M51 Image - Not sure what am i doing wrong in my settings

Somewhere to ask questions about the best way to use SharpCap
Forum rules
‍

If you have a problem or question, please check the FAQ to see if it already has an answer : https://www.sharpcap.co.uk/sharpcap-faqs
Nittany
Posts: 38
Joined: Wed Jan 25, 2023 3:41 pm

Re: M51 Image - Not sure what am i doing wrong in my settings

#11

Post by Nittany »

Hello Robin -
Here is the picture with darks and @ 15s and 300 gain. Any further recommendations? Just stack longer?
Attachments
M51_Dark_Comparison_04092023.jpeg.jpg
M51_Dark_Comparison_04092023.jpeg.jpg (496.96 KiB) Viewed 1847 times
Nittany
Posts: 38
Joined: Wed Jan 25, 2023 3:41 pm

Re: M51 Image - Not sure what am i doing wrong in my settings

#12

Post by Nittany »

Still looks grainy.
Attachments
Stack_80frames_1200s_WithDisplayStretch_1.jpeg
Stack_80frames_1200s_WithDisplayStretch_1.jpeg (934.6 KiB) Viewed 1847 times
User avatar
turfpit
Posts: 2258
Joined: Mon Feb 13, 2017 8:13 pm
Location: UK
Contact:

Re: M51 Image - Not sure what am i doing wrong in my settings

#13

Post by turfpit »

Nittany

This is your image with noise reduction applied (Neat Image in this example).

Stack_80frames_1200s_WithDisplayStretch_1_filtered.jpg
Stack_80frames_1200s_WithDisplayStretch_1_filtered.jpg (935.46 KiB) Viewed 1836 times


From the ZWO website, the read noise v gain graph for the ASI678. Keep gain > 182 to take advantage of the HCG mode. I would try gain=200 (with the same exposure) and increase the frames stacked (how many depends on your tracking).

ASI678-read-noise.JPG
ASI678-read-noise.JPG (31.18 KiB) Viewed 1836 times


Note that the ASI678 is described as a Planetary Camera on the ZWO website. Bortle 8 skies will always be against you for deep sky.

Dave
FstarGazer
Posts: 7
Joined: Sun Apr 02, 2023 7:46 pm

Re: M51 Image - Not sure what am i doing wrong in my settings

#14

Post by FstarGazer »

Hey Turfpit, what kind of noise reduction did you do on this? Had some extraordinary noise in my recent pictures as well. I figure it was too low exposure time of only 20s on M1 with gain 200 and the 533 mc pro under a full moon.

Nice result on m51 though.
User avatar
turfpit
Posts: 2258
Joined: Mon Feb 13, 2017 8:13 pm
Location: UK
Contact:

Re: M51 Image - Not sure what am i doing wrong in my settings

#15

Post by turfpit »

Thanks. Neat Image was used in this example. There are many image processing applications which have noise reduction facilities. Google astro images noise reduction.

Full moon will not have helped. In my opinion, M1 (and M51) are not 20s exposure objects (unless using a RASA scope or Hyperstar) if good results are required.

Dave
Nittany
Posts: 38
Joined: Wed Jan 25, 2023 3:41 pm

Re: M51 Image - Not sure what am i doing wrong in my settings

#16

Post by Nittany »

Thank you Turfpit. Really appreciate your recommendation and suggestion. I like noise reduction you did on this. I will try it in Photoshop (Assume i would be able to do that?)

Also, yes ASI678MC is a planetary camera and i am tracking to keep above 182. I normally start with 200 and see if it stacks, if not then i will increase gain.Thats how i got to 300. For this picture, i stacked 21 mins. Maybe i need to stack 30 mins.

Thanks again.

turfpit wrote: Mon Apr 10, 2023 11:07 am Nittany

This is your image with noise reduction applied (Neat Image in this example).

Stack_80frames_1200s_WithDisplayStretch_1_filtered.jpg


From the ZWO website, the read noise v gain graph for the ASI678. Keep gain > 182 to take advantage of the HCG mode. I would try gain=200 (with the same exposure) and increase the frames stacked (how many depends on your tracking).

ASI678-read-noise.JPG


Note that the ASI678 is described as a Planetary Camera on the ZWO website. Bortle 8 skies will always be against you for deep sky.

Dave
Post Reply