The EQ3 DSO Challenge

[Stub Mandrel]

Well done! An almost impossible target for me from home, sadly as roofs get in eth way as well as similar LP issues. Have you got a longer scope to use on it?

[Nigel G]

20 minutes ago, Stub Mandrel said:

Well done! An almost impossible target for me from home, sadly as roofs get in eth way as well as similar LP issues. Have you got a longer scope to use on it?

Thanks Neil, I have a 750mm FL which would be a better frame, the only trouble is on the EQ3 it ends up at very odd orientations with the camera hanging off the bottom, it has a fixed dovetail and its not a very stable scope at all but I think its worth a go.

Nige.

[jjosefsen]

I fiddled a good couple of hours with adjusting DEC and RA tension/backlash, seemingly it improved a lot.

The other night I had a go at M81 & M82 I was thrilled to see that the mount performed MUCH better, the images turned out significantlybetter than expected.

Im currently processing in pixinsight, this time with flats as well as bias frames, I have a lot of noise in the background im trying to deal with and a nasty purple gradient in the bottom of the stacked image.

Could this gradient be due to bad flats perhaps? Tonight I might try to stack it all without calibrating it with flats to see if that makes a difference.

[Stub Mandrel]

5 minutes ago, jjosefsen said:

Could this gradient be due to bad flats perhaps?

Might be the moon?

[wimvb]

Gradients can have all sorts of causes. Dion from astronomy shed even had gradients caused by ground loops. Don't ask me how that's possible. When he had systematically removed the sources for ground loops, the gradients had disappeared. If you use PixInsight, remove the gradient with dbe and carefull placement of the samples.

[jjosefsen]

1 hour ago, Stub Mandrel said:

Might be the moon?

That is a very good point actually, it came up behind the neighboring building in the last half of the session.

[alacant]

2 hours ago, Nigel G said:

the Eagle neb is low in the sky

Excellent effort. Even here at 38N it's a challenge, so from UK to get anywhere near is amazing.

[jjosefsen]

Quote

Finally something that starts to look like success  - please excuse double post in the deep sky forum as I want feedback as its my first Ha+RGB (or is that HA+OSC?)image.

 

Is that shot with a DSLR and a Ha filter?

Edited August 15, 2017 by jjosefsen

[Stub Mandrel]

4 hours ago, jjosefsen said:

Is that shot with a DSLR and a Ha filter?

Yes, modified DSLR, stacked using super-pixel mode, so i had to downsample last year's colour image by 50%.

When I start doing this properly I will use super-pixel mode to stack the RGB as well and then I can get clever with the processing as I can split it to Ha, R, G & B all at full resolution and do things like combine Ha with red.

[Stub Mandrel]

Set up again, and doing the Filamentary in Ha.

I cross checked my Pa of my box with polarfinder, way out looks like the RTC has got reset :-(

Disregarding all advice I set the PA as accurately as possible and only slightly unbalanced the OTA in DEC.

Once I got guiding, it was clear things are better. Just came in for ten, went out and it's reading RA 0.66" DEC 0.50". Let joy be unconfined!

I'm going to stick on this target until the clouds come or the tree eats it.

[wimvb]

Nice! I think that polar alignment should only be out a tiny bit. Too much will mean the guiding will have to work harder. When I used Lin_guider, I let the mount drift for a while until I saw in which direction the DEC would guide. Then I switched on guiding in that direction only. This would quiet down the dec guiding, almost independent of how good PA was.

Sometimes I find Lin_guider to be more Push Here Dummy than PHD. 

(Also note the 'Accumulate frames' settings which let you average corrections over a number of frames before applying.)

[mikey2000]

Those are good numbers!

 

Mines guiding away at the Elephant Trunk at the moment.  It's a bit higher than the Filamentary but I still can't get better than .75RMS RA and .5 in dec.  Still, the pics are coming out with nice star shapes and only one annoying DEC glitch.  Today, I plonked the tripod down and it just sort of fell into a very good PA, so I'm letting the Dec guiding work both directions.  It's only performing minor tweaks.  For the most part, the scatter-graph has the dots inside the 2" circle, which is fine for me.

 

I'm just wondering if my sky is dark enough to get anything useful on the Trunk with an unmodded camera.  Time will tell !

[Nigel G]

I had a pretty good session last night with no cloud to mess things up, PHD guiding was good enough to leave the kit doing its stuff with a check from time to time, although I did have to do a meridian flip as I noticed the camera very close to one of the tripod legs.

PHD had a few wild spikes and I also noticed a regular quiet clicking on the mount about 1click per 2 seconds, might need to strip down and investigate. I kept 40 of 45 subs, 5 had slight stretched stars.

I dithered after every 5 or so subs to try and reduce the Canon banding, with the meridian flip it did help.

Sadr ( Gamma Cygni ) & Cygnus, 40x240s ISO800 2H 40m, darks, flats & bias. Modified 1200D, Equinox 80 & EQ3.

PHD2, DSS, StarTools & PS.

Cheers.

Nige.

[Stub Mandrel]

Nice one Nige. Just stacking my filamentary neb subs from last night, I lost about or or five to jumps in DEC and a couple more to (probably) knocking something, but had 21 that look good.

[Nigel G]

I have been messing around with StarTools and M16. A vast improvement to detail and better colour I think by using "Artistic detail aware"  in the colour module. and a little less developing.

I'm surprised how much difference it made. Might have to reprocess a few more again  

Click on image for full size. 2nd is reprocessed.

Nige.

Edited August 16, 2017 by Nigel G

[Nigel G]

I'm a little disappointed to see that the EQ3 images didn't get a mention in the 30s challenge winners, but when there's large scopes, big mounts, dark sky's, mono CCD's and such to compete with. The 3 winners are awesome images. Nevertheless we shall keep trying, maybe something will come up, as for the NLC challenge, still not seen anything around here that passes as NLC, guess you got to be lucky or live in the right location. EDIT: Tonight is my lucky night  they are here now, whinge and you will receive  

Whinge of the day out of the way  

Looks like its going to be clear here again tonight, no work tomorrow either  

Nige.

Edited August 16, 2017 by Nigel G

[jjosefsen]

Second attempt at imaging, first time using pixinsight.

I overdid the editing a bit, but had a lot of background noise I was trying to get rid of, and some gradients. Spent the last 2½ days fiddling with everything in PixInsight and I just wanted to get something "out" to see a final result.

When i used the SubFrameSelector script in PixInsight to weigh the images, it found that the "quality" particularly SNRWeight decreased during the session, possible due to the moon clearing the surrounding buildings and getting higher in the sky.

 

Scope & mount: SW Explorer 150 on EQ3-2 unguided

Integration time: 60,5min (121*30sec) + flats and bias.

Camera: Unmodified Nikon D7100

Moon: About 50%

[Stub Mandrel]

2 hours ago, Nigel G said:

I'm a little disappointed to see that the EQ3 images didn't get a mention in the 30s challenge winners,

A shame really, not helped by the lack of decent conditions making it near impossible to get loads of data.

Here my Filamentary Nebula, FWIW. There's still plenty of background noise despite cooling and Ha filter, but the stars are small and round:

 

[Nigel G]

18 minutes ago, jjosefsen said:

Second attempt at imaging, first time using pixinsight.

Great image, nice colour and good detail, Well done.

Practice makes perfect, after 18 months with StarTools I find new tricks all the time  

20 minutes ago, Stub Mandrel said:

Here my Filamentary Nebula, FWIW. There's still plenty of background noise despite cooling and Ha filter, but the stars are small and round

Not bad at all Neil, your picking up a lot of Ha and tidy stars, time will sort the noise out  

Nige.

[jjosefsen]

1 hour ago, Nigel G said:

Great image, nice colour and good detail, Well done.

Practice makes perfect, after 18 months with StarTools I find new tricks all the time

Nige.

Thank you!

Have you used PixInsight before?

If so, how do you like Star Tools compared to PixInsight?

Edited August 16, 2017 by jjosefsen
Manners! :P

[Nigel G]

9 hours ago, jjosefsen said:

If so, how do you like Star Tools compared to PixInsight?

I did trial PixInsight for 40 days. I got about the same final image as with StarTools, BUT I know StarTools tricks and processes whereas I do not know PI.

Startools was quicker with processing but thats not what its about.

Imagers that know PI well would not use ST over PI, I can't say the same for the other way round.

I think PI has more tricks and can produce some top images, I have not seen a top quallity narrowband or mono LRGB processed with ST yet ( top imagers prefer PI or other software).

I know people who use PI prefer to stack there data using PI too.

StarTools was designed for the imager with shallow pockets, I would say PI has the potential to produce a better final image.

Hope this helps.

Nige.

[Stub Mandrel]

Another try at the Filamentary Data.

 

[Nigel G]

Thats loads less noise with a bit less Ha showing,

What exposure times was this ?

Do you or have you thought about dithering after each sub, I found it works well with both Canon banding and camera noise, although I dither about every 4 or 5 subs.

Nige.

[Stub Mandrel]

There's loads more Ha in the image I have here. It looks completely different in Astra, PS and on SGL, despite me trying to get all my programs to usethe same colour profiles.

Five minute exposures, dithering is going to be a bit of an issue as I would have to find a way to get the computer to control the camera.

Looking at the histograms I could easily go up to 30 minute exposures if the guiding didn't have those odd dec glitches now and again!

[Nigel G]

I know its not using an EQ3 but this is what turned up just after my whinge about NLC  It pays to whinge now and again  

The problem is after NLC normally comes a weather change, heavy clouds or clear sky, heavy cloud is what came shortly after, followed by an all night downpoor.

Nige.

 

Edited August 17, 2017 by Nigel G