GalaxyGael

20 minutes ago, ollypenrice said:

This is an interesting topic for all sorts of reasons. I think you could take your point still further by noting that, until quite recently, the best images of Jupiter ever taken from the earth were taken by an amateur with a C14. Take a bow, Damian Peach. Mr Peach now has access to larger telescopes but the point remains. This is remarkable.

In the mid 1990s, when I discovered astronomy, I was in awe of the deep sky images made by David Malin using a large professional reflector. With the exception, perhaps, of certain very small targets requiring large-scope resolution, I and thousands of other amateurs can now take better ones using three inch refractors.

Surely it's the existence of this astonishing technology which has triggered the present level of participation in astrophotography. People do it because they can.  Far fewer people wanted to spend 40 minutes glued to a manual guidescope after hypersensitizing their roll of Tech Pan in order to end up with a monochromatic smudge.

Cycling can only become popular once someone has invented the bicycle. Ditto astrophotography.

Olly

True, it has entered the pug'n'play era with automation and the advancements in CMOS are astounding. Less need for more complicated new optical designs for scopes to a certain extent. Add to that, new algorithms for processing that are becoming single click and will later be (my future prediction) integrated into real-time EAA.

I still use slit CCDs with 28 um pixel cooled to -60C in the lab because it was bought 10 years ago, but is astonishingly linear and the noise, while high, is very precise and consistent when calibrating spectral data. For imaging the new backlit, high QE sensors (even OSC) have changed the game. I still love a CCD, havent used one in anger for years since I like my autofocus to finish on the same night as I image But I like them emotionally as they are the closest digital imaging tech to the Bell Labs era of discovery with physical twist knobs rather than keyboards.....I digress

New CMOS being developed at the moment will remain zero electroluminscence that some older CMOS (like the amp glow when reading CCDs), a little higher QE, deeper wells, reduced power requirements for cooling from transistor design and the possibility for photon counting. CMOS have a lot of future capabilities for deep IR and hyperspectral imaging beyond insgle line scans, doubt they will make headway from ground based astroimagers. But the combination of new imaging capabilities, open source full capability capture and processing software, complete integrated travel rigs that are sublime as imaging setups have (thankfully for folks like me) removed the need to be out there for hours in the night. 10 minutes setup, press play and go back inside and that includes lifting the whole rig out and plugging in. Amazing

Indeed, a wonderful finding, and nice to see this team work with others to confirm their data including Bray Falls in the US who also put in over 110 hours to independently confirm it in wider field with O[III] and blue filtered data for continuum subtraction. The paper in RN AAS is a nice start, but radial velocity and spectral measurements will hopefully figure our whence that gas came and where its going. The plethora of PNs, and oxygen and hydrogen rich nebula scattered in the skeleton of M31 is lovely to see with such deep exposures at the pixel scale and focal length of the masses ;).

They found that interesting pillar of O[III] emanating from close to the core and a huge O[III] containing nebula bursting in the direction of the main O[III] gas cloud. Interesting stuff. They didn't pick up the small dwarf galaxy just a little away from M32 that often shows in broadband images though.

wonder what a team of 100 of us within a usable pixel scale and fov region could do if we each contributed 10 hrs.

I would be very keen to do this as a new type of SGL challenge @MartinB 🤔 with someone.... you never know what's out there. One of you will need to have PI and have a penchant for continuum subtraction maybe....

CS

Hi all,

Does anyone know the diameter of the dovetail part of the 2.5in (FTF2535HD and similar) feathertouch focuser adapters? I refer to the diameter of the opening with the PTFE coated inside with clamping screws.

A typical example is adapter A25-2003-1.

Thanks.

2022 was the wettest, cloudiest over our way too, but those are lovely and (personally) very much like the NB monkey head with a decent plethora of the star field 👍. Hope 2023 is better

18 minutes ago, old_eyes said:

At 300mm FL I assume you are using a camera lens. What F ratio are you operating at? The Epsilon 180 is F2.8, and therefore pretty fast (near RASA fast). As I noted, I only used 2 hours exposure to get that image, so depending on your F-number and skies, you should not have to wait too long for a nice image.

No, it's a 60mm f/5 quintuplet and already getting all the colour through after 1.5 hrs.  Not like your 180ed or my 130D but thankfully it's a fairly bright target and comes through nicely on the scope/camera combination with similar fov to yours. Houses cut it off for me 1 hr after meridian so it will get 2 hrs or so before moving onto the main targets of the next few nights. It's a nice target group though

Lovely, started a project on this with the smaller fra300 and asi2600mc, nice to see the features.

Nicely done, I like this target too. Quite a few of nice Barnard objects at that scale/fov when I went looking to make a wish list. 

Nice one, decent fov at 750 mm. About the max fl for me too with 3.76um pixels. 

Very nice indeed, trying to build up exposure time doing this target group myself with 300mm fl and aps-c 2600 OSC, similar fov. 

1 hour ago, tooth_dr said:

I use SGPro which doesn’t do synchronous dithering so I just accept loss of a sub.  Two minute subs makes this ok. In the past with my CCDs and 20 minute subs, I used APT to synchronise dithering, since losing a long sun was a disaster. However APT doesn’t offer the framing wizard so I’m sticking with SGPro.  I have briefly tried NINA but didn’t stick with it. 

Good to know, I'm a 2 min sub afficionado also. I switched during the summer to Nina and found it to be amazing, coming from the dso sequencer in sharpcap. 

Looks like you have all possibilities covered there. Very flexible arrangement. On the synchro dither, do you sacrifice a sub on one camera and link the dither wait period to sync with the next pair of subs or another method?

3 hours ago, ollypenrice said:

Very deep indeed on the VdBs. We don't often see this one, the Heart and Soul grabbing all the attention, but it's a nice region. The Stock cluster is lovely.

Olly

Thanks Olly, I had two clear and very cold nights where the 60% moon didn't rise above the roof tops until later in the night. First of a couple of images where I had a scope this wide, liking it a lot including the ability to carry the whole assembled rig out in one piece.

6 hours ago, tooth_dr said:

Very nice indeed: soft blues, central red region and wonderful star field colours.  You got the balance between stars and nebula just right imho. 

Thanks Adam, stars and all their clustering are my favourite of all objects even though whats behind them was tempting to exaggerate. The reds with zero filtered broadband appeals to me too when it comes out right, when the colours are mixed with dust, reflection nebulosity etc.

My latest and likely last image of 2022 was the mixed reflection and emission nebulosity region around the vdB14/15 and Sharpless 202. Captured with OSC and a small 60 mm refractor, which I borrowed and really like.

Toyed with more severe star reduction but I like starfields too much and nebulae are best supporting actors (to me) in broadband, so this is the compromise that I like that shows the slight hazy reflection on thin dusty overlayers such as near Stock 23.

Some acquisition details:

Askar FRA300 quintuplet, 300mm at f/5

ASI2600MC Pro at gain 100 and -10°C

610 × 120 s (20h20')

OAG with 290mini and iOptron GEM45 

Processed in APP and PS CS5

Clear skies all

Very nice, neat idea to get RGB with the osc to mix with mono. Assume no filter wheel at all?

20 minutes ago, ollypenrice said:

I would struggle to do without PI's ABE, DBE, SCNR green and now BlurXT. I also use LHE but as a layer in Photoshop!   That's all I use but I rate them as 100% essential.

Olly

HLVG (Hasta la Vista Green) is almost identical to SNCR and is free for PS, maybe you know about it already...

I think NoiseXT even on non-linear images in PS is very useful. His starshrink tool, when careful is OK too.

Here are vdB14 and vdB15, a pair of reflection nebula that merge with ionized hydrogen emission nearby. Also see some gentle light scattering from thin dust around the open cluster Stock 23 and elsewhere in the region.

Capture with the Askar FRA300 and ASI2600MC Pro at -10c with gain 100. no filters aside from the integrated IR cut in the 2600.

610 x 120 s (20h20') integration in Bortle 6/7, about 60% moon. Stacked and processed in APP, with PS CS5. Captured with N.I.N.A. over 2 full crispy cold nights. This version resized to 2048px height.

Curious to see also, although it's APP and Photoshop for me. I did see a luminance image comparison on astrobin and my first thought was that it seemed to have some artefacts similar to  topaz ai, which I do not trust. Need to know, irrespective of training, how it does the process since adding what it determines to be correctly scaled hst data(?) or another process based on data extraction from some source other than the image being processed, is dubious to me imo (but I do not know how it works I side). Let's see in time. It might well be a cleverly trained sharpening, blurring and erosion option, where it learns the sharpening or related processes based on ideally captured data, rather than adding other data. That would be interesting. Would like to know either way out of curiosity.

https://www.astrobin.com/full/ylvwu6/0/?utm_source=astrobin&utm_medium=email&utm_campaign=notification&from_user=106258

Mind you, that astrobin process may have fallen foul of the blurxt settings?

My only image for an age...what an Autumn !

So this is a bundle of nice clusters including the fuzzy butterfly, lawnmower cluster, ying-yang cluster (NGC 663, NGC 659, NGC 654, IC 166) and some others. Widefield with an Askar FRA300 and asi2600mc, ~10.5 hrs of 2 min subs under a 95% moon without any extra filters. Captured over the last two nights in the fresh bitter cold.

Processed in Astropixel Processor with 2nd order LNC with 3 iterations to help with moonglow gradients and a Bottle 6/7 sky. PS CS5 to finish.

You're off to a really good start for a first image. Read up on APP tutorials because the all important stretch is handled there really well, and might be an easier entry to good stretching that more manual options which you can also learn and master once you get a feel for various degrees of stretching, which are useful for different types of targets down the line. Olly outlined the things to watch for in a stretch but APP takes care of that for you, to different levels of stretch. 

Learn and practice light pollution removal tool and star color calibration to get a well corrected background and object color, and then the tips for the right hand side sliders to get a first round of post processing. 

The red button with a question mark on it in APP brings up the how-to dialog for all those sliders. It gives a great starting point to have an image for further processing, especially if you are using APP to stack. 

Very good start by the way

That is a beauty, a fine wine for your eyes. Great the scope carries on with another long term owner. 

Having a good angle between the laser and the sensor, and a suitable distance will allow you to see the periodic reflections from the sensor. If you have not done so, its useful to do this in near complete dark so you can identify all the dots, and then let some light in so you know where you are!

In a good sensor the cover slip that is just over the sensor (you cannot see this easily) is perfectly parallel and since it is a slightly brighter reflection it should be fine. I use the dimmer actual sensor reflection, even on an OSC sensor. My aim was to get what records the data to have no tilt just in case the cover slip had some (but its moot really in the end). It is easy to identify as this dot will be in line and periodically spaced to the rows of other reflections from the sensor. Focus on the dot that has a close-by partner dot, which is the cover slip. The other (third) one further away is likely the AR or Ir-cut glass, which you can ignore. Depending on the angle of the laser, you sometimes might not see this reflection anyway. I did not notice any adverse effect from microlenses, bayer matrix arrays or the texture common to larger CCD pixels (CMOS are flat), so I always use the central periodic dimmer reflection of the sensor itself. Seeing the square array of dots really helps to identify it unambiguosly and that square array of dots will rotate around the central dot. Once the central dot stays put, you are good to go.

For gauging the movement, 2-3 mm is quite a large circle, but will depend on your optical system as to how much that will cause mis-shapen stars. It can be annoying to make so many small adjustments, but that sensor central dot can be made to almost rotate on point. Mine has the tiniest of movement, it used to make a huge circle since ASI did not place the sensor flat in the first place. As a reference, when ideally flat, my ASI2600Mc tilt plate has a clear gap on one side that you can look through :). yours might be much better.

Happy tweaking with a small hex key in the dark !!!

ASIDE: eventually I had to put mine on a shelf in the closet and get my knee pads on.

The is such a lot of information in this deep exposure, very nice Göran.

Based on Maurice' squery and your slight modification can I ask a question also on the reds/browns in these regions from the experience of all of you?

I image just in RGB from OSC (ASI2600MC), and with a relatively deep exposure, I sometimes tackle this issue. Here is 19hrs on IC1396 region with the Epsilon 130D, and aside from reds, blues, there are also the purples and browns that come from adjacent stars (I assume) reflecting/scattering from the ionized emitting gases. It is these colors that attract me to RGB over NB in general. Thisimage can be pushed more to the red, but I think the balance is close enough to right. When you add Ha to your images, is the Ha signal the guide to what is 656 nm red (like Maurice's Ha stack), and other regions where there is dust is subsequently colored based on that overall balance. Or does the layering of Ha cause its own color balance issues when added to an RGB image that is correct before Ha addition? What do you use as a guide to ensure that added Ha is not coloring signal that is e.g. pink photoluminscence from nanosized carbons in the dust for example, or other types of dust.

Sorry to hijack your thread Göran

On 31/03/2022 at 11:01, Concordia000 said:

I have the Moonlite and it never slipped for me. Admittedly I don’t use a full frame camera nor a filter wheel or an OAG.

The Moonlite is quite heavy and they only make motorised versions now. It’s a great focuser but if you want the best feel for a manual focuser, go for FTF.

My imaging train is also light. I use either an M63 threaded reducer/flattener (which would fit the Feathertouch). Moonlite has M68 thread meaning I could use the big 3inch reducer that eliminates all vignetting. M63 to M68 adapter is a easy fix for either option. For max weight, I have the 3inch TSRED379 reducer, a couple of spacers and the ASI2600MC. that's it. Comes to ~ 1.5 kg.

Forgot to add that TS still have a few manual moonlites in stock that will fit with the M90 adapter I have to mount it to the scope. So I can get the FTF2525 or the 2.5 CFL moonlite for this carbon tube, and searching around shows that both companies are have some issues/limited stock/only motorized options for moonlite etc. I need to upgrade this focuser if I am to use it for imaging instead of visual, so advice welcome.

I found a review on this scope from years back here on SGL, the TS version (mine is Tecnosky) and it has the Baader diamon steeltrack. That is a great focuser, but only 2".