matt_baker

It's been a while! I've been busy but now I'm back with a bang. Here's some Pelican Nebula data that I took in September that I've finally managed to get round to process. Hope you enjoy!

P.S. Don't mind the pesky OIII halos

43x300" Ha
24x300" OIII
Camera: ZWO ASI 1600MM Pro
Telescope: TS Optics 90mm CF Triplet
Mount: Skywatcher HEQ5 Pro

https://www.mattsastro.co.uk/portfolio

I'd say when you've done your linear stage and transferring into the non-linear. Don't do a harsh stretch, just enough to keep the stars in good shape then mask them out to just focus on the nebulosity from that point onwards

Congrats, guys!

Always a pleasure to work with such good data sets from IKI

I've managed to fix it, last time I just wasn't patient enough with the tiny adjustments to get it almost spot on with the backlash

I'm physically rocking it back and forth and it moves quite noticeably but not a ridiculous amount 

Always noticed on my HEQ5 Pro that the RA axis has a wobble even if I've dialled in the backlash as much as I could without it binding

Just wondering if anyone else has faced the same issue or know what the potential issue could be? 

It wouldn't bother me normally but I've noticed the guiding has been rather off on this axis. 

Matt

Okay so I've spent a lot more time on this iteration, with the primary goal of conserving details in the cores without worrying too much about stretching the IFN out. 

As much as I like the IFN, I feel if it's stretched out too strongly, it just adds more noise than anything else to the image so I was subtle about it.

The definition of the core in M81 particularly I felt was much better than previous attempts, stars are better kept too and the addition of the Ha is how I like it.

Honestly with the amount of tweaking I did, I forgot the workflow but a general one would have been:

L:  Crop - DBE - Decon - TGV - MMT - ArcSin - Starnet - Curves - HDRMT - LHE

Ha: Crop - DBE - Selective subtraction with red channel using PixelMath to only highlight HII regions - TGV - MMT

RGB: Crop - DBE - PCC - SCNR - Addition of Ha using PixelMath - TGV - MMT - ArcSin - HDRMT - Combine with Luminance

HaLRGB:  Curves (saturation and colour balancing) - HDRMT - LHE - MLTSharpening - Star de-emphasis script - Export

I've also attached a TIFF since JPEG's can degrade the quality somewhat

Matt

v3.tif

Second attempt at this set. Really spent some time trying to tame the core, stars and IFN nicely while not going overboard.

Got a new monitor and calibrator recently. Does wonders for colour accuracy!

Hope you guys like it!

C&C more than welcome

First attempt, just need to work on getting more detail from the core

On 20/07/2021 at 08:31, neil phillips said:

Snatched the GRS just before cloud hit.  245MM Orion Newtonian EQ5Mount. QHY462C Camera. GSO 3X ED Barlow lens QHY UV IR CUT Filter. 

RGB 

01:28 UT

I'm surprised you can get such a decent image from these kinds of latitudes, especially considering you're not using an ADC. Are there any tips you can give except "get better seeing" aha

Matt

M101 - The Pinwheel Galaxy

ZWO 1600MM Pro, shot at 1.61"PP

Decided not to drizzle as I wouldn't have been able to use MureDenoise.

24x180" Gain 76 Offset 15 bin 1x1 for each RGB, probably should've done 2x2 seeing as it's colour data

240x90" Gain 76 Offset 15 bin 1x1 Luminance

30x300" Gain 200 Offset 50 bin 1x1 Ha.

Admittedly not the best scope to use for galaxy imaging with 488mm fl but I thought I'd give it a go either way 

I've done many iterations of this in the past week but this one I feel is the best of them all so far. I had an issue of overcorrecting flats so had to calibrate and stack all of the data again and reprocess which got rid of some uneven blotching as well as discarding some bad blue frames since I was getting fringing.

I found that I could best handle the noise with MureDenoise as a first pass, then Jon Rista's linear denoising method, one round of TGV but 2 rounds of MMT after did wonders compared to just the one iteration. I would say that's the biggest reason I was able to get so much from the data.

I also selectively added in the strongest areas of HII with pixel math as not to make the galaxy too red bias and to highlight the main areas

All in all very happy with the outcome.

2 minutes ago, Stuart1971 said:

You did it correctly, it should really be done outside under normal operating conditions, as the cold makes a big difference, ideally it should be done outside in the cold...as when done in the warm, and then used outside, the chance of gears binding will be very high.....👍🏼

And I agree, why doesnt everyone do it this way....🤔🤔

I'd always had it on my mind but was shying away from it because I thought there was a reason people didn't do it like that and decided not to question it until it really bothered me and tried. 

For initial backlash adjustment after reassembly sure, make sure it's not binding and not rocking but for fine adjustment, be out in the field and dial it right in.

Ever since I stripped, regreased and replaced my worm bearings, I could never get the Dec backlash to what it was when I got the mount. 

This issue plagued me and I tried multiple times again and again to minimise it by following tutorials, mainly astrobaby's, but it just never worked as I intended it to. There was pretty much no backlash on the Dec axis by rocking, neither was there anything on the gears but having gone outside and started guiding, PHD measured my backlash to be 6 seconds.

I took the necessary steps to ensure that it was accurate by calibrating at Dec 0 and slewing north slightly to cancel out any backlash. All guiding settings were correct for my setup too.

I decided a couple of weeks ago however to adjust the backlash while outside and everything loaded onto the mount, slewing to Dec 0 and doing backlash measurements, recalibrating and running GA for 5 minutes each time until the backlash was very negligible, which worked incredibly well and now it's essentially not there anymore. Dec guiding switches direction almost instantly with no issues.

I guess my question is, howcome more people don't adjust it with this method? Am I damaging the mount by doing so or is there another reason?

Matt

Complete reprocess along with adding in 2.5 hours of Ha bringing it to 11.5 hours in total.

Full acquisition now:

Ha: 31x300", L: 229x90" , R: 24x180", G: 22x180", B: 21x180"

Pixel scale is 1.61" Per Pixel, but nice to see how much detail I could recover with Decon and sharpening

Ha taken with Gain 200 Offset 50

LRGB taken with Gain 76 Offset 15

Have included two - one cropped and one wider. Will attempt the drizzled set and compare the differences

Any questions or comments on areas of improvement would be greatly appreciated!

Added 2.5 hours more L and filtered bad frames in RGB. Will add Ha soon. Decided to also not drizzle this time to see the effects 

4 hours ago, Craney said:

Careful things don't spiral out of control.  

Great pic btw.

4 hours ago, teoria_del_big_bang said:

Great Image, Colour looks good to me.

I got some LRGB data lat night on this as there was no moon about seemed a good time to do it but I need a lot more data 🙂 

Steve

Thanks! Just processing last night's data now so I'll update when I'm finished

11 hours ago, GiorgioF said:

Really excellent result! Could you post a light without crop? Just to understand the dimension of the subject in the frame.

 

Of course, will do when I get home as the pubs are finally open here in England

11 hours ago, Ouroboros said:

Lovely image. I can’t see the purple fringes on my iPad screen. 

Thank you! I've got more data in the last couple of nights so I'll be adding that and hopefully get a better result

M101 - The Pinwheel Galaxy

M101 is a face-on spiral galaxy 21 million light-years away from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.

Equipment: 
TS Optics 90mm CF Triplet APO
Skywatcher HEQ5 Pro (Belt Modded)
ZWO 1600MM Pro 
ZWO 8 Position 31mm Filter Wheel 
ZWO LRGB Filters
ZWO EAF
QHY5L-II M & 50mm Guide Scope
Remote controlled with Stellarmate RPi 4

Acquisition:
115x90" L
20x180" R
20x180" G
20x180" B

Processed in PixInsight

Not sure what's causing the purple fringes considering it's a triplet. Have done RGB before with this setup but didn't experience it this badly. Maybe a couple of bad frames that made it into the stack?

AstroBin Link:

https://www.astrobin.com/full/o3nstc/C/?nc=user

Really impressive., Alex! 

The data to bring out the IFN like that without introducing noise is incredible.

Well done!

Matt

Congrats to the winners!

26 minutes ago, Knight of Clear Skies said:

Good to see some public data being used with some imagination to produce something new. There are lots of resources out there which can be used to complement our own images.

Could you have used Registar to align the frames for you?

I did think of using registar but I don't have a licence so I can't save the registered subs.

It's also the fact that the images are at different rotations

Went back and stacked all 4 this time instead to reduce the noise significantly and spent more time trying to properly align.

Also made the GIF reversible to better represent the motion

https://www.astrobin.com/full/1kus37/0/?nc=user

Thanks!

Relativistic jet motion from M87.

Raw data taken from MAST archive from propositions dating from 1999 to 2018.

Each set contained 4 frames of which I picked the best one from each year, manually aligning and rotating in photoshop by using difference blending mode and free transforming.

Applied false colour and smoothed in SAOImageDS9

Instrument: STIS/NUV-MAMA

Filter: MIRNUV

More than a year ago I attempted the exact same thing, just with a Celestron C14, so I had to be very accurate with my alignment. 

The best piece of software for the job was iMerge. It takes the first frame of the AVI and you can layer each of the next ones over each other as when you hover over them, it becomes transparent and you can align the panes. I had to have around a 30% overlap as the mount would have a tendency of drifting during capturing.

I shot mine with my guide cam that only did 1280x960@30FPS but I was lucky that the seeing that night was pristine and the moon was high in the sky. Seeing is your best friend when doing any lunar or planetary.

I would recommend taking 1000 frames per panel and taking the best 20% of those to stack in autostakkert. Also experiment with drizzling 1.5x and seeing how that turns out.

Consider investing in a 685nm IR pass filter to negate the seeing effects to improve sharpness.

Here's how mine turned out. 53 panes stitched in ICE, deconvoluted in Pixinsight and further sharpening and processing in PS. 

Edit: I also kept one exposure time and gain throughout the entirety of capturing. I exposed for the brightest area to avoid clipping and left it as that. 

Also rotate your camera so it goes down along the terminator, work your way down it and go from there