First time in imaging this one, I have a feeling that it is considerably larger than the area that I have done, even if it isn't, there appears to be a fair bit of Ha surrounding this region.
Lost about an hours data throughout the night due to the auto guider dropping out (connection loss). Not sure why it does it, it isn't running through a hub or near any electrical wires. Hopefully won't be an issue in the coming weeks.
It is a bright region so I may just leave it where it is data wise, could add a lot more time to get better SNR but there isn't much faint stuff to worry about. There is only one remotely dark region in the field towards the top left.
Tried adding synthetic RGB stars (combining in HSO), it has worked to an extent on some of the brighter stars but it has also been dulled down a bit as I removed the ringing artefacts. Happy with the result for now though.
Replaced one of two potential flexure areas in the imaging train, tilt has moved from being diagonal (top right to bottom left) to just being at the top now. Looks like I will need to get a Precise Parts part made to remove it. OR it is slight tilt in the sensor as it feels stiff at the moment.
Sharpness, colour, and contrast in the nebulosity are superb.
Wouldn't worry about the image plane tilt - I can't see it myself.
The rings around the stars do need work.
Very best,
Mike
Thanks Mike, totally agree on the stars. I think the best way is to reprocess the colour data again
Just realised that the visible tilt disappeared because of the meridian flip. This means that it isn't flexure as much as it is a repeatable error in the system. Not sure but it may be the compression ring on the rotatable focuser; tighten the knob to stop the rotation. May need to use a screw driver to equally tighten the focuser in place or at least heavily stiffen it.
Thought comes from my previous telescope which suffered from the same problem, the focuser tightening knob caused 0.1-0.2mm tilt. Who knows when the next clear night in Melbourne will be!
Quote:
Originally Posted by RickS
Very sharp indeed, Colin!
Thanks Rick, think I need to play around with your colour mask script a lot more
Apart form the dark star rings...not bad Col Given you used 3 filters it is looking a tad yellow-blue bi-colour in appearance maybe you could bring out the third colour a little more? It might look a little less harsh with just a bit less sharpening too anyway you could try just out of interest but I like your FOV there though, just right really for this object...mine is a bit smaller than I would like
Apart form the dark star rings...not bad Col Given you used 3 filters it is looking a tad yellow-blue bi-colour in appearance maybe you could bring out the third colour a little more? It might look a little less harsh with just a bit less sharpening too anyway you could try just out of interest but I like your FOV there though, just right really for this object...mine is a bit smaller than I would like
Mike
It is a tad green isn't it, I just used the whole image as the White balance and didn't play with the colour after that. Planning on having another crack at the colour to see if I can reduce the ringing around the stars. Still trying to figure out the best way of dealing with the stars without causing other ring artefacts around the stars. Still so much to learn
The very last thing I did on the luminance before combining it with the colour was run a relatively weak UnSharp Mask. I was unsure whether to use it or not but I figured I'd go all out and remove all softness hehe
Your FOV is smaller than mine and I feel mine is too small. If I could afford it I'd love a 16803 One of the reasons I bought this scope is that it has a 55mm corrected circle!
Quote:
Originally Posted by glend
I think it looks fine but i would dial back the magenta so the star halos are dissapated.
Totally agree Glen, my star processing leaves a bit to be desired
Not a bad narrowband there. Those blue star halos are they from the O111 layer? You probably need a star mask on your O111 layer so the stars are excluded to prevent the ringing. Narrowband can be prone to odd effects like that. Your O111 may've been a bit out of focus and the stars were larger than in the Ha. With my Astrodons I focus using the luminance and luckily the Ha O111 and S11 seem to be parfocal as focusing narrowbands by themselves is a bit slow and tough to do.
I saw your image last night when I was looking for something to image and I decided to image it so thanks for the inspiration. That vertical wall is an interesting feature.
Not a bad narrowband there. Those blue star halos are they from the O111 layer? You probably need a star mask on your O111 layer so the stars are excluded to prevent the ringing. Narrowband can be prone to odd effects like that. Your O111 may've been a bit out of focus and the stars were larger than in the Ha. With my Astrodons I focus using the luminance and luckily the Ha O111 and S11 seem to be parfocal as focusing narrowbands by themselves is a bit slow and tough to do.
I saw your image last night when I was looking for something to image and I decided to image it so thanks for the inspiration. That vertical wall is an interesting feature.
Greg.
The halos are caused by both the SII and OIII, both having larger stars than the Ha. I do focus each filter individually using a bahtinov mask. I have been considering trying to use FWHM values to see if that works better. 1-2s exposures on a bright star are more than enough for narrowband focusing with the bahtinov mask but it doesn't seem to be working for me. They've been in every narrowband image I've taken with this setup so far so it could be something else to try.
Glad it aided to inspiration, wish I had Andy's FOV though
Quote:
Originally Posted by rustigsmed
nice prawn (and the little gem) Colin - excellent field. as you have and others have noted, just the stars could do with some attention later.
Thanks Russell. I did a rework a couple of hours ago, got to the point of saving and then PI crashed on me! GRRRR
It might be easier to open in photoshop, (as you probably know)
IMAGE -> Adjustment -> Selective Colour - magenta slide down... took me 15 seconds.
i can appreciate you working on your PI workflow/halos, however. (this wasn't slid all the way down about 75% less magenta)
It might be easier to open in photoshop, (as you probably know)
IMAGE -> Adjustment -> Selective Colour - magenta slide down... took me 15 seconds.
i can appreciate you working on your PI workflow/halos, however. (this wasn't slid all the way down about 75% less magenta)
Now that just makes me feel bad!
Having never really used Photoshop I have a MUCH better grasp of PI than I do any other image editing software. Actually use PI for my normal photos as well if that gives you some idea of how little I've used PS
Not bad Colin apart from the stars (always an issue with NB). One simple way to improve it of course is to select the stars and desaturate the magenta.
Not bad Colin apart from the stars (always an issue with NB). One simple way to improve it of course is to select the stars and desaturate the magenta.
Cheers
Steve
I had tried that, the problem I am getting with that is that I have been trying to preserve the colour of the stars and as the rings are more saturated than the star, the rings are more difficult to remove. Have even tried making ring masks by subtracting a smaller mask from a larger and then multiplying the resulting mask. Had some success but not to a point that I was happy.
At any rate, been through and spent the last few days on and off working on star masks. Think I have finally got there! Have the stars at a point that I am happy and just for you Mike, I have gone and taken away the final Unsharp Mask
Nah just some purple stars..a little magenta in stars looks good in narrow band images IMO but it might just be a bit too purple and a little stark here and as you say the small stars are purple.
I do agree with the magenta stars, they don't bother me, unless they have rings and begin to look like thousands of little eyes peeping back at you! (have the first rendition in mind )
I've gone and done a DePurple/Magenta, dulls them down a bit and makes them less intrusive. Ideally I would like much smaller stars as some of them are quite large but for this I would require a nice tall mountain to get above the atmosphere This version is more of a proof of concept as I was overly kind (no mask, found hue and then desaturate!).
My next goal in star masking is actually to be able to select those tiny little ones. So far, not much success! Luckily they only problem they cause is being a bit overly saturated for personal tastes.
Out of version B and C, I actually prefer B, even disregarding the butchering of C (late night laziness ). Thanks for your keen eyes Mr Mike
It's a bit painful to do but removing all the stars from the NB images for the colour combine produces really nice results, Colin. That's the real core of JP Metsavainio's tone mapping technique. Now that you're a ninja master at star masks it should be easy. I mask the stars then hit them with repeated MMT (remove a few small scale layers) and MT Erosion.
...a giant prawn 
Given you used 3 filters it is looking a tad yellow-blue bi-colour in appearance maybe you could bring out the third colour a little more? It might look a little less harsh with just a bit less sharpening too 
anyway you could try just out of interest but I like your FOV there though, just right really for this object...mine is a bit smaller than I would like 
One of the reasons I bought this scope is that it has a 55mm corrected circle!
