Martyn87

@TiffsAndAstro looks great, the pillars are definitely visible! What's your setup? 

Thanks for the replies both. I have read through what I thought were the relevant bits of the user documentation, although I'm going back through it again now (with a bit more understanding, as last time I read it I don't think I'd even taken a single exposure yet) and think I might have found the answers to a couple of my questions at least.  

The scope is indeed a Celestron SCT, C6 to be precise, so about 1060mm focal length. I'm hoping to be able to do some testing on stars soon but I've been able to get an image at least, so I'm hopeful it should work ok. The guide camera is an IMX 290 Mono so I'm keeping my fingers crossed! 

I've a couple of LED street lights in close vicinity of my back garden, but luckily I can position the scope in such a way that one is blocked by my house, and the other by next doors shed, although it would be useless for visual observing as it's much too close to the house. 

Might have to try getting in touch with the council about them though, seems people have been quite successful in getting the shields fitted! 

Is there such a thing as an idiots guide to guiding with PHD2/NINA? I've got the physical side of the setup done, OAG is in the image train, guide camera and main camera are in focus (roughly, on terrestrial objects), OAG is aligned with the long edge of the sensor and the back focus is set correctly at 105mm from the Celestron x0.63 reducer, but I've no idea how to use the thing, and I don't want to waste a whole night trying to figure out what I'm doing wrong, so I'm hoping someone can point me to a good guide?

A few things I'm struggling with at the moment: 

The mount; do I have this connected in PHD2 or NINA? I'm thinking it must be NINA otherwise I can't control it, and connect PHD2 as the guider? 

Calibration; Do I just set this off and let it do it's thing? I'm assuming it'll need to be polar aligned first?

Focus; how perfect does this need to be? I'm assuming I can't use a bahtinov mask as I will be getting the edge of the light on the scope.

Do I need to configure anything to say how often to guide? or does it just guide continuously? 

Sorry for all the questions! 

I really need to uninstall AliExpress from my phone... 

Nice little dovetail mount bought and installed last week, AngelEyes 355mm losmandy style. 

Then today, my first guide cam arrived, Toupteks IMX 290M model. 

Had a bit of a busy night tonight, knocked up some spacers/radius blocks to help me fit a new dovetail on the C6, and an adapter to get my DSLR onto an ASI OAG-L. Got to use the printer, dremel and soldering iron on the same job! 

Both designed in fusion and printed on my FlashForge Adventurer 3. 

Thanks @ONIKKINEN, I guess it's time to get a guide camera ordered! 

So I've tried stacking again without the darks, and now I'm seeing this weird noise across the image. What would cause this?

Taken last night, M27, 82 x 30 secs, C6 with F6.3 reducer, stock Canon 550D DSLR on an EQ6R Pro

Absolutely stunning!

Thanks @carastro, I used the NINA flats wizard which let's you set a target for adu, but I didn't really know what I was aiming for so just left it at default values. I can check later and take these again if needed. 

23 minutes ago, ONIKKINEN said:

That is a superb first shot, well done.

I echo the advice about dithering and only flats as calibration frames. About not seeing the tabs, they might just be hidden. Click the little arrow to the right of the screen to reveal the tabs, and you can also drag the screen more to the left to have it take more space so you can see the tabs.

Thanks @ONIKKINEN! 
I'd totally missed the arrow on the right hand side... there were the missing tabs. Told you it would be me!  

I was indeed using the script. I'll give it a go manually later today and see how it goes. I managed to get the script to work by moving to another drive, Managed to use 89Gb in 7 minutes which is quite an achievement

I'm not seeing any of those tabs to be honest. Is this part of the stacking process? I'd stacked in DSS but I've tried doing it again in Siril but it's asking for SO much disk space! 

@alacant This is what I'm missing. I'm sure it's just under a sub-menu somewhere, I've just not found it yet 

24 minutes ago, alacant said:

Excellent shot.
To minimise noise, banding and colour artefacts use, light and flat frames ONLY:
550D?,Therefore  ISO800 with no in-camera dark or bias frames; simply subtract the offset. Method here.
Cheers and HTH

Thanks for this! I'm not seeing those settings in Siril but I'm sure I'm just missing it, but I was using ISO1600 which may have introduced some noise. Back on it tonight at 800!

23 minutes ago, Clarkey said:

Depending on your set up you can manually dither every few frames - but it is a faff. Also, so software allows you to dither without guiding. If you are just using an intervalometer with the camera, then manual it is!

Personally, I am impressed with anyone who images during the summer. I am waiting for astro darkness to return with the cloud and rain🤣

I'm using NINA for setting captures rather than an intervalometer, but I guess it's basically the same thing! Once I'm guiding, I'll definitely enable dithering. 

Looking at my subs, there's a clear difference in background brightness between the first and last, quite looking forward to astronomical darkness coming back! 

I'm already getting the itch to buy a better camera, even though last night was the first time I used this DSLR 😂

6 minutes ago, WolfieGlos said:

Do you mean flats? Lights are your captures of the target.

Good idea! I use Amazon specials that run off of a USB power bank, cheap enough but proper dew straps with a regulator would be better. I’ve got by so far, but it’ll be upgraded at some point. 
 

Errr. I didn’t stack after the session due to our newborn waking up. So I fed her, slept, and now typing whilst feeding again whilst the wife readies the house for visitors today! So won’t be until later at least.

I only dedicated half of the session to M27, I’m intending to add more tonight with our predicted 3rd night running of clear skies 🤩

Sorry, I did indeed mean flats! I'll get my head around these calibration frames eventually! 😂

I'm thinking I might grab one of the celestron heater rings and aluminium dew shield. I think I have a power supply that will do the job already. 

Ah I'm glad those days are behind me now 😂 fingers crossed for tonight! 

35 minutes ago, WolfieGlos said:

Yes, you need to be guiding to dither. You can do it manually by moving the RA and DEC by hand, but you have to sop imaging, move it, reestablish guiding and then start imaging each time. Not ideal. I tried it once with a star adventurer 2i, never again! 

No, dark frames should match the temperature of the lights. Bias are captured at the fastest shutter speed (say 1/4000th second) with the lens cap on. Easy to do, and can be done at any time. They can also be reused for future sessions.

Thats a great first image, coincidentally I was also imaging it for the first time last night 😊

Thanks @WolfieGlos, dark frames were done immediately after my lights last night / this morning, so should be OK. I've taken some flats and bias this morning but they don't seem to have made a noticeable difference, maybe I did something wrong, or just have no idea what I'm looking at 😂

Guiding is definitely on the cards, just as soon as I make a decision on a guide camera! After last night though, I think I might have to sort some dew prevention first, I lost a good half of the frames I'd taken because the corrector was covered... 

How did your image come out? 

4 hours ago, Hals said:

Very good for a first attempt. Way better than my first go.

Just an observation, you appear to have a lot of "walking noise" in the image. You should consider dithering between your subs, that will take care of it.

It's a long time since I used a DSLR for deep sky imaging but I remember having to do the Holy Trinity of darks, flats and (for the DSLR especially, bias frames).

It's nice to get an image in the bag though, very well done 👍

Thanks @Hals! Am I right in thinking I need to be guiding to dither? If so, I'm not quite there yet, I have an OAG waiting to go but no guide cam to put in it.

@Vroobel I haven't added flats or bias frames. Looks like I should be able to do some flats today but I might have missed the boat on bias frames as they have to be done at the same temperature as lights...? 

Evening/Morning all, managed to get my very first DSO tonight, after much faffing with polar alignment, I managed to get a good bit of time on M27, but unfortunately lost a good few exposures to dew  rookie error! 

It's far from perfect and I have work to do on gear and processing, but this is where I'm at:

C6 SCT @ F6.3

Unmodified Canon 550D 

approx. 90 x 30 second exposures @ ISO 1600, 20 darks, no light added yet.

 

Currently taking my first ever photo of a DSO...

Are we talking DSLR or astro-specific cameras? The former might be a bit more difficult, as some of them don't support cumputer control at all. The latter should be able to be made to work in most cases. 

Edit: apologies, saw that you mentioned a couple of astro specific brands at the end of your post. I'd be surprised if you couldn't find usable drivers for those, but definitely worth checking before buying anything. 

Sbig - https://diffractionlimited.com/legacy-product-support/

QSI - https://qsimaging.com/drivers-software/

First step into guiding thanks to @cosmos! 

What about doing some Solar photography maybe? We seem to have clear skies during the day much more often than at night

When I first bought my telescope, I had a good few nice nights where I sat out looking at stars, the moon etc for a few hours, but I didn't have the gear to do any proper astrophotography. Now I have most of the gear, those nice nights seem to have vanished completely. I'm hopeful it'll clear up soon but I'm also a realist, I like in the UK, the weather is crap. The way I look at it though, once my rig is built, it costs me nothing. I've bought most parts used so they're unlikely to lose too much more value, so if I only get enjoyment out of it a few nights a year, I need to make the most of it.