Master Calibration Frames Help

[Anthonyexmouth]

OK, just redone my flats and dark flats. 300x each

when i look at tutorials on making master flat files they only mention bias frames and then lose me in what they are doing

Can anyone give me a step by step on making master darks and flats please. Can i use DSS or do i need something else?

[david_taurus83]

DSS has a tab for flat darks/dark flats, whichever you want to call them. Just put all your flats into the correct tab and all your flat darks into the correct tab and DSS will do the rest. It stacks them into a master flat dark and subtracted that master from all your individual flats. Then the newly calibrated flats are stacked into a master flat.

 

If you wanted to do it manually, like in Pixinsight  for example, you would create a master dark flat in ImageIntegration and then in ImageCalibration you would use this master dark flat as a master dark to calibrate the individual flats. Then use ImageIntegration again to stack the calibrated flat files into a master flat. At that point you dont use the dark flats or master dark flat again. You just use your master flat and master dark on your light frames.

[Anthonyexmouth]

1 hour ago, david_taurus83 said:

DSS has a tab for flat darks/dark flats, whichever you want to call them. Just put all your flats into the correct tab and all your flat darks into the correct tab and DSS will do the rest. It stacks them into a master flat dark and subtracted that master from all your individual flats. Then the newly calibrated flats are stacked into a master flat.

 

If you wanted to do it manually, like in Pixinsight  for example, you would create a master dark flat in ImageIntegration and then in ImageCalibration you would use this master dark flat as a master dark to calibrate the individual flats. Then use ImageIntegration again to stack the calibrated flat files into a master flat. At that point you dont use the dark flats or master dark flat again. You just use your master flat and master dark on your light frames.

i just noticed that DSS does that. didnt see the master at the bottom of the directory. does that mean in future i just use the master when stacking my future lights?

[david_taurus83]

35 minutes ago, Anthonyexmouth said:

i just noticed that DSS does that. didnt see the master at the bottom of the directory. does that mean in future i just use the master when stacking my future lights?

Which master? If master dark, then yes, as long as it's the same exposure duration, gain and temp as your next set of lights, you can just use that single master in the darks tab.

 

The same applies to the master dark flat. As long as it's the same exposure, gain and temp as your next set of flats, you can use that master dark flat by itself.

[Anthonyexmouth]

3 minutes ago, david_taurus83 said:

Which master? If master dark, then yes, as long as it's the same exposure duration, gain and temp as your next set of lights, you can just use that single master in the darks tab.

 

The same applies to the master dark flat. As long as it's the same exposure, gain and temp as your next set of flats, you can use that master dark flat by itself.

what do you mean by using the master dark-flat  by itself?

 

[david_taurus83]

1 hour ago, Anthonyexmouth said:

i just noticed that DSS does that. didnt see the master at the bottom of the directory. does that mean in future i just use the master when stacking my future lights?

 

29 minutes ago, Anthonyexmouth said:

what do you mean by using the master dark-flat  by itself?

 

As above, you asked if you could use a single master dark in future on your lights, which you can as long as the parameters match. This is what most people refer to when they say they have created a darks library. It's a selection of master darks at various exposure, gain, temp etc for use with light frames that have the corresponding parameters.

 

I'm saying, you could use a master dark flat the same way on your flats. It would just need to match the same parameters of the flats. For example, I shoot all my flats at 5 seconds. Every filter, 5 seconds and i adjust the flats panel brightness to achive the correct ADU value or histogram if you prefer. That way I can calibrate all flats together , LRGB Ha, Oiii and Sii with one single master dark flat with a matching 5s exposure, matching gain and matching temp. 😀

[Anthonyexmouth]

Ah cool. I let apt manage my flats exposure length then used the same settings for my dark/flats. Only using a osc so not as complicated. Are the subs of any use after the masters are created?