37 replies to this topic

[bobzeq25]

Since people are posting their images with an LPro, and saying there's "nothing wrong" with using one, let me post mine with no filter at a light polluted site.  Red Zone, Bortle 7, mag per arc sec squared low 18s.  C8 RASA, 183 one shot color camera.

 

Yes, you can get something with an LPro.  You can get something better without.

 

Edited by bobzeq25, 07 March 2021 - 07:25 PM.

[Ivo Jager]

Pleiades M45 TOTAL FAIL!  80xISO400_120s (+) 50xISO800_120s for a total of 4.3 hours of exposure time. ES ED102 triplet, unmodified Canon t5i, Optolong L-pro filter and stacked by DSS. .jpeg version of one ISO800 sub attached.
No color, very little nebulosity and totally unable (for me) to process in Ps. Four hours of exposure over two clear nights which are hard to come by this year in the Pac NW totally wasted. if not for covid, I would be part of an astronomy group, member interaction would speed up my learning curve but now I’m left with blindly taking shots in the dark and waiting to see what happens.
No idea why it failed so poorly, it felt so good while imaging. Will try to double exposure to 4-min. Pleiades is on its way out hoping for two clear nights soon.

It think most of this has been said, but for good measure;

 

Don't mix ISOs, dither between frames, improve your flats, and don't use a narrowband filter for reflection nebulosity objects. Turn off color balancing if performing luminance-based processing (recommend).

 

Acquisition and pre-processing decisions and quality have a direct (and dramatic!) effect on what can be extracted in post-processing. As you learn more about signal processing (not image processing), you will learn how essential post-processing tools and procedures like synthetic luminance generation, deconvolution or noise reduction (e.g. algorithms that need the cleanest, most unadulterated data they can get) react to sub-optimal pre-processing and acquisition decisions.

 

Getting things right from the get-go will not only make for better images, it will also make for a much more enjoyable, shorter, and repeatable post-processing experience.

Edited by Ivo Jager, 07 March 2021 - 08:06 PM.

[meach8]

Thank you all, your feedback is much appreciated. I think bits of everything said are possible. For the first time I did the t-shirt method for flats, and also the cheap tracing panel method. May have another go at the flats. Pleiades for me is straight up at dark setting west into a more hazy, light polluted area. Bad weather kept me from shooting it a month earlier when it stayed up high longer. Too late for Pleiades but I’m up for shooting unfiltered on a clear night.
For those who processed my master…thanks. It’s obvious there is more data there than I thought.

Not everything I do is a “total fail”

 

 

 

 

[cybermayberry]

this isn't a quick adjustment of MY original, is it?.....it's beautiful

Yes, that your data. The biggest issue seems to be a result from flats. I used curves to darken the effected areas.
Your doing much better then your given yourself credit for

[cybermayberry]

this isn't a quick adjustment of MY original, is it?.....it's beautiful

Yes, that your data. The biggest issue seems to be a result from flats. I used curves to darken the effected areas.
Your doing much better then your given yourself credit for

[PederP]

Since people are posting their images with an LPro, and saying there's "nothing wrong" with using one, let me post mine with no filter at a light polluted site.  Red Zone, Bortle 7, mag per arc sec squared low 18s.  C8 RASA, 183 one shot color camera.

 

Yes, you can get something with an LPro.  You can get something better without.

 

Pleadies 2019 V3 small.jpg

looking at your image i do not agree..

You are comparing an image from an experienced user, experienced in editing, using a cooled camera and a RASA, to dslr shots with zoomlenses, edited by newbies like myself.

Edited by PederP, 08 March 2021 - 11:30 AM.

[NatureKnyt]

You can do a good job using PS after APP.  But you can also do a good job with just APP, if you learn to use it well.

 

Something of a personal choice. 

 

But, if you think you may later move to PI, I'd learn APP better, and do it all in APP.  It's better preparation.

I guess that's my question - I do see some good final results just using APP, but I haven't been able to find the resources that go into detail. Having watched most of the videos onsite and a few around elsewhere, my impression is that the right side does only tweaks and in general relies entirely on your data inputs. If you need to do HDR adjustments for things like Andromeda core or Orion, it doesn't seem to have that capacity. Or for selective adjustments to parts of an image. 

[bobzeq25]

looking at your image i do not agree..

You are comparing an image from an experienced user, experienced in editing, using a cooled camera and a RASA, to dslr shots with zoomlenses, edited by newbies like myself.

That's NOT what I'm doing.

 

I'm looking at how much of the spectrum an LPro cuts out.  It's substantial.  That will lower snr about as much as cutting out some of the light pollution will raise it. 

 

See this thread about galaxies, it applies to other broadband targets like M45.

 

"if I want to go deep with a luminance image of a faint field of galaxies - the reduction of light pollution - which does happen - is not enough to compensate for the loss of galaxy signal - which also happens."

 

"I never liked LP filter because it messes up color balancing (i.e. too many stars were too bluish) so I rely on processing to remove or reduce gradients with PixInsight and works well."

 

"I dropped LP filters a few years ago, after finding they often hurt SNR in as many cases as they may have helped."

 

"All my light pollution filters have made their way over to my guide scopes. I stopped using them on my main imagers, but they can help with picking out stars in heavy LP areas."

 

https://www.cloudyni...nswer-is/page-2

 

Most of the effect of light pollution is reduced by gradient reduction in processing.  These filters make sense on emission nebulae (which don't emit much in the gaps).  ONLY.  Even then they distort star color, but for emission nebulae, the gain in contrast is worth it.

 

The image was just to drive the point home.  <smile>

 

Bottom line.  Pretty much all serious imagers use gradient reduction.  Some will additionally use a broadband LP filter, some won't.  Of those who do, pretty much all of them use them on emission nebulae, only.

Edited by bobzeq25, 08 March 2021 - 02:56 PM.

[PederP]

That's NOT what I'm doing.

 

I'm looking at how much of the spectrum an LPro cuts out.  It's substantial.  That will lower snr about as much as cutting out some of the light pollution will raise it. 

 

Most of the effect of light pollution is reduced by gradient reduction in processsing.  These filters make sense on emission nebulae (which don't emit much in the gaps).  ONLY.  Even then they distort star color, but for emission nebulae, the gain in contrast is worth it.

 

The image was just to drive the point home.  <smile>

I just don't see the same thing you do.

Here is a crop and a new edit of the old zoom lens L-pro data.

 

Use it on galaxy too

 

Anyway. If I was a master at gradient removal, I might benefit from giving up the filters. But I have done a comparison that tells me at my current level, L-pro is a great help to get a bit further.

[limeyx]

looking at your image i do not agree..

You are comparing an image from an experienced user, experienced in editing, using a cooled camera and a RASA, to dslr shots with zoomlenses, edited by newbies like myself.

Maybe a more representative sample (and this is FAR from a good image - I am just starting out).

 

Bortle 6, SkyGuider Pro, Nikon D5300 with a 300mm prime 20 year old Nikkor (admittedly not a zoom). This is about my 4th image and I am very slow to pick this up. No filter. 

 

Around an hour of integration. 
Better quality version on Astrobin (although it's an older process of the data)

https://www.astrobin...c7t8/C/?nc=user

Attached Thumbnails

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[bobzeq25]

I just don't see the same thing you do.

Here is a crop and a new edit of the old zoom lens L-pro data.

 

Use it on galaxy too

 

Anyway. If I was a master at gradient removal, I might benefit from giving up the filters. But I have done a comparison that tells me at my current level, L-pro is a great help to get a bit further.

General information, not trying to twist your wrist.  Astro Pixel Processor makes gradient removal easy.  PixInsight has an AutomaticBackgroundExtractor tool, one of the few things in PixiInsight that (on most targets) also is easy, the default settings work pretty good.  You do need to set correction to Subtraction, it's PI weirdness.

 

StarTools WIPE is a bit tricky.

 

All that said, if the filter works for you, by all means continue to use it.  Seriously.

Edited by bobzeq25, 08 March 2021 - 07:07 PM.

[F.Meiresonne]

Why is Startools wipe a bit tricky?

[bobzeq25]

Why is Startools wipe a bit tricky?

I found the sliders both very important and unintuitive.  Once I got it figured out, it was OK, though I'm still not sure I got the best out of it.

 

By comparison PI's ABE is a piece of cake.  <smile>  Not something I'd often say about PI.