drjolo

The bright star in the bottom left is 12 Vul, and the nebulosity that surrounds the NGC6823 open cluster is Sh2-86. If you look at the enlarged crop, there are some more fuzzies to identify. There is a small comet-like nebula on the bottom right from the NGC6823, planetary nebula Kronberger 9 in the bottom part of the enlarged image, and tiny planetary nebula PN G059.7-01.0 in the left part of the frame, more or less in the middle of the height. Dark nebulae visible in the right part of the image are not present either in the Barnard catalog or in LDN, but they are enumerated in the Dobashi catalog. I captured subframes for this image in the summer of 2023 during several nights under different conditions. The telescope used was Tecnosky Owl 90/540 with FF/FR with a QHY268M camera on the EQ6 mount. HSO and RGB filters were old CCD ones from Baader: 400:300:400 minutes with HSO filters, and 3x40 minutes of RGB for stars. The palette I wanted to achieve was gold-turquoise, but well, the outcome is not quite there But it is somehow consistent with my previous HSO image from this year https://stargazerslounge.com/topic/414746-cygnus-heart-narrowband-mosaic/

I do not do many deep sky mosaics - I have made a few, and they have always been two-panel mosaics so far. But the frame below was in my mind for a long time already, so late spring this year I started to collect subframes and captured the last one in September. Then I waited a long time for a proper mood to process that material - it was a little bit scary to me But eventually, I picked up these over 50 hours of data that weighed over 60GB, calibrated, stacked, and processed in Pix and Photoshop. The final color palette is not referenced by anything - I have just mapped the narrowband data to the colors of my choice, added RGB stars, and that is it. I hope you like it 😇 4K version after clicking. Tecnosky 90/540 Owl, 0.8x FF/FR, EQ6, QHY268M, 3x HSO 3x300 minutes, 3x RGB 3x40 minutes. Suburban sky, different conditions, summer 2023.

Recently I purchased 67mm Hoya ProND filters for my everyday camera. The set contains three filters - ND8, ND64 and ND1000. Once I have seen them I immediately decided to test them on the Sun. ND1000 filter alone was still too bright and I needed to stop down SIgma 100-400 lens below f/11 to reach 1/8000s exposure. I feared that resolution might be already limited with such a stopped lens, so I stacked ND8 and ND1000 filters to get "ND8000" and all worked fine. Images below are 1:1 crops from Sigma 100-400 lens and Sony A7II camera - these are single 1/8000s shots at f/7.1. And a single 1/100s shot of the Moon with the same setup (but no ND filters). I was a bit surprised some color could be revealed from the single shot only using a few adjustments in Adobe Camera RAW.

3315 group is slowly hiding at the western edge, but 3321 and 3320 sunsposts have just appeared on the opposite side. 3319 is present in the center. Celestron SCT 8", ND5 filter, Baader SC filter, ASI290MM camera. And the 3319 group evolution during one hour - how many changes can you spot?

Thank you @knobby! The solar filter itself has an 18cm inner diameter, so not quite full aperture

Another day in the life of 3315 sunspot. Celestron SCT 8", ND5, Baader SC, barlow and ASI290MM.

Thanks, @Stu! Today's seeing was not as good as yesterday, much worse, actually. And the moments of stability were much shorter, so the captured image is not as detailed, as the previous one. Full disk - SCT8" with 0.63x reducer and PlayerOne Saturn C camera. Sunspot - SCT8" with barlow and ASI290MM camera.

Today morning I spent almost one hour waiting for seeing to get better, and during this time it happened two times, so I was able to set focus and then capture a short video to stack into the image below. Celestron SCT 8", Baader solar filter, Baader SC, ASI290MM, stack 200 of 2000 frames. FL about 3000mm (GSO ED barlow). Original image, negative, and with some 3D effect added

A friend of mine (quite an advanced observer) was also impressed with this device. I think some adaptations may be done with 3D printer help.

You may also check C-Munipack https://c-munipack.sourceforge.net/ I wrote a short intro to it some time ago https://astrojolo.com/more-than-pictures/photometry-with-muniwin/ If you want to get fainter then you need to improve SNR - either by increasing aperture or by increasing exposure time. If you cannot go over 30 seconds, then you may stack images. Munipack itself allows stacking or averaging.

Several sessions - six nights or so, as I recall in the backyard and one starparty. I received mine at the end of February. I do not use it with batteries but checked what you described, and yes - I cannot place a polar scope cover when the batteries are inside.

I have been using my GTi for several sessions already and did not touch the RA screw since the first time I adjusted it. The total RMS guiding error is consistent at about 2". RA screw is accessible when you remove the label sticker. The DEC cover comes out clean and easily

I was not aware of this filter until now. It looks promising, and I am thinking about it as well

Thanks Steve! From the same session two more captures with other prominent areas:

Hm, if you do high res spectra with 1,800 grating, you may try to calibrate on atmospheric telluric lines around Ha band - they should be already present in the spectra, but identification is required. If you have calculated dispersion of your system in A/px or nm/px it would definitely help. I did it once https://astrojolo.com/spectroscopy/menkalinan-spectroscopic-binary-star/