Noise reduction on or off?

[skydivephil]

Hi, I have Sony a7s mirrorless full frame camera and I want to do some deep sky astrophotography with my celestron 8 inch telescope.  If I am taking a bunch of long exposure, dark frames, etc should I have the NR on the camera on or off? i understand that deep sky stacker will try and reduce the noise for me - so does the camera NR help or hinder this process?

[xtreemchaos]

turn it off mate theres more data in your pics and you can do your NR when processing,clear skys charl.

[Daniel-K]

 

 

[Daniel-K]

18 minutes ago, skydivephil said:

Hi, I have Sony a7s mirrorless full frame camera and I want to do some deep sky astrophotography with my celestron 8 inch telescope.  If I am taking a bunch of long exposure, dark frames, etc should I have the NR on the camera on or off? i understand that deep sky stacker will try and reduce the noise for me - so does the camera NR help or hinder this process?

DSS will not reduce the noise for you, you should take calibration frames. IE darks flats and Bias then DSS will subtract them form your lights 

[skydivephil]

1 hour ago, Daniel-K said:

DSS will not reduce the noise for you, you should take calibration frames. IE darks flats and Bias then DSS will subtract them form your lights 

Thanks for the reply, I will take the the calibration frames but should I keep the camera noise reduction on or off ? It seems to me that you are saying keep it on, but forgive me if I didn't quite follow you. 

[Cornelius Varley]

15 minutes ago, skydivephil said:

Thanks for the reply, I will take the the calibration frames but should I keep the camera noise reduction on or off ? It seems to me that you are saying keep it on, but forgive me if I didn't quite follow you. 

Noise reduction should be switched off.  Darks and bias frames in DSS will take care of the noise.

[Robd]

As stated by others,  turn it off.  In camera noise reduction will take a second image with shutter closed. Ie a dark,  and then subtract it from the original. Each image will therefore take twice as long + processing time. 

Take darks at the end of imaging session - whilst packing rest of gear away.

You can build a library of darks to use later. As long as they are same exposure, iso and temperature.In DSS you can save the master dark for subsequent use,  saves re stacking them again.

Rob 

[skydivephil]

1 hour ago, Robd said:

As stated by others,  turn it off.  In camera noise reduction will take a second image with shutter closed. Ie a dark,  and then subtract it from the original. Each image will therefore take twice as long + processing time. 

Take darks at the end of imaging session - whilst packing rest of gear away.

You can build a library of darks to use later. As long as they are same exposure, iso and temperature.In DSS you can save the master dark for subsequent use,  saves re stacking them again.

Rob 

Hi Rob, thanks for that, so just to clarify, once i have a bunch of master darks, I don't need to keep taking darks every time I have an imaging evening? Is that the same with flat frames too?

 

[Robd]

No problem. You will have to update your dark library occasionally - electronic noise will change over time 

 

Flats should be take for each session. They should be same iso as images 

They should be taken with the same camera orientation and focus position. Also do not turn off the camera if it has sensor cleaning process. Flats are used to fix vignetting and dust bunnies,  cleaning, change of focus or orientation will make the flats differ to the lights.

Rob