ASI1600 APT Calibration Frames

[spillage]

Hi All,

I am sure this is the right place for this.

 

I am running the asi1600 mono along with apt. My stacked images seem to be quite grainy and I am sure my calibration frames are the root cause.

Can anyone give me any input into the ADU level used in APT to create their flat frames.

So far I have tried 15k,20k and 25k flats along with darks and dark flats.

No sure if these screen shots will help in anyway. I must admit I am a bit lazy when it comes to calibration frames so maybe I need to go back and redo them all.

This was 600s in ha x30 so I would expect it to have more than enough data.

[RolandKol]

Hi @spillage I will not be able to advice, but some more data will help other members to investigate.

 

Have you taken these recently during full moon? Location Light Polution?

What HA filter you used, was it 7nm?

What was the cam sensor temp?

 

Flats are not really fixing the grain, but vinieting and dust bunnies....

I personally target for around 30K adu.

Plus, you can drop the link to your Master files...  I am sure some Master of Dark Arts will check them

P.S.

I am not a pro in this field, but I have the same cam for several months only and....

I have similar results from London...
 

[spillage]

@RolandKol

I am sorry, I was a bit vague with the details.

Yes this was taken over the last two nights but other images have also been a bit grainy.

Ha filter is the baader 7mn

Running the camera at -20.

 

I will run some new darks over the weekend as it looks like cloud again and see how this works out.

[RolandKol]

Forgot to ask about dithering...
and about DSS stacking algorithm you used, was it Kappa-Sigma Clipping?

 

[spillage]

Yep I do use kappa sigma and I dither every 5 frames. No bias used.

[RolandKol]

Any luck to improve?

it looks like all wizards of darks arts left us
I get quite noisy images also and will try Darks Flats instead of Bias tonight. 

But I doubt it will help a lot...

[spillage]

Turns out I have major issue with my sensor and dew. Makes my flats look like a granite worktop so the camera has to go back for repair  

[RolandKol]

It looks like every 3rd cam goes back...

Mine will go back also  but not because of dew, but the dust in the sensor chamber ....

 

[spillage]

2 minutes ago, RolandKol said:

Mine will go back also  but not because of dew, but the dust in the sensor chamber

have you tried cleaning it yourself? Its not that bad to do and saves you not having it for a few weeks.

[RolandKol]

1 minute ago, spillage said:

have you tried cleaning it yourself? Its not that bad to do and saves you not having it for a few weeks.

Dust is in the chamber... on the sensor... 
It is not bad... usable, - but I will send the cam back at the end of the service term.