When I swapped out the mounting plate for a longer one and balanced it perfectly I then managed 10min plus subs! Longer if it weren't for light pollution.

- Daniel

Thank you, after your comment. When I say mess up, the stars start to trail, I don't have any guiding equipment on the telescope, so I have not used PhD Guiding. Anyway, I looked more into balancing the scope better because it did not balance along the declination axis when trying to slide the telescope up and down the rings. I looked up on other Internet fora and found a solution that involves attaching counterweights via a small bag using velcro on the other side of the eyepiece. After being shocked at the prices of ankle weights and things like that, I decided to make a compromise. I attached a rucksack onto the telescope and then I can put bits and pieces in it to counterweight the camera as shown below.

I forgot to ask, is the camera modded?

How did you take flat exposures? i am not asking about dark or bias files/exposures, i just ask about flat, because this is the only thing i don't take so i want to learn, then i can do a lot in DSO.

I just use the t-shirt on the telescope method for flats. Wait for the daytime and take a photo then just so then you can see the difference. I live in a light polluted area, but don't bother when the moon is nearly full or is close by.

naddieuk wrote in post #18604422
I just use the t-shirt on the telescope method for flats. Wait for the daytime and take a photo then just so then you can see the difference. I live in a light polluted area, but don't bother when the moon is nearly full or is close by.

So the T-shirt method, i was thinking more about lights boards and similar than shirts, i don't wait until daytime.

Well, i didn't ask about light pollution case, i do have NB filters, so with Ha only i can shoot even if it is full moon, but i definitely avoid the moon nights anyway for other filters, i just asked if your camera is modded or not, thanks about the flat part.

This is with an unmodded camera.

naddieuk wrote in post #18607392
This is with an unmodded camera.

Nice, so then i will try with my DSLRs something then without my astro camera just for fun, thanks!

Keen to hear how the new balanced setup works! Hope it was just a balance issue!

Awesome solution by the way!!!!

- Daniel S

P.S regarding flats ... if you cannot be bothered to shoot them, you can kind of fake them. I'll probably be burnt at the stake for saying this ... but just grab your stacked stretched light sub, apply a "photoshop despeckle/dirt removal filter" (or equivalent) and presto, a gradient image ready to subtract from your light sub!

legoman_iac wrote in post #18608407
Keen to hear how the new balanced setup works! Hope it was just a balance issue!

Awesome solution by the way!!!!

- Daniel S

P.S regarding flats ... if you cannot be bothered to shoot them, you can kind of fake them. I'll probably be burnt at the stake for saying this ... but just grab your stacked stretched light sub, apply a "photoshop despeckle/dirt removal filter" (or equivalent) and presto, a gradient image ready to subtract from your light sub!

From what i hear that flat is used to remove vignetting and dust or spots.

I've used the fake flats to remove vignetting, see attached two screenshots of slides from a talk I gave to my work few years back. Can upload full res of these are too small?

The final image is the large one with each thumbnail on the side, as follows:

- single raw sub
- stacked subs
- stacked and stretched (lots of vignetting)
- fake flat

Hope this helps?

- Daniel

Until now i did few targets without flat files, good if it can be done with processing, but vignetting is one issue, what about other issues such as light leak or dust spots on filters or camera reflected in the results?

I imagine the fake flat is not as good as a real flat ... and always best to capture it for real. Just sharing my hack which I read somewhere.

Regarding other issues, guess you can try moving your framing around so the dust spots appear on different areas and can be hidden once stacked.

Other issues, I wouldn't have a clue. Sorry. I'm no expert. Not even an amateur. Just occasional hobbyist, and lately, not so occasionally, haha.