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Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 03, 2019 5:50 am
by Merlin66
Marty,
Another factor would be the amount of off band; the further from the Ha CWL the more likely the chance to pick up the Continuum......

Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 03, 2019 10:23 am
by marktownley
Looking at the unstretched pictures taken with the Quark, and then Quark + PST, both are wide bandpass. Be interesting to see what a 'raw' unstretched / no contrast full disk looks like with your PST. Personally I think you have 2 'wide' etalons. Here's a shot with my Quark double stacked with a naked PST etalon on my ED80 from 2017.

Imageha-active-regions-q80-colour by Mark Townley, on Flickr

Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 03, 2019 1:16 pm
by MalVeauX
Good point about being on band. I'm probably off-band a little. I usually try to push towards the blue side as it seems to have more contrast on the surface. But that was the Quark by itself. If I ever get a clear day, I will try to tune the Quark and the PST and try to document it with different examples at the limb. That could very well be the problem! I figured if my filaments were dark, it was on band, but maybe it's not?

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 03, 2019 2:02 pm
by Bob Yoesle
Looks like you nailed it Mark! Your greyscale is perfect:

https://www.flickr.com/photos/brierleyh ... otostream/

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 08, 2019 5:43 pm
by MalVeauX
Heya,

I managed to test a little bit today. I tried tuning the Quark differently to see if I could match the PST. I usually tune the Quark to 9 o'clock as I find it has more contrast there. Tuning the Quark at 12 o'clock was my first round of testing, but then clouds came in. I think it helped a little? Didn't solve the issue with the double limb, but I think it improved it. So maybe I'm just not tuned to match on each etalon quite yet?

I also noticed in some places I could see the double limb, and in others, it seemed to be supressed. Maybe some kind of sweet spot? Or an issue with tilt or being on/off band? Not uniform?

Image

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Image

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 08, 2019 7:28 pm
by marktownley
I think this is an improvement Marty, that first image is a cracker!

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 08, 2019 11:27 pm
by Bob Yoesle
These are a major improvement Marty! Very much closer to being on band I would say.

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 09, 2019 7:29 pm
by MalVeauX
Some more testing today.

I left the Quark at 12 o'clock and then just tuned the PST a little back and forth to see what would happen. It would basically go from a featureless grey smear to a starkly over-exposed white. So between the two I just went for the most uniform across the FOV with contrast. Tested it on the limb and on the current AR to compare to yesterday's. Still a hint of the double limb present I think.

Image

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Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 09, 2019 8:35 pm
by marktownley
You're getting there Marty. Like I mentioned, I think both of your etalons have a wide passband. You're doing a lot of stretching / contrast etc in your post processing which I think also enhances the ghost of the double limb.

When I double stack in the quark and PST my tuning process is to tune the PST etalon to get uniform illumination, then to tune the quark to get onband.

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 09, 2019 9:11 pm
by MalVeauX
Thanks Mark, that's a good point about starting with the PST and then the Quark for tuning. I'll try that next session.

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 10, 2019 2:58 am
by Valery
MalVeauX wrote: Wed Jan 09, 2019 9:11 pm Thanks Mark, that's a good point about starting with the PST and then the Quark for tuning. I'll try that next session.

Very best,
Due to a small size of a PST sweet spot, this will probably work only for a very narrow FOV.

Valery

Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 10, 2019 6:37 am
by marktownley
Valery wrote: Thu Jan 10, 2019 2:58 am
MalVeauX wrote: Wed Jan 09, 2019 9:11 pm Thanks Mark, that's a good point about starting with the PST and then the Quark for tuning. I'll try that next session.

Very best,
Due to a small size of a PST sweet spot, this will probably work only for a very narrow FOV.

Valery
The PST etalon is in a telecentric beam so i'm not seeing a sweet spot Valery in my setup (f43 or f32)- sweet spot is only in a collimated light beam.

Re: PST Etalon with a Quark, Log & Results

Posted: Thu Jan 10, 2019 2:38 pm
by Valery
marktownley wrote: Thu Jan 10, 2019 6:37 am
The PST etalon is in a telecentric beam so i'm not seeing a sweet spot Valery in my setup (f43 or f32)- sweet spot is only in a collimated light beam.
Hah! I thinked that you adviced to use a PST etalon in it's native F/10 - collimation - refocusing mode and then use a Quark with it's telecentric! My mistake.

Re: PST Etalon with a Quark, Log & Results

Posted: Sat Jan 12, 2019 7:19 pm
by MalVeauX
Heya,

Had a chance to try and test tuning again. I tuned the Quark far blue and far red to see which direction was the closest to match the PST etalon. The red shift was the worst of the two directions. The blue shift, all the way, where my Quark is normally sitting, was off a bit too. But I found around 10~11 o'clock on the Quark and a little gentle sweeping through the pressure range on the PST etalon allowed me to get a little closer to being on band. Still not quite there. But maybe a little closer than before? I started marking on the components where to align them so I know where to start next time and will keep testing and tweaking what can be done with this.

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Quark_PSTEtalon_Tuned.jpg
Quark_PSTEtalon_Tuned.jpg (116.43 KiB) Viewed 8629 times
Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Sun Jan 13, 2019 11:14 am
by marktownley
They're all good but I do like number 4. Any chance you could put an unprocessed (straight from stack) version of this image? I'm curious as to what your raw data looks like before processing.

Re: PST Etalon with a Quark, Log & Results

Posted: Sun Jan 13, 2019 1:19 pm
by MalVeauX
marktownley wrote: Sun Jan 13, 2019 11:14 am They're all good but I do like number 4. Any chance you could put an unprocessed (straight from stack) version of this image? I'm curious as to what your raw data looks like before processing.
Sure thing,

Here's the Quark on it's own and the Quark + PST Etalon, no processing, just raw output from 100 frames stacked.

Quark (single):
Exposed to fill histogram to try to get as much into one shot as possible to test processing.
Quark_SS_Limb_01.jpg
Quark_SS_Limb_01.jpg (82.74 KiB) Viewed 8600 times
Quark + PST Etalon (double):
Exposed to fill histogram without clipping to again get as much into one shot as possible to test processing.
Quark_PST_DS_01.jpg
Quark_PST_DS_01.jpg (119.25 KiB) Viewed 8600 times
Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Sun Jan 13, 2019 8:48 pm
by george9
Very nice improvement. There was a bump of a prom with a filaprom to a subtle AR below it today (much like what I see above), but if these were taken yesterday, it would have moved by now. Amazing what the processing brings out (earlier post).

George

Re: PST Etalon with a Quark, Log & Results

Posted: Sun Jan 13, 2019 10:21 pm
by MalVeauX
Heya,

I tried some more tuning options and processing options and I'm happier with the results today on the limb. Even though the double limb is not 100% eliminated, it makes processing it out a lot easier and more natural looking to me at least. Here's today's results under really excellent seeing (the limb was a treat to just watch despite no major features):

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Mosaic made with an ST80 masked to 60mm with the same imaging train. 4 images stitched together.

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SolarSetup_ST80_01132019.jpg
SolarSetup_ST80_01132019.jpg (91.03 KiB) Viewed 8570 times
Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Sun Jan 13, 2019 10:33 pm
by marktownley
Spot on Marty!

Re: PST Etalon with a Quark, Log & Results

Posted: Sun Jan 13, 2019 10:44 pm
by MapleRidge
Hi Marty...

These images are really sharp and the limb details show so much detail despite being such small proms. Your setup is working very nicely :bow

Brian

Re: PST Etalon with a Quark, Log & Results

Posted: Sat Jan 19, 2019 7:27 pm
by Bob Yoesle
Hi Marty,

Upon reflection and going back to some references, I believe there could be a couple of things going on with your images. The recent images are better with regard to the double limb, but it is still subtly revealing itself. According to Bray & Loughhead in The Solar Chromosphere (1974, page 19):

A second consequence of tuning the filter progressively further into the wings of the line is the eventual re-appearance of the photospheric limb, even in the absence of of parasitic light. ... high-resolution observations show that the photospheric limb first begins to re-appear at Ha +/- 0.65 A... As one moves further out from the centre line, the photospheric limb rapidly becomes more prominent and appears as a sharp regular boundary crossed at irregular intervals by isolated chromospheric features (Plate 2.8)... If the bandwidth of the filter is sufficiently broad it follows [from the foregoing] that the photospheric limb will be present, regardless of the wavelength setting of the filter.

Plate 2.8 SM.jpg
Plate 2.8 SM.jpg (57.81 KiB) Viewed 8394 times

From your images, the presence of the double limb can represent that the filter system bandpass is perhaps a bit too wide to completely eliminate parasitic continuum from the photosphere. However, it seems to be more likely that you simply are tuned a little too far off the H alpha line. I have noted many of your images look somewhat "peculiar." I thought this might be due to excessive processing as noted by Mark. I believe the plates below demonstrate you may indeed be +/- 0.5 A or more off-band with most of your images, which seem to show the "dark mottles" that are more prominent off-band, but which are largely absent when on-band:

Plate 2.5 SM.jpg
Plate 2.5 SM.jpg (65.48 KiB) Viewed 8394 times
Plate 2.6 SM.jpg
Plate 2.6 SM.jpg (66.66 KiB) Viewed 8394 times
Plate 3.1 SM.jpg
Plate 3.1 SM.jpg (72.96 KiB) Viewed 8394 times
Plate 3.4 SM.jpg
Plate 3.4 SM.jpg (75.13 KiB) Viewed 8394 times

The predominance of the dark "spiky" mottles in your (positive) images appear to reveal you are perhaps +/- 0.5 A off-band as seen in Plate 2.6 and 3.4, and the double limb might indicate you have some additional leaking continuum from filter band-pass issues (e.g. transmission profile "wings"). On the other hand, you might be tuned closer to +/- 0.65 A, and the double limb would be present no matter what the filter system bandpass is.

The only way to tell if you have a band-pass issue (continuum leakage) is to get tuned on-band, and if you are not seeing a double limb, then you have very good double stacked filter performance, and going off-band and seeing the double limb is normal.

Re: PST Etalon with a Quark, Log & Results

Posted: Sat Jan 19, 2019 7:51 pm
by marktownley
MalVeauX wrote: Sun Jan 13, 2019 1:19 pm
marktownley wrote: Sun Jan 13, 2019 11:14 am They're all good but I do like number 4. Any chance you could put an unprocessed (straight from stack) version of this image? I'm curious as to what your raw data looks like before processing.
Sure thing,

Here's the Quark on it's own and the Quark + PST Etalon, no processing, just raw output from 100 frames stacked.

Quark (single):
Exposed to fill histogram to try to get as much into one shot as possible to test processing.

Quark_SS_Limb_01.jpg

Quark + PST Etalon (double):
Exposed to fill histogram without clipping to again get as much into one shot as possible to test processing.

Quark_PST_DS_01.jpg

Very best,

Try your stacking with 'cropped ' selected on AS3 Marty 👍

Re: PST Etalon with a Quark, Log & Results

Posted: Sat Jan 19, 2019 11:27 pm
by MalVeauX
Thanks all,

Will test more as soon as these storms pass!

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Sat Jan 19, 2019 11:38 pm
by Merlin66
Marty,
I've started to play "seriously" with imppg to hopefully improve my processing skills.
One thing I do notice is that depending on the processing I can "pull" the double edge out of almost any image....
As per my previous early comments I think CWL on Ha is a clear winner to reduce the double edge but it may also be aggravated by your processing techniques?
Just trying to help.....

Re: PST Etalon with a Quark, Log & Results

Posted: Sat Jan 19, 2019 11:48 pm
by Merlin66
Here's the above DS jpg file in a quick (not perfect!!) run through ImPPG.
Marty_Quark_PST_DS_01_imppg.jpg
Marty_Quark_PST_DS_01_imppg.jpg (141.73 KiB) Viewed 8369 times

Re: PST Etalon with a Quark, Log & Results

Posted: Mon Jan 21, 2019 5:04 pm
by MalVeauX
Yea, I'm sure I'm aggravating the limb with processing. I'm trying different approaches to see if anything can work without blasting the double limb as bad.

I agree I'm probably still not perfectly tuned on band. It's hard to know where I am with the tuning since there's no guarantee what any particular setting is on either etalon. And the number of combinations of each setting on the Quark versus the PST etalon is a significant number to test. Basically I need to just put my Quark on a setting, then slowly tune through the PST etalon and see real time what happens on the limb. I need some long sessions for this, the weather has not been playing nice.

Hopefully I can test this soon!

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 22, 2019 10:06 pm
by Bob Yoesle
One thing I do notice is that depending on the processing I can "pull" the double edge out of almost any image...
Hi Ken,

For me it was a long learning curve to discover exactly what an on-band image should look like. I still have trouble at times, especially in the typical relatively poor seeing I have, to take the time needed to perfectly tune two etalons, which seems at least 4-6 times more difficult than tuning a single etalon. Perhaps more significantly, in my experience consumer H alpha etalon quality in the past few years seems to have decreased due to needing to make etalons more affordably.

Added to this - at least for my air-spaced etalons - is that changes in barometric pressure and temperature can have subtle but detectable changes in the CWL of the filter system. So while I may start pretty close to exactly on-band, later I may need to make some fine adjustments to optimize the tuning due to these pressure and temperature changes, which can effect both the refractive index of the etalon gap, and change the spacing of the etalon plates themselves via spacer expansion and contraction.

This might be one area where the solid-spaced temperature tuned etalons may prove a little more stable under changing atmospheric conditions. The downside is the lag time in making tuning changes, and perhaps the accuracy of the temperature setting reflected in the wavelength display (if present). On the other hand, I don't really know how sophisticated the temperature regulation of these etalons is, and what if any changing thermal related gap spacing might result in over time.

See if you can pull the double limb out of one or more of these images. They are some of my better unprocessed and minimally compressed jpeg conversions of the 900 mm and 1800 mm FL tiff files out of Registax, using double stacked pre-Meade SM90 etalons:

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 23, 2019 12:36 pm
by marktownley
Those double stack 90s are sublime Bob. Very Jealous!

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 23, 2019 2:07 pm
by Bob Yoesle
Thanks Mark - I was lucky to be able to get these etalons when such quality was available and still relatively affordable.

I should note that the above images were wavelet processed in RegiStax6, but had no additional post processing, and the their RG630 ERF's were replaced by a single Baader DERF for improved IR rejection and image brightness.

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 23, 2019 3:14 pm
by bart1805
Wow, they look way better than all of my processed images. So agree with Mark: jealous!
About the double limb. If there is no double limb visible in the images it is not possible (in my opinion) to make it visible. It simply is not there.
But if you have an image of a normal single stacked etalon, you see the double limb. And if you proces "hard", use a lot of contrast and gamma for example, you can make it disappear. Off course it is still there, but not visible in the processed image. I personally don't really like these kind of images, but that is just a matter of taste.

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 23, 2019 7:28 pm
by MalVeauX
Heya,

Played around with tuning today a little. Had a chance to see if I could do some tests between clouds, which I was lucky to have some decent seeing and some finally fairly good weather and a nice new sunspot has evolved, so a great way to test tuning. I can't seem to eliminate the double limb. However, I can definitely see differences in the tuning with respect to sunspots, where the double stack removes more of the umbra, and in the single stack the umbra are very visible and dark. Quite interesting.

Single stack (Quark only):

Image

Image

Double Stack (Quark & PST Etalon):

Image

Image

And here's a double stack of the filament and proms (the limb is worse compared to before):

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++++++++++++++++++++++
++++++++++++++++++++++

Here's a limb + prom + new AR example, unprocessed other than stacking and a little histogram/level adjustment to see the limb:
Limb_Example.jpg
Limb_Example.jpg (123.75 KiB) Viewed 8291 times
Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 23, 2019 9:04 pm
by marktownley
The limb shot is excellent Marty. Don't worry about the ghost / residual of the double limb; with the etalons you have you are on peak performance. The only way you are going to improve is by doing what Valery does and try many etalons and cherry pick the best. There's nothing wrong with the images you are getting.

Re: PST Etalon with a Quark, Log & Results

Posted: Fri Jan 25, 2019 4:46 pm
by MalVeauX
Another go at AR2733 with the Quark & PST Etalon tuning testing.

Here's the limb & prom (Quark & PST etalon):

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Here's AR2733 with just the Quark (visible umbra):

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Here's AR2733 with the Quark & PST etalon (umbra are no longer visible):

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Image

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Fri Jan 25, 2019 11:04 pm
by MapleRidge
Hi Marty...

These recent additions look great, especially the structures in the faint prom.

Well done :bow

Brian

Re: PST Etalon with a Quark, Log & Results

Posted: Mon Jan 28, 2019 6:48 pm
by MalVeauX
Heya,

Tested some more today with the Quark & PST Etalon.

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Image

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Mon Jan 28, 2019 11:30 pm
by MapleRidge
Marty...

These latest images look great!!!

Brian

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 5:08 pm
by MalVeauX
More from today with AR2733 & the double stack:

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Image

Image

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 5:25 pm
by Bob Yoesle
Now you're cooking Marty! Pretty much right on band to me. The normally processed greyscale bright and dark mottles look exactly as they should, and there is no discernable double limb.

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 9:28 pm
by MalVeauX
Thanks, :bow

I've marked on the two etalons where to orient them for consistency. I still tweak here and there, but ultimately it seems to be best at this position.

The above were at 10ms exposure time, no gamma (neutral) and gain is running 160 to 200 for these, filling histogram into the 60~70% range.

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 9:55 pm
by Astrophil
Marty, those are really really great images. You have that system working well. Congrats.

Phil

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 10:04 pm
by MalVeauX
Thanks Phil,

I have the C8 Edge & 214mm tri-band ERF. Just waiting for the filter holding cell to arrive from Germany.

This system will then transfer to that new setup. I will probably try it reversed with the PST etalon with its collimating lenses in the F10 beam of the C8 and then the Quark after, to maybe do a better job (with the blocking filter being last and likely more ideal I would think?).

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 10:05 pm
by marktownley
I think you will do well with the edge HD, your seeing is better than mine.

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 10:15 pm
by MalVeauX
Hoping so! I love my 6" refractor, but I'd like to use something a little bigger and something color-free for planets and night astrophotography. The big old achromat is great in narrowband, but it's not great for visual spectrum on bright subjects. Can't complain, this 6" telescope was $250!

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 10:43 pm
by Valery
MalVeauX wrote: Tue Jan 29, 2019 10:04 pm Thanks Phil,

I have the C8 Edge & 214mm tri-band ERF. Just waiting for the filter holding cell to arrive from Germany.

This system will then transfer to that new setup. I will probably try it reversed with the PST etalon with its collimating lenses in the F10 beam of the C8 and then the Quark after, to maybe do a better job (with the blocking filter being last and likely more ideal I would think?).

Very best,
Hi Marty,

C8 Edge will not work properly with PST etalon in it's native confifuration. Back space of this telescope is less than required 200mm+

So, the best is to work as with 6" refractor: Quark Chromosphere will work at F/43 (very nice for narrow bandwidth) + 0,6x reducer + IMX174 camera. You can add PST etalon naked (no it's native lenses).

Good luck.

Valery

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 10:45 pm
by Valery
MalVeauX wrote: Tue Jan 29, 2019 10:15 pm Hoping so! I love my 6" refractor, but I'd like to use something a little bigger and something color-free for planets and night astrophotography. The big old achromat is great in narrowband, but it's not great for visual spectrum on bright subjects. Can't complain, this 6" telescope was $250!

Very best,
I see you never looked through a 6" F/8 achromat + ARIES Chromacor-I or II ! They both are gamechangers in such a combination.


Valery

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Jan 29, 2019 10:47 pm
by MalVeauX
Good to know Valery, thanks, so my configuration will remain as it is here when I move it over to the C8.

I'm sure a Chromacor would be nice. But, at the end of the day, the C8 Edge is more compact (less moment arm) than my huge refractor and has more resolution for imaging purposes.

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Wed Jan 30, 2019 6:08 pm
by Astrophil
Marty, I'm sure you get the C8 working well. Looking forward to seeing your results.

Phil

Re: PST Etalon with a Quark, Log & Results

Posted: Fri Feb 08, 2019 4:36 pm
by MalVeauX
From this morning with the 150mm and the Quark & PST etalon:

Image

Image

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Image

Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Feb 12, 2019 3:39 pm
by MalVeauX
Here's some RAW stacks with only histogram stretching and a little deconvolution via IMPPG from the previous data set with no other processing performed. This is the Quark + PST etalon. These are 180 frames stacked each (out of 2000).

prom_ds_crop_01.jpg
prom_ds_crop_01.jpg (89.86 KiB) Viewed 7889 times
prom_ds_crop_02.jpg
prom_ds_crop_02.jpg (114.24 KiB) Viewed 7889 times
Very best,

Re: PST Etalon with a Quark, Log & Results

Posted: Tue Feb 12, 2019 7:32 pm
by marktownley
Love these raw stacks Marty! But, then you can probably tell from the images I post I err on that side of things with my processing...

You have the etalon combination nailed!