My Omega Centuri attempt

[RyanJones]

Caught a break in the clouds on Friday so I thought I'd give omega Centuri a go :)

60 x 20 sec subs @ iso 400

[raymo]

Hi Ryan, keep at it. It is hugely over exposed, as I'm sure you can see.
It also seems that your focus is off. How are you focusing?
I have attached a pic to illustrate what it should look like. 30 seconds @ ISO 1600 with 200mm Newt.
Because it is so bright you can actually get a pretty good result with a single exposure like this one.
If you do that you can of course see the result immediately on your screen,
and shorten or lengthen your exposure as required.
raymo

[RyanJones]

Hi Raymo,

Yeah, it's definatly over exposed. The focus seemed perfect with my bahtinov filter :(. I'll be honest I'm starting to get a little frustrated :( I don't know what I'm doing wrong but I know a lot of it is in my post processing. I find my self chasing one part of the pic and it's ruining the rest then I try to correct it and I loose the bits I thought looked good. :( I can't seem to get a balance :(

[Imme]

What program are you processing with?

[raymo]

There should be minimal processing necessary at this basic level. Start from
basics. Take one 15 second exposure, enlarge your playback image on your
LCD screen and make sure your individual exposure is well focused.
If focus is good take a couple more, and stack them[in DSS if that is what you are using]. DSS contains all you need to produce a good image at this
basic level. Align the three colour cones, and move them left or right to produce a nice not too dark sky background; reduce the highlight if the core is
over exposed, and saturate the colours to the desired level. All done.
I assume your Bahtinov mask is the correct size for your scope.
As an alternative you can enlarge the stars in LiveView and focus that way.
Its possible your focus is o.k. the pic is so enlarged its hard to be sure, even when downsized on my laptop.

[RyanJones]

I'll keep thst workflow in mind for next time Raymo. Maybe I'm just trying to do too much ( far more than I need ). I have a habit of deleting my subs after I've run them through DSS to keep things tidy. I had another go at it with the TIFF I had. It's better but not perfect.

[RyanJones]

Hi Jon.

I'm using DSS followed by Photoshop CC 2018.

All suggestions welcome :)

[raymo]

If you have enough memory it is a good idea to keep all subs. I went back
over many of my subs from way back, and got better results from some of them, startlingly so in a few cases. I'd take some more, rather than try to
improve these.
raymo

[kosborn]

Don't delete the subs! There's lots to learn and processing is a definite skill. I've gone back to look at data where I didn't like the final result only to find the problem was the processing not the original image capture. Storage is pretty cheap...


Kevin

[RyanJones]

Ok. So the general consensus is don't delete the subs :) check :) I'll sort a way to keep them but keep them tidy. Removable disk etc.

Question to all then. I have found recently that my photos coming out of DSS are very gray and it takes a lot to extract the colour which it didn't before. I'm fairly sure this was after I made some recommended setting changes but I have no idea what ? Now clearly I'm a complete novice at this so does anybody have any suggestions as to what I might have changed to cause this so I don't have to guess at it ( the eany meany miny mo approach is clearly not working for me, I need to revert to knowledge )

[raymo]

They should be grey Ryan. It is then up to you to produce the end result that you want. When the stacked image appears you will see three tall cones displayed in the bottom half of the page. To get correct colour the contours of the cones should be aligned so they look like one cone.
The sliders that move the cones [RGB] are a pain in the ----, ultra sensitive.
To adjust the darkness of the background the cones as a whole have to be moved left or right.Easier to move them one at a time rather
than ticking the "move together" box at the bottom of the screen. Move left for darker and vice versa.] Don't make the sky too
dark as that will remove some of the detail in the image.
Generally a good starting point is to have the left side of the cones
intersect the curved line that starts at bottom left of the screen about 8mm
up from the bottom of the page. When you're happy with that go into
saturation and set the slider to 17, and click "apply" If you are then happy that the background has no overall colour cast, and no part of the image is over exposed you can
alter the colour saturation[set at 17] to suit your preference, and then
you're done. If there is some over exposure, click on the middle option,
[I've forgotten what it is called], between RGB and saturation.
Three pairs of sliders will appear. The upper one of each pair should not be touched. The top one lightens or darkens the the darker parts of the image, and should be set at the outset to 80.
The middle one adjusts the mid range tones, and should start off at 33.3
or thereabouts.
The bottom one adjusts the highlights, and should start off at 50.
So if you want to darken the sky a little, set the top slider to 90 or 100.
If you want to adjust the overall brightness use the middle slider.
If some parts of the image are over exposed, use the bottom slider to
reduce or remove this.
Hope this helped. DSS is pretty basic, and doesn't take long to master.
Incidentally, if there is a red, green or blue overall colour cast, just slide
the appropriate colour cone to the left a tiiiiny bit[very fiddly, often
overshoots]. When making changes to brightness etc: it is not instant, you will see the changes taking place in small rectangular areas.
raymo

[RyanJones]

Thank you for your help Raymo. I really appreciate it. :)
I had just been leaving all that alone but I'll give it a go !
Cheers:thumbsup:

[Atmos]

I've never really used DSS myself but having images come out very grey is something I've heard a lot.

I'll also add that it is very good to keep your data :)

[raymo]

You're welcome Ryan.
Colin, it is the raw result of the stacking that appears, it is not meant to be
a ready to go image that just might require some minor tweaks. The final
result is entirely up to the user of the software.
raymo