What is all of this noise in my image!

[Startoucher101]

Hello everyone! Three days ago, I captured the lagoon and trifild nebula with my unmodified camera;Canon EOS 60d. I took 125 imagies 60sec each. Then I stacked them in DSS and I processed the image a bit but I was dissapointed. My image was full of noise! I think that this is walking noise(I don't use guiding yet,so I cannot dither). I also didn't add dark frames. I should also mention that walking noise is getting worse and worse through the year. In the colder nights I didn't have any issues with it but now in the really hot I have! How can I overcome this problem?

[Startoucher101]

[Startoucher101]

Sorry about my teribble image!

[carastro]

Looks like walking noise, where pixels are creeping along as the imaging guides.  I can't remember the solution for it.  Might be worth googling walking noise.

Edited July 16 by carastro

[carastro]

Ah yes, I think dithering was one solution. 

[ONIKKINEN]

You should still dither without guiding to cull the pattern noise a bit.

Easy to do as well, just slew a small amount in both RA and DEC in a random direction every few exposures. The more frequently you dither the more effective it is in removing pattern noise, but as a starting point try dithering say every 5 minutes. You want to move at least a good 10 pixels or so, but no real harm going over that so a "decent" amount by just eyeballing it.

If you dont want to, or cant slew the mount just bump the scope a bit, and it will effectively dither the image. I did that when i was starting out and was not guiding yet.

Edited July 16 by ONIKKINEN

[Startoucher101]

Ok that was easy! I have an EQ GoTo mount(the staradventurer Gti). Maybye a good amount of slew speed would be 2 or 3 right?

Thank you again clear skies!

[ONIKKINEN]

15 minutes ago, Startoucher101 said:

Ok that was easy! I have an EQ GoTo mount(the staradventurer Gti). Maybye a good amount of slew speed would be 2 or 3 right?

Thank you again clear skies!

Probably better to go with the slowest speed, 10 or so pixels would probably be less than a second at faster slew speeds so its easy to lose track of your framing.

Its easier to see how much to move if you turn on the grid lines in your camera screen and place a star on a corner of one grid. Then just dance that star around the corner of that grid by slewing and you know you have moved the scope enough.

[Startoucher101]

Ok thank you!

[Rallemikken]

2 hours ago, Startoucher101 said:

I took 125 imagies 60sec each. Then I stacked them in DSS and I processed the image a bit but I was dissapointed. My image was full of noise!

Two hours total on that target with a Canon DSLR is not enough anyway. Seems slike a rather short scope. Those colors in the background is typical if you stretch the image too hard. In the strive to fish out details and colors in the target, you also raise the saturation of the background. Takes some experience to handle. That's why you NEVER should toss away the dataset; trust me; in a couple of years you will do a new stack. Maybe with more data, remember to use the exact same setup.

As mentioned, start dithering. And make some rules; I never stack datasets with less than 5 hours exposure, or less than 100 good subs (after the deletion of  the obvious bad ones). And make a library of darks. The old Canon's have lots of hot pixels, shoot 20-30 of each exposure time + ISO combo. Mayby one for cold and another for warm weather if it vary much, but that is really not so critical. I often blend subs with different exposure time and ISO settings when I stack in Siril, using only one set of darks. Works well, as long as you pay attention to what to include in the final stack.

[Elp]

The image may also benefit from a horizontal banding reduction (one button press in Siril), Canons are prone to it.

Also don't use bias frames with a Canon (I don't think you did anyway).

Noise smooths out the more hours you put into the stack to a point, and also with dithering.

[Startoucher101]

I used bias frames with that image!

[Startoucher101]

So, I have to use more data

Dither

Use dark frames

Rallemikken,Elp thank you!

 

[alacant]

30 minutes ago, Startoucher101 said:

I used bias frames

Canon 60d?

Don't use any in-camera frames except flats. Instead, simply subtract the offset. Method here.

Oh, and wait until the moon is out of the way.

HTH

Edited July 16 by alacant

[michael8554]

You didn't say what the ISO setting was. 

Michael 

[Startoucher101]

Thank you everyone for responding! Well,my ISO was 1600.

Also, how can I do astrophotography without darks? I hope subtacting the offset will work better.

Thank you again!

[alacant]

15 hours ago, Startoucher101 said:

how can I do astrophotography without darks

Sensor calibration using in-camera frames is not recommended for eos models, especially those still using the d4 firrmware and 18mp sensor. Doing so will introduce artefacts of their own, including noise and banding. This makes post processing more difficult.
Keep it simple. Use in-camera flat frames only and subtract the offset from those. Siril makes this particularly easy.
Cheers

**edit: IIRC, 60d offset = 2048, but please do check.

Edited July 17 by alacant
ortografía - spell

[Startoucher101]

Ok,thank you I use SIRIL anyway...

[runway77]

Something is not right. I have never seen the noise from a DSLR to be so bad. I own a Canon 650d but in compare with this it takes very clear and nice photos. Try to use an alternative software like Siril to stack and process your images. 

[david_taurus83]

If you use APT to capture you can dither without guiding.

[Startoucher101]

Yes, something is not right! I use SIRIL to process my imagies and NINA to capture them. My first astrophotos a few months ago didn't have so many noise! They had just a bit of walking noise but hard to see... I switched to NINA from APT but the next time I will try to work with it. Also how can I do unguided dither in APT?

 

Thank you,clear skies!