first go at auto guiding

[TiffsAndAstro]

just doing some darks and biased and i'd thought id ask

my main imaging focus is a bit soft i think, but rosette nebula is too low now after maybe 90 mins.  wondering if anyone can have a quick look notice any obvious auto guiding problems. it seemed to go well. 

i can't change the scale from pixels in phd2 its greyed out. 60 sec subs not really any wind decent ag focus, dither 7 pixels (used online calculater thing)  every 3 frames 

next up smiley face for as long as i can stay awake

[TiffsAndAstro]

My photo ,(above) obscures what I think is Nina's average error? So my error is 0.35 arc seconds?

Edited April 9 by TiffsAndAstro

[michael8554]

1. Can't see the settings as the screen grab is overexposed.

If you hit the print screen or Prnt Scrn button at the right of the top row of your keyboard you get a copy of the screen in the Clip Board that you can paste.

2. Everything is green on the status bar.

RA =  0.29,  Dec = 0.20,  Tot =  0.35 look good.

As long as your Imaging scale is larger than about 0.4arcsec/pixel you should have round tight stars.

3.   "i can't change the scale from pixels in phd2 its greyed out"

I can only suggest you reload PHD2.

Don't erase it, you will loose your settings.

Just reinstall, it will overwrite.

Michael

 

 

[TiffsAndAstro]

11 minutes ago, michael8554 said:

1. Can't see the settings as the screen grab is overexposed.

If you hit the print screen or Prnt Scrn button at the right of the top row of your keyboard you get a copy of the screen in the Clip Board that you can paste.

2. Everything is green on the status bar.

RA =  0.29,  Dec = 0.20,  Tot =  0.35 look good.

As long as your Imaging scale is larger than about 0.4arcsec/pixel you should have round tight stars.

3.   "i can't change the scale from pixels in phd2 its greyed out"

I can only suggest you reload PHD2.

Don't erase it, you will loose your settings.

Just reinstall, it will overwrite.

Michael

 

 

I changed it from showing pixels in Nina rather than phd2 that should be ok.

Apologies for the photos but I wanted a quick way to get an image on here. Doing a screen shot on that laptop then saving then transfering to my desktop is a pain.

I think my image scale is 2 arc seconds per pixel. Stars didn't look tight in test shots, but I was possibly really zooming in. Stacking stuff now.

If I did learn anything last night it's

1 resetting up guiding etc when changing target loses me imaging time.

2 image targets after meridian flip or Google auto meridian flip and implement. I skipped a cuiv the lg on meridian flip, guess I'll go watch it now

 

Ty for looking and helping. Seems I have auto guiding at least working ok in theory.

[michael8554]

"Stars didn't look tight in test shots,"

2 arcsec/pixel may be Under Sampling, leading to enlarged stars.

Or poor focus ?

"cuiv the lg" ?

Beats me.

Closest I could find was  Cuiv, The Lazy Geek

Michael

[TiffsAndAstro]

24 minutes ago, michael8554 said:

"Stars didn't look tight in test shots,"

2 arcsec/pixel may be Under Sampling, leading to enlarged stars.

Or poor focus ?

"cuiv the lg" ?

Beats me.

Closest I could find was  Cuiv, The Lazy Geek

Michael

Cuiv the Lazy Geek, sorry. he does a lot of videos on nina.

i guess this pattern i'm seeing after background extraction, is walking noise? i was dithering every 3 frames (by 7 pixels) so bit disapointed  

my 2 hours on markarian's chain also has similar noise. ill try not using drizzle on both later, but its a bit disapointing

Edited April 10 by TiffsAndAstro

[michael8554]

Was that 7 pixels of the imaging camera, or the guide camera ?

12 pixels of the imaging camera on every image is common.

Michael

[TiffsAndAstro]

16 minutes ago, michael8554 said:

Was that 7 pixels of the imaging camera, or the guide camera ?

12 pixels of the imaging camera on every image is common.

Michael

7 pixels in nina  i checked (i think) astro tools to calculate it. or some online calculator  ill try 12 next clear skies, ty. 

[Clarkey]

Nina works on the guide camera so you need to work out your pixel scale for both scopes and adjust accordingly.

I would recommend using multi-star guiding in PHD2 - looks like you are using single. Also, you make want to adjust your dither settle times / accuracy as the guide scope is still adjusting when the next image is starting. (This mat also explain the walking noise and soft stars). You also need to put your scope and camera details into PHD2 to get an error in arc secs. Currently this is reading zero. The RMS value you have is all in px, so slightly meaningless.

HTH.

[PhilB61]

No need to recalibrate guiding on every new target provided you are guiding directly through your pc and not using the ST4 port. As mentioned above you need set up a profile with guide camera and scope details directly in PHD2 using the new profile wizard if you have not already done. The guide rms figures are currently in px's so if your guide camera scale is say 4arcsec/px then you actual rms is 4 x 0.35= 1.4 arcsec which may account for the elongated stars you are seeing. This error will be more or less depending on your actual guide camera image scale.

[TiffsAndAstro]

2 hours ago, PhilB61 said:

No need to recalibrate guiding on every new target provided you are guiding directly through your pc and not using the ST4 port. As mentioned above you need set up a profile with guide camera and scope details directly in PHD2 using the new profile wizard if you have not already done. The guide rms figures are currently in px's so if your guide camera scale is say 4arcsec/px then you actual rms is 4 x 0.35= 1.4 arcsec which may account for the elongated stars you are seeing. This error will be more or less depending on your actual guide camera image scale.

I used the online tool and it said 7 pixel dither would be correct for Nina. I've not changed the multiplier in phd2

Rather than minimise walking noise I now seem to have it

 

if you look at my second pic above, I took it after I changed scale to arc seconds in Nina.

Correct cam and scope etc are listed if I look in phd2

Also dithered every three frames because I could only find examples of other people guessing. 'more' for shorter subs. I guess it's my baseline

 

Edited April 10 by TiffsAndAstro

[TiffsAndAstro]

Also, while my numbers seem to be good, and polar alignment was just a couple of seconds in both axis, my gear is cheap, so it's more than possible my gears overall error/accuracy is larger than these reported numbers.

Not sure where that leaves me, but next clear skies I'll test guided but not dithered. Maybe the inaccuracy of my gear will provide enough 'natural' (lol) dithering by default.

Edited April 10 by TiffsAndAstro

[TiffsAndAstro]

3 hours ago, PhilB61 said:

No need to recalibrate guiding on every new target provided you are guiding directly through your pc and not using the ST4 port. As mentioned above you need set up a profile with guide camera and scope details directly in PHD2 using the new profile wizard if you have not already done. The guide rms figures are currently in px's so if your guide camera scale is say 4arcsec/px then you actual rms is 4 x 0.35= 1.4 arcsec which may account for the elongated stars you are seeing. This error will be more or less depending on your actual guide camera image scale.

I put a quick stack above. Stars shapes look ok and are least of my issues we

Apologies if I sound snarky it's not intentional. I'm on mobile phone right now  and old

I'm genuinely grateful for all the help and suggestions from everyone.

Even 900sl

[TiffsAndAstro]

I recalibrated ag between those two targets but the (looks like) walking noise looks very similar in both after drizzle stack in siril.

This makes me think it could be either the amount of dither (I calculated it twice online to make sure) or how often, which seems to be based on guessing.

Next clear skies my plan is one hour no dither, one hour 12 pixels see how the turn out.

M106 because it's up and relatively big?

Unless anyone can suggest another test? Or target.

 

 

[TiffsAndAstro]

also trying some variants on stacking, i noticed half my flats look black, half white and one grey one. i did them via nina's flat wizard and it worked really well one other time i used the wizard. 

could this be caused by crap flats?

im running a few more test stacks with/without flats etc

*****

its crap flats. no idea how crap flats could introduce what looks like walking noise. will post a quick stack stretch for second opinion. i can see hints of rosette nebula, if i squint. but it could just be noise and/or because just 45mins total integration on a stock dslr.

 

Edited April 10 by TiffsAndAstro

[PhilB61]

3 hours ago, TiffsAndAstro said:

I used the online tool and it said 7 pixel dither would be correct for Nina. I've not changed the multiplier in phd2

Rather than minimise walking noise I now seem to have it

 

if you look at my second pic above, I took it after I changed scale to arc seconds in Nina.

Correct cam and scope etc are listed if I look in phd2

Also dithered every three frames because I could only find examples of other people guessing. 'more' for shorter subs. I guess it's my baseline

 

Do you know if that dither number is 7 pixels of the guide camera or of the imaging camera? I dither every 3rd or 4th sub on 120sec exposures. I think it's a good idea to experiment and see what works best for your setup.

My comment regarding the guiding figures was in relation to your second image. If you look next to your rms figures you will see in brackets (0.00") that is your guiding figure in arcsec but for some reason yours is not being displayed. I would guess there is some missing info either in NINA or PHD2 relating to guide scope focal length or guide camera pixel size.

Regarding your flats, If they are taken in the same session they should look very similar. If they are vastly different I would want to know why as yes that could mess up calibration. Having a uniform and consistent light source is necessary, I found taking sky flats didn't work for me and now use an Android tablet, display a pure white image and regulate brightness with sheets of white paper.

Stars in your last image look good and round, at least on my phone.

[TiffsAndAstro]

1 minute ago, PhilB61 said:

Do you know if that dither number is 7 pixels of the guide camera or of the imaging camera? I dither every 3rd or 4th sub on 120sec exposures. I think it's a good idea to experiment and see what works best for your setup.

My comment regarding the guiding figures was in relation to your second image. If you look next to your rms figures you will see in brackets (0.00") that is your guiding figure in arcsec but for some reason yours is not being displayed. I would guess there is some missing info either in NINA or PHD2 relating to guide scope focal length or guide camera pixel size.

Regarding your flats, If they are taken in the same session they should look very similar. If they are vastly different I would want to know why as yes that could mess up calibration. Having a uniform and consistent light source is necessary, I found taking sky flats didn't work for me and now use an Android tablet, display a pure white image and regulate brightness with sheets of white paper.

Stars in your last image look good and round, at least on my phone.

ty for this. i changed the value in nina to 7 pixels as this is the value i got from the online tool. this then effects how much guidescope dithers. i just wanted to get the correct value, didn't really study the reasoning  

using just my very overexposed flats seems to have removed the walking noise. I've post a quick post process of rosette nebula and for about 46minutes, i think its ok. it at least shows my guiding/dithering seems ok. rosette is not a great target to remove background/gradients i think. espectially with so little integration time.

[Elp]

I don't think 7 pixels is enough. I used to do 10 and that wasn't enough, so now do 30 every 10 minutes or so.

[Elp]

Using a 600d it's advised also not to use bias frames, instead subtract a fixed value (think it's 2048) from your frames when calibrating. @alacant can advise.

Edited April 10 by Elp

[TiffsAndAstro]

4 minutes ago, Elp said:

Using a 600d it's advised also not to use bias frames, instead subtract a fixed value (think it's 2048) from your frames when calibrating. @alacant can advise.

I have no idea how or what I'd even  subtract 2048 from.

Any idea what terms I can Google for info?

[Elp]

 

 

 

[WolfieGlos]

15 minutes ago, TiffsAndAstro said:

I have no idea how or what I'd even  subtract 2048 from.

Any idea what terms I can Google for info?

I don't know about other software, but in Siril it can be applied through manual stacking. I've tried it recently with my 800D and it made a small difference to the image statistics, but to my own eye looking at a stack, it made no difference. You would apply it in the flat preprocessing stage, and just type "=2048" instead of specifying the stacked bias master.

I don't know about the 600D, but personally at this stage, I would say don't worry about it and sort out the fundamentals of guiding / dithering / flat issues. You can return to bias later.

With regards to flats, NINA is great for astrocam flats but I don't find it much so with my DSLR. If you're really struggling, you can try using Aperture Priority (Av) mode on the DSLR and it will automatically set the exposure, I find a white t-shirt and IPAD screen with a white picture on max brightness to be best. Much easier, and I've never had any flat frame problems, from the first time I ever used them.

I've got to say, you've certainly come a long way so far Tiffs, lots of questions which is great 👍 I learnt a lot of this over a prolonged period of time, but you'll get there faster than I did 👍

Edited April 10 by WolfieGlos
Siril Links added

[TiffsAndAstro]

3 minutes ago, Elp said:

 

 

 

ty so much will have a read now. while i intend to get a proper osc camera, i still like the idea of having a dslr i can use in a very portable battery powered setup so anything that would improve my 600d is welcome

[TiffsAndAstro]

13 minutes ago, WolfieGlos said:

I don't know about other software, but in Siril it can be applied through manual stacking. I've tried it recently with my 800D and it made a small difference to the image statistics, but to my own eye looking at a stack, it made no difference.

I don't know about the 600D, but personally at this stage, I would say don't worry about it and sort out the fundamentals of guiding / dithering / flat issues. You can return to bias later.

With regards to flats, NINA is great for astrocam flats but I don't find it much so with my DSLR. If you're really struggling, you can try using Aperture Priority (Av) mode on the DSLR and it will automatically set the exposure, I find a white t-shirt and IPAD screen with a white picture on max brightness to be best. Much easier, and I've never had any flat frame problems, from the first time I ever used them.

I've got to say, you've certainly come a long way so far Tiffs, lots of questions which is great 👍 I learnt a lot of this over a prolonged period of time, but you'll get there faster than I did 👍

ty for your kind words. i have plenty downtime to watch youtube videos and ask dumb questions on here

i was pretty much doing what you suggest with flats before i used nina. and the previous (and only) time i used nina flat wizzard it seemed great. i need to pay more attention to the images from my camera whether its taking flats lights or whatever. also before processing. 

i think i have autoguiding going well enough. and my focus have improved lots, though maybe still room for improvement. im actually still very happy about not even using my polar scope

no more emission nebulas before i get a osc though. besides, its galaxy season and pinwheel looks to frame reasonably big in stellarium. 

meridian flip management is my next problem i think. my mount flipped out last night on markarian's chain when (i think) it got to the meridian. 

also maybe a new user profile (or whatever the correct term) in phd2 see if it will then show the x/y thing mentioned above. without that im dubious if my guiding is as good as stated.

Edited April 10 by TiffsAndAstro

[WolfieGlos]

21 minutes ago, TiffsAndAstro said:

meridian flip management is my next problem i think. my mount flipped out last night on markarian's chain when (i think) it got to the meridian. 

NINA should handle it automatically (as long as you enable it), so if it did flip, then well done 👍 I've been doing them for over a year now since I got my HEQ5, but I still watch it when flipping just in case 🙂

21 minutes ago, TiffsAndAstro said:

also maybe a new user profile (or whatever the correct term) in phd2 see if it will then show the x/y thing mentioned above. without that im dubious if my guiding is as good as stated.

I'm also going to be investigating this for myself, along with the multi-star guiding @Clarkey mentioned. I set PHD2 up following a guide (might have been Astrobackyard) early days and it uses single star, and I rarely have issues, but my own guiding last night spent most of the time above 2", which is atrocious. But then none of my images showed trailing and my HFR's ranged between 2.4-2.8...usually they are circa 2.1-2.3. Sometimes we can get obsessed with the numbers, but just looking at the output with your own eyes sometimes can suggest otherwise, but it's definitely best practise to get it as good as possible.

Edited April 10 by WolfieGlos