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Messages - Diane Miller

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General / Re: Strange-looking master dark
« on: 2017 February 02 16:22:50 »
It is still there but much less obvious on an integration of 40 frames at ISO 800. 

General / Re: M42 -- finally have something halfway worth showing
« on: 2017 February 01 13:56:05 »
Apologies -- I didn't read the fine print.  I went back to the last .xisf file and did another round of SCNR for greens (I had only done it at 0.5 before) and star reduction.  It's pure now.

Now I'm seeing there is a fine sprinkle of dark noise-like spots, most visible in the mid-tones.  I wonder if I didn't do cosmetic correction properly?  Or another likely cause?  I'm still dubious I'm handling darks correctly, as I have read there can be problems with Canon DSLRs.  I am integrating the darks into a master and then using it to calibrate the lights.  In ImageCalibration for the lights I load the master dark and do not check Calibrate or Optimize.  I also load the master flat and do not check Calibrate for it.

General / Re: M42 -- finally have something halfway worth showing
« on: 2017 January 31 13:33:56 »
I see now I had a misalignment of a layer in Photoshop where i added a lower exposure for the core.  It was partial opacity and the stars didn't quite overlay correctly.  Fixed now so I'll re-post.

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 / Re: Strange-looking master dark
« on: 2017 January 30 09:10:24 »
I looked at some recent master darks from sessions with the Canon 5D Mk III and 1DX Mk II (when I needed a larger frame), and none show this issue so it is apparently a noise issue with the Canon 7D Mk II.  For daylight shooting, it does exhibit somewhat more noise than either of the other two bodies. 

I'll do a dark set at ISO 800 for comparison and report back.  If it is "clean" (as I suspect) then the question becomes, as I better off at ISO 800, or is the difference so trivial in the processed images that I'm better off at ISO 1600?

General / Re: Strange-looking master dark
« on: 2017 January 30 08:52:25 »
Good idea Bernd,

I see no banding in either light frame.  It seems to just be in the darks and biases.  In them, it is in the same place, although the edges are a bit fuzzy.  But if I open the dark set in Blink and step through them, it jumps around noticeably but in the same general area of the bottom half of the frame.  It is almost swamped by the noise and each "band" is very indistinct.  Maybe I should be using ISO 800 instead of 1600 -- will do some checks and compare with the Canon 1DXMk II body.

I'm not doing photometry so it apparently isn't an issue but I was curious what might be going on.

General / Re: Strange-looking master dark
« on: 2017 January 29 11:55:07 »
FWIW I have looked back at master biases before and after a recent Ha mod and they are the same before as after:  In both cases, at ISO 1600 I see no banding but at 3200 I see a somewhat similar pattern to this master dark.  No idea what that might mean, or if it would cause any problem with processing.  I'm currently shooting everything at ISO 1600 and that master bias is "clean."  (And I'm not using it for the master dark -- that is just an integration.  I'm currently relying on using darks shot at "the same temp" (ambient, anyway).

General / Re: Strange-looking master dark
« on: 2017 January 29 10:38:22 »
My second screenshot, of the integration parameters didn't show.  Trying again:

General / Re: Strange-looking master dark
« on: 2017 January 29 10:36:08 »
Yes, it is the master dark, stretched with the default settings.  I did a different target last night, at 3.5 min exposures, and just ran that master dark with the same results -- I always delete the first and last frames to reduce the chance of a frame with some light leak or a shorter time as a battery died.  Same result.  I opened several of the raw frames and stretched and see the same lines, but a little more indistinctly.

I'm not finding the crop option mentioned, but here I'll  is a screenshot of the same stretched master dark, zooming in to the left side.  I see no artifacts there or on any edge.  Also here is a screenshot of my integration parameters. 

I'll check back to some older darks, although I usually delete the raw folders after getting the master.  Wondering if this started after the Ha mod??  Strange thing is, after the mod I redid the bias masters for the ISOs I use (1600 and rarely 3200) and I saw it in the 3200 master bias but not in the 1600 one.

Assuming it is "real,"  is it a problems?  I haven't seen any trace of it in the linear master or nonlinear processed files so far.

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 / Re: A graphics glitch?
« on: 2017 January 07 11:48:46 »
Thanks Rob, that did it.  Yes, I'm using a Wacom tablet but it does the same if I use the Apple Magic Mouse. 

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.

If I go with a CCD camera and filters, can I use my telephoto lenses with it?  (I.e. what adapter?)

With a good enough mount I have 1200mm of good optics, with the Canon 600mm f/4 II and the 2X teleconverter, and it only weighs a little under 8.5 lbs (add 3/4 lb for the 2X).  And an excellent 400mm as well, that can take the 1.4X and 2X converters.

KBLU as in Blue Canyon airport?  Will do -- is there a web site with information?  (Sounds like you are a pilot?)

A great drop-in place is the tiny Independence airport, between Bishop and Lone Pine on 395 -- high and dry and quite dark. 

I should think more about a "real" astro camera and filters.  One of my issues is limited acquisition time, between dark and raining dew or the local fog bank rolling in.  I know I can collect on different nights, though.  I think the first thing is to go to a better tracker.  The Astrotrac has its limits. 

I'm thinking about an Orion Sirius.  I know there are many to choose from, but a somewhat portable one would be nice.  Shooting from the house is limited to the north, but we have a decent dark sky site less than an hour away where I can set up next to the car.  And I'm not exactly built like a fullback.  I'm one of those 3/4 scale people and my husband isn't to be counted on for hanging out in the dark unless we're camping under an airplane.  We do that a couple of times a year -- there are several small almost deserted airports in dark areas within a few hours of flying.  So portability is a requirement.

But Mike has convinced me to do SOMETHING!  That's an amazing difference.

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