happy-kat

The inverted image looks like great desktop wallpaper potential

I like the annotated image as well. What telescope lens did you use?

That's a great capture and work around of the CA.

With a DSLR a dark flat is the same everything as a flat but with the lens cap on. Darks are the same as the lights but with the lens cap on. I  haven't read yet to check if there are differences to this for an astro camera seeing as in general both are CMOS.

The name is very apt

Last night the sky was quite murky  but I managed to try out using the evoguide with the ASI462 and sharpcap. I didn't quite finish learning/applying the Brain function to use what that considers the optimum setting for the camera. The sky was too murky to have any success using the Y mask so will try it again when the stars are clear and much brighter so focused manually. 

I set sharpcap to livestack but also save the individual files which I then stacked in DSS, 5 seconds x35 frames with no calibration files using the virtuoso v1 and evoguide with FFv2. Tonight I would have tried again but the sky is so bright I cannot see any stars anywhere and there's no Moon. I used rubber bands to fix a red dot finder to the ASI462 and was able to complete alignment using that in conjunction with the Sharpcap display. The main purpose was to have a go using this camera for DSO galaxy captures as an alternative to the DSLR, nothing lost in having a go with what I have, binned the image 50% in processing in StarTools.

The evoguide is too short in the available back focus for using most diagonals, none of my existing diagonals worked there was a thread testing this, apparently a shorty barlow used in front of the diagonal may give enough back focus to then reach infinity focus I have yet to try that with mine.

I use a red dot finder mounted in the camera flash hot shoe, this gets the aim reasonable onto the target area, then I use an android device connected to the canon DSLR using the USB lead with an OTG cable and the app is DSLR Controller (it may support your canon), gives me the ability to both control the camera but also get a big screen to see more stars in to fine tune both focus and what I am pointing at. Just a red dot finder in your hot shoe may be the bit to help you without more tech.

On my synscan mount with the wifi dongle I'm using 1 star alignment, choose the star centre and accept then I go straight to 1 star alignment again and choose a different star (have restricted views) centre and accept and repeat selecting 1 star alignment again choosing either another star or the first star then centre and accept. This method of building my own stars for aligning with what I can see on a given night has so far given me good goto.  For the OP with alignment issues.

Went to look outside yesterday and the sky was clear but so murky Regulus was barely visible so abandoned that. Another clear night tonight and an improvement on yesterday, though pretty murky still. Setup as a test of getting alignment working for me. Usually I'm hampered by choice of star that I'm offered for the sky I can see with two star alignment but I got around this by using one star alignment. Chose the star Denebola, crude RDF sighted the star and fine tuned using the camera which was left setup in the evoguide and a nice big view on the 7" tablet connected. Then did another one star and chose Procyon, the slew had it quite close to the centre of the tablet screen just needed a slight tweak. Repeat and choose Denebola again and almost perfect, repeated Proycron and it was spot on, as was Denebola. Since switching to using the wifi dongle and now this method I've cut setup time significantly and goto was subsequently spot on certainly in the 120 degree span of the sky I can use. 

Could try (for purple stars), layer module invert foreground purple turns green, go to colour module cap green 100%, layer module invert foreground.

That's pretty good at disguising that there was any chromatic aberration there at all.

You have a larger sensor in the 550d and larger pixels, I think in comparison an imaging camera in budget would give you a letter box view of your currently attainable wide field of view with your DSLR. Have a look using the imaging resource on a favourite target.

Though galaxies can be smaller and you'd get a tighter view on those targets with a smaller sensor and pixels. The astronomy tools in the resources bit of the site.

Interesting, I'll look again when on desktop. I take it you processed as OSC and didn't split the channels to get at the blue directly.

Thanks for sharing your scratch pad.

With reference to my experience with an altaz mount imaging to the South and North in the NH is most demanding and star trails show quicker. Orion and family are very much in the South now, if you setup to image to the East with the same equipment would you get 1 minute exposures you were OK with?

I realise you are using an EQ mount but thought it might still be worth commenting.

after recentering the star do you then pick the icon to say this is where the star is? and you are using the least powered eyepeice? biggest number likely a 25mm

you could use left and down too far so that could end in up and right to centre the target using lowest power ep

Another is the yatton yellow #13 I think though I've never tried it. 

Another idea would be to process the image and using Heal create a star less image to process the nebula. Then start again and using develop a conservative stretch for the stars mask and save (the pdf manual has how to use Heal module for starless image may need a couple passes), then use the Layer module to combine the stars back (without the bloat).

I've found its about managing the CA and making it less obvious, getting rid totally is perhaps less obtainable, stopping down is one option as is just being off focus making CA less strong.

You should be able to tighten the blue up using the notes method I think as you work just on that channel.

There are some tips in the startools forum under user notes on special techniques, covers CA.

My current preference is to using a mask exclude the CA prone stars from the colour module so they remain in luminance state, though the user notes allows for fine tuning of the blue bloat.

As I had a new processed image (though work in progress as will process it again) from using no spacers in my setup thought to add it here for reference too. As I use an altaz mount the final dimensions are driven by stacking on intersection.

50ED Evoguide | EVEFF-V2 | Canon 1100d | ISO 1600 | Virtuoso V1 | 117 lights | 121 flats | 115 dark flats | 26 minutes 13 seconds | predominantly 15 seconds

Captured December 2021 and stacked many times and flats plus dark flats are the current blend with lights for best results. I am still trying different combinations and will likely process the data many times as it is as Pleiades is too far South now for getting more data. Way many flats and dark flats but was experimenting. DSS + Startools. Image is not clipped but I was fairly aggressive with removing background gradients, local street lights bortle 5.

50ED Evoguide | EVEFF-V2 | Canon 1100d | ISO 1600 | Virtuoso V1 | 117 lights | 121 flats | 115 dark flats | 26 minutes 13 seconds | predominantly 15 seconds

Not extending the tripod legs fully helps with stability