Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - Diane Miller

Pages: [1] 2
General / M42 -- finally have something halfway worth showing
« on: 2017 January 30 22:03:18 »
After 4 months of many speed bumps, I'm getting some usable data from my Orion Sirius and simple software setup.  Using a Canon 7D Mk II on a Canon 400mm DO II lens.  36 exposures, ISO 1600, f/4, 90 sec.   Processed in PixInsight.  Still in kindergarten there (and with the mount, my first EQ) but at least getting a start.

Would still be at Step One without the excellent support and information here!  Huge thanks to everyone!

General / Strange-looking master dark
« on: 2017 January 28 21:16:01 »
I recently did a set of 50 darks (Canon 7D2 DSLR, Ha mod, ISO 1600, 90 sec) and when I stretched it I saw this.  I haven't seen a result like this before.  The air temp was very close to freezing.  A set i did a month ago with similar conditions and parameters didn't show this banding.

Here is a screenshot.

General / A graphics glitch?
« on: 2017 January 06 19:51:28 »
Apologies that I don't know what it is called, but this thing pops up sometimes and sticks to my cursor.  I sometimes manage to shake it loose but I'm not sure how.  What am I doing wrong?

Mac Pro tower (Mid 2012), OS 10.10.5.

General / Do I want to have a body converted for more Ha sensitivity?
« on: 2016 September 20 10:16:51 »
Apologies if this is in the wrong forum -- still a newbie here.

I'm making slow progress figuring out processing and finding reds weak.  I'm using a Canon 7D Mk II DSLR and sometimes a Canon 1DX Mk II, with camera lenses.  The 7D2 is mostly now a spare body for regular photography and could be "sacrificed."  I'm wondering how much advantage it would be for picking up more reds to do this conversion to let in more of the Ha wavelength:

Or can I do enough by learning to bring out reds better in processing?  (Or both.)

General / Processing order
« on: 2016 September 14 09:48:06 »
I have been doing these steps in this order (DSLR camera):

calibrate lights
cosmetic correction
subframe selector

But should I debayer before cosmetic correction?


General / Color noise "stripes" in integrated light
« on: 2016 September 13 09:42:05 »
I have gotten to an integrated light and have done a dynamic crop.  I haven't done any denoise as I don't yet know how.  I did ABE with subtraction and then repeated it with division.  I got a result that seems a bit high in contrast, but this exposure was too long for the brightest areas.  (It will be redone in a few months with two or three exposures.  This is just early in the learning process.)  I'll try DBE for comparison but in the meantime I'm wondering about the color noise in the BG, which follows a stripe pattern, which is going in the same direction as the drift between frames.

This is happening in the Star Alignment step.  I assume it's another parameter I have wrong.

Screenshots are here:

Flats were calibrated with master-bias and integrated.  They are gray and show some noise but not in this pattern.
Lights were calibrated with master-flat.
Did CC, debayered, SubframeSelector, StarAlignment and integrated.
Lights debayered and registered files have a lot of color noise but not in this pattern.

I was using the Canon 7D2 with a LP filter, ISO 1600, 2 min subs at f/4.  Astrotrac.  About 26 "approved" lights used.  No darks taken this session. 

General / Horrible result with an integrated master light
« on: 2016 September 11 20:44:30 »
I'm using a simple Astrotrac and a Canon 7D Mk II with the Canon 400 DO II lens.  I shot the Orion nebula last April with a LP filter from a moderately LP area.  I got 35 sub and shot flats but no darks.  Each sub was 2 min at ISO 1600, and the stars were decently round but there was some drift during the set.  I followed the steps as best I could of calibrating the flats with a master bias (the master flat looked OK) and integrating, then calibrating the lights with the master flat.  Did CosmeticCorrection and Debayered then did SubFrame Selector.  There was some variation and I threw out the worst ones to leave about 25 good lights.  I registered them -- there was a little drift but I got no errors in the process.  Then when I integrated I got the mess shown in this link.  I've seen a similar thing with the strange trailing shapes in the Rejection High, but never this bad.  The drift went in about the 2:00 direction from the first frame to the last.

This exposure is blown out and I meant to do two others at shorter exposures for blending, but never got around to it.  So this one is just a learning experience.

I'm obviously doing something very wrong.  Is there any guessing what, without seeing the screenshots of all my steps?  I've run it 3 times with the same result.  I'm using the best steps and parameters I can glean from Jim Morse's cribsheet.

See the last 2 files here.  The last one is one of the raw files as seen in Lightroom.

Thanks for any help!!

General / When to Debayer
« on: 2016 September 11 17:14:24 »
I'm using a DSLR.  Should I Debayer before or after using the SubFrame Selector?

Thanks in advance!

General / System Parameters settings in Subframe Selector
« on: 2016 September 09 12:49:42 »
I'm using DSLR cameras, the Canon 7D Mk II and the Canon 1DX Mk II.  How do I determine what to use for Subframe scale and Camera gain? 

General / Calibrating flats
« on: 2016 September 08 16:03:16 »
Next quandary:  With a DSLR (low noise as they go), when I calibrate the flats (taken at very short exposures) should I just use the master bias, or should I also put in the master dark?

Obviously getting out of my depth here in trying to put together info from various sources...

Thanks in advance for clarification!

General / Quandary about calibrating lights
« on: 2016 September 08 13:20:08 »
I'm using a DSLR, which is low noise as DSLRs go:  either the Canon 7D2 or the Canon 1DX2.  When I get to the step for calibrating lights I find 3 scenarios given by trappedphotons: about halfway down.

Jim Morse's cribsheet uses the master bias, master dark and master flat, but if I'm reading trappedphotons correctly, that scenario is for when you are scaling the master dark.  I don't know if my cameras provide sensor temperature data so I haven't tried to use dark scaling.  I just shoot the darks at as close to the same temp as I can.  (Temp will often drop 5-10 degrees during a run for me.)

So in that case of the darks, which of these three scenarios is the right one for me?


General / Unable to find a valid set of star pair matches
« on: 2016 September 07 10:52:03 »
I've gotten this error on the last 2 runs I've tried.  I only have an Astrotrac but I have gotten decent PA both times.  There was poor seeing and some wind, so the stars were not completely round, although focus was good.  I eliminated the worst frames before starting.  Just wondering if I'm doing something wrong.  Is there some parameter to loosen the tolerance a little?  If I reduce the number of stars from 500 I get more frames that give matches. 

Is this just a function of the files not being good enough?  Is there any fix up front for bad stars?  I was going for some nebulosity (the Lagoon) and did blow out the brightest stars.  Could that be part of the problem?


General / One more batch preprocessing question
« on: 2016 September 01 12:55:49 »
Ran BPP on a couple of sets of the Milky Way core (from two different nights with slightly different conditions).  Same camera, settings and lens.  Had what looked like good flats, biases and darks for both runs.  For both I got very subdued grayish-cyan images when I did the screen stretch on the integrated lights.  Then last night I shot the Rho Ophichui region, very similar sky conditions to the second of the core region shots, with slight LP and some haze.  Same camera, lens, settings.  Same processing as far as I can tell.  But the integrated light came out very orange after the stretch.

The files are here:

Will go back to digging thru study material, but can somebody give a quick opinion: Am I doing something wrong on either the subdued or the very orange results?

Many thanks!

General / Problem with master bias
« on: 2016 August 29 18:06:16 »
I'm trying, after some time off, to use PI again.  Very frustrated with lack of information.  I'm shooting with a DSLR (now the Canon 1DX2) and hoping to use the Batch Preprocessing routine until I get more advanced.  I'm just trying to make a Master Bias, setting it to show the rejection files.  Sometimes I get the right 2/5 or so of the frame showing nothing, sometimes the pattern fills the frame.  Sometimes I see vertical stripes and sometimes horizontal.   But the horizontal ones seem to be when the fiale fills the frame -- some sort of camera orientation issue??  I'm attaching a screenshot after doing STF.  The camera was in horizontal orientation, files shot in a dark closet with lens cap on, ISO 800, shutter speed 1/8000 sec, f/32 to try to block out any stray light.  Have seen a similar problem with the Canon 7D2 I used previously.

Parameters were:
Combination: Average
Normalization: No Normalization
Weights: Don’t Care (all weights =1)
Scale estimator: Median Absolute Deviation from the median (MAD)
Check the two boxes for Generate Integrated Image and Evaluate Noise
Pixel Rejection (1):
Winsorized Sigma Clipping
No Normalization
Check all boxes
Pixel Rejection (2):
Sigma Low 4.0
Sigma High 3.0
Range Low 0.0
Range High 0.98

Are my parameters wrong for a DSLR?  A camera orientation issue?  WHAT SHOULD THESE FRAMES LOOK LIKE AFTER STF?

Thanks for any help!
I tried to attach screenshots but then I couldn't post, even after I downsized them as JPEGs.

General / Amount of noise reduction in superbias
« on: 2015 November 24 13:57:53 »
I'm using a Canon 7D Mk II.  My bias master looks pretty grainy but I'm not sure if that is what is considered noise that should be removed by a superbias.

I tried a superbias and got noticeably broken up vertical lines.  I had used 200 subs so used 6 for Multiscale layers.  Out of curiosity I ran it again using 7 and got a smother result.  Then I tried 8 and it was even smoother.

Which is best?  Is the parameter to be used dependent on the number of megapixels on the sensor, or some other characteristic of the camera?

Or would the difference be trivial when used to calibrate the darks and flats?  I'm not using darks (yet) and the flats look good -- to me -- when I apply STF.

Pages: [1] 2