alexbb

Thank you! How did it go?

I remembered that I had this data unprocessed too so I gave it a try. The dynamic range is huge on this one, from the darkest areas in the galaxy to the brightest. To bring up selectively some regions I'd need to make some uneven masks which is not really my style. So the image is a bit flat compared to others, but I tried to display it more "naturally" if that's allowed to be said. For this image I used data from multiple sessions as follows: Canon 550D + Canon 50mm F/1.8 @F/2.8; Canon 6D + 70-200mm F/4 L @70mm wide open; - 3 panels with each setup, 21-27 min each panel with each camera Canon 550D + Carl Zeiss Jena 135mm F/3.5 wide open; 2 panels covering the galaxy region, 15min exposure for each panel; 4 panels covering the Rho Ophiuchi area, 15-51min exposure/panel Canon 6D + Canon 70-200 F/4 L @200mm wide open; 4 panels covering the Rho Ophiuchi area, same as above. And here's the picture: Clear skies! Alex

Thank you all very much!

@GreatAttractor, thank you so much for ImPPG, I used it to align the frames! https://stargazerslounge.com/blogs/entry/1808-imppg-image-post-processor/

Unfortunately I failed to plan and a roof was right in the Moon's apparent path so I had to pull the mount a few steps back during the first part of the umbra. The other part went well and earlier during the evening I shot a plane transit too. Still a bit disappointing for me for not being careful enough. And in case the animation doesn't load:

Many thanks to you too and clear skies!

Thank you all very much!

Thank you, Roger! Glad you like it!

Thank you, Alexander! I'll see what I can do. The Ha channel is already boosted compared to OIII. The OIII is strong in this one

I've been recording data for a long while on this one. I restarted this year with the 200p, but in the final image I also included data shot last year with the 130PDS. I have now in total 7h of Ha and 8h of OIII from last year + 12.5h of Ha and 13.5h of OIII from this year + 2h of each LRGB from the past week. The 130PDS was carried on top of the AZ-EQ5 last year and this year the EQ6-R carried the 200p. Poor tracking last year, but a bit of deconvolution helped and the poorer data went in in a very small ratio. The EQ6-R guided at 0.6"-0.8" RMS all the time. Perhaps not really enough for a desired 1"/px scale, but deconvolution helped here too. Until now, it seems that the Astronomik OIII filter reflects much less than the old Optolong OIII filter. The camera used was the ASI1600MMC and guiding was done through OAG. Before calling the image final, what are your thoughts on improvement? Thank you and clear skies! Alex

Thank you all! Can't wait for Orion to rise again, though I have plenty of other targets to shoot every time of the year.

I found both the non reducing OVL flattener and the SkyWatcher 0.85x reducing flattener needing a bit more than 55mm back distance. I was limited by focus in-travel limit to ~60mm back distance (from the end thread) with both and decent results. The ASI183MC's sensor is smaller than a Canon crop sensor, but also the pixels are smaller so the defects will appear emphasized. I heard that the TS 0.79x reducing flattener is better suited for this scope. Search the forums for info about this one.

I received one Saturday and I had a chance of testing it. No dew on an unprotected Canon 50 1.8 STM. A half charged 10000 mAh powerbank went flat in ~3 hours though, the heater felt quite warm at hand.

Thank you, Cara! Skies were decent, though far from the best I had in that area other times. Usually it's a Bortle 2 there, but now there was something lurking in the air, you can see some weird gradients to the right, perhaps some passing cloud not visible in a single frame. Still a Bortle 3 maybe. I exposed for 3 minutes with each camera. 2 x (9 subs for one panel with a bit of moon and 7 subs for both other 2 panels, without moon). I put them on the AZ-EQ5 and dithered every frame. Alex

This is one of my first tries at Milky Way wide field. The aim is to cover this area at high(er) resolution over the summer/years. For now, last night, I managed to shoot a bit over 1h with 2 Canons. 50mm @F/2.8 with the 550D and 70mm @F/4 with the 6D. Here it is:

Thank you all, appreciated! Maybe some sunglasses are required for a better view Why don't you give it a try? If you didn't have OIII data, you certainly have now

Thank you!

With the summer coming, it seems that clouds will go away for a while too. I was able to resume data acquisition for the M27. I have now ~6h of Ha and ~7.5h of OIII, shot with the ASI1600 through the 200/1200 newtonian. The plan is to gather in total ~12h of Ha, ~12h of OIII and ~3h for each LRGB, maybe some iR too. I'm making the data I have so far available for you too, maybe you want to have a play and I'm also curious of your processing outcomes. I have 7h of Ha and 8h of OIII shot last year with the 130PDS and the above mentioned. You'll figure out which is which. I only ran a DBE on them. Here's my first version: Clear skies to you too! Alex M27-F588-2018-04-22-O3-480min-stackAPP_DBE_crop.fits M27-F588-2018-05-12-Ha-all-420min-integration2_DBE_crop.fits Ha-200p-22200s_DBE_crop.fits OIII-200p-27000s_DBE_crop.fits

Thank you! I used an unmodded camera, but really good skies help a lot. There's a lot of dust in Orion though, not only Ha. The last version with ~double the exposure time is this one:

From the looks of it, the CQ350 seems heavy... any online findings about the weight?

If everything above fails, PIPP will easily do

Yes, you're right, the flattener was the TS one without reduction. Since I read the article I always erroneously assumed that it was the reducing one. I even considered the combo myself. Thanks for spotting!

Maybe this is also worth checking: http://interferometrie.blogspot.com/2015/08/100550-esprit-optics-fitted-for.html

The significant difference comes from the low read noise and the recommended typical usage. With a CMOS sensor camera you'd probably want to take more shorter exposures. The mono Panasonic sensors found in the ASI1600/Atik Horizon/Qhy163 has a full well of ~20000 electrons which is converted by the ADU to a value represented on 12 bits (0-4095). Using a gain for the highest dynamic range, the ADU will indeed limit the resolution of read data. But for the highest dynamic range, the read noise is highest and this is not the best way to use such a camera. As I said in the beginning, with these CMOS sensors, for optimal results you should increase the gain - in order to benefit from the lower read noise. This also decreases the dynamic range. For an ASI1600, above a certain gain the dynamic range decreases enough so that the recorded data can be represented on a 12bit integer value so the ADC is no longer the limiting factor. What you need to do is to record as many exposures as you can. Be aware that compared to the typical usage of a camera with a CCD sensor with long exposures, a sub taken with a CMOS sensor will be much darker and a stack of subs as well. In order not to lose relevant data, make sure that the stack is represented on at least 32 bits. Some applications (ie. Registar) doesn't work with 32bit float fits files, but most of them do (PixInsight, APP, GIMP 2.10). If you want a comparison, is like having a cup filled with water (stack of long exposure CCD subs) or the same amount of water in a bucket (same amount of hours stack of short exposure CMOS subs) - the water will have different heights.

This is very nice!