New to mono

[Mike in Rancho]

The latest toy to add to the stable is a mono cooled astrocam, so I am in beginner learning mode all over again. Both as to the cam, and NINA.

So, much experimentation lies ahead. I also still don't have much in the way of filters, or even a wheel/drawer, so am limited and for color I will still be using the Nikon. Both APS-C, which helps with that, but the pixel size is a wee bit different.

I have been taking luminance shots with my UV-IR cut filter. The only others I have are an L-eNhance duoband and my lone SII narrowband.

This was first light, about 43 minutes that I managed to get on M81-82. I think I was testing this as 5C for cooling temp. Oh there were also passing clouds and I don't think I culled all of them out. Or I messed up my flats/light leak prevention...not sure.

M81, 2022-04-18, 87x30L, Orion 6 NA, ZWO ASI2600MM Pro_stacked ST8 1Ags.jpg (435.14 KiB) Viewed 1954 times

Then, after some creative scaling and registration, I took some older D5300 data with the same framing and tried LRGB.

M81 composite L-R-G-B ST8 1B.jpg (476.87 KiB) Viewed 1954 times

This could definitely use some Ha, as we are trying out in Brendan's thread. No Ha filter yet though, and I haven't figured out if I can use some trickery with the L-eNhance. Maybe an LRGB combo with the D5300 that I then split the red channel from? Or just take the mono file and pretend it's all Ha. There may not be much in the way of OIII on this target, and the captured Hb is hydrogen anyway.

[Mike in Rancho]

After that I tried to catch up on our April Challenge target, Silver Streak. Still playing with the Newt, which at only 608mm focal length kind of gives this a Markarian's chain feel to it.

I managed to get 3 hours on target here with pretty good skies, and tried cooling to 0C this time. Also managed to clean my primary mirror prior to this and do a fresh collimation, both of which I think helped a lot, even though I am hindered by the MPCC still.

NGC 4216, 2022-04-21, 180x60L, Orion 6 NA, ZWO ASI2600MM Pro_stacked ST8 1C.jpg (225.76 KiB) Viewed 1953 times

From earlier in April I had some D5300 data with the same framing, albeit this was before the mirror clean and probably badly needing a collimation. I didn't yet try to scale/register these datasets, so not a proper LRGB in ST. Instead for a quick look I just took each finished image into Gimp as layers, where I manually scaled, displaced, and rotated the RGB set until it seemed to line up right, and then chose (I think) the blending mode that only imparted some color while retaining the lum for detail. ST would probably be more primo for this even just as layer operations, but I'd have to do all that scaling and registering first. That may be one of my later experiments too.

180m 2600MM w 150m D5300 RGB.jpg (263.32 KiB) Viewed 1953 times

[Mike in Rancho]

This ended up my "final" combination of 2600mm and D5300 data. I never got back out to acquire more data, but just worked on things when I had a chance. And rather than fiddle with Gimp layers I wanted to do it all in ST. But, as cool as ST Layer is, I couldn't do something similar due to the file resolution restrictions. And the fact that while an x, y displacement feature is included in Layer, scaling and rotation aren't.

Now, ASTAP can align data with different scaling (as well as rotation, flips, mirrors, you name it), but color files can be an issue if they are "stretched out" to match a lum reference. And it doesn't allow you to choose a reference file, unfortunately. So, I still had to use Gimp to scale down the mono lum file (I could have used ST bin also, but the save would only be 16-bit) to match the RGB set. Then I split the RGB into 3 mono fits files. This allowed ASTAP to do it's thing, and spit out my four aligned files for compositing as L, RGB in ST. I really didn't feel the Nikon data was worthy of using for any Synth L.

The "target" was supposed to be NGC 4216, the Silver Streak, but really I think M99 down in the corner stole the show.

NGC4216 180x60L 300x30RGB ST8 1A.jpg (495.9 KiB) Viewed 1895 times

[Mike in Rancho]

Then the other night, after spending some time learning some more NINA but still ending up with really flawed data (unsure why, maybe porch lights?), I swung up for a few minutes on the new nova in NGC 4647. Bad data here too, but I was able to cull some subs and end up with 24 minutes somewhat salvageable.

Really quite cool that thing is (was?) a star actually inside that small faraway galaxy, yet is as bright as many MW foreground stars here.

Mono lum only, no color data.

NGC 4647, 2022-04-30, 12x120L, Orion 6 NA, ZWO ASI2600MM Pro_stacked ST8 1B.jpg (453.96 KiB) Viewed 1895 times

[admin]

That's a lovely result and a great demonstration of the benefits of decoupling color and detail!
It gives you such great flexibility and lets you spend precious exposure time as needed (usually best spent on luminance).

[Mike in Rancho]

Thanks Ivo.

It is kind of cool how all the practice, all the threads, here and on CN, particularly learning and understanding the Compose module, now becomes directly useful to my own stuff.

The luminance captures are turning out to be a lot of fun. The QE of this camera just knocks my socks off, it's pretty unbelievable compared to the Nikon. And not bad at all on the blend, as long as I don't use any DSLR to add into the L as Synth. Though if/when I try some RGB filters, those might have the quality to use as such.

This week's much-needed upgrade though was a new coma corrector. The Baader, oft-seen around here, seems great at f5, but it's been a struggle for me at f4. Last night I tested it out and wrote up a comparison here: https://www.cloudynights.com/topic/8228 ... pstar-95x/

And this was the end-result, again just of a test session and all of 15-minutes integration. Being so short, it is probably a wee bit overstretched which is noticeable around the stars. More time will probably give me more options within AutoDev.

While the settings were essentially the same, the new CC seemed to really lend itself to SVD, allowing both better quality sample selection and better end results than the Baader, even beyond the fact that the stars now resolve into dots that are actually centered with the diffraction spikes. Who knew?

M 13, 2022-05-05, 30x30L, Orion 6 95xCC, ZWO ASI2600MM Pro_stacked SHARPSTAR ST8 1A.jpg (472.25 KiB) Viewed 1806 times

[admin]

Wow, those are some amazing differences - you got to be happy with that!
It's a pleasure seeing you use ST to its full potential!