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Topics - Terry Danks

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General / Ha Calibration Woes . . .
« on: 2019 March 21 14:32:39 »
I am experiencing problems calibration all Ha frames.

Two things . . .

1/ Only Ha frames are giving me grief. LRGB calibrations are fine, and . . .
2/ I went back and redid some Ha frames I just calibrated a few days ago with no problems but now they come out terribly!

This is on two machines. Same "new problem" on both.

Attached is a screenshot with the "good" calibration on the left and the "bad" on the right. Default STF settings on both. All backgrounds in calibrated Ha frames are now clipped, or almost clipped.

I have used the Batch Preprocessor, set to "Calibrate only. I have also tried producing new flats, darks and bias frames in case my masters had somehow become corrupted, but I still get these very dark calibrated frames.

To my knowledge, I have not changed any settings on either machine but am at a loss as to what is causing this sudden misbehaviour.
Any suggestions?

General / SFS: Subs taken through cloud vs clear, dark sky?
« on: 2019 February 28 05:57:02 »
Last night I know there was thin, high cirrus cloud about. When I checked the subs against those taken another night, when it was clear, I expected to see figures in the SFS that would allow me to distinguish "bad" subs, i.e., those taken through the cloud, from the "good" subs, taken in a clear sky.
I saw nothing in the FWHM, Ecc, or SNR figures that pointed to the "cloudy subs" being better, or worse than the "clear" subs.
This does not seem logical and I am puzzled.

Is there really a significant advantage to using weighting expressions calculated by the SFS and written into the fits headers over the weighting the Image Integration Process does on its own when noise evaluation is active?

My concern: It seems there is a possibility that any expression I formulate to weight subs may well be less sophisticated than those used by the far more competent programmers who wrote the Integration Process in the first place, opening the likelihood of my doing more harm than good?

I've never done this before.
I use the SFS Process to affix weights to the fits headers. Seems to work. But when I run the Image Integration tool, the Process Console always reports the error as in the attached jpg.
I must be doing something wrong. No idea what. 
Suggestions as to what I've done wrong?

IIRC, prior to the SFS bugfix, the graph area of the process showed a white grid . . . but no data.
Now I am getting a flat, no info grey only in the plot area.
Still no plots. Plots appear fine in the old script still.
Still a bug? Or have I messed up something?

General / Problem With Dynamic Crop . . .
« on: 2019 January 17 09:31:29 »
While I found this topic.

I still seem unable to apply identical crops to multiple frames in PI v. I've tried creating a new instance before actually cropping the reference image. No joy.
I tried double clicking the crop applied to the reference image in the history explorer. No luck there either.
I am following the instructions in Warren Keller's book (2nd ed., p86) but the tool seems not to be working as described.
What's the secret to avoiding the need for another alignment after cropping the L,R,G and B master frames?

General / Gradient Merge Mosaic Error
« on: 2018 May 22 16:19:03 »
I am getting an error message when trying to stitch two panels together:
"Current Image Width Differs From First Image Width."

When I cropped the images to be the same width, I get the same message except change the word width to height.

Makes no sense?

So, I made the two panels the identical size and height. No error message but all it did was overlay one entire image with another?

General / GOES Belt Satellite Trails: Best rejection?
« on: 2017 October 21 11:49:06 »
I am processing an image with numerous GOES trails. I have 22 lums and have selected Linear Fit Clipping as Rejection 1 in the Image Integration tool. No idea about Rejection 2, 3 or Large Scale Rejection settings. Have tried Winsorized Sigma as well.

Trails are substantially muted . . . but still present.

Is there a better way to suppress these evil things?

Bug Reports / "Access violation" PI will not open?
« on: 2017 August 21 08:36:43 »
Win 10 Home 64 bit
PI v. 1.805 1353

Encountered this the first time Aug. 20. PI would not open and error notification appeared:

"Access violation: invalid memory read operation at address 00000000000000"

Tried again and it opened.

This morning though, it will not open at all.

Uninstalled and reinstalled v.1353. Same behaviour. PI will no longer launch at all.

General / BPP Ability to save calibrated files as fits . . .
« on: 2017 August 14 10:55:46 »
I seem to be losing my mind.
I set the BPP to "calibrate only."
I need to save calibrated files as 32 bit, floating point fit files in order to run Bob Franke's CCD Band-Aid routine on them. It won't work with XISF files.

I was able to select the output format for the BPP before, but can not find that option in the latest version, v.1.46.
How can I get the latest BPP (v. 1.46) to output calibrated files as 32 bit, floating point fit?

General / Globular Cluster colors . . .
« on: 2017 April 25 14:50:28 »
I see many globular cluster images that seem to have nothing but bluish stars.
These are ancient assemblages of mainly red dwarf stars though, with relatively few blue stragglers here and there.
It seems to me they should be more a ruddy red colour rather than predominantly blue.

To apply colour correction, I have done background neutralisation in the normal fashion first and then colour correction by defining a preview that includes the entire cluster . . . much like a spiral galaxy. This seems incorrect though as globulars should not integrate to white.

The G2V method seems beyond me in that identifying a G2V star requires access to some really detailed charts.

So, my globulars look blue too.

Any suggestions on getting colours of these clusters more resembling their true physical colours?

General / Opinion and Suggestion: What PI Needs . . .
« on: 2016 May 14 12:09:33 »
In the announcement thread, I posted my disagreement with the approach that would seem to be taking PI in the direction of becoming an all-inclusive vehicle for hardware control and data acquisition, as well as for processing. If I sounded churlish in doing so, my apologies.

I appreciate there are tutorials on how to use PI . . . and even a small industry that produces same. I have watched many, and subscribe to one. I am grateful for all of them!

That said, I have not found what I feel really should be available. The tutorials presently available are very "tool-oriented" as opposed to "project-oriented" as I see it. What I feel is needed is an advanced series of tutorials that take a data set for a specific type of DSO and process it through from beginning to end. As I see it, about four are required, one each for galaxies, emission nebulae, globulars and galactic open clusters. Each of these objects, while similar in demands in many aspects, have some specifics more important to one than the others.

The ideal would be that all who desire to do so, be able to attend a PI workshop. I am sure I speak for many when I say "ain't gonn'a happen" for me.

Why could not these workshops be put on-line for those of us unlikely to ever see a workshop even in our own country, let alone our local area.
Money is not the issue. Charge for them by all means! I can't be the only individual more than willing to pay to access such.

I've been using PI for years, but still feel I have not scratched the surface of what could be done with my data by a true master of the software.

General / “Invalid Overscan Region(s) Defined” ????
« on: 2015 November 23 10:51:00 »
PI v x64
Batch Preprocessing Script v1.42

“Invalid Overscan Region(s) Defined”

I'm stuck. Every attempt to use the Preprocessing script now ends with this error.
No idea why it started happening. I've reinstalled PI to no avail. Same computer I was using before.

I even went back to some old data and tried with the exact same
master cal. Frames. Same error.

Any suggestions as to where this error originates is appreciated.

Thanks . . .

General / Having more than one process icon open at a time?
« on: 2015 September 19 12:26:01 »
Incredibly naive qustion.

I have process icons saved for DBE and AT Wave. But when I ask PI to load one, "Process>Process Icons>Load Process Icons," it insists on overwriting the one loaded previously? I seem able to have only one process icon loaded at a time?

What am I doing wrong?

General / My superbias looks wrong?
« on: 2014 November 12 04:40:55 »
Hi All:

I have watched Warren K.'s tutorial on superbias. My camera is a noisy STL-11002XM.

I took 50 bias frames, integrated them and applied PI's Superbias using 6 layers(not the default 7 as I was using 50 frames), as per the tutorial.

The resulting superbias looks good, well quite indistinguishable from the regular bias, really.

But when I do the subtraction of the superbias from the regular bias, again as per the tutorial, I get the result in the screenshot.
According to the tutorial, "only randomly distributed noise should remain." Not what I have at all.
The 24-bit LUT setting for the STF was applied to the pixel math result in the screenshot.

Suggestions as to what I have done wrong would be appreciated.


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