Why is there so much noise in my picture?

[TheDadure]

So, about month ago i took this image of horsehead and falme in yellow light pollution zone,and i was pretty satisfied with it considering the equipment and weather,but unlike my other images this one has too much noise in it.

I did everything the same this time as the last time just stacked it and autostreched it in pixinsight,but unlike my other images this one was 30x2mins exposures and iso 3200.I took 10 darks and bias frames.

So is it because i shot only 30 images,or because of high iso settings,or maybe something else.

camera was EOS 1300d(pretty basic camera) and lens tair 300mm f4.5

(image has some dark spots on it when i tried to do something with noise in photoshop but forgot to undo it)

Can i do anything to lower the noise and not destroy details in the image?

ps. Image is cropped to fit horsehead and m78 in frame,i haven't used any filters and camera is not modified

[PeterCPC]

Firstly I would not go above 800ISO to limit noise. If you are in an orange light pollution area you would benefit from using a CLS filter. Also, if you equipment is able, I would take much longer exposures and dither between exposures. Dithering helps a lot to reduce noise.

Peter

[Thalestris24]

You need to take flats. Also, you should think in terms of ~30 for numbers of calibration frames.

Louise

[steppenwolf]

In the circumstances, I think this is a pretty fair image. However, as Peter has said, keeping the ISO to a maximum of 800 would be a good idea and more exposures will certainly improve your signal to noise ratio.

The black spots could well be dust motes so it would be worth air blowing the sensor and the rear elements of the lens and taking some Flats as well as the Bias and Dark frames as these will have a marked positive effect on your images.

Are you guiding? If yo are then Peter's suggestion of dithering between images is a good idea, if you are not guiding then a fractional random movement aup/doen and left/right by nudging the direction keys set at minimum movement will achieve the same goal.

[peter shah]

Generally DSLR cameras have an internal UV IR blocking filter. Unfortunately many of them cut majority of the Ha wavelength out effectively decreasing the amount of signal to the sensor. 

Its still a very nice image with good colour balance.

[serbiadarksky]

I use the same dslr as you..thr 1300D is awesome.

I use iso1600 with 5min exposures with lens closed to f4.

I stack images in Photoshop and apply NoiseReduction in PixInsight.

This is the result, zoom in the background

[Thalestris24]

59 minutes ago, serbiadarksky said:

I use the same dslr as you..thr 1300D is awesome.

I use iso1600 with 5min exposures with lens closed to f4.

I stack images in Photoshop and apply NoiseReduction in PixInsight.

This is the result, zoom in the background

Dark skies?

[serbiadarksky]

1 hour ago, Thalestris24 said:

Dark skies?

Bortle 4, sqm is 20.55..yellow just like his garden

[Thalestris24]

1 hour ago, serbiadarksky said:

Bortle 4, sqm is 20.55..yellow just like his garden

I count that as a dark sky!

Louise

[TheDadure]

thanks for advice everybody, next time i will apply everything you mentioned