tomato

Well, this is an instance where my experience has a different perspective. I am currently imaging at 1050mm FL at 0.94 arcsec per pixel. I monitor my subs through NINA and sometimes (rarely) I can take 20+ 3 min subs with the HFR values staying steady, but other times it can drop off straight away, and gets worse with every sub, even though the OAG performance is steady. Visually the subs don't look much different to my eye but they are firmly at the bottom of the list after any star analysis in APP. Focus stability on my rig does depend on orientation, elevation on the sky and temperature, stability improves after midnight when presumably everything has thermally settled down. I have a dome so the kit is permanently set up but this time of year I can see daytime temperatures of 30 degress inside so it definitely isn't a constant temperature environment. It is worth noting that my rig is both big and heavy, as this I think is a contributing factor to focus stability. This isn't a big deal for me as I use the autofocus routine in NINA, but putting a Bahtinov mask on and off every 5 subs would get tedious.

I’ll watch this thread with interest as I have the same issue, although I image galaxies at 0.94 arcsec per pixel, which doesn’t make for tight stars. Still a very good Needle BTW.

Thanks Lee, Yes, there have been a few late nights on the trot lately, but you won’t hear me complaining about the lack of sleep. The clouds will no doubt return soon enough. Steve

April is again proving to be a productive month, it's nice when the clear nights coincide with the season for a galaxy fan like me. Some of these have been posted in the imaging challenge thread, as far as I know it's ok to post them again here, apologies if not and Mods please remove if I have infringed the rules. All taken with the Esprit 150/ASI 178 dual rig, binned 2x2, all calibrated and stacked in APP, all processed in Startools, APP and GIMP. Thanks for looking. NGC3169 & NGC 3166, 6.6 hrs total integration , two interacting galaxies in Sextans. 7.8 hrs on Arp 84, "The Heron" two interacting galaxies NGC 5395 and 5394 in Canes Venatici. This is 7.8 hrs on NGC 3938 in Ursa Major, no popular name as far as I can find out, but "Another Little Pinwheel Galaxy" would be quite apt, I reckon. And I wasn't planning to image any of the big hitters this season but after seeing so many fine examples of M51 on this sub forum, I couldn't resist. This is 3.6 hrs integration.

49 hours, that's longer then my working week used to be! A superb image.

Great wide field image, lots of other galaxies visible also.👍

I am feeling like I am hogging this thread a bit but I know my galaxy imaging window is closing fast now for this season. So this is Arp 84, "The Heron" two interacting galaxies NGC 5395 and 5394 in Canes Venatici. It is the same imaging rig, dual Esprit 150/ASI 178 cameras retro fitted fitted with Peltier coolers. 7.8 hrs total integration all binned 2x2 so imaging at 0.94 arcsec/pixel. Captured over two effectively moonless nights, elevation >60 degrees, guiding at 0.5-0.6 total RMS. L 78 x 3 min RGB 26 x 3 min each Calibrated and stacked in APP, processed in APP, AP and GIMP. I have rotated the image clockwise 90 degrees from the capture orientation otherwise the Heron would be flat on his back.

Assuming you have the camera installed at the correct backfocus distance for your RC (or somewhere close) and the scope is pointing centrally at a bright star, set Artemis to loop at half second intervals and then move your focuser in and out. It’s not quite live view, but you will get feedback quick enough to make progress. Please don’t give up on the 314, it was my first ‘proper’ Astro camera, it is what got me hooked on AP.

This is 3 hrs of Lum on the Esprit 150/ASI 178 rig, binned 2x2 so imaging at 0.94 arcsec/pixel. It is not an ideal subject, only about 30 degrees above the horizon and right above the neighbour's roof, guiding wasn't exactly brilliant. The images have been stretched to within an inch of their lives to try and establish if anything was visible. The first image is the whole of the FOV, with 3C 273 in the centre. A pixel wide protrusion is visible on the stretched image in the same orientation as the jet, see stretched crop and library image. Is it the jet? Well, it is in the right place and the right size, and it is very, very faint, but then there are other jet like artefacts(?) visible in the image so maybe I'm being a little optimistic. However, if it is the jet then it is a testament to how far AP equipment has come. OK, I’m using a 6” refractor, but the camera costs £322 from FLO. AP is a strange hobby, this is the poorest quality DSO image I have taken this season, yet it's the one I'm most excited about. Thanks for looking.

Nice one, only looking on my phone but some of the brighter HST objects are visible. This is another project I want to do but will probably miss this until next year, Astro darkness rapidly diminishing and I guess it would be best for the region to have a decent elevation on the sky.

That's a cracking image, one of the best I have seen on SGL of this FOV, and only 5.5 hrs integration, you have made the most of every minute. 👍

If you are combining the channels in APP, you can adjust the individual channel sliders in the combine RGB tool on the left hand side until you get the desired colour balance then save this file. I would agree with @tooth_dr, your original looks to have a pink hue overall. Having said that you have some great detail, and the outer arms of M106 are very well defined, something I struggle to achieve. Great framing also.👍

Those incredibly luminous globular clusters are also in there.👍

Planetary processing, that might work. I do have a nice candidate for the jet on the one hour stack, it just happens to be in the wrong place...

Here is my next effort, 6.6 hrs on NGC 3169 & NGC 3166, two interacting galaxies in Sextans. Captured over two nights using the dual Esprit 150/ASI 178 rig, the cameras are the uncooled type, but have been retrofitted with Peltier coolers and fans to keep them at a constant 3 deg C, to hopefully achieve more consistent calibration. Capture details: L 66 x 3 min R 26 x 3 min G 15 x 3 min B 25 x 3 min All binned 2 x 2 so imaging at 0.94 arcsec/pixel OAG on a Mesu Mk 1 mount, running at 0.65" total RMS. Calibrated and stacked in APP, processed in Startools, AP and GIMP.

Totally agree, I’ve got an hour on 3C 273 so far and there is no sign of the jet.

I don’t think the short sub approach will work on the 3C 273 jet, it appears to be separated from the core of the galaxy which is also less diffuse than M87, and then there is the remoteness to deal with. It’s going to be my next target now it’s at the optimum elevation. Best of luck!👍

Hi Jonny, I think the general rule of thumb is the total RMS guiding error to be no more than half of the imaging resolution, so you are OK if your HEQ5 can continue to perform at the higher end of it’s demonstrated performance range.

I started off doing Bahtinov Mask focusing by eye but moved on to Bahtinov Grabber, after I found out about it. I found it easier to fine tune to a number rather than by eye.

Nicely done. I see what you mean regarding the bright stars, my tiny FOV set up for galaxies such as these means I rarely have a bright star in the frame to contend with. I suppose you could crop them out and see how much further you can stretch it but that would lose the nice wider perspective on the galaxy. My own attempt on NGC 3184 was OK with 4 hrs integration but was disproportionately better when I added in a second session of 4 hrs, even though the data was inferior to the first night's imaging.

Another glorious image Goran. It strikes me that with your equipment and skies, it doesn't matter where you point your scopes, you will find something interesting. How about doing a "Hole Observatory Deep Field" , just point your scope at an empty piece of sky, and see what you find? 😉

I couldn’t see any difference between PI’s and APP’s calibration and stacking routines, except I find APP easier to use. PI has a vast range of tools however, and some of the scripts are excellent, the photo metric mosaic script for example, got something decent out of my data where all other packages failed. For AP processing I would spend the budget on PI rather than PS given that there is now Affinity Photo as a cheaper alternative to PS.

It’s does seem to be easier to see on shorter integrations.

Thanks, I’m with you, nebulae are beautiful, but they are a bit local.😊

Thanks for the comments and info, Steve. Wow, how big and bright are those globular clusters? I think it’s amazing that they can be detected with amateur kit at that distance.