Catanonia

7 minutes ago, vlaiv said:

As far as resolution?

Sure - measure average FWHM. It should be ~1.6px. If it is larger than that - factor of two values will give you how many "times" you oversampled. Say you measure FWHM of 3.2px then you oversampled by 3.2/1.6 = x2 and you should bin x2 to get proper sampling rate (I just used numbers that give convenient result - but it's never that "easy"   - usually you get some "random" value like 2.4px so factor is 2.4/1.6 = 1.5 and there is no easy way to bin x1.5 as binning is integer operation).

If you are chasing IFN however - round it up to nearest higher number say you get x3.4 - then bin x4 or if you get x1.5 then bin x2 (or even higher for IFN).

thanks vlaiv, will look into this and do some measuring

9 minutes ago, vlaiv said:

You can just bin linear data that you now have.

Mind you - you won't end up with smaller image when viewed on computer or phone screens - unless zoomed in. Posted on SGL for example - it will look the same as image itself is scaled to fit the page.

Btw - you are a bit over sampled as is and you need at least bin x2 to get to appropriate resolution.

See star sizes and galaxy? That does not look very sharp when viewed at 100% zoom.

mmm, will have to look at this. Was 2mins at 1x bin on the Rasa8 and 2600 MC Pro.  Is there anyway to measure what I should be and what I am ?

Just seen this on another group and thought I would share it.

A diffraction mask that apparently removes star spikes from secondary mirror vanes in Newtonians.

https://www.thingiverse.com/thing:1260926?fbclid=IwAR2YhQg6gAeTeblz4GIq8g7J8iLOLhl4n6IliEY5ceXxL_nsbk2L2Xqkh9g

Never tried one myself and I have no association to the link, just thought I would share it.

8 minutes ago, vlaiv said:

IFN is all about SNR.

You should consider binning data that you already have - say even x4 in order to keep noise down.

In the end good denoising routine will help smooth things.

 

mmm, I could try that next time, 1 set of data for the IFN at 4x bin and use what I have now for the actual galaxies.

Might try and see if I can 4x bin the existing data for the IFN and see what happens. Will of course mean I will end up with a 1/4 sized image, but that should not be a problem with the size of the 2600 chip.

Thanks for the C&C, appreciated.

Since I started this hobby, quit and restarted again, I have always been chasing the IFN (flux) around the Bodes Galaxies (M82 / M81)

I tried many years ago with a Skywatcher MN190, then with a Boren Simon F2.8 Newtonian, but never got the results I wanted. 

I was beginning to think that it was not possible in the skies (bortle 6) that I had.

Fast forward to this year and new kit, it was time to try again, this time with a Rasa8 and ASI 2600 MC Pro.

I think I cracked it at long last  !!!!!!

Bodes Flux from Bortle 6 South Cheshire

• Rasa 8 with ZWO 2600 MC Pro
• NEQ6 Pro Mount
• 138x 2min subs at bin 1
• Darks, flats etc etc
• And 98% processed in PixInsight with only Photoshop for final level and black border.
• PI work was using EZDenoise, a few masks, Histograph, Curve and a little LHE processing. I processed the Galaxies and IFN in separate images and then combined them.

Still a lot to learn in the processing as trying to extract the IFN leads to noise that is hard (for me) to control.

Would love your C & C's on this one as like I said, so much more to learn, especially around the processing of dust lanes.

TIFF and JPG below

FInal Combined.tif

As you step down your exposure times, you are obviously limiting the amount of photons and colour hitting the camera pixels.

This is great as more images means less noise, less chance of tracking issues etc.

When you come to process try the following after calibrations etc

• Colour balance / calibration (depends on the software)
• Up the saturation of the image and even try the vibrancy to get some of the colour back. Be careful not to add noise to the background.

M42 is always a winter favourite and since coming back to the hobby, after quite a few years, I was keen to attempt it again with my new kit.

The 1st image is my new rendition taken a few nights ago with my RASA8 and ZWO 2600 MC Pro on top of a NEQ6 Pro mount.

It comprises of 130x 1min subs for the main image and about 60x 1s subs for the core of the nebula.  (Even 1second sub were almost blowing the core on the Rasa !!!!!)

I really wanted to get the dust lanes and still keep the detail of the nebula along with natural colours rather than artificially changing the colouring on individual areas of the image. I think I achieved that.

The 2nd image, for comparison, is the last time I imaged Orion about 10 years ago on a 8inch Boren-Simon F2.8 Power Newtonian  with a QHY9M camera. I am happy that I have progressed since then and am still learning.

Both images from Bortle 6 skies in South Cheshire

Not sure if this qualifies, but sometimes I like to animate DSO's so people can see how they get their names.

I give you the monkeys head nebula

@AMcD  Thanks for the screenshot, now I am using https://www.meteoblue.com/  Looks like I am done for the night in the NW as the front edge of the front has hit us   Was hoping for a full night of imaging

1 hour ago, AMcD said:

I am about to go to bed, leaving my set up to complete an imaging run on the California Nebula, before it slews, plate solves and re-focuses for a run to the Rosette for three hours or so.  All being well, the system will park the scope and close the observatory roof at about 3am, or sooner if weather conditions become unsafe.  If there are any problems the observatory will send me an email!   As you say @Catanonia, quite amazing.

Sweet setup, that is just lazy   I currently have my rasa8 on a NEQ6 mount in the middle of the garden, so have to be semi awake in case of emergencies

Back to the hobby after a 5 or so year gap and how much things have changed.

I was once sat in my roll off roof obs with a laptop tethered directly to everything freezing my butt off imaging.

Now I have just glanced over to my iPad Pro and watched the ASI Air Pro stop imaging, stop guiding, meridian flip, re-focus, re-guide and start the imaging run again in precisely the correct framing all without a single movement from me.

AMAZING !!!!!

17 hours ago, gorann said:

Bortle 2-3, but this is a very very bright object so in NB it should not be that critical.

PS. I have no experience with the Chinese Optolong filters but I hear they are giving bad halos around stars, so I do suspect the proven Japanese company Hutech that produces the IDAS filters are still a bit ahead in quality - no halos at least with the NBZ.

I have stopped using the lEnhance for a while now and replace it with an older LP filter I had (can't remember the make). I get much nicer colours now and better images.

The lEnhance works I suppose for those that need it in LP area's, but in my Bortle 6 it seems to block way too much and requires me to up the exposure lengths on the RASA8 and defeat the object of the scope.

@ollypenrice  Did you ever solve this problem and if so what was the cause /  solution ?

What Bortle skies is this under Gorann ? 

Reason for asking is I almost the same setup, just a lEnhance filter and nearly did the Rosetta the other night.

Yup, 2 or more months of constant cloud and then last night a slight glimmer of hope as ClearOutside predicted some 50% changes of clear skies throughout the night.

So perfect conditions for the RASA8 and why I brought it, to make use of these small windows of clear skies.

I had several targets in hand, Bodes / IFN and M45

Learning from my mistakes (I have only had the RASA since July), I put my sub length right down, removed the lEnhance filter and went for it.

So here is M45 in 60 x 1minute subs in Bortle 6 skies with a basic LP filter in front of the ASI 2600 Pro MC

I had to ditch 1/2 of the subs due to constant cloud invasion, but managed to get 60x 1min subs and I think it worked out quite well.

Also noticed that after removing the lEnhance filter, my star colours are back to a more natural colour. 

Some VERY BASIC processing concentrating on the background and not the actual galaxies and I have captured the IFN 

Comparing to stock photos of the IFN, no mistaking it and never thought this would be possible in Bortle 5 - 6 skies.

Now many hours of processing to produce a merged HDR  image. This will take time, something in UK skies we have plenty of.

1 hour ago, The Lazy Astronomer said:

Agree. Expose until background sky level swamps camera read noise. Once that point is reached, exposing for longer doesn't really gain anything, plus it may saturate a (relatively) large number of pixels, losing colour information in stars and bright areas.

Experiment is the main reason. Also using a lEnhance filter for LP.

Never learn unless you try

Ever since I started this hobby I have wanted to get the flux captured in between the Bodes galaxies.

I image from my backyard in Bortle 5 - 6 skies and about 5 years ago with a Skywatcher Mus F5.3 I nearly captured it with about 15 hours of data.

Now tonight is perfect conditions and I have a Rasa8 F2 and ZWO 2600MC pro and currently capturing 10 min subs !!!!!!

I hope I can get the flux, if this does not work in my skies nothing will.

Here is the 1st 10min sub (preview from asi air) with a lEnhance 2inch filter

WISH ME LUCK

17 minutes ago, megrez said:

Amazing. That RASA8 is certainly a good scope for the limited observing time that we get here in the UK. I really must save up for one.

Certainly well worth the £1900 for the image time / quality you get with it.

But you really need to match it with an APC sensor, that adds some more wonga to the ticket.

15 minutes ago, heliumstar said:

I am poor at judging the quality of astro photos but this looks very good to me!

What mount are you using with your RASA 8?

An old NEQ6 Pro  (not the new one with the handle). It is in serious need of a tune or replacing.

Was guided with a ZWO mini guide scope and ASI AIR Pro

Skies have been awful recently in the NW of UK and one of the reasons I got the RASA8, to make use of the limited clear hours I do get.

Last night there was a 3 hour window and I managed to grab 2 hours of data with the RASA8 and ZWO 2600 MC Pro in 2 min subs

The lEnhance filter is perfect for my Bortle 6 skies, gets rid of the LP I do have, whilst allowing the HA to come through. The lExtreme would be overkill for me and would remove too much HA.

So very happy now with the RASA, certainly does what I want it to, grab quick images as and when the skies allow in the damp and miserable NW of UK.

Hope you like.

11 hours ago, megrez said:

That's beautiful. What filter did you use?

Optilong lEnhance 2inch and then fake OSC SHO mapping

I was quite surprised at how difficult this target NGC 7822 was compared to the surrounding areas. It is quite faint which was a surprise. Even the RASA was struggling to get "loads" of data out of this, so I went for 5min subs to try and get as much as I could.

Skirting with the clouds in a Bortle 6 backyard, I managed to grab 3 hours with the RASA8 and ZWO 2600 Pro MC in 5 min subs.

Hard to process as well, I think I was getting some glare / vignette. I think this is my over sized dew shield I have on the RASA

Also the framing was off, not quite getting the large blue gas ring on the outside of the image (a little of it can be seen top left)

Anyways, hope you like it.

2 hours ago, Tommohawk said:

Thanks. Re multi star guiding wonder if it also makes it easier to pick up guiding after any passing clouds? Although guiding was good there was one brief period where star was lost, but seemed to resume OK.

Thanks. RASA 8 - that's the tool for the job! Look forward to seeing your results.

Didn't realise how faint this object is in comparison to NGC7000 etc etc.  Well I got 4.5 hours of good 5min subs with the RASA 8, hope it works out ok

From Bortle 8, excellent   Yeah another wow from me and not just the image, but 29 hours.