Vox45

Yes I did check to see if if my Canon produced "RGGB" patterns. It is the case. So I've applied this method from Cloudy night I posted earlier in this thread : https://www.cloudynights.com/topic/667524-preparing-color-balanced-osc-flats-in-pixinsight/ It is possible to prepare a balanced CFA master flat in the same way with PixInsight. Here is the procedure I use: Prepare the master flat as usual. Use the SplitCFA process to create images containing the four separated CFA channels. Use the LinearFit process to equalize the four images. Use the channel with lowest intensity as the reference, and apply LinearFit to the other three images. For me, the CFA0 (red) channel has the lowest intensity in twilight sky flats. Use the MergeCFA process to recombine the four images, and save the resulting CFA image as a file. I name the resulting image file "grey-master-flat". Use this color-balanced master flat (without debayering) to calibrate the light subs. I ended up with a flat file like this: A single frame calibrated with the master flat/bias/dark now looks like this (debayered/strech for the purpose of showing the result, I do not do this before registering and stacking) once star aligned I get this (!!!) and after stacking I get this final image: All those vertical bands ! and the dark corners on the upper and lower right side. I am doing some tests right now, with different combinations of duration/light intensity and with/without the CLS-CCD filter and I am getting results all over the place. I am obviously doing something wrong, I will need to dig a little deeper and read again the "Inside pixinsight" book

Very nice picture indeed, I did not know this galaxy, amazing details ! What software did you use to frame your picture and write your signature and info on the target ? It looks quite nice and adds a nice touch when sharing with others

So I had my first go at M42, it was quite difficult to process. I used DSS for the 1st picture and Pixinsight for the the second one. I prefer the second one but I find it a lot more noisy and blueish .. After a couple of hours playing around I tend to lose track of what is good or overprocessed.. I need your fresh eyes people Please, any constructive criticism is welcome as I have not a lot of experience processing deep sky images Processed with DSS Procesed with Pixinsight Thanks!

no I am running the debayer process like this I debayerd my master flat to see what it looked like ... My "problem" might be related to this thread I found on Cloudy nights https://www.cloudynights.com/topic/667524-preparing-color-balanced-osc-flats-in-pixinsight/ I will try and see what happens

Hello all, I am having this issue where I import FITS files in Pixinsight and on debayering them I get funny colors like this: If I use the same FITS files in DeepSkyStacker I get this ... So I started to remove steps from the routine and when I removed the Master Flat from the "Image Calibration" step I got this (single light frame) ... so it looks like this part of the process screw things up and I have no idea why ... Anyone with Pixinsight experience here ? I have a hard time understandig why flats would change the color of the debayered light frame... Thanks!

Plate solving uses a photo of a star field (from a guide scope or main camera, it does not matter) and searches in a catalog of stars to match that star field to the same pattern of star. You can easily test this by uploading a photo you already have and it will solve it and give you the name of the objects and coordinates http://nova.astrometry.net/upload You do not need to do a 3 star alignment. Plate solving is giving you the exact coordinates your mount is pointing to, so 3 star alignment is redundant. -> polar alignment is needed to prevent field rotation on long exposure and it helps guiding a lot -> 3 star alignment is to tell your software where the mount is pointing. Plate solving does the same thing as long as you sync when you get the platesolver solution -> guiding is not related to plate solving, it only keeps you mount from drifting due to bad PA or mecanical errors of your mount In my routine : (1) I polar align using plate solving. In my case I use Ekos and Indi (a linux set of tools and protocol a bit like ASCOM/Eqmod) (2) I then point my target using my sky atlas softaware (Kstars) and ask it to slew to that target (3) the plate solving tool takes a photo that is then solved using the astrometry index that I have downloaded locally on my machine (and RPI3 in this case) (4) When the exact coordinates has been "solved" The software updates my mount coordinates to that solution (4) The mount is then moved to get closer to the target and the process is restarted until it gets within a predefined acceptable range of my target (30'' for example) so without any 3 star alignment I usuall get my target smack in the middle of my camera sensor after 3 or 4 iterations So in your case you could use a photo from a previous session and ask the software to solve this photo and slew to the exact coordinates... that is possible as well. Or you could just point to the same target in your skychart software. Both methods are valid.

Great ! Thank you for your answer Now I just need to wait until the sky clears

Hello all, I want to sell my Sirius (HEQ5) mount but I've been asked if I could provide a "PE" graph. I have no idea how to do this. I know that ASCOM/EQMOD have some tools but I am not sure were to start and if there are other tools out there that could simply and efficiently create a graph that would mean something to potential buyers. I know that some shops provide the service of tuning your mount and gives you a periodic error graphs ... I do not know what software they use to do that though. I've hear of PEMPRO and K3CCDTools but they looked like very old tools. Any ideas ?

Yes this is part of my plan for a futur setup

Nice write up but there is a broken link when trying to get to page 4 😕 http://www.astrofriend.eu/astronomy/tutorials/tutorial-setup-off-axis-adapter/04-tutorial-setup-off-axis-adapter.html

It took a while to get used to the new site but now I am fine with it except for one thing... I have bookmarked the "new content" page and after going through all the new content, I click at the bottom of the page "mark site read" What is bothering me is that any new entry of a new or an ongoing threads display the last comment on the thread instead of the original post. So I get the title of the thread such as: "wow this is interesting" and the last comment would be : "indeed" Not very helpful ! I sometime get a dozen of threads such as "lunar picture" or "saturn" and such .. all with the same comment from the same person who decided to up their comment counts with: "great job!" Unless there is a way to configure this, it is quite annoying. I'd rather be able to see the original post as a preview of what the thread is about... There, I feel better now /end rant

did you apply the new firmware that deals with overheating ? https://www.techrepublic.com/article/raspberry-pi-4-running-hot-new-update-will-cool-your-board-down/

Ho I see what you mean now thanks for the pictures

Interesting, would you have any picture so I can better visualize what you did ? I am running Indi/kstars/ekos on an RPI3B+ and I am quite happy with it. I want to go for the extra memory and CPU speed and, of course, the UBS3 ports of the RPI4 I plan to recycle the RPI3 to work with my 3D Printer using OctoPrint

spoken like a true DIYer I just don't see how to fit a plate on those round rings that came with my OTA, I think it would be a bit wobbly

I think that changing the rings to ones with a flat surface would do the trick, I could then just bolt the bottom of the box to the ring with 4 anchor points... no need for a plate of any kind then .. It is hard to tell from the picture if the knobs are higher than the top of the ring though... If so, that would mean that I would need some kind of spacer to elevate the box ... introducing potential flexure 😕 https://www.firstlightoptics.com/tube-rings/william-optics-90mm-cnc-tube-rings.html

No as I will be using an OAG. I would just like to mount the box which will be 3D printed. I guess I could just make holes in the box and secure it to the 2 screws on the scope rings but that would make the box a bit wobbly, I'd rather bolt the box to an aluminium plate and the plate to the rings... A custom made plate then ?

What a lovely idea ! Once I get enough (good quality) material, I might actually do the same What a nice way to be remembered.

That is why I bought the 3 volumes of Burnham's celestial handbook. For the pure pleasure of perpetuating his memory. If you don't know who he is, his life is a tragedy So, maybe you could put this all in the form of a book and self-publish it ?

Hi all, I've made several iteration of a power distribution box/hub attached to the side of my SW80Ed like this It has worked fine for long time but now I would like to refine the design and add a couple of items to it. -> make it smaller and slimmer -> add an arduino nano board and electronics to operate a "myfocuserPro" focuser control -> add a RPI4 inside the box (instead of a RP3B+ that hangs outside the box) -> mount it on the top of my scope so it is easier to balance, is more rigid and has less wind drag (if there is a lot of wind, my current box act as a sail ...) I see that prima luce Eagle boxes are mounted on top of refractors like this: That is the basic idea of what I want to build but what kind of plate should I use to mount the box on top of my refractor ? A custome made aluminium plate maybe ? Or do I need to change the holding brackets like they seem to have done in the example above ? Please let me know if any of you guys or gals have an idea on how to solve this

He has published a very good book as well ISBN-13: 978-1937538439 https://www.amazon.fr/Astrophotography-Thierry-Legault/dp/1937538435

I think the problem is that I went in there with a lot of assumption on what focal lenght and diameter really meant. I was sure that I would get a better view with 1800 FL compared to 1000/1200 Newtons, but was shocked by the poor view of the 3550mm of the 14'' SCT ! So I spent quite some time this afternoon to research what a Mak is really about, how it came to be and what kind of optics it uses and learned quite a lot. Most of it was covered in the first answers here (thanks guys) and some more on a couple of in-depth explanation of meniscus corrector plate, achromatic corrector and spherical aberration on different websites... What I take away from this experience is that pure numbers was not the only factors in play: size of the scope, thermal equilibrium, EP, mount, seeing, wind, collimation can all throw a wrench in the proverbial works ... I'll try to reassure my pal Pascal shown here with the MEADE 14'', unaware that he would be crying later, and the guys back at the club that they did not spend 10K€ for nothing (they were a bit upset)

- smaller central obstruction - lack of spider vanes - 'solid' collimation I can see all this playing a big role. thanks for your remarks Ha, I did not think of this ... I will have to compare under better conditions, It was quite shocking to me to see in the 14'' that, although Saturn was bigger, the view was less contrasted and detailled ...

I was attending a star party at a new astroclub I just joined and was the only one using a Maksutov-Cassegrain 150. The general public was quite happy with the view of jupiter and saturn in my scope and soon members of the club started to take interest in my small OTA compared to their big Newton OTA. I had the best view of all scopes that night and even the club's MEADE 14'' was put to shame in term of contrast... This was very shoking to me. I knew that Maks were "planet killer" but I never had the chance to put one in direct competition with other scope under the same conditions... I assume that the MEADE was maybe not used to its full potential as this is a new acquisition by the club. Also, the EP might have played a role as well. But, compared to all other scopes present (mostly Newton scopes) the Mak was the only one to resolve Cassini's division and see 3 bands on Jupiter on a night with a so-so sky. So I started to wonder what was making Maks so good at planetary observation ? Focal lenght ? I read that on visual observation FL does not have a lot of importance... Diameter ? 180mm is less than the Newtons present (200mm) so resolution is lower than a Newton... Even my old C6 with the same aperture did not give me as good a view, so the cassegrain part is not in play (?) Anyone can weight in on this subject ?

I usually solve under 10sec using the local installation. I can understand that people would be reluctant to use plate solving if every solution took minutes to get solved. To speed up solving, you need to have your FOV exactly right in the configuration and download only the appropriate index files. If not, you will need to go through all index files and there are a lot ...There are a couple more tips to speed things up in the documentation. To get the exact FOV you can do a blind solve and Astrometry.net will tell you. If I use astronomy tool calculator I get 2.49 x 1.66 deg FOV for my setup, a blind solve gives me 2.44 x 1.63 deg FOV. Not a big difference, but it is accurate. In my case, I only use plate solving. I never do any kind of star alignment, I just sync to the solution when on target. I even use astrometry to get my polar alignment right.