Dan Paris

Hi, A galaxy group that I wanted to shot from a long time, the Draco Trio (NGC 5985, NGC 5982, NGC 5981) Luminance : 120 * 30sec Chrominance : 30 * 30 sec each channel 200/800 Newtonian telescope ...

Looks good to me Michael, I like the deep red of the Nebula and the star colors

Very good picture with lot of fine detail, also in the faint outer arms, and I like that it is not "overprocessed" as is often done for this galaxy.

Thanks a lot Mike, and thanks everyone too for your kind messages, it was indeed a pleasant surprise :-) Congrats Kees77 too ! Dan

Great Chris but as Greg says you may try to remove the orange gradient near the horizon

Just beautiful !

very good Michael ! Did you try to boost the background to see if you captured IFN ?

Thanks ! There're 15 frames for the sky (tracked with astro-tracer).

No problem with 30s at ISO800, I assure you. This is a stack of 30sec. exposures at f/2.8 and ISO 500 Even at 500 ISO, the brightest stars are saturated. Regarding the need of a tracker : if you ...

Placed 1^st in the challenge. Shot from the top of Petit Vignemale (3,032m), Parc National des Pyrénées, after an early ascent.

Yes exactly, assuming you use the same sensor or a sensor with similar behavior.

Here is a useful link : https://www.cloudynights.com/topic/573886-sub-exposure-tables-for-asi-1600-and-maybe-qhy163/ The tables are calculated for an astro-camera sharing its 16mpix sensor with ...

At 18mm full frame, for 30sec exposures, while blur in the sky is easy to notice (because stars are distinct sharp and bright sources) but much less of a problem for the foreground. So while it ...

OK, so on your tracked RAW files, sky background is around 8000 ADU, with a photon noise around 300 ADU (hard to measure on a wide field picture because there're stars all over the place). If I ...

Shortening the exposure is precisely a way to address the OP problem (too much blur in the foreground). If the photon noise is 20 times the read noise for, say, an exposure of 30sec, it is a better ...

I guess that your exposure time is indeed too long. Regarding the ISO : your sensor has a dual gain architecture, with a drop in the read noise around ISO 600, so there's no real noise benefit with ...

I'm wondering whether the exposure time on your tracked sub-exposures is too long. There's a limit above which extending subs exposure time is counter-productive. Among the various noise sources ...

Thanks Michael, actually under my light-polluted skies with this low-read noise CMOS camera and my f/4 scope 15sec is almost a "long" exposure time (read noise is already 30X smaller than photon ...