Eagle Nebula

[Gavin1234]

Thought I’d try Eagle nebula tonight.
It’s probably not the right target for my scope seeing how small it is in the fov. This is one is 7 x 10 min subs. Also a cropped version to try make it easier to actually see the eagle �� .

Some of the stars in the centre a kind of morphed together, is that because my focus isn’t good enough?

[xelasnave]

Your ficus does seem a little out.
Do you have a mask?
Alex

[Gavin1234]

Thanks Alex. No mask but it’s been a while since I checked the focus. I can usually get it to about 0.85-0.95 HFR but not much lower than that. I think I might have bumped the focus knob while setting up last night.

[Imme]

Hi Gavin,
During an image run I check focus at least once per hour to adjust for temperature changes.

[rcheshire]

Hi Gavin.

Apart from focus, the brighter stars appear over exposed, too big and merge together, particularly near the brighter areas of the image.

EDIT: I read your Helix post - camera is an ASI071MC - APS-C colour CMOS:thumbsup:

Balancing read noise and saturation is tricky. A combination of slowing the exposure down / or less exposure time and dithering to handle noise. A 10 - 15 pixel dither is a good value between images - if your gear supports it.

[Gavin1234]

Thanks Rowland and Jon. I’m taking some more frames of Triffid/Lagoon at the moment. This time I took more time setting it up properly. I managed to get the HFR down to about 0.78.

Can anyone tell me what is an acceptable HFR to have?

Also, this time I actually did a proper polar alignment. Up until now I’ve just been plonking my mount down facing true south and doing a two star alignment. I’m embarrassed to say that I actually thought that was polar alignment until I saw the polar align option on my hand controller tonight.

Trying 150 gain at the moment but I think 120 might be better. The auto stretched preview is showing the core of lagoon as very bright.