M3 Processed in PI...advice and critique please

[ollypenrice]

13 minutes ago, alacant said:

Given another 5 minutes, so would StarTools LOL.

More seriously, it does seem a good package. I must have a look at it.

Of course, now I have to produce a flat, grey background with the cropped data. Uh-Oh! 🤣

Olly

[ollypenrice]

OK, so I ran DBE in Pixinsight to get the background to neutrality - equal values in R, G and B - and reduced the green noise slightly with SCNR then went into Photoshop. Stretched in Levels till the background reached 22 then used curves. Pinned the background at 22 and fixed it below that, then gently gave it a bit more stretch above the background. A few tricks to intensify and adjust the colour, some sharpening of the globular core and here it is. The data are very good. An excellent capture. Tight focus, no tracking errors, low noise. The background was not bad at all, suggesting either a decent site or a very good LP filter! Red and blue stars are well separated in terms of colour.

That was fun! (And it's raining here...) Thanks.

Olly

 

 

[oymd]

20 minutes ago, ollypenrice said:

OK, so I ran DBE in Pixinsight to get the background to neutrality - equal values in R, G and B - and reduced the green noise slightly with SCNR then went into Photoshop. Stretched in Levels till the background reached 22 then used curves. Pinned the background at 22 and fixed it below that, then gently gave it a bit more stretch above the background. A few tricks to intensify and adjust the colour, some sharpening of the globular core and here it is. The data are very good. An excellent capture. Tight focus, no tracking errors, low noise. The background was not bad at all, suggesting either a decent site or a very good LP filter! Red and blue stars are well separated in terms of colour.

That was fun! (And it's raining here...) Thanks.

Olly

 

 

wow Olly

Those colors are beautiful!!

Thank you so much.

I shot this last Saturday night, from my back garden. I live in South West London, Zone 3, so fairly central London. I do not have a LP filter? It was shot stock from the telescope with focal reducer.

Your comments are very encouraging, as I do not have a guiding setup, and this was just using the Sky-Watcher AZ-EQ6 Pro mount with the handset fixed on M3, no guiding. What would guiding then with say, a 290MM Mini had offered?

That looks really nice. Love it!!

So, I have my answer then!

My acquisition and calibration methodology is OK, my image processing is TERRIBLE!!

That will help me focus my effort on going through my PI book and reading it more.

[ollypenrice]

11 minutes ago, oymd said:

wow Olly

Those colors are beautiful!!

Thank you so much.

I shot this last Saturday night, from my back garden. I live in South West London, Zone 3, so fairly central London. I do not have a LP filter? It was shot stock from the telescope with focal reducer.

Your comments are very encouraging, as I do not have a guiding setup, and this was just using the Sky-Watcher AZ-EQ6 Pro mount with the handset fixed on M3, no guiding. What would guiding then with say, a 290MM Mini had offered?

That looks really nice. Love it!!

So, I have my answer then!

My acquisition and calibration methodology is OK, my image processing is TERRIBLE!!

That will help me focus my effort on going through my PI book and reading it more.

I'm astonished - quite literally - that this was unguided. A guider might possibly have tightened up the stars some more. They are round but this does not, contrary to popular assumption, prove perfect tracking. If errors are about equal on both axes you'll get round stars but still lose a little resolution. But would guiding have given you a better result? Quite possibly not on this occasion. It would allow longer exposures on faint targets but CMOS cameras depend far less on this than CCD and your skyglow would limit exposure time anyway.

And then I'm doubly astonished by your location because I've often processed guests' images from light polluted areas and they look nothing at all like yours when opened up. They are literally bright orange. It's often said that OSC cameras are worse hit by LP than mono. Well yours is doing fine! I saw your signature said London but I thought you must have been imaging from somewhere else.

Here's a version with a bit more pop. The JPEG on here looked a bit muddy when I uploaded it.

Olly

PS Sorry, I forgot to fix the bright star artifact, top left. Very easy, though.

 

Edited April 28, 2020 by ollypenrice

[tingting44]

17 minutes ago, oymd said:

that will help me focus my effort on going through my PI book and reading it more.

Hi buddy, did you get the PI book from Rogelio? im dying to order an online copy, just cant justify any purchases right now tho unfortunately