Adreneline

3 hours ago, geoflewis said:

Nice early transit capture Adrian.

Thank you Geof. I contemplated getting the CEM25 set up and all the gear but decided that would put the kiss of death on it for me and everyone else for 50 miles around - at least. I feel so sorry for all those who went to so much trouble and got nothing at all.

"Onward and upward" as my mother used to say.

She also used to say "It won't always be dark at seven" but sometimes with AP it feels that way.

Clear skies to us all.

Adrian

The weather gods were against here in southern Derbyshire and even when the cloud did clear the seeing was still rubbish.

Taken with a Canon 70D and 70-300mm zoom lens.

Thanks for looking.

Adrian

I like both but prefer the first one - it seems to have more depth.

Thanks for sharing.

Adrian

Thanks @vlaiv for your very complete response. I need to try to absorb the detail and significance of this. It seems to me though that providing I don't overstretch the image then any differences will be negligable. I think I might up the number of Dark-Flats and use them.

Many thanks for the time you have taken to help me with this.

Adrian

25 minutes ago, vlaiv said:

what do you get as mean pixel value?

872 vs 866 - not significantly different:

Adrian

14 minutes ago, vlaiv said:

It might not even be visible there is issue (even if there is) unless you stack and stretch very hard, so there might be an issue that does not show on normal level of stretch and you can end up with good looking image anyway.

Thanks vlaiv for the response. The image on the left is using Bias - the one on the right is using Dark-Flat. I don't believe there is any great difference although on my MBP the Dark-Flat image appears to have a slightly darker background, but it is marginal. I cannot see any great difference in noise.

Adrian

Hi Everyone.

I've been playing around with the Batch Processing Script in PI with Lights obtained from my ASI1600. The Master Dark is 120s at gain 139, offset 50, -20 degrees to match the Lights. One of these is calibrated with 0.3s Bias frames and one is calibrated with 1.7s Dark-Flats. I've zoomed-in by equal amounts in the top right corner of the image and then performed a STF AutoStretch and captured the screen.

Is one of these better than the other?

Is there no significant difference between the two images?

Should there be a difference or will it only become really apparent if I reduce the Bias exposure to the minimum possible value?

Any advice / help would be appreciated.

Adrian

13 hours ago, gorann said:

Great image! Could I ask what Canon 200 mm that is - very impressive star shapes.

Hi Göran

@JamesF is correct with the lens. I have been using the Samyang a lot over the last 18 months but decided to invest in a lens I can use for AP and is more easily used on my dslr for everyday use if I wish. The Samyang is great but being fully manual it can be a bit limiting at times.

Regarding the star shapes: I removed the stars to process the nebula and then put the stars back having processed them separately, taking care not to over stretch the image. I have to say the corner star shapes are better on the Canon than on the Samyang.

Thanks for the kind comments.

Adrian

29 minutes ago, kirkster501 said:

I was expecting a lot less than that......

The story of my life when buying AP equipment  

53 minutes ago, ollypenrice said:

You might not want to, of course, but it can be done.

It can indeed! I chose to apply it as Selective Colour layer before I put the star layer in place so the colour modification is only applied to the nebula.

Hopefully this looks better.

Thanks again Olly.

Adrian

36 minutes ago, ollypenrice said:

If you have Photoshop or equivalent you could, if you wished, get this even closer to natural colour by going into Selective Colour. You might not want to, of course, but it can be done.

Thanks Olly. I am always interested and grateful for any advice on improving my images and I will certainly give this a go.

I have played around a bit with Selective Colour but have to say I'm not sure quite what I am doing; my current approach is somewhat random and I usually end up ditching the end result. I am definitely a fan of trying to get something that looks natural.

Thanks again for the help and advice.

Adrian

2 minutes ago, MarsG76 said:

Very nice rosette.... good imaging.

Thanks for the kind comment - glad you like it.

Adrian

11 minutes ago, ollypenrice said:

Certainly a great combination of lens and camera - plus sympathetic processing.

Thanks Olly.

33 minutes ago, Icesheet said:

That looks like a fantastic little set up! How do you find the CEM25 EC? It’s been interesting me for a while as a set up for my ASI1600 and Samyang. Gets tiresome pulling out the EQ6 for that.

I know exactly how you feel. I used to have an NEQ6 and it was all getting too much for my ageing back and hands to lug in and out each time I wanted to do some imaging. Also I didn't need and was never likely to use it's payload capability and there was never any prospect of a permanent setup or observatory. The CEM25-EC is excellent for my needs.

36 minutes ago, kirkster501 said:

I am using a G2-8300 with Samyang, with guidesciope and autofocus.

The best thing of all, other than the fact that it is much lighter, is the fact that I don't need to guide. I accept that if I was to start using a longer focal length lens/scope then guiding may become necessary but my interests these days is very much more about imaging large areas of nebulosity without recourse to mosaics. I can now be ready to image within 15 minutes and the recent switch to an ASIair makes things even easier and quicker. I would definitely recommend the CEM25-EC.

36 minutes ago, kirkster501 said:

Great image to the OP by the way!

Thank you!

Adrian

6 minutes ago, Icesheet said:

Im curious how you focused the lens with the ZWO EAF?

I’ve mounted the EAF on the supplied bracket onto my TS Optics tube ring and used a toothed belt and pulley from Motionco. 

 

Thanks for the kind comment. 
HTH

Adrian

31 minutes ago, geordie85 said:

Fancy selling it? 

I’m afraid not. I’m thinking it is going to become a permanent attachment to my 414ex osc. The FoV is very similar and taking L plus NB with the 1600+200mm and colour with the 414+135mm should work well. I keep seeing people recommending 2x2 binning for rgb to combine with L and NB so should be about the same me thinks! Just got to sort a nice lightweight mounting arrangement. Brother-in-law with 3D printer to the rescue.

Thanks for your interest though. 😊

Adrian

4 minutes ago, tooth_dr said:

Onto a winner there, looks like a great combo.

Thanks Adam. I like my 135mm Samyang but I think I could get to like the Canon more. It's heading in the right direction for the 1600 pixel size.

Thanks again.

Adrian

This is my first serious attempt using my Canon 200mm lens with ASI1600, unguided with all data collected with a ZWO ASIair and focussed using a ZWO EAF.

The image has minimal cropping and the star shapes are pretty reasonable even at the extremities of the image. The image comprises 20x120s of Ha and 10x120s of OIII, processed in PI and PS.

Comments and criticisms welcome.

Thanks for looking.

Adrian

For those considering buying an ASIair I used my new ASIair+EAF acquisition last night for the first time with my relatively new iOptron CEM25-EC with ASI1600 MM Pro, Canon 200mm lens and ZWO-EFW.

Once I had got my head around the iPad app I have got to say I was sold on the ease with which you can control the mount with Sky Safari, the ease with which you can focus the optics with the EAF and the simplicity of the process for setting up an imaging run. The interface is a joy to use with everything easily accessible at any time on one iPad screen. First impressions are I love it!

Not only is everything controlled from just two apps on the iPad but there is now just one 12 volt cable going to the mount. I still need to play around making sure cabling is as tidy as possible, from an esthetic point of view as much as anything.

Transferring images from the ASIair to the laptop was straightforward although I did run into one problem when I came to process last night's imaging run with previously taken flats. ASIair saves the .fit file with 'H' in the filter keyword of the fit header. SGPro stores 'Ha' in the keyword so PixInsight batch processor decided there were no matching flats to calibrate the lights.

One final interesting fact was there is no opportunity to change/control offset on the ASI1600; gain can be set at any value but offset is set at 50 by the software with a comment in the ZWO website to the effect it is not necessary to change it. Interesting!

This is one of the targets I imaged last night - 20 x 120s of Ha of the Rosette, processed in PI (ABE, HT and LHE only).

I also collected 12 x 120s of OIII but not had chance to look at that - or the 10 x 120s of Sh2-240, although I don't expect to see too much there.

I finally have an imaging rig I can take to a dark site and run from a power tank (if I had one) or the car.

Hope this is of interest to someone.

Adrian

Hi Everyone,

I used my new ASIair with my nearly new iOptron CEM25-EC for the first time last night and ran into a few issues - well one really.

Following a polar alignment and successful setting up of ASIair and connection to the mount and Sky Safari on the iPad I slewed to my first target star - Capella - to check things were basically working as expected (exactly as I would have done using iOptron Commander + ASCOM + CdC) but Capella was no where to be seen. After several more fruitless attempts and several rechecks of the PA I slewed to what I expected to be Dubhe and after a plate solve I instead found myself almost centred on IC2574 - in the right ball park but off the mark. I then chose to sync the mount with Sky Safari. After that subsequent slews to the Rosette and Sh2-240 were all spot on, tracking seemed excellent (no guiding) and I concluded a successful run of imaging following which I parked the mount only to discover the RA axis was about 10 - 15 degrees off the parked position. Not what I expected.

This morning I have discovered the time on the mount handset is still BST despite the fact that the iOptron manual implies the mount picks up its time signal from GPS. I also had DST set on the controller so I had assumed it would automatically switch to GMT at the appropriate time.

So last night I was imaging with GMT on the iPad and I presume ASIair, and BST on the mount. Would that account for the slew problems?

What should the DST setting be? 'Y' or 'N' - recognising it seems to have no affect on the time stored in the hand controller. I've read the iOptron manual several times and I can't seem to figure out what I should set - it's a bit ambiguous to my reading.

As a footnote - despite the problems - the ASIair is amazing and the iPad control app is a joy to use.

Thanks in anticipation of some help / guidance.

Adrian

16 hours ago, MartinB said:

processed mainly with PS but PI for Starnet

I really love this image. I really like seeing these large targets in their entirety with a bit of surrounding space. Details are good but I would rather have FoV.

Star removal is an interesting tool in the processing box. So far I've tried Straton (works on linear, and the most expensive), Starnett++ (works on non-linear and free!) and Annie's Astro Actions (works when ever you apply it and comes bundled with a bunch of useful PS tools for AP) and all have their place.

I quite like fully processing an image and then removing the stars with AAA; it often reveals details the eye missed with the stars present but purists on this and other forums are often singularly unimpressed by starless images. As Starnet++ only works on non-linear images I have found it best not to stretch too far before removing the stars otherwise your options for further stretching get limited but that may be my own processing limitations coming to bear. With Straton you have to remember to register the images before you whip the stars out - done that a few times - but does allow more freedom on taking the image non-linear.

Now, I think I'd best go back and have another crack at my Veil images having been inspired by yours.

Thanks for sharing.

Adrian

Removed the stars with Starnet++ this time and tried harder to sharpen the image without introducing too much more noise.

Changed the colour balance too!

Thanks for looking.

Adrian

On 04/08/2019 at 12:02, fireballxl5 said:

Any ideas?

I've had this problem and I have found the way to avoid it is to start PI afresh from the Desktop icon and then use Load (from the File menu) to load the file.

If I right-click on an image file and select "Open with .." PixInsight I consistently get this error message.

I'll have to give the re-install all the files solution a try as suggested by @SyedT.

I am impressed by your dedication and commitment to try to achieve a discernible end result. Very well done for trying.

Very good images too!

Adrian

3 minutes ago, MartinB said:

Did you find much OIII?  I'm feeling inclined to go for HaRGB.

You are correct - the OIII is quite weak. I try to resist over-stretching the OIII data, in fact I try to ensure I stretch OIII the same as I stretch Ha to keep the same relative levels - probably why my images look a bit pastel coloured in nature. I did try RGB in a previous attempt using an Atk428ex with the Samyang but, other than getting some coloured stars all I got was a lot of noise and light pollution. RGB is a bit frustrating here for just about all targets.

I've attached my registered Ha and OIII masters; if you (or anyone else) would like to have a go at processing I would be delighted. I really struggle with these feint targets. As you will see I have cropped the originals to get the image above. As is typical I get a fair amount of OIII bloat which is why I chose to remove the stars, process the underlying data and then put the stars back in using a lighten layer in PS.

Adrian

sh2-240-Master-Ha_r.fit sh2-240-Master-OIII_r.fit