geoflewis

Gorgeous..!!

Thanks Donal, I appreciate the very encouraging feedback. Cheers, Geof

Thanks Martin, I appreciate the feedback and after comments on another forum I had another go at it, so here it is.... I tried to control star sizes better and preserve the colour in the nebula core, whilst also showing a bit more structure in the outer shell. The changes are subtle, but I prefer this version, so what do you think? Cheers, Geof

This is precisely the method I use to dismount my C14 on an AP mount on my pier, but even that way I still prefer to have some assistance to hand when remounting it just in case.... Cheers, Geof

Thanks both. The plate solve in Astrobin identifies the small spiral galaxy as IC1296. Cheers, Geof

Hi all, This is my first attempt at capturing the outer halo of the Ring Nebula (M57). I was unsure how to process and combine the data, so pretty much it was trial and error with me making it up as I went along. My initial capture of Ha data was using too short (5 min) subs, so even though I had over 30 of them, I still struggled to show the halo and blending with the RGB data was not succesful. After taking advice over here I increased the exposures to 15 mins and shot 15 new Ha subs. The halo was more clearly defined, but the combined HaR overwhelmed the core of the nebula, so I processed the RGB separately and used layers to retain the blue core. Finally I layered the L. I learnt some stuff along the way, but still I'm really not sure what I'm doing when blending Ha and L with RGB. Thanks for looking. All and any feedback is very welcome. Regards, Geof

I don't know, just lots of boxes all telling me that something wasn't working. I just clicked ok to them all then exited the install, so as not to mess up what I already have

Well I downloaded and tried to run it, but got about 20+ errors, which were all meaningless to me so I gave up.....😕

Thanks Alexander, Does installing the beta overwrite all the existing settings meaning that I'll have to import them again, or will they survive the update? Regards, Geof

Hi Alexander, I think that I've eventally got the star cats working via manual download. I'll look out for the beta for the OAG overlay. Many thanks, Geof

Hi Alexander, I just installed v19.2 on my new laptop (Win10 Pro, i7, 16M RAM), but am having a couple of issues: The extra star catalogues won't install from within the application (Configurations Window Extras tab), so I copied the cat files 5 to 8 from a previous instal (v15.2) on another laptop to the Appdata/stellarium/stars/default directory, but they have no effect on stars displayed when I run the application. When I check the Configurations Window Extras tab it is updated to 'get cataloque 9 of 9' but when I hit the button it errors with the message 'Error downloading stars 8 Error creating SSL contect ()' I copied my occulars.ini file into the modules/oculars folder and initially all seemed correct, but then I noticed that the off axis display is not showing for my QSI camera, even though all the correct details are entered. I tried creating a new sensor, but the OAG overlay is still not showing. Any ideas how to resolves these please? Geof

Cracking image Dave, great to see the very successful result of your recent efforts Cheers, Geof

Thanks Steve, Geof

This image of M39, which I needed for my personal Messier list, was taken with my QSI583 camera through the 4" APO using my new 2" nose and extension tube fitted to the QSI STL 2.156" faceplate that I've only previously been able to use with the C14 and Optec telecompressor lens. The 2.156" faceplate affords a wider opening than the standard T-ring faceplate, but more importantly for me means that I can much more easily swap the camera between the 2 scopes. The image comprises 1 hour (6x10min) each LRGB all bin 1x1. The bright blue stars of the cluster stand out very well against the very busy Milky Way starfield. Thanks for looking. Geof

Superb...!!

I’m following this thread with great interest as I too have experienced great difficulty blending Ha with LRGB to reveal the outer halo of M57. Unfortunately my image processing laptop died, so I’ve just ordered a new one from Dell, but the shipping timeline is a few weeks. Currently I’m still trying to capture Ha data on my Obs laptop, which is a low spec machine, not suitable for heavy image processing. Hopefully I’ll be able to get back to image processing by mid November. Cheers, Geof

Wonderful image Steve, I never tire of M13 be it looking at superb images like yours, or drinking in the view at the eyepiece of my C14. Cheers, Geof

Hi Mick, welcome from another Norfolk located retiree.... I look forward to seeing you around here. Cheers, Geof

Hi Vlaiv, I didn't get any reply from the software developer, but I did hear back from one of the more experienced users, who also happens to use the same model camera (QSI583) as me. We had a few email exchanges, too long to copy it all here, but here are a couple of extracts from what he told me.... Geof, Just because a pixel has a value of 0 does not mean that it is clipped. If the master dark for a given pixel has a value of 300, with no photons reaching the sensor, then the "dark subtraction" process reduces the value of that pixel in the light frame by 300, assuming that 300 ADU of the light value is due to a thermal noise contribution. Geof, I reported the pixel values that are displayed in the IP status bar, at the right-hand end. They are 8 bit values. Below is the histogram of the 25 minute master dark. It shows 99.9% of the pixels with 8-bit values of 0 or 1 and an average 16-bit value of 261.  Geof, 5 minutes for Ha is not very long, so it is not surprising to me that you have a lot of 0 data after calibration. I usually shoot twice that for luminance data 1x1 and 8 minutes for 2x2 color. I wonder if you tripled that time where your data would be. So nothing conclusive there other than I've been shooting way too short exposures, so I'm wondering whether that is distorting my results. I've sent my camera off to be serviced as I'm wondering whether the cooling is not as reported, since I noticed that one of the fans stopped working, plus I needed to have the desicant recharged anyway. When it comes back I'm going to shoot a new darks library for longer exposures at both bin1 and bin2, probably 10 min and 15 min initially as I'm not ready to go longer. I will also shoot some new flats, flat darks and bias, so that I can revert to also including bias in my processing. Once that is done I can try imaging again with longer exposures to see what difference I get. Once I have a bunch of data to process, I'll probably download the trial for APP to see how calibration, stacking, etc. compares with my existing ImagesPlus software. I'm also tempted by PI, but from what I read that software eats computer resources for breakfast and I'm not ready to splash out multi £k on a new computer. I feel that I've learnt a huge amount from this discussion, not least finding some tools in my existing astro software that I'd not previously used, so many thanks for your detailed analysis and explanations. Cheers, Geof

Hi Nigel, I’m interested in your observation, so what would you recommend please? Regards, Geof

Thanks Vlaiv, I thought it would be too easy a solution 🤔. I have posted the question to the ImagesPlus User Group and will see what answers, if any, that I get. The software developer used to be very active on the user group and in the early days even directly supported me via email, with me in turn helping him with beta testing. However, this has not been so in the past couple of years, so I'm not sure that he is actively supporting the product anymore. Also there have been no development releases for maybe 3 years, or more. If there is no response via the user group, then I will write to him directly, but I'm increasingly reaching the conclusion that it is time for me to invest in an alternative like APP or PI, where there are more users worldwide, more ongoing development and more active support is available. Up until now I have been put off by the steep learning curve of a new processing application, but there comes a point...... Regards, Geof

Thanks Vlaiv, Sorry for my slow reply, but being on holiday I was out with my wife much of the day and your analysis is too complex for me to review on my phone, so I'm only just now reading it on my laptop. Good points about using sigma clip for my calibration masters, something that I never paid any attention to previously, just using the default in my software of average. I will certainly make that change in future and indeed I have resacked them that way and now there is no cosmic ray hit showing in the mast flatdark. I already use sigma clip combine method for my calibrated light frames, and yes, I do dither my lights, but I also use an additional filter in the software to correct any residual hot pixels not fixed during calibration, so usually my final stack lights are good. Regarding the banding in the corners of my master flats, yes, it is something I have noticed, but I don't think that it shows in the final processed image, not least because that reagion is usually cropped out. I don't know what causes it. Maybe it is something to do with my LED light panel, which has a slight flicker when on the low intensity that I need to shoot flats at my target range of 25k ADU. I have been thinking of increasing the ADU to say 30k to see if that makes any difference. The panel has variable intensity, but for all the LRGB flats I have to use the lowest intensity setting or the camera shutter is captured during the exposure. I could increase the intensity for the Ha flats to reduce the required exposure from the rather high 90 secs, but I just used the same intensity as set for the LRGB filters. I will definitely exeriment some more after I get home the week after next. Thanks for the link to your notes on ImageJ calibration, but I think this is going to be too complex for me to follow. As you advise, I think the better way forward is to trial something like APP, again something that I can do once I get home. In the meantime, I intend to write to the developer of ImagesPlus to ask him about the auto calibation process and why it is black clipping so may pixels. The software does include a manual calibration process, which uses the same calibration frames as auto. The manual calibration set up option also includes a dark scaling setting with the default set at 1.0. I found that when I set this to say, 0.75 then the number of clipped pixels was dramatically reduced to ~100. Even with dark scaling factor at 0.9 the 0 pixels was a few thousand rather than the sevearl hundred thousands at scaling of 1.0. I really don't understand what this dark scaling factor is as I can't find any explanation for it in the limited documentation that I have for the software, so I'm going to ask about that too. I wondered whether the setting in the manual calibration set up might carry through to the auto image set processing calibration, but that seems not to be the case the dark scaling factor getting reset to 1.0. Do you have any ideas what the dark scaling option might be Vlaiv? Here is a screen shot of the set up screen fyi... Many thanks, Geof

Thanks Olly, I think it's an example of great minds think alike 😎 Cheers, Geof

Brilliant, I never thought I’d see anything as good as that from an iPhone, but I’m sure the 28” helps a lot 👌. I prefer the x2500 video over the x12000 - not at all miserly in IMO..!! Cheers, Geof

Vlaiv, Again many thanks for your analysis. It's reassuring to know that the raw light, raw dark and master dark look ok, so now I have to understand what went wrong with the calibration, but I have no idea how to do that. The astro processing softwarwe that I use (ImagesPlus) provides an auto calibration tool where I load lights, darks, flats, flat darks and bias (though actually I don't use bias) frames. I then hit the 'process' button and it runs throught it's steps automatically with the output being the calibrated, aligned and combined stack ready for post processing. See screenshot below... Is it possible that my flats and flat darks are the problem? I use an LED light panel for my lights and with the Ha filter the flat exposures were a fairly long 90sec, which I matched for the flat darks. Here are a single flat, the master flat (from 20), singe flatdark and master flatdark (from 20).... C14+Optec-Flats(-10C)_2019-09-20_Flat_Ha_90sec_2x2_Ha_frame1.fit C14+Optec+QSI(-10C)_20Sep2019_Ha_MasterFlat.fit C14+Optec-FlatDarks(-10C)_2019-09-20_Dark_Ha_90sec_2x2_Ha_frame1.fit C14+Optec+QSI(-10C)_20Sep2019_Ha_MasterFlatDark.fit I am interested in your suggestion to use ImageJ (though I never heard of it previously) and your tutorial for it. I did just Google it and it looks frightening to me..... I have also been thinking to switch to PixInsight (PI) or Astro Pixel Processor (APP) as I hear more and more that these are the best astro image processing tools, especially APP for calibration and stacking. I await you next lesson please 😀. Geof