Adam1234

3 minutes ago, fozzybear said:

Can't beat Panasonic actually drove over mine back in the day just to test it out when in the computer industry

Wonder if it might be worth me getting a cheap laptop at some point to use purely for imaging 

Just now, fozzybear said:

As per @smashing put the laptop inside a storage box on it's side to retain some heat 

I'll be definitely trying that!!! 

2 minutes ago, fozzybear said:

maybe some more info on the make of the laptop and if you can remember what the message was. you could go into eventvwr if a windows laptop and look at the errors

It's a HP pavilion, I should have had a good look at the error message or taken a picture, completely forgot exactly what it said now... 

I'll have a look in eventvwr as you suggest later and have a look what it says

2 minutes ago, smashing said:

I have mine placed in a small plastic container to try and keep it a little bit protected from the elements...the fan kind of keeps it warm(ish) although I do get paranoid and will put a towel over the box if it gets much colder

Plastic container sounds like a good option, I shall try and get hold of one

Not sure it's the most appropriate section for this post, so admins feel free to most to the most appropriate section...

Decided to take advantage of clear skies tonight, first in months for me. Was going well imaging M33, until I checked my laptop just now and it had shut down!!! 🤬🤬🤬 

It's plugged in so it didn't lose charge, but I wonder if it was the cold that caused this? When I turned it back on there was a message about battery issue but seems to be working OK now (will check again shortly).

Has anyone else had this while imaging? If it was caused by the cold what's the best way to stop this happening in future? I did have a small towel draped over the top, and have now placed a towel underneath as well to try keep the bottom warmer.

Hopefully the laptop shutting down didn't damage my camera (asi1600) in any way...

Hi all, 

I found this interesting PowerPoint presentation made by Jordi Gallego in 2010 - 'Image Integration Techniques: Increasing SNR and outlier rejection using Pixinsight' (http://www.astrosurf.com/jordigallego/articles.html)

In the presentation he describes how to use the 'Average SNR Increments' statistic in the Process Console to fine tune the rejection process to maximise SNR while keeping the desired outlier rejection level when integrating. 

However it seems that this term is no longer being used, what statistic should I be looking at instead, either from the process console or elsewhere within PI? I don't think SNR estimates is the right one as this seems way too high, and said number increased when I applied a rejection algorithm (ESD) compared to no rejection and based from what I have read I would expect the SNR to be highest when there is no rejection.

It seems like this term has not been used since at least 2013 as I found a post on the PI forum from 2013 where someone else asked the same question but received no responses. 

These are the stats currently displayed in the Process Console after Integration:

Thanks

Adam

+1 for Sky Safari on mobile. I have Sky Safari 6 Plus and think it's great!

I have stellarium on the mobile as well, but I prefer Sky Safari on the mobile and Stellarium for PC

Do you have any telegraph poles near you? I have seen the same effect on some of my subs when the lines get in the way of my view. 

Thanks, I've started using a combination of MaskedStretch and HT rather than relying on STF

Hi, I would personally keep all of your light frames from the previous sessions and stack them all together with new light frames from your next session (s).

It is possible to stack frames from each session, and then stack the resulting images (I've no idea if the result would be the same or worse than stacking all frames together, someone else may be able to answer that). 

The reason I would suggest keeping all your light frames regardless is that as your processing skills improve you may wish to revisit old data, and it certainly helps if you have the originals files, especially if you want to re-process from scratch using different software and experiment with registration/stacking/rejection parameters.

Sounds about right!!

Great image, well done! At least someone managed to capture the conjuction! 

It was wall to wall cloud here in the UK, I was rather (highly) disappointed but can't say I was surprised.

Wonderful image!

I'd agree with Tomatobro, I prefer the 9 hour image.

Hi Mike, I was playing around with this script myself yesterday and was also trying to work out these settings. 

For the Gain and Gaussian noise - PI can calculate these values for you using the MureDenoise Detector Settings script IF you have 2 uncalibrated flat frames and 2 uncalibrated dark frames. I did not have these (i discarded them once I made my Masters) so I had to calculate/estimate the values manually, it took a while but I think I managed it in the end. According to the scripts documentation, it is more accurate to have the detector settings script calculate these values for you.

Here's how I calculated these manually:

Gain (e/DN) = there's a process under Image, I can't remember what it's called, but it will tell you the gain value. E.g For my ASI1600mm at 200 Gain the value was 0.498e/ADU, but because my camera is 12-bit I had to divide it by 16 to convert it to 16-bit to get 0.03e/DN which seemed in line  with what other people reported. I'm assuming your CCD 16-bit, in which case you shouldn't need to convert. 

Gaussian Noise = this one had me stumped for a while, but it turned out it can be calculated by dividing the read noise by the gain (e/DN).

The variance scale is just how much noise reduction it will appy, so I guess start at the default 1.0, and reduce if the NR is too much. 

FYI I discovered that if you perform an STF after applying Mure it goes all horrible. Way around this is to apply STF before Mure and create a process icon for that particular STF, so if you remove the STF you can then apply the original STF. Or just don't remove the STF.

Hope that helps!

Adam

I've been playing with the MureDenoise script in Pixinsight today - spent ages trying to understand what values I needed in the gain (e/DN) and Gaussian Noise (DN) since I don't have the individual uncalibrated flats and darks anymore to use the DetectorSettings script. Anyway, after lots of research on the net and using the ASI1600 graphs I managed to calculate an estimate of these values (found out I had to convert the ASI1600 12-bit values in 16-bit - what a headache trying to understand!) FYI using Gain 200 I have calculated 0.03 e/DN for Gain and 46.70 for Gaussian Noise.

Anyway, now I've got that bit pretty much sorted I had a decent looking result come out of MD using the Variance Scale default of 1.000 (much better than the original image before MD anyway!). 

My question thought is this - I applied the MD with STF applied so I can see the result - great! I then close STF, and then decide I want another look at the image and apply STF again - why is then that applying a new STF makes the resulting image look horrible, but looks fine with the original STF? Is it something to do with a change in the background levels affecting the auto-stretch?

I'm guessing the way around this for the remainder of the linear processing would be to either keep the original STF applied and don't remove it, or create a process icon for the original STF. This seemed to work anyway. 

 Here's the original stacked image before MD (with STF), after MD with original STF and after MD but with new STF (all cropped).

Original before MD

After MD (Original STF)

MD (New STF)

Cheers

Adam

Thanks for sharing, all the best for imaging in 2021

Well that is another celestial event ruined by the weather, and probably a once in a lifetime one as well. I've been off work for Christmas for a week and so far not an inch of clear sky, nor was there any clear skies for the last several weeks/months prior. September was the last time I had a good string of clear nights with an odd couple nights in November. 

Someone please turn off the weather, or provide me funds to move somewhere with astro-friendly weather.

Thanks, I did wonder if it may have been a cosmic ray. 

It was certainly removed during stacking at least anyway. 

Hi all. I'm playing around with Pixinsight (learning Pixinsight I should say). re-processing data for NGC6888 that I captured in November. I've  calibrated my subs and was checking them out before moving into image registration, and I noticed this weird line in one of my Ha frames.

Any idea what it is? It's in the original image as well, but doesn't appear to be in any of the other subs. The image has been autostretched and heavily cropped.

My first thought is hot pixels, but I'm unsure as it's not in any of the other subs. TBH I'm not even sure what I'm looking for with hot (or cold) pixels, no idea what they are supposed to look like,

As a side note, I tried running cosmetic correction (not that I know what I'm doing with that either) - used the real-time preview so I could see what effect it has, but as soon as I turned on the preview the image turned really grainy and I'm unsure why, adjusting the parameters didn't really do much, and certainly didn't remove the weird line. Safe to say I didn't apply any cosmetic correction. I don't think I'll be using CC in a hurry at the moment until I know what I'm doing with it. Any pointers will be appreciated.

FYI here is the original, and calibrated (with dark and flat) full frame version of the above crop

original

calibrated

Thanks again for the great data. I had fun this with one as this is my first image processed using Pixinsight so I'm actually pleased with the result!

- DBE 

- combined to SHO

- background neutralisation

- histogram transformation

- histogram adjustment to balance colours

- Ha added as luminance

- ACDNR

- HDRMT

- Star reduction

- starnet star removal

- selective colour in PS to bring out the golds and yellow

- stars added back in

- slight adjustment to remove excess colour from background

Adam

Incredible image, well done 

It was clear here for me yesterday evening, even though CO said up to 80% cloud cover, BBC weather showed the 🌙 icon with some cloud, and metoffice said clear all night (so annoying that all apps say a different story!!🤬)

Decided to set the scope, all set up for imaging, was imaging by 7pm, checked outside again at 7 30 and clouds had come in after my 3rd sub 😭😭

Checked metoffice again, and hey presto it had changed it tune from clear to cloudy ☁️ ☁️ 

FYI I'm now the proud owner of a PI license 😀

Been playing around with it over the last week, going through the instructions in the Mastering Pixinsight book and re-processing my image of the Crescent Nebula along the way. 

Not finished processing it yet but it will be interesting to compare my processing with PI vs Siril/Photoshop, will post up the comparison when I'm done!

Impressive amount of galaxies!