Author Topic: PRE PROCESSING IN PI VERSUS BPP OR DSS IS FAILING WITH USE OF ASTRONOMIK CLS  (Read 2091 times)

Offline acmalko

  • Member
  • *
  • Posts: 54
In this outputs of Statistics, the output format was set to 'Normalized Real [0,1]'. By multiplying these values by 65536, the 16-bit [0,65535] representation ar obtained.

This means that the CFA channels have following means (and in parentheses: the medians):
Code: [Select]
CFA0:  9728  (9797)
CFA1: 35053 (35190)
CFA2: 35058 (35196)
CFA3: 35119 (35278)

The ADC of the ASI294 has only 14 bit, but the data of the ASI294 are multiplied by factor 4 to the range 0 to 65535 by the camera driver. The values above for the green and blue channels are therefore OK.

Bernd

Humm ok, I understand ;) There's no overexposition

What about the idea of problematic underexposed red channel ?

Offline bulrichl

  • PixInsight Guru
  • ****
  • Posts: 524
The consequence would be that a slightly higher noise is introduced by the calibration process. However, the red channel has strong signel compared with the lights, I don't think that this would result in a large effect.

Bernd

Offline acmalko

  • Member
  • *
  • Posts: 54
Perhaps should we analyse a flat rather than the masterflat ?

Offline ballyhoo

  • Member
  • *
  • Posts: 74
I am open to any suggestions. At this point I am a bit discouraged that I will not be able to use PI to pre- process with my filter.  At least I can use it for post processing which is the most important part. DSS is pretty good for Pre.

single flat

https://www.dropbox.com/s/0qncy9absk6z678/flat%20%20ES%20039_007.fit?dl=0


EDIT:

I ran integration again w "equalize flux."

Same result. But when I extracted the channels it is certainly the red channel that is the problem.

Offline bulrichl

  • PixInsight Guru
  • ****
  • Posts: 524
The image you provided the link for was an integration after applying DBE. You did not answer my question:

Does the integration of light frames (that is: BEFORE applying DBE) also show this artifact?
And further: does each calibrated light frame show this artifact in the red channel?

As a first step one has to exclude steps that are not involved in causing the problem.

Bernd

Offline ballyhoo

  • Member
  • *
  • Posts: 74
Yes the artifact is present prior to DBE, sorry. I mistook your question.

Offline ballyhoo

  • Member
  • *
  • Posts: 74
It is also hard for me to be sure, but the artifact appears to occur after the deb process. I say that because I do not think I see it after  CC, but then it's hard to tell since there is no color.

Offline ballyhoo

  • Member
  • *
  • Posts: 74
Also each calibrated light shows this artifact, after DEB process, and I do not think prior to that, IT is only there in the red channel

Offline bulrichl

  • PixInsight Guru
  • ****
  • Posts: 524
OK. Unfortunately I don't understand your answers completely. What do you mean by "Also each calibrated light shows this artifact, after DEB process, and I do not think prior to that, IT is only there in the red channel"?

You say that the artifact is not in the uncalibrated light frames. In order to clarify whether the artifact is formed during calibration, please upload 1 or 2 calibrated light frames. Please take frames that are calibrated with MasterDark AND MasterFlat. I'll take a look into it.

Bernd

Offline ballyhoo

  • Member
  • *
  • Posts: 74
I Am not sure how to explain other than as stated. However, I performed a workaround that appears to have provided good results: no artifact. In the Deb process, I selected iterative K sig clipping instead of mutli-support for noise evaluation, and the former works fine. Do you know why that would be the result?

Offline ballyhoo

  • Member
  • *
  • Posts: 74
i was wrong the prob reappeared, more detective work required.

Offline ballyhoo

  • Member
  • *
  • Posts: 74
I applied Deb to every light file type, from C.c, C. both of these have the artifact. When I apply Deb to  light frames only, no artifcact. When I applied Deb and full process but w no flats (only calibrated darks and bias, no artifact.   So far it is an issue w flats, or Deb process with flats.

Offline ballyhoo

  • Member
  • *
  • Posts: 74
OK. Unfortunately I don't understand your answers completely. What do you mean by "Also each calibrated light shows this artifact, after DEB process, and I do not think prior to that, IT is only there in the red channel"?

You say that the artifact is not in the uncalibrated light frames. In order to clarify whether the artifact is formed during calibration, please upload 1 or 2 calibrated light frames. Please take frames that are calibrated with MasterDark AND MasterFlat. I'll take a look into it.

Bernd


Sorry for all the messages Bernd,

So, given that the artifact only occurs w fully calibrated light frames [with calibrated flats] and the artifact arises or is found following the debayer process,
which files would you like to take a look at? Thank you!!

Offline bulrichl

  • PixInsight Guru
  • ****
  • Posts: 524
I would like to apply a full calibration of 1 or 2 light frames. You uploaded already the MasterFlat. So I would need 1 or 2 lightframes and the MasterDark.

Thanks, Bernd