CKemu

Equipment:

• Scope: SW Esprit 100ED
• Mount: SW EQ6-Pro
• Camera: ATIK 490EX
• Ha for Flame/Horsehead, RGB for M42

Photographed M42 on the night of the 17th - it's been over 8 months since I've had the scope out, so remembering order of operation, the software etc was a slight challenge, so gave myself a quick target and one I enjoy imaging. Did a short run of 15 x 5 minutes per channel, slapped together in Photoshop, with a quick stretch on the data.

The Ha shot of the Flame and Horsehead is the continuation of a project from last January, finally added the data to make the panel for the Flame look less noisy, I want to do a third panel to the left, in order to capture the tail of the Horsehead region. Two panels 16 x 10 minute exposures in each panel, stitched and stretched in PS. My stars I feel are a little smidge eggy, but given how rare the chances are to get out, I feel I shall just have to live with them.

I've barely had chance to use the mount, and learn it's quirks - for the most part I had 0.4"-0.6" guiding in RA, but my DEC became a mess as the night went on, it'd guide within 0.4-0.8" for minutes at a time, and then violently swing 4-5" before correcting, guiding fine and then doing it again, with no pattern to when it'd do it...I re-jigged cables, thinking snags, and it was a mess to be fair until I tidied - but it still did it, so assuming balance was off as it got lower on the horizon....? Eh not sure and being in the UK with seldom chance to spend time gremlin hunting, this will remain an unsolved mystery.

Shot over three nights from my garden in Looe (Class 4 Bortle).

ATIK490ex | SkyWatcher Esprit 100ED | OAG/Filterwheel/Flattener | 4 x 30 x 240s (8 Hours in L,R,G,B) + adjusted master flat for dust motes.
Deep Sky Stacker for rejection, registration and alignment - all layers, levels and saturation done within Photoshop CC.

It's been five or so months since I last even had the scope out, and longer yet since I "finished" an image, so I'm certainly rusty, heck I am looking at it now and just noticed gradients (grumble), but overall pretty pleased with the result and really enjoying the clear weather and sunny days allowing me to keep the scope out and ready to go for the next night.

Oddly, I think my favourite part of this image is spotting the background galaxies and trying to find out how far away they are - IC4617 for instance is 489 million light years away, and there's fainter ones in the image, that makes me wonder just how far we can see in this image.

This Autumn has been terrible, between 50-60mph southerly winds with sideways rain, to consistent cloud cover (except during full Moons, which I swear is some kind of conspiracy!) - the scope has been a glorious lounge decoration for months.

I get one clear night, and naturally get guiding gremlins, but at -3c, I decided to let them play out as I remote controlled my scope in the garden from the warmth of the office (Suspect cable snags, it was a rushed setup!)

So here it is, the only data I am likely to get this December, 16 x 600s in H-Alpha of the Horsehead nebula, with a smidge of flame. I'd like to go and do a panel to the left and right of this.

17 hours ago, Richard_ said:

I've attempted two mosaics in the past. The first one on the veil nebula, the other on M42 Orion. I think the sweet spot for me was about 45 minutes of data per panel to allow them to merge well in pixinsight merge mosaic tool. 

For the Orion data, I think I had about 25 mins of data for each of my 3x2 panels. There wasn't enough data as there were issues with star alignment between panels with bright stars (see the weird artifact on the right). Due to weather and trees getting in the way, I wasn't able to add more time so I never finished this. 

For the veil nebula, I shot a 2x2 and added in some existing data as a centre panel which overlapped all four panels. 

The centre and top left panels were similar enough in gradient and background noise to cause no issues, but I had less time on the other three panels and you can see some artifacts around bright stars which border between other panels. Eventually, I ended up with about 45 mins on each corner panel with and the end image aligned perfectly fine without issue on the bright stars. There is a slight difference in background gradient, but that's likely caused be me

Fantastic mosaics, and they're something I enjoy the challenge of, but I always curse the multiplication they lead to. 20 x 20 min subs = 6.7 hours per channel - so 20 hours per panel, so about 120 hours for my estimated 6 panels for the California Nebula. Now I live in the UK, so 10-400 years of winters to get the data!

I've done a few before, my most recent mosaic was the Orion nebula 2 years ago, pretty much the last project I undertook as my camera died and I drifted out of the hobby for a bit (life etc)

This was 6 panels, with the 414ex, so small image and sensor crop lead to the larger panel count, might re-do this with the 490ex - I live in Bortle 4 skies, so perhaps increase the exposure time on this to.

11 hours ago, Richard_ said:

That mount and guiding is spot on to give you 1200s subs! The image looks really clean, are you going to add other narrowband/colour channels or are you keeping it mono with just Ha? 

Thank you! Honestly the mount has performed better, but various factors made it "rough" last night due to being more focused on getting the FF/guidecam to co-operate. I plan to build a complete picture of the California Nebula, initially in just Ha, and then will go back to do OIII and SII.

Just need to figure out how many panels to build the shot, and how many 1200s subs per panel.

I recently got a new mount, moving from NEQ6 to EQ6r-Pro (The NEQ is still in service, but for my observing/bar star parties). Also went from the ATIK414ex to the 490ex and with a bigger sensor comes little eggy stars in the corners, so got the matched field flattener for my Esprit 100ED.

...learning did then occur!

Never even thought about back focus and upon realising my ATIK stack of hardware came to 59mm - BEFORE any adapters are involved, I had some lessons to learn.

1x ZWO OAG2, 1x 2mm M54 to M48 adapter and 2.2mm of spacers later - I got my first light with this stack, on an object I've never actually tried to image before. Image is 5 x 1200s in Ha.
 

If you have a long post, it would be easier writing it in notepad / Word etc first, and then copy / pasting it to the forum, therefore stopping the post from "timing out"?...if that's a thing, also if it's that long, might want to include a brief synopsis ...a "TL:DR" at the bottom 😛

It is never easy eh...........manufacturing companies need to create a "BASIC" set of mechanical conventions and tolerances,.....because DEAR FUDING LORD my patience is being worn thin right now.

11 hours ago, tomato said:

I guess you could screw it all together then see just how much of the sensor FOV is unusable (if any).

Think that's the plan, take a few shots and check out the stars afterwards - for a hobby that requires patience, I am terrible at having patience and hate wasting clear nights though! ha
 

10 hours ago, The Lazy Astronomer said:

FYI, don't count the filter thickness in your backfocus, instead add 1/3 the filter thickness on to your required backfocus. 

Doesn't really help much though as you'll still be ~5.8mm out. But worst case is you may need to look for a thinner OAG, or perhaps a Starlight Express filter wheel with a built in OAG. Frustratingly for you, it may require more £££ to be spent, but not a horrific outcome (your title had me thinking something had gone badly wrong!)

The ZWO OAG is quite thin, no idea if it would attach to my ATIK EFW2 - will have to research, but that would save a good chunk of space. More £££, well I can cope with a few more if it gets me in to a position where I can use the full sensor width - but I shall test this once the part comes and "waste" a clear night.

The title stems from frustration more than actual disaster!

59 minutes ago, newbie alert said:

What oag are you using?

33 minutes ago, tomato said:

That does seem a lot of mm for your OAG, I use a ZWO item, 16.5mm thickness, which would just about make it.

I'm using the ATIK OAG for their EFW2.

So I have the Skywatcher 100ED Field Flattener ("FF" from now on) and the following imaging train:

FF > M48 to M54 Adapter (2mm)* > OAG (24mm) > Filter Wheel (22mm) > Baader Filters (0.7mm) > ATIK 490EX (13mm)

*this is on order from FLO, so currently unable to test this setup.

61.7mm total
Required back focus is 55mm ...fuuuuuuu-dge.

6.7mm which I can't really shave off, but I have an imaging circle of 40mm and the chip diagonal is 15.97mm, do you think I will get away with it? I see posts with people sweating over 1mm, but they're often DSLR users! Perhaps this is something that can't easily be answered, gosh I wish there was a tool to simulate this m'larky!

11 hours ago, Anthonyexmouth said:

ok, high cloud has cleared a bit now. what about this one?

 

I think it might have been the high cloud earlier. 

 

 

0001 Filamentary Nebula -10.00 120 2022-09-16.fits 22.31 MB · 5 downloads

 

 

Yeah, that is a heck of a lot better - the stars aren't doughnut brightness, and smudged in to discs. Glad to see you're getting data! I'm sat looking at clear skies waiting for an adapter to come before I can start making useful data again. 

1 minute ago, Anthonyexmouth said:

Odd, auto focus is consistently giving me good numbers. 

I don't know what to say, except to disable your Auto Focus and go in manually, your stars are disc like, slightly hollow and not right, and that's just using my eyeballs, HD corrected with glasses and a lot of coffee in my system!

6 minutes ago, Anthonyexmouth said:

What are you using to measure fwhm? PI is telling me 4.3.

Using the script for FWHM, I am getting 4.410px.

The smaller the FWHM, generally the better, my recent test images from my ATIK490EX / Esprit 100ED gave me 1.34px. Your stars are really out of focus, I would either suggest a Bahtinov mask to tighten the focus, or manually tweak it until that number starts shrinking in your test shots.

12 minutes ago, Anthonyexmouth said:

Really? Looks ok on my screen and the auto-focuser seems to be working ok. Bit of high cloud here

I would have to agree, the whole frame seems soft and out of focus. I popped it in Pixinsight to look for aberration in the corners, and it' hard to tell due to focus.

Okay so, last problem...well for now.

The out on the FF is an M48, and IF I interpreted the Atik OAG manual correctly, the OAG has a female M54,....so:

https://www.firstlightoptics.com/adapters/astro-essentials-m54-0-75mm-to-m48-adapter.html should do the trick? 😛

17 minutes ago, teoria_del_big_bang said:

Ah actually now I look closer I think the link to the item is not what you need, another site suggest ths has M65 male and female threads.

https://astromart.com/classifieds/astromart-classifieds/telescope-refractor/show/astro-essentials-filter-cell-adapter-for-sky-watcher-esprit-flatteners

Steve

Thank you for going to the trouble of looking this up for me - really appreciated, indeed it seems I am missing that part, ...kinda hoping that it comes with the flattener...but I doubt it - seems odd that they'd ship a scope and a dedicated FF but not the component that links the two together. I know I didn't chuck it away, found a photo of all the parts I got laid out on the table - and that bit was never there.

I see FLO stock the above item:

https://www.firstlightoptics.com/pro-series/astro-essentials-filter-cell-adapter-for-sky-watcher-ed-series-flatteners.html

If I am reading that right the FF has an out of M66 and my OAG has an M54 - so I also need to find a convertor for that, this stuff is never easy! 😛

Just now, teoria_del_big_bang said:

So is it the dedicated FF for the Esprit 100ED?

If it is I have the same setup but I cannot remember fitting an adapter but let me look at my setup as I am just tinkering with it now so wil take a few pics and see if that helps you.

Steve

Yeah its the dedicated FF for the 100ED.

15 hours ago, symmetal said:

As well as being 1.4x larger across, the new sensor has pixels around half the size so the field curvature effect of the focused image will be much more apparent with the new sensor.

This will be fixed by buying the field flattener, but this means you do have to worry about spacing but it's fairly straightforwand. 🙂

You will need 55mm between the rear mounting face of the FF and the sensor of the 490EX.

Atik 490EX front plate to sensor = 13mm +/- 0.5mm

EFW2 thickness = 22mm

So the extra spacing required between the rear of the FF and the filter wheel is 55 - 13 - 22 = 20mm

The filter glass thickness does effect this spacing though and you need to add 1/3 the filter thickness to the original 55mm quoted for the FF. For 2mm thick filters this is around 0.7mm making 55.7mm spacing required. Therefore your 20mm spacing mentioned above should be nearer 20.7mm.

However, as your new sensor isn't that large compared to say an APS-C size sensor the FF spacing isn't so critical so you can probably forget about the extra 0.7mm and the 20mm extra spacing should be fine.

The FF has an M48 rear thread and I assume your EFW2 is M42 so the thickness of any M48 to M42 adapter used will count as part of the 20mm.

So your new optical train will be

Skywatcher Esprit 100ED > Field flattener > 20mm spacing > ATIK EFW2 (Filter) > 490EX 

Hope that helps 😊

Alan

That's fantastic, thank you very much for the help with that. Really clear and helpful

So I own an Esprit 100ED - and it's served me wonderfully since buying it from FLO in 2018.

I have used it with an ATIK 414ex for years, but finally got the spare money together to get the 490EX, which has a bigger sensor.

Long story short, I noticed eggy stars in the corners, so I have ordered the Field Flattener from FLO, however having read the manual for the scope as to how it attaches, apparently you need to unscrew the draw tube adapter and screw in the adapter that fits the FF, cool, but I don't have that, it wasn't in the box with the scope, I can't seem to find it sold separately, so does it come with the FF? Was it simply missing from the original scope items (I have a canon T adapter in there for some reason...).

Any help would be appreciated, as honestly trying to find answers via Google has sucked so far.

Finally got first light on my ATIK490EX (See above!) I recently purchased the camera and the EQ6R-Pro, and honestly super happy with the results, despite clouds rolling in, 27mph gusts of wind, I managed to calibrate the mount, get it guiding and take this single exposure of NGC 6888 in H-Alpha (20 min).

So did my usual pan around the image to check on the stars/focus etc and noticed that in each corner of the image, my stars are...well eggs.

I wondered if I would run in to this issue as I've gone from my 414EX to this camera which has a bigger sensor.

Now is this going to be fixed by simply buying the Skywatcher 100ED field flattener, or am I going to have to worry about spacing, my optical train is currently:

Skywatcher Esprit 100ED > ATIK EFW2 (Filter) > 490EX

If I am going to have to consider spacing, any advice will be greatly received! I've been out of the imaging loop for a year now thanks to work, weather and my 414ex developing faults.

Late in Orion season and after many months of not being able to use my scope due to weather and work, I settled on looking at this object as I have never seen it before, and had little knowledge of.

Hazy sky, gremlins from not using my scope for so long and learning my ASI120mm and mc no longer work due to ZWO's "interesting" implementation of USB2 being broken by Windows 10 updates to force "correct standards" on USB devices caused plenty of headaches!

This was more of a test/getting back on the horse/just taking the opportunity to image - and whilst it lacks data, I am fairly happy with the result.

Technical:

Telescope: Espirit 100ED
Camera: ATIK414ex (Faulty with hardware issue, but ..well it mostly stacks out!)
Imaging/Guiding: ATIK EFW with Baader H-Alpha and OIII filters, ASI290mm for guiding (Glad I had it for solar imaging). Guiding, not sure if I need to recalibrate or just do a better job, but my RMS was 0.8"-1.4".
Stack: 16 x 600s Ha, 20 x 600s OIII (FWHM around 2.5-3.3) Shot over two nights.
Process: DSS using one Ha reference frame across both stacks. StarNet removal of stars. Photoshop CC (Current), Ha Red Channel, Ha x O3 artificial Green, O3 Blue, Levels, Colour balance/selective colour, Ha Lum/stars.

Was a joy to get back out, see something new and recall how cold it is at midnight!

The Sun isn't doing much currently, but there's a few proms and I was hoping to see something of the potential active region rotating in to view.

Got the scope out and focused up, no haze in the sky and conditions seem favourable. However the view through the scope was poor, little granulation showing and despite knowing where the optimal tuning is on the scope, I went through every position just to double check and still no hint of the proms visually. (Using GONG as my reference to find them).

Plugged in the camera, focused up and whilst I can see a smattering of detail on the surface at super low contrast, proms are not showing up at all, and increasing the exposure just creates a bigger and bigger halo around the sun washing out any potential proms.

I did a quick Google, and there's talk of this phenomenon occurring if the "ITF" is rusted. I have seen a few pictures with what looks like absolutely obvious rust, however upon disassembling mine - I am unsure, the filter is reflective (reflects my face back at me) and if I point it at the grass, I can see the world in shades of red. I will say the surface has a milky and slightly green look to it, but not sure  ..any thoughts would be greatly appreciated.

1 hour ago, Erling G-P said:

Managed to bag it, despite a very limited window towards Virgo

28 x 3 minutes = 84 minutes total.

 

SW 200PDS w/ SW 0.9 CC & Canon 700Da cooled.

1 hour ago, michael.h.f.wilkinson said:

Very nice, it surprising how even smaller scopes with shortish exposures can capture mag 15 supernovae. I managed this one in just 33 minutes with a 6" scope

This is just a crop

Absolutely stunning results from you both, and it really is amazing that a mag 15 nova can be captured with reasonably small scopes from galaxies 60 million light years away! Fantastic work! Glad to see other peoples shots of this nova.

Being a furloughed bar manager has it's benefits.

Couple of experiments in processing and trying to image less that optimally positioned objects has been interesting.

Bi-colour heart nebula section:
15 x 1200s H-alpha
12 x 1800s OIII

Honestly wish I had more data on this one, and a much better OIII signal, but learning new techniques and fighting 25 mph gusts of wind kept data levels low on this one.

Fish Head Nebula:
Ha 15x600s
OIII 17x600s
SII 8x600s

It's been fun capturing these and processing the data, so much to learn, but starting to get my stars under control now.