Tommohawk

They both look really good apart from the noise - I just checked my best effort with a DSLR and I was using 8 minute subs, so probably you need more and/or longer subs.

Wondering what scope youre using, and what camera? 

Yeah looks very nice to me, you're definitely on the right lines. There might be a bit more colour in there - maybe a bit of a tweak in the processing? 

A simple question, pretty much as per the title. With a refractor if R G and B are not par focal, how can the luminance be in focus? Non parfocal RGB setups seem common, so I'm puzzled how luminance can actually work properly in these cases.

Grateful for any thoughts!

On 18/01/2021 at 11:49, carastro said:

I find this a difficult target to get a decent result on.  I think you have done well.

Carole 

Hi Carole - hope you're keeping well and thanks for your positive comment. Actually having left it a few days it looks better! I guess by the time I'd spent hours squinting at it and generally prodding the data around I just got a bit cheesed off with it.

4 hours ago, MartinB said:

I sometimes think of processing as taking a long walk into the trees so that we can no longer see the wood.  If you go hunting for artefacts and processing "failings" you will find them, even in Hubble images.  Take a step back and have a look at the image that you have created.  It's great, not my favourite colour scheme but that is immaterial.  One thing I do look for in  jellyfish images is the faint wisps of OIII around the fringes and these are showing very nicely.  There is no need for you to apologise for this image, it's a cracker!

   Thanks Martin you're too kind! I have to be honest I like working with NB and whilst I know its not everyone's cup of tea, I quite like the palette. TBH part of the reason I've favoured SHO is because I've been disappointed with my LRGB images. But I've sorted out some issues with that, so hopefully will get back to some more conventional colour work soon - skies permitting!

BTW I watched your SGL night time landscape talk on catch up and really enjoyed it - lots of nice ideas, thanks for sharing!

And thanks all for the other likes too!

Looking pretty good I'd say! More data always going to help - BTW have you calibrated with darks and offset/bias?

Hi all. I was having a bit of a sort out of old data partly to clear some space on the hard drive and came across lots of Veil Nebula and Jellyfish nebula stuff.  I spent ages processing the Veil and was just about to post it when I realised I'd already processed it in a different folder, and posted the result here 12 months back. Out of interest the second effort was no better!

Anyhow, the Jellyfish gave me grief when I tried to process previously and I abandoned it - but thought I'd give it another go before scrubbing the data. I think this is my most tricksy target to date - but then I say that about all of them!

Added some Ha to the SII and OIII, and tried to avoid stretching the stars but not a great result. I ran it through Starnet which only served to highlight just how noisy the background is, plus big artefacts on Propus and Tejat, so havent posted that. Theres quite a lot of subs - but somehow not much detail. I tihnk the main issue is I've stretched the OIII to blazes which has make it all a bit blotchy.

Ha 92x300secs, OIII 75x300sec, SII54x300sec, ASI1600cool at -20, Astropixel processor + PS. I think this was undithered.

Happy to hear any thoughts!

Yes lovely and crisp - lots of detail, nice job

3 hours ago, Adam J said:

I have done exactly this on my ASKAR 180 vlaiv but place the 2inch L-3 filter in line with my 1.25 filter wheel with baader LRGB. It effectively clips down the red and blue filters while keeping everything para focal. 

Now why didn't I think of that! 

Thanks. Posted this a while back, but post #1 shows: 14x300s Ha, 90x60s R, 56x60s G, 63x60S B

So I think thats 279 minutes total - -but you might want to check the maths!

Worth bearing in mind that magnification isn't everything -some binoculars like these just aim to make everything brighter. That might not be what you want, but worth bearing in mind - super portable and they get good reviews.

I think there are similar less expensive offerings. 

Just FYI I did some design work using OSLO for a coma corrector, built into the secondary housing. I abandoned this for various reasons, but one thing that became apparent is that the tolerances for curvature and element thickness/separation are much tighter for a shorter corrector. The trade off with a longer corrector is that it can intrude into the light path, depending of course on the position of the secondary relative to the primary. 

Anyhow, the point of all this is that the Baader MPCC MkIII is remarkably short, and yet seems to achieve good results in the review I mentioned and in Martins assessment too. 

Let us know what you go for Stu and how you get on with it.... I'm sure whatever you choose the skies will clear for you. 

Link to coma corrector review - doesnt cover all options but I found it useful.

theres a great review on coma correctors out there - I'll try and find link

Whatever you guys do be sure to post some comment or review, because at some point I want to replace my 200P. Also not sure which coma corrector you would fancy?

There's always the Boren Simon offering - either F2.8 or F3.6. Apparently the reducer also does coma correction.

Or maybe tempted by the F2.8 Sharpstar/TS clone ? 

Personally I think a good F4 Newt is safest bet, but thats just my best guess. The Vixen ought to be good too, and is F3.8 with the corrector - never needs collimation is the bold claim!

Yes, like that very much.... and all done in 90 minutes! Nice star colours too. Is this with the Celestron RASA?

Some nice detail there - and agree combining Ha and RGB can be challenging

I've has a 200P for a good few years, and I reckon it's excellent. I also have a 10" quattro but my impression is what you gain in speed you lose in overall image quality. You also need a more expensive coma corrector - out of interest I tried my SW coma corrector which works great on the 200P, and it's awful on the quattro.

I've had the same thinking process, but my conclusion is that if going for a faster 200mm reflector you need to spend more - maybe one of the TS optics offerings, or perhaps a Vixen?

Looks good to me - though my red colour vision isnt great so I'm missing quite a bit!

Just wondering what ISO you use?

Sounds like most of my imaging sessions!

It's got the makings of a nice result - seem to be getting good Ha data especially for quite short exposures.

Having moved a couple of months back, I'm still trying to get my best position sorted. Quite a nice open view of the sky, but unfortunately slopes upward to  the South about 20 degrees, LED streetlight to the North, and as I;ve just discovered a constant jet of vapour from the neighbour's condenser boiler just a few meters away to  the East. Hey-ho.

I did some Ha on California nebula a couple of weeks back, and hoped to add to this - but the boiler vapour was proving a nuisance so thought I'd have a go at the Pleiades in RGB. I'd only tried this once before and that time the blue filter was causing big issues with  my scope in the shorter wavelengths. I've since swapped to Astronomik deepsky which fixes this nicely.  

I whizzed through RG and B and then idiotically spent 2 hours capturing Ha - well, not capturing Ha as it turns out. I had in my mind Olly Penrice's lovely shot of M45 which shows lots of background detail which I assumed was Ha but turns out to be just dust. Time would have been better spent capturing Lum, but I've abandoned Lum capture with the refractor until I get round to upgrading to the Astronomik L3 filter. I used APP to generate an RGB superluminance instead.

Anyhow quite pleased with the outcome, though I think I've lost some of the background star colours. Cropped it a bit. Maybe a bit bright overall.

Red 60 x 60 secs, Green 25x 60 secs, Blue 54 x 60 secs. Calibration using darks only. ASI1600cool at -20, 61EDPH with reducer, NINA, Astropixel processor, PS.

Hope you like it, happy for any thoughts!

Super image - plain Ha does look great. I struggle with bigger stars in Starnet, and in the past have had to resort to hand touch up.

Having said plain Ha looks great, do you plan to add SII OIII?

I did quite a lot of long exposure stuff with Canon 550D with ambient 30 deg and sensor didn't suffer any problems - well, not that I could see. BTW you can check chip temp in EXIF data. 

Full frame sensor might put real demands on the peripheral image and you may get some shape changes or CA even if manufacturer says imaging circle is OK. Plus of course full frame sensor camera is typically much more expensive.

Re 4/3 format - probably biggest issue is just with  mechanical / software compatibility, though TBH I'm not sure of the latest on this. Also if you have a scope with a 43mm imaging circle and use it on a 4/3 sensor (22.5 mm diagonal) you are wasting a lot of image. Most hybrid imagers ie astro/non-astro go for Canon APS-C which I used for some years and works well.

I guess you mean the altitude screw adjustment - it's not a problem with my HEQ5 mount, but looks like the EQ5 may be different. Be aware that when you tighten the opposing screw things will shift a bit. I try and get everything set before doing polar alignment eg put the scopes on etc and adjust tighten both alt screws - then there's minimum risk of PA shifting. Would it help if the screw was just shortened a bit?  I guess the supplier doesn't know your latitude so has to send long screws both sides to cover all situations.

Not sure if that helps

2 hours ago, Planetarian said:

Thanks for the info. It seems like the P1000 can't beat serious telescope setups, so still worth going with a proper rig instead of the camera. 

I cant say I know that particular camera - it looks great, but just not the right tool for the job!

BTW Currently I use a Lumix FZ1000 for non-astro stuff and I really like it. But I tried doing some astro stuff with it just out of interest and was very disappointed. You'd probably get some good lunar shots with the P1000, but you  wouldn't need a mount, just a tripod.

Well Nikons are used for astrophotography, but you mean specifically the P1000?

The main problem with bridge type cameras is that whilst the zoom range is fabulous, and perfectly good most uses, it's bound to be compromised for astro uses. It's likely star shapes will be a bit off and even though  there may be no significant CA for for general use I bet it would show on stars.  I used to use a very good Sigma zoom on my Canon 550D and the results weren't great TBH.  

For DSOs you'll need long exposures which ideally would mean guiding too depending on the focal length you use.

For planetary higher mag stuff you would ideally record uncompressed video which is not an option on most cameras. 

But if you have an HEQ5 and a Coolpix camera why not give it a go? You would probably get passable results, depending on your expectations.  You will also need to watch battery life (turn off IS probably) and focus manually - but all doable I'm sure.