weird horizontal line (s) - Forums

Topic starter

Jan 31, 2017

Hi all,

I'm new to the forum and looking forward to chatting with the community.

I've only imaged several times but seem to have a fairly consistent problem. I'm getting a noticeable horizontal lines across my final tiffs after stacking. My setup is quite simple: Canon 600d with a tamron 70-300mm and a Celestron AVX mount. It's been suggested to me that I should manually dither to get rid of the artifact but I'm not sure I want to babysit my mount at -20 here in Canada. My m31 as I have posted had this but it was faint and I was able to more or less get rid of it in processing. I've attached an attempt at m42 (core shot) at f6.3, 800iso, 20 sec lights. This is a stack of 60. I use dss and choose sigma clipping option. Oh, just to clarify, I don't autoguide. Also, it's grossly stretched to show the line. https://www.flickr.com/gp/rkonrad/10xL4t

Thanks!

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MaroOgaro

Jan 31, 2017

What about single light frame ? The same line?

Richard Konrad

Topic starter

Jan 31, 2017

I don't *think* so. The m31 picture's light frames are fine but I don't have access to the m42 lights until tomorrow or so.

Richard Konrad

Topic starter

Feb 1, 2017

I just checked. There is no such horizontal line in the single light.

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glennb44

May 30, 2018 · Edited: May 30, 2018

Its gotta be a satellite in that area? I would've expected it to be removed in the processing if youve used calibration frames (bias,flats and darks) in processing.
If its there on other pics then its the camera - but the calibration frames should get rid of it.

GlennB

Michael Timm

May 30, 2018

It could be the "Canon banding" problem. PI has a Utility to remove these bands. Just check Google for the keywords canon banding, maybe you'll find similar bands than yours.

Richard Konrad

Topic starter

May 30, 2018

Thanks for the replies. It's cool that messages come a year+ after posting. Most appreciated. This mysterious line appears intermittently in various stacked tiffs after stacking. When it does it's in the same place. (different targets) I've been told it's "walking noise" due to less than excellent polar alignment and with no dithering, this makes it worse. But why in the same place? Unfortunately I can't afford PI but I have tried a banding algorithm with Startools which at least helps with the intrusive line going through the actual image. I image with a dslr alone and no guiding so I'm about to try EKOS (from KSTARS) which has a dithering option for non-guiding setups. Hopefully that helps. We'll see though from my latitude (Canada), this season doesn't have a long dark period at all.

I'll be in touch. Thanks.

Richard

GregGurdak

Jun 4, 2018

Hey you simply do it something wrong during post processing… that’s all .. batch demosaic + square raw colour … probably you have to set up manually colour control … for you Canon model … find out what pattern RGB your canon is using…