StarTools

My plans Friday night were to star capturing NGC 1333, but that didn't happen. Now, earlier I made more mods to the Newt including a flocked primary mask and removal of the secondary spider for straightening the vanes. Alas, that apparently failed as during focusing I noticed split ends still plaguing my spikes.

So I just performed a little more surgery right there on the mount, adjusting the spider knobs and then adding a little unbend with some vice grips. This displaced the secondary underneath the focuser, of course, but oh well, that's just a field illumination problem. I recollimated as-is, then with NGC 1333 off the table, thought about a good star for sharp spike testing.

Alnitak!

Seeing and guiding were poor, but I followed this one all the way down to 25° alt! Of course I took my RGB near meridian, then L, and lastly Ha. After culling bad subs, total integration 3.3 hours. 72m L, about 25m each RGB, and 55m Ha. Stacked in WBPP, composited as LRGB with NB Accent.

There's a lot of range here, and thus plenty of options for OptiDev. After a couple flops, I got one that I liked and that didn't throw off SVD with poor apod creation. I also kept in mind that I would later be filling much of the field with NB Accent, and thus trying to stretch out the Ha captured via LRGB was not a priority. SVD seemed to work well despite the short integration, and I only had one little star (Alnitak's close buddy) with ringing that needed deringing repair later using Shrink.

Likewise I adjusted the blue reduction bias in Color to permit a bit more (one mouse wheel click) blue at this stage, in anticipation of the reddening to come. This gave some more strength to the blue giant cores and blue reflection areas to hold off the effects of NB Accent.

That said, nebular NB Accent on this target is still overwhelming, particularly if using pure red. I again used the screen one stretch with that blending in mind, and also lowered second screen strength parameter to 66%. Which also helped preserve both some detail and some orange color in the Flame. Elsewise the Flame just completely blows out from the power of the Ha here, and sliders like brightness correlation were opposite of the way I think I needed it to work here.

Interestingly I had a line on the left side that at first I thought might be an unrejected satellite trail. Then I realized that the line is pointing directly to Alnilam, off screen! A bit fuzzy, but that's way out there from the originating star.

Who would think that Alnilam would trash my HorseHead shot, not Alnitak (which actually stretched out rather well, I think).

Overall, I'm happy with the sharper and straighter spikes, though they aren't perfect. Yet.

I'd say the target is worth capturing more time on, in order to get better and cleaner detail and more stretch on faint nebulosity, not to mention hopefully some better seeing.

Mike, That is quite nice, imho. I really like the difraction spikes on the bright stars , i think they add value to the picture. It could perhaps use a bit more integration time just to reveal a bit the darker clouds under the horsehead.

Certainly a target i want to revisit too, allthough it will not be this year, i have my mind set on other targets. I do have a rather good picture on the horsehead allready allthough it can be much improved.

After weeks not to say months, it looks we will have a clear night in Belgium, wel at least partly, and the coming nights should be good too. Still unsure though, here in Belgium the weather always plays tricks, you are never sure. Temps will be dropping too, below zero C. Sure hope it clears up, Belgians can use some dry weather, many regions have severe issues with flooding, due to the heavy rainfall we had for days, even weeks...

Everyone should have a nice horseyhead! I don't think I will re-shoot it myself this year, but we'll see. Mine from last year was in the early days with my AT130, before I sorted out the light leaks.

I had a similar rouge diffraction spike with my RC6. An out-of-frame Phecda drove me nuts looking for satellite trails, until I noticed that it lined up with the in-frame diffraction spikes. Mine was in a non-nebulous region, so I just used Heal to make it go away.

Yeah not a half-bad horseyhead!

I looked in my archives and found I tried it 3x before. A couple in early 2021 with refractor, while a rank beginner, were quite gruesome. By late 2021 I had a fair horsey with the Newt, via DSLR but also L-eNhance. Now I'm of the mind this really begs for RGB with Ha enhancement.

Yes Freddy I think I will add time when I can. Probably soon, then deem it finished for now. Then I need to get to some more scope mods, since fixing these spikes shifted my illumination field. I've been trying to procrastinate shimming the focuser, but I think that's finally caught up with me.

Good luck on the clear Belgian nights.

Very appealing image, Mike. Stars look REALLY good, Alnitak is rarely handled that well.

The flame is already too red IMHO. But otherwise you probably loose the NBA impact completely. Can you tell how much nebulosity is actually added by NBA? You don't happen to have a before/after image?

I should revisit the target myself since I don't have a decent image. But if there are clear skies I think I'd rather go for M 78 (or M 42 if only a short window in the clouds is forecasted).

Mike in Rancho wrote: ↑Sun Jan 07, 2024 9:00 am My plans Friday night were to star capturing NGC 1333

Why would you do that?

Regards
Stefan

Stefan B wrote: ↑Mon Jan 08, 2024 12:36 pm Very appealing image, Mike. Stars look REALLY good, Alnitak is rarely handled that well.

The flame is already too red IMHO. But otherwise you probably loose the NBA impact completely. Can you tell how much nebulosity is actually added by NBA? You don't happen to have a before/after image?

I should revisit the target myself since I don't have a decent image. But if there are clear skies I think I'd rather go for M 78 (or M 42 if only a short window in the clouds is forecasted).

Thanks! I was expecting Alnitak to be trouble, but it wasn't. Good ol' OptiDev.

NBA is needed here IMO to help fill things out, even throttled back to preserve some orange Flame. I didn't make any kind of saved gif, but of course I used the before and after toggle. But also as noted, since I knew I was going to NBA, I didn't try to stretch out the Ha captured in broadband and kept that in check. I'll see what I can make, though when I revisit processing again - likely after I decide to capture more data.

The Flame is interesting. As I understand things, it is comprised of hydrogen like so much else here, so why orange and not red? Perhaps dust, Alnitak, maybe even some internal stars?

My old duoband of this looks pretty hokey, since everything is just the two colors. But there's a lot here: red Ha wall, orange Ha Flame, several blue reflections, and cool stars. So I think broadband or broadband plus Ha is the way to go.

Stefan B wrote: ↑Mon Jan 08, 2024 12:36 pm

Mike in Rancho wrote: ↑Sun Jan 07, 2024 9:00 am My plans Friday night were to star capturing NGC 1333

Why would you do that?

You mean mangle my spelling? Who knows.

As for 1333, I saw one on the internet. Then by chance it was the CN target last month, but didn't participate. Just trying to catch up! But even if I can't catch the surrounding dust, the reflection and red colors of the main target are pretty neat, and the field has some great star colors.

Mike in Rancho wrote: ↑Tue Jan 09, 2024 7:08 am I didn't make any kind of saved gif, but of course I used the before and after toggle. But also as noted, since I knew I was going to NBA, I didn't try to stretch out the Ha captured in broadband and kept that in check. I'll see what I can make, though when I revisit processing again - likely after I decide to capture more data.

That'd be great if you could do that when you're in a reprocess.

Mike in Rancho wrote: ↑Tue Jan 09, 2024 7:08 am The Flame is interesting. As I understand things, it is comprised of hydrogen like so much else here, so why orange and not red? Perhaps dust, Alnitak, maybe even some internal stars?

I guess we can be pretty sure that the flame is coloured differently than a 'pure' hydrogen emission nebula since basically all broadband images show the flame in a different color compared to the hydrogen wall behind the horse. I also saw it in my old horsehead image (https://www.astrobin.com/om1f7p/?nc=&nce=; don't be too harsh, I was just starting out). My guess would be dust. The German Wikipedia tells that there's a star cluster behind lots of dust; many stars with accretion discs. By the way I also asked ChatGPT and it also came up with the dust...

Mike in Rancho wrote: ↑Tue Jan 09, 2024 7:08 am You mean mangle my spelling? Who knows.

As for 1333, I saw one on the internet. Then by chance it was the CN target last month, but didn't participate. Just trying to catch up! But even if I can't catch the surrounding dust, the reflection and red colors of the main target are pretty neat, and the field has some great star colors.

Didn't even notice the typo You' re right of course with NGC1333 being an interesting target even without the dust. But I won't visit this target for quite some time

Regards
Stefan

As you're discussing the colors of the Flame, I figured I look back at my own from last winter. Your Flame is decidedly more red - maybe a lot more saturated? That is OSC + duoband for NB Accents. I'd have to do some digging to see if I have notes on exactly how I processed it.

[I also realized that I haven't included this in any of my family calendars yet - so it's like having a freebie for the 2025 version (yes, I worry about being able to get 12 new images each year)]

Ok, you forced me into action before getting any new data.

That's a nice HH. Could indeed be a less saturated Flame than mine. Also, for me, it would be lacking some blue. Alnitak should be bluer than most if not all of the Pleiades, no?

But here's my LRGB only, processed the same just no NBA. Hmm, boring. At such low integration, it really needs that separate Ha file.

My Flame definitely became redder using NBA. Though being hydrogen being blended as pure red, I suppose it ought to. I just didn't want to use so much NBA that the Flame washed out and became the same color as the wall, like my old duoband of it.

A few nights ago, right before this most recent atmospheric river, I grabbed a few more hours to essentially double my integration on each filter.

I am still having a bit of trouble with shifted color casts across the image, and so had to take Wipe to 95%. Otherwise I end up green casted on the left and blue casted in the lower right. Maybe something with my flats or the sequence of my filter runs?

I've been doing my RGB close to zenith in three single chunks, followed by L as the target moves along, and then Ha as it starts setting low to the horizon. Or trees in this case. Then I move the OTA back to mid-run to take all the flats. I wonder if I have a little mirror shift doing things this way, causing mismatched vignetting profiles. Maybe I need to rethink my filter sequencing.

Anyway more data allowed more stretch, particularly as to Ha for NB Accent, but I still kept my broadband stretch relatively tame. I just can't readily pick up the brown-colored dust in my skies, which I should have in the lower right below the horsey. My blue cast over there didn't help either.

The NB Accent thus is stronger, which I think shows better coverage overall but also better Ha structure. That said, it does redden the dust, and of course the Flame. But, it is Ha, so what can you do?

Not sure this edit is any better, but it's...different. I also used this as a testbed for playing with the graphic equalizer!


Too red?

I could try the same thing but with the Balmer purple setting....

I am really liking the rainbow pattern on the big spikes tho.