Fir Chlis

First clear night for about 10 days, so I was itching to get going. I’d hoped to do some exposure/gain testing, but the sky was still a bit bright (sky background 11.6), with some remains of twilight and a near quarter-moon, so I went straight onto observing. I’d put together a list of good objects gathered from threads on here and Cloudy Nights.

I made a flat before sunset and made a dark before live stacking each object.

I wanted to keep trying the SharpCap Brain and, for the first time since I tried it, it came up with a recommended gain that wasn’t 300, so I tried gain 0 with 60s exposures on the Bubble Nebula for 10 mins. The result wasn’t that good, but it did confirm that my set-up seems capable of 60s exposures with no (to my eye) evidence of star trails.

I followed this with NGC3718 and, now it was darker (sky background around 2.5 -  it’s usually around 1.3), the Brain returned to gain 300, and an 8s exposure for 10 min. I’m really pleased with the small objects in this, and this morning I loaded it into SharpCap to annotate it. I’d downloaded all the catalogs I could find in the Cloudy Night posting “SharpCap and Deep Sky Image Annotation”, and this is what it came up with. I’m very happy to see that I’m picking up some objects at magnitudes of 18.5 or so, and even one at 19.2.

Next target was NGC4631, the Whale Galaxy, again (to me) a really nice image. This was (Brain) gain 300, 4s, 10min.

Now I tried to do my exposure/gain test at gain 300 on M51, but only managed to get runs at 4s (10min) and 8s (8min) before clouds rolled in. The 8s run does seem to confirm the benefit of a longer exposure time. This is my first image of this object and for me it was a Wow! moment when I saw the detail emerge. Tonight was the first night I’ve watched closely the frames stacking, and seen the noise gradually diminish.

It was getting late now so I went for one final target M97, Owl Nebula, which I’ve only ever seen before as a tiny white fuzzy blob. This was gain 300 at 15s for 10min. A bit fuzzy, so one to revisit another night, but I like the colour.

Geoff

@Jonathan_Shields I need to experiment with gain settings on the 585MC, but the SharpCap brain function is consistently suggesting 300 as the best gain settling for me. After a few sessions without them, I started using darks, and I’m sure they have helped, especially when trying higher gain settings.

On 31/12/2023 at 10:47, Richard N said:

Incidentally I would strongly recommend using Aladin for examining EAA images. It’s a free tool used by professional astronomers. It does require some knowledge of the various surveys available to get the best out of it. I put my images in and sync them to a deep sky survey such as Panstarrs or SDSS. I then overlay data from Sinbad or Neds. It’s then straightforward to identify faint objects. You can then drill down to get all sorts of astrometric data and papers related to the objects. Took me a couple of hours to use it effectively. Time well spent. 

On 31/12/2023 at 10:28, PeterC65 said:

I've also observed a Quasar via EAA, 4C+16.30, just a little dot but I was thrilled to be able to observe it at magnitude 15.7.

 

Something I do occasionally with EAA is to check the magnitude of the faintest star I can see, usually when observing a star cluster or just a star field. I zoom in on a promising patch and compare it with Stellarium. The faintest star I've managed to observe so far was magnitude 17.5.

 

I've just seen this thread, and had a look at some of my EAA images in Aladin, while waiting for the next observing session. This looks really interesting and I've had a go at checking out what is in my images.

Quite by chance, I found that my image of M77 had a quasar in it - so that's something new for me. And by comparing with Stellarium, I've found that I am seeing stars with magnitude 17.95 (and maybe dimmer), but this is the limit for Stellarium (with all the catalogs loaded) so I can't confirm if I'm seeing dimmer stars.

I've been able to get data from Simbad, when clicking on objects in my image in Aladin, but I haven't found how to get data out of NED. As you know, Simbad highlights in red, and clicking on an object will often bring up a web page, but quite a number of times it will just say that the object isn't in Simbad (unknown by Simbad). When I overlay my image with NED, there are far more objects (highlighted in blue), but when I click on them I don't get any information unless they are in Simbad.

Geoff

Try these videos on YouTube - a series on how to set up this mount. 

EDIT: I just realised that you seem to have sorted polar alignment. 

Geoff

And this one on polar alignment  

A bit of a naff title for the thread but, being in my very early days of EAA, I'm finding it really useful to browse through the postings in this sub-forum to get ideas of what to look at. My scope goes onto the lee side of the house, depending on the wind strength and direction, so I generally just look at Stellarium and pick out randomly whatever Messier or Caldwell objects are in view from there, so the pictures on here are helpful in picking future targets. 

I'm still in the honeymoon period of looking at as much as I can each session, but I think I need to set aside some time each session for testing. I'd like to see what is the longest exposure I can get before starts begin to trail and still need to experiment with exposure /gain combinations. Although with the very dark skies here (I admit it - I'm very fortunate to live under Bortle 1 skies), long exposures matched with the lowest read noise gain settings on my camera do seem to over expose.

Cloudy last night, so I went through my pictures and had another look at these two images - Horsehead Nebula - something I used to try and pick out visually. So the first time I saw it on camera I was really quite moved, seeing this icon in real time from my own home.

Gear is Skywatcher 200PDS on HEQ5 Pro, ASI585MC, Sharpcap live stacking, Bortle 1.

First image is 5 March, 152 x 4s (~10min), gain 300, flat and dark applied, with Sharpcap histogram stretch. Second is 6 March, 25 x 8s (~3min), flat and dark, stretched. Despite the diffraction spike from Alnitak and the satellite trail, I find it to be a very dramatic image. The differences between the two images do appear to show the benefit of a longer total exposure time. I think you do need a darkened room to see the images at their best - I've just had to shut the blinds.

Geoff

14 hours ago, PeterC65 said:

I used to use the Astronomik UHC filter for EAA but it is designed for visual use and passes IR which is detected by the IMX585 as it is sensitive to IR. Because of this I switched to the L-eNhance which cuts IR and gives less washed out images with less fringing around the stars.

Thanks for the Jupiter photo - useful to see that it doesn't have masses more detail than the one I managed the other night. At least I now suspect that with my set-up, I'm not going to be getting much more detail.

I started to test different gains with the same exposure, but images became saturated very quickly with the higher gains and, with wind gusts, the imaging wasn't too sharp. At 15 seconds I was getting star trails - maybe gusts, maybe limitations of my gear.

I'll have to try the UHC sometime but, after a bit of reading, I'm unclear whether filters are going to give me much a Bortle 1 area.

And I failed to see Pons-Brooks, because (as I realized this morning) I was entering JNOW coordinates into Sharpcap, not J2000.

This was the best from a not terribly good night - C7.

10 hours ago, PeterC65 said:

Your setup is similar to mine. I also do EAA with an Explorer 200PDS and an IMX585 camera (the Player One Uranus-C in my case).

 

 

Thank you. I'll have a try at testing the stepped changes in gain that you suggested - and maybe longer exposures.

I've not tried a filter yet - I do have an Astronomik UHC which I used to use for visual - so that's another thing to try out. I'm very fortunate to live under Bortle 1 skies.

As for Jupiter, I was using the Sharpcap planetary stacking, but the live results weren't brilliant (a bit blurry), so I tried a bit of enhancement afterwards. I'll need to try some of the wavelet sharpening in Sharpcap next time. Given that you have a similar set-up, I'd be interested if you have a best image of Jupiter - it might give me an idea of what I could achieve.

14 hours ago, Elp said:

Some great results there.

If you're willing to learn it, the jump you've had from visual to EAA will be magnified if you start to employ AP capture and processing into your workflow. I mostly image because I can't really do visual due to LP, the detail you pick up doing AP just can't be matched, though I do remember the visual sessions more.

If you're sticking to EAA for now, increasing the total time per target will help. Using colour narrowband filters will help massively with emission nebulae but you'll have to increase the exposure time (or total time).

Thank you. It's going to have to be EAA for the moment, as I only have the one camera and, as I understand it, I'd be needing guiding if I was going to try AP. And I like the immediacy of EAA - it's still new and exciting to see the detail in objects that used to be small fuzzy blobs.

But last night I did stack all my objects for 10 minutes (was about 5 minutes previously) and I think I'm seeing some improvement.

I’m sure this is a common story, but, after years of visual observation, I’ve recently dipped a toe into the waters of EAA – and what a difference! No more twisting and turning to look in the eyepiece of a Newtonian, no more freezing out in the dark, no more exhilaration at seeing a tiny fuzzy blob, but also no more of the amazing clarity of the Pleiades seen through a visual eyepiece, which I don’t think can be repeated on a computer screen.

With advice from FLO, I got my Skywatcher 200PDS/HEQ5Pro set up for automated control from a laptop, and bought an ASI585MC, as an affordable camera that should be suitable for EAA for DSOs. Now I can sit indoors in comfort, connected to the controller laptop via VNC, and I’ve been very happy with the results so far. It’s not astrophotography quality (which I don’t expect from EAA) but what I’m seeing now compared to visual observation is amazing.

I’m an avid reader of manuals, so I’ve gone through the Sharpcap manual and numerous YouTube videos, but it’s a steep learning curve, frustrated by the familiar problem of clouds night after night.

These are pictures from my first session (M81, M82, and M1), like a kid in a sweetshop, picking off as many Messiers as I could without really knowing what I was doing. All were at gain 252 (magic number for the 585MC), 8s exposure, no darks or flats. M1 has been cropped and enhanced using Registax, the others are as seen, saved from Live Stacking.

Next session had a very bright moon, and I was astounded at the detail in the image. Jupiter seemed blurry during live stacking, but after stacking the video file in Autostakkert and enhancing a bit in Registax, the result is OK. But with my setup I’m not sure if I will get any more detail, as Jupiter is very small in the FoV.

Third session, I tried for a comet, Pons-Brooks and I discovered the perils of not using darks, with a green line appearing at the left of the images from a hot pixel in some of the other objects from that night. I also tried the Brain function in Sharpcap, which proposed gain 300, but I found that this introduced a lot of noise.

Fourth session, I used the Brain function again, but rounded the proposed exposure to the nearest of 1, 2, 4, 8, 15 seconds – followed by capturing darks and flats, and this seemed to improve the image quality for some objects. These were all at gain 300 with exposures of 4 or 8 seconds. Bubble and Iris seem quite nice, but cocoon is rather grainy – I’m not sure why – maybe because it needed more stretch to make it visible.

So I’m pretty pleased so far with my new camera, but would be very happy with any thoughts on how to improve what I’m seeing.

Cheers

Geoff

I’m a new starter too, having just got a camera for my scope. My solution, inspired by discussions with FLO, was cobbled together from bits I already had. 

I have a plastic crate under the tripod, with EQMOD cable and camera connected to a laptop in the crate. I have a TP-link Powerline adapter which, with the mains extension cable running back to the house, extends my WiFi network out to the scope. 
 

I then have a laptop in the house, connected to the outdoor laptop using VNC, and a VNC app on my phone, which I use when going outdoors to focus. 
 

I’m sure I’m not the first so do something similar. 
 

Next thing to try is setting up ASCOM Server on the remote laptop, so I can have the lid closed on the outdoor laptop. VNC mirrors the laptop display, so if the lid is closed you just get a black screen. 
 

Geoff

8 hours ago, Cosmic Geoff said:

To save you the trouble, the internal cells are 

Battery pack (Lithium nickel cobalt manganese, Li(NiCoMn)O2)

It is probably not user repairable, but these devices are supposed to have a relatively long life.

 

Thanks - FLO just told me that they aren't repairable. It's only two years old, but I suspect it's lack of use /charging. Put away for the summer, and last winter was awful up here - very few clear nights, so the scope hardly came out. 

Hi folks

Just found this week that my Celestron 6.1 PowerTank battery is failing (the small flat slab shaped powertank). I've tried to get it apart to see if I can change the internal battery - I've taken off the four obvious screws holding it together, but can't see obviously how to get the cover off. Does anyone know?

Thanks

Geoff

Thanks again. I see what the issue is.
 

With the OTA rotated so that the supplied (500g) finder scope points towards the mount, the counterweights easily balance, but as I have it oriented (to give, for me, optimum positions for the eyepiece without having to rotate the OTA) with the finder scope away from the mount, this is more than the two weights can balance. 

Geoff

Thanks - I’ll have a check on that. 

I’ve recently bought an HEQ5 Pro with the 200P scope, but was a bit surprised that the two supplied counter weights don’t seem to quite balance the scope, as it is sold as a set, even at their outermost position on the rod. I don’t know if anyone else has seen this.
 

Geoff

Thank you for the welcome messages. Good nights here are pretty few and far between, but when they are good they are very good. 

I started nearly 20 years ago with a Helios 4.5” reflector on an EQ2 mount, but didn’t do too much with it in a light polluted suburban area, though I did learn a lot about setting up and operating an equatorial mount. I’ve still got the log book that I started in 2002, and still record every session. 
 

Since moving to the Western Isles, I’ve been on and off, but got really serious in the middle of last winter, and started to try and observe all the Messier objects that are viewable from my latitude. 
 

Geoff

Hi folks

A quick hello, as I’d posted a couple of weeks ago in the wanted section, having broken the leg clip for my Skywatcher/ Synscan handset, and had a few responses, but I see that the rules have changed, so I don’t now have access to that forum until I’ve been a member for a while, and made some more posts. 

If anyone is able to apologise on my behalf that I haven’t got back to anyone on that thread, and say that I will do so once I get access, that would be great. 

In the meantime, I’ll try and get some more posts done!
 

Many thanks 

Geoff