m51

[alacant]

Hi everyone

Yeah, I know. yet another one of the collision, so apologies in advance.

The excuse for this one was to try DarkTable's parametric masking. Yet another step away from the well trodden norm:)  

Anyway, here is 80 minutes either side of the meridian, dangerously close to dew point but somehow surviving.

The atmosphere was super still last night which may explain a reasonable galaxy. Gave up on the stars!

Thanks for looking and DSLR users, do please post if you're had a go at this.

700d on gso203 @ ISO800

Edited May 10, 2021 by alacant

[bottletopburly]

 You can’t beat. Galactic collision 👍Dslr using the 200pds roughly 4hrs 

[Paul M]

2 hours ago, alacant said:

DarkTable's parametric masking

I'll Google that later...

In the meantime, that's another nice image.  Always nice to see other galaxies in the frame.

I first imaged M51 with my 1200D about a year ago. I've still not beat that very humble image yet with my dedicated ZWO camera. If I revisited that data now I'd likely get more out of it. My processing skills have improved more than my imaging skills!

[Andy R]

First and only attempt last year with a modded 600d and Nexstar 6se. I’ll never get bored looking at images of M51. 
 

 

[jacko61]

This was my first proper attempt at guiding, stacking and processing in Gimp.  Canon eos 70d on a celestron c8. Taken about a month ago.

 

[powerlord]

These are all so good. Pretty disappointed how last night's turned out. Was hoping for better. Shot with ED72 and asi224. couldn't really get any colour data out. I had a UHC filter on, maybe that didn't help. Or I need to get my finger out and  sort out the 200p.

I did a live stack in asiair, which was as well as can't get APP or DSS to align (don't detect stars). 300x10 seconds

[alacant]

36 minutes ago, powerlord said:

UHC filter

Hi

Lovely shot. Nice and close.

Yeah, i'd put good money on tghe UHC being responsible for the colour. The UHC seems just as aggressive as the new generation duo band filters, so you're missing quite a bit of the galaxy spectrum.

Maybe keep what you have and add some simply more frames without the filter?

Cheers

[powerlord]

Thanks, I'd like to, but can't stack anything unless I can get stacking/registration working ☹️. Cant even use the calibration frames I took

[powerlord]

Maybe useful info for others -

So, low res, big bloated stars - Neither DSS or APP was having any of it for star registration, so stacking was a no go.

IF I was going to get anywhere, I needed to be able to stack outside of asiair pro.

So finally I re-read Siril tutorials to try to get to grips with another astro program designed by people seemingly without ever using another piece of software written in the last 30 years.

Well.. what do you know - Siril stacks it no problems. All 300 frames. Result is pretty much identical to the asiair (which to be fair does a really good job, but at the time I had no calibration frames, so it was just stacked without them).

I can't in all honestly say that the result is any different in Sirl though even with bias and flats.

Weirdly when I tried to add the dark master (which DSS had produced), though it pre-processed ok, the result was that it had removed nearly every piece of data from the image leaving only a few tiny stars.

After fannying around for hours, I finally traced this to the dark. Remove the dark, and just use bias and flats and it was fine.

Whether this is an issue with my dark master, an issue with Sirl, or an issue with the operator's failure to grasp the finer details of a program written for aliens I'm not sure - but that's as far as I got.

For interest, and as they are tiny anyway, here is the stacked fit raw from asiair (not calib frames), and the stacked fit from sirl (+bias+flat)

Note: ASIAIR stack is the lot - including about 50 at the end in daylight. Sirl is just the 300 that were good.

It's clear tonight, so need to decide if I have another go with same setup, no UHC, or go back to the DSLR (maybe add barlow?) and try with that - again without UHC.. as looking at my DSLR attempts I think there's more detail there if I'm honest.

OR.. I make the jump and finally setup the 200p now it's collimated.. but tbh I don't think it's gonna even make the 80+ degrees I'd need for M51 without hitting the tripod...

ASIAIR Stack350_Light_M51_30.0s_Bin1.fit SIRL_Light_M51_30.0s_Bin1_stacked.fit

[alacant]

 

Hi and well done for sticking at it.

1 hour ago, powerlord said:

can't in all honestly say that the result is any different in Sirl though even with bias and flats.

 

There is a difference:

One makes processing far easier;)

You have the 200p, so if you have a mount to support it, I'd try that too. The field of view will be similar to our shot for which we also used a dslr.

But for either, flat frames aren't really optional. So...

- flat frames

- bias frames

- dither between light frames

- stack using a clipping algorithm

That's for your dslr. We've never used a 224, but I'm guessing you're gonna need dark frames too.

Oh, and clean the optical train!

There is some nice detail. HTH.

 

Edited May 10, 2021 by alacant

[powerlord]

thanks. yeh mucky - but I swear it looks clean to me.

I did actually dither there for the first time, so probably no loss that darks don't work for some reason.

and Sirl was set with clipping algorithm.

Are those my fits processed ?? if so - how did you get those results! - you even pulled some colour out. looks amazing! Is this the dark expensive art of PixelInsight ? or something poor mortals can aspire to ??

stu

[alacant]

1 minute ago, powerlord said:

PixelInsight

Nooo... We allowed our trial to expire;)

6 minutes ago, powerlord said:

how did you get those results!

StarTools. I'm sure conventional methods would get you there too, but could take quite a bit longer.

HTH

 

 

[jacko61]

For the picture I posted earlier, I found GIMP fairly straightforward to use after watching a tutorial on youtube a few times. Just the basic actions so far - curves, contrast and so on but It's worth trying, especially seeing as it's free   

Graeme

Edited May 10, 2021 by jacko61
spelling

[powerlord]

i use affinity photo - you've done a better job than me then - I'll give it another go.

Startools! - everytime I've tried that (following the tutorials) I just get junk out. hmm.. I must be doing something wrong. I even watched SGRs talk with Ivo Jager and followed his steps.

[powerlord]

1 hour ago, alacant said:

Nooo... We allowed our trial to expire;)

StarTools. I'm sure conventional methods would get you there too, but could take quite a bit longer.

HTH

 

 

Any chance you could just write a quick how to steps below ?

[alacant]

1 hour ago, powerlord said:

get junk out

Oh dear. We prefer StarTools' database approach. It really is a breath of fresh air after all these years of levels, curves and having to work with non linear images. Of course, if you're getting better results with Affinity, stick with it. In the end it's probably down to what you're familiar with anyway.

Cheers

[alacant]

14 minutes ago, powerlord said:

quick how to

Just work through the modules in order.

Autodev

Crop

Bin

Wipe

Autodev

Deconvolution

Colour

Then season to taste.

HTH

 

[bottletopburly]

25 minutes ago, powerlord said:

 

Startools! - everytime I've tried that (following the tutorials) I just get junk out. hmm.. I must be doing something wrong. I even watched SGRs talk with Ivo Jager and followed his steps.

Have a word with Ivo , @jager945 post on his forum or on here  your  fits file to be processed , inc your acquisition details ,camera , integration time , calibration details and I’m sure he will gladly guide you on the correct way.

[powerlord]

OK ill have a go with it first with this pic. Everytime I've tried with previous stacked images and following those steps I end up with something resembling an acid trip.

[alacant]

8 hours ago, powerlord said:

following those steps

If you like, record your screen during the session and link here. It will probably be easy to see what's wrong. Usually something simple.

 

8 hours ago, bottletopburly said:

his forum

Which is here.

Here are the first few steps (video deleted) and yes, even after all that, the data is still held linearly. You can go back and completely redo it if you don't like it. Anywhere along the workflow:)

Cheers

Edited May 10, 2021 by alacant

[vlaiv]

This was taken a long time ago - one of my first DSOs - 8" f/6 with ASI185 (sorry no DSLR). Heavy light pollution - maybe total of 2h of exposure (don't think it was more than that).

Can't remember processing, but stacking was most certainly done in DSS.

[Stu Wilson]

On 05/05/2021 at 17:02, alacant said:

Hi everyone

Yeah, I know. yet another one of the collision, so apologies in advance.

The excuse for this one was to try DarkTable's parametric masking. Yet another step away from the well trodden norm:)  

Anyway, here is 80 minutes either side of the meridian, dangerously close to dew point but somehow surviving.

The atmosphere was super still last night which may explain a reasonable galaxy. Gave up on the stars!

Thanks for looking and DSLR users, do please post if you're had a go at this.

700d on gso203 @ ISO800

Great image as usual. Loads of little fuzzies too 😉

[powerlord]

6 hours ago, alacant said:

If you like, record your screen during the session and link here. It will probably be easy to see what's wrong. Usually something simple.

 

Which is here.

Here are the first few steps, and yes, even after all that, the data is still held linearly. You can go back and completely redo it if you don't like it. Anywhere along the workflow:)

Cheers

thankyou! I've no idea why you did what you did from the defaults, but following the same steps then doing some colour, etc I managed to get something better than out of affinity. I clearly need to watch more tutorials on startools. perhaps it's worth buying after all - I'll play with it more.

here's what I managed to arrive at from the SIRL one. The one from the asi air for some reason startools seems to think is black and white if i choose linear/dslr, and chosing linear gives weird colours. but the SIRL one works fine as linear/dslr... not sure whats happening there.

 

[alacant]

1 hour ago, powerlord said:

startools seems to think is black and white if i choose linear/dslr

StarTools (correctly) processes colour and luminance separately. You'll see only black and white images until you either preview in wipe or combine with colour using the colour module. I'm assuming your 224 is colour.

The asiair version seems to be lacking proper calibration so maybe just forget that one for now.

 

1 hour ago, powerlord said:

why you did what you did from the defaults,

It's known as 'The Dark Art'!  You have to 'feel' the data. You can only guage it by practise; no two astro images are the same. The more more you process the...

Anyway, well done. To go deeper, perhaps have a look next at the HDR and Deconvolution modules.

Be sure to read the StarTools data preparation guidelines. 

Cheers

 

Edited May 10, 2021 by alacant

[powerlord]

Woohoo - progress!

Last night I got 2 hours of data - no UHC filter, and this time I whacked the gain up to 300 on the asi224 and increased the exposure to 60 seconds. This brought the histrogram up to about 1/4 up which is about as high as I could go. versus night before when everything was really right down to the left.

Now DSS stacks no problem, and I had proper bias, dark, flats (my darks were wrong last time as I had light leakage I didn't notice in histograms). I dithered as well.

I am really pleased with the results, I feel I'm making real progress thanks to all the help and advice on here - thanks again 🙂

Next step, I suppose try and combine both sessions in stacking which I've not done yet so will have to read up on how to do that.

Still - I've  got real colours coming through, I think there's even a red swirl there.

Considering this is with the asi224 and ED72. There's no way my 200P/EQ5 can get to that sort of DEC, so no chance of using that.

Next step - I want to try it all again but with the ASIAIR controlling my AZGTI in EQ mode.. I reckon it might fair better than the old EQ5 - it was really struggling to guide under 3" RMS and sometimes the DEC went on a wander 20" off or so.

 

oh - needless to say, I've bought startools! though still waiting for my serial so screen captures for now.

 

Edited May 11, 2021 by powerlord