7 replies to this topic

[Kryff]

Hi Guys,

       I am just setting up my Sequence Generator Pro and am finding it difficult to find any ADU settings for my filter set.

       I have the 36mm ZWO 7nm LRGB and Ha, Oiii, Sii filters.

       Any sugestions of some ADU for SGP to get me started with the Flats Wizard would be greatly appreciated.

Edited by Kryff, 16 October 2019 - 11:04 AM.

[vehnae]

For flats anything between 15000-50000 ADU is fine. The exact amount does not matter, the "goodness" of a flat is determined by the total signal,  e.g. 10x 30000 ADU frames is just as good as 20x 15000 ADU frames.

 

  ++ Jari

[cfosterstars]

For SGP with my ASI1600MM-PRO I shoot for 30000 ADU for flats and use the flats wizard. I used gain of 76 with offset of 40 for LRGB for my APO at F/5 and a gain of 139 with offset of 40 for my F/10 SCT. I get flat exposures of between 0.09 to 0.17s for LRGB and collect dark flats for each filter for calibration. I do not use bias frames. For my NB filters, I use gain of 200 and offset of 40 for my narrowband filter for both scopes. I have both astronomiks and astrodon filters but have used ZWO filters and use the same settong for all. 

[Kryff]

Jari,

Thanks, I'm trying at 25000 but not getting great results. I think the light panel is too bright so am trying to find a way of reducing its output as it is not a variable light source.

Edited by Kryff, 18 October 2019 - 04:47 AM.

[Kryff]

Thanks cfosterstars,

I will have a look at my Gain and Offset settings in conjunction with the panel brightness.

[ThatsMyCoffee]

Jari,

Thanks, I'm trying at 25000 but not getting great results. I think the light panel is too bright so am trying to find a way of reducing its output as it is not a variable light source.

Add a few sheets of clean white printer paper.  Add or remove as needed.

Edited by ThatsMyCoffee, 18 October 2019 - 06:08 AM.

[cfosterstars]

I cover my OTA with two layers of tee shirt fabric and have a OD 2 sheet of mylar on the LED panel and set it at the lowest setting. The OD mylar you can get from amazon and its cheap.

[Jcwillis4]

Make sure that your gain and offset are identical to your light frames.  If you use Gain 200 flats with gain 75 lights, you'll end up over or under-correcting.  I have a cheap tracing light panel I use with a piece of white acrylic plastic to diffuse and then use sheets of white paper to dim out as needed.  For my narrowband filters, I typically have to be on the highest light setting, and on the lowest for my LRGB ones.

 

After I find the right timings to get to the ADU value I like (between 15k and 25k depending on the filter), I set up a sequence to take flats for each filter, and in the event settings I place a sequence pause with a note of what power level and how many sheets of paper I need.  I create another target for taking flat darks that match the timing and gain of the flats that have another pause and note to cover the scope.  Saving that sequence allows me to reliably take all my flats in a quick go after each session.  That and my dark library for the light frames covers all the calibration files I need for the ASI1600.