Bibabutzemann

maybe it would be helpful to rotate your camera and shoot the same target. Just to see how the reflection changes if at all.

NGC 7000 , 3.2hours with the L extreme and EOS 1200Da cooled I just did a quick processing, because i may add some data in the future. Just wanted to show the perfomance of this awesome filter under full moon conditions. No background extraction was necessary, which i still find mind-boggling.

Hi Karol, nice setup! 2 years ago when i decided which scope to get, i also considered the 400mm canon and so ive also read your Blog back then😃 Great to see you hear now. I think the reflections could also come from stray light. Are you using a dew shield?

Many clear nights means i can afford high integration times. Thanks to the HEQ5, it does everything so well that i sleep tight at night. 10.4 hours L-extreme, 2 hours RGB with my EOS1200DA cooled IC 1396 in false color with RGB stars

Iris Nebula ~13 hours under Bortle 5 (Heidelberg, Germany) Equipment: 130PDS, EOS1200Da cooled, HEQ5 Processing with Siril, GraXpert and Photoshop Its really tough for me to process. I noticed when i do really long exposure times like 10hours+, the star bloating of even small stars becomes difficult to manage. My primary mirror baffle will arrive next week, hope that will improve this issue. 160min of M13:

im pretty positive your mount never received the guiding commands which are displayed in the log. The up and down of the RA is the periodic error (peak to peak is arround 13min), the linear north movement of the DEC is the polar allignment error. This is a graph you would get when you run the guiding asstistant while guiding is turned off. Also the periodic error seems to be pretty big for an AZ EQ5. Is this a new mount?

this looks strange. Are you sure the mount received guiding commands? Normally you can hear that. What type of guiding setup are you using? Ascom Pulse Guiding? Im still impressed of how much signal you could gather. Do you have low light pollution?

I used an EQ3 for 1.5 years with my 130PDS and i wasnt unhappy with it. But not all Eq3 have same perfomance, so maybe i was lucky with mine. And it struggled with long settle time after dithering and was more wind sensitive. If you want to play it save, go for the HEQ5. I got one used for same price as a new EQ3 and its a big step up.

I mixed something up. The moment of intertia gets reduced (not the torque), which makes the system more stable in the RA axis. Here is my setup in use (ready for taking flats) Cable management is a bit chaotic, because im still experimenting with my peltier cooled DSLR. Finally found a fan that doesnt cause vibrations (thx 'be quiet!') Same night i was able to resolve a star which is 61mio. light years away! Ok its an exploding star, but that still counts 🧐 Because of limited view, only 7min exposure time.

my 130 PDS is balanced exactly like Jamgoods on my HEQ5 with one Counterweight. But nothing wrong having two counterweights closer to the mount, because less torque.

Im not sure about that. When i do a 2nd degree background extraction, the software cant create such complex patterns. Just like a 2nd degree function can only make one curve. Also these patterns are dependant on orientation and focus postition. So i would say they are correlated to the light train. I was just unsure if this is specific to my setup or something normal that i shouldnt think too much about. For now i will focus on doing better flatframes.

Ok maybe i didnt understand correctly. Do you apply unband to every single frame before registration and stacking?

Debanding is not a tool i use anymore since i dither. It only worked on images with much background but did a bad job unbanding nebula photos in my experience. "I don't think applying BE to a flat frame helps in analysing what you think is wrong. " Yes, seems like!

Thank you @Stefan73 and @alacant ! i compared all our flats. I did a background extraction of 2nd order in Siril, to see if any complex gradients are left. First is Stefans, 2nd is mine and last is alacants. On all three i could make out that "hook" like structure in the middle of the flat, but it was less pronounced on alacants. I tried with flocking and and a baffle ring, but still didnt get rid of those gradients. Maybe im overthinking and i should just focus on doing better flat frames.

yes of course! Would be very thankful!

I would be also happy to see your stacked flat frame, to see what i can expect from a well tuned 130PDS 😃

M94 5.3 hours of Data, Bortle 5 sky For background extraction i used a new tool. Its called Graxpert and is completely free. Works fantastic. German youtuber astrophotocologne initiated the project and he also published a tutorial in english just yesterday. Equipment: 130PDS+MPCC3+EOS1200DA cooled+HEQ5

Its a standalone software only for gradient removal. It doesnt surprise me that you didnt heard of it. Alnost nobody in this forum heard fromt it, since they released it yesterday You can download it here , there is also a manual in english. Its really simple to use. Just crop your stacked image, but dont apply any stretch before using graxpert.

Flaming Star Nebula captured in February. I collected 12 hours of data with the L-Extreme Filter and only 1.5 hours of RGB for the stars. Equipment: 130PDS+EOS1200D+MPCC3+EQ3 Pro Processed in Siril+Photoshop

Here is my try on your image For background extraction i used a brand new tool called Graxpert. Learned from it today from the german youtube astrophotocologne, who initiated the project. It works so good and is completely free. Then i applied slight stretch and color calibration in Siril and removed Stars with Starnet++ I processed the starless image with streatching and heavy noise reduction in camera raw filter. I also used the clone stamp tool to reduce the large star halos. Final touch was some defringing of the starlayer in camera raw filter and leveling the background.

maybe someone could provide me with 20 flat frames they have taken with the 130 pds and a similar size sensor. Then i could rule out if this gradient is only specific to my gear.

Yes i also learned that in Siril it should work better with only a few points. But that only works if you assume a more or less linear light pollution gradient. But in my image there is a more complex gradient that combines with the light pollution, causing this mess @ONIKKINEN oh i forgot to mention, i tried doing background extraction to every single frame. Problem areas still remained the same sadly...

Hi Olly, thanks for your input 1) the problem exists even if i dont do bias frames at all. I hardly notice any difference. To prevent light leaks i always take bias and dark frames with the camera not attached to my Newt. But i rarely take dark frames. I only find them helpful when i use the l extreme filter to avoid banding. 2) In my processing steps maybe i wasnt clear enough. Point two was calibrating every single flat frames with the master bias. 3) Here i should also clearify that im doing a median stack with the flats. But in Siril you can also choose a normalisation method. I choose multiplicative because i learned that in a tutorial. But even without normalisation or when i stack my images in DSS the problem remains. So i doubt that this is a processing specific issue. Yes, i should certainly should cut 10mm off! I noticed that even when the focus is all out, the tube still protrudes. I dont understand that design choice. Until now i didnt wanted to cut because i thought when i will buy the GPU CC i will need the whole tube. I assumed wrong there.

@ONIKKINEN I dont know if this has to do with sirils conversion into fit file, but in APT the histogram is at around 50% when i took these flats. But i will try out different exposure times next time I took the flats when the scope was already indoor, but i didnt touch the focuser or camera. But next time i will take some flats mid session. I will check for further light leakage. The view finder is already blocked. The rotation in the master light comes imdeed from the fact that it was taken over two nights. I dont remember if i touched the camera or if this rotation comes from different polar allignment. Now i made another stack with only one night, but the problem remains the same. Maybe you are right, and i chased a symtom here. As you showed so nicely with the colourful image, there is a dark area around the center, which could indicate over correction. i had the same dark area the center in my m101 image. But i cant help thinking , that some internal stray light leads to the complex gradient. Maybe its like alacante suggested, that the mirror clips doing some work here. But perfect flats should handle these gradients as well. Maybe my screen is too dependant on viewing angle, and therefore leads to over correction in the center area. I will certainly try out different flat techniques next time. Thanks for giving so much thought to my problem, you gave me lot of things to consider 😃 I will report back when i find something out!

If i would only show the stacked flatframe, the vignetting would dominate and i couldnt show the problem. Thats why applied background extraction. Normally my worklflow in Siril is like this: 1. median stacking of 25 bias frames 2. calibrate flat frames with master bias 3. multiplicative stack of 25 calibrated flat frames 4. calibrate lights with master bias and master flat 5. Registration and additive stacking of calibrated lights Here (google drive) is a zip fail containing: A single flat frame, a single light frame, Master flat, a single Calibrated light frame, Master light (calibrated)