The "No EQ" DSO Challenge!

[Filroden]

Just got the right adaptor to connect my new 85mm lens to the ZWO and reach focus. Not tried at infinity (I don't have a clear enough view) but it reached focus at every other distance (unlike the original adaptor I mistakenly ordered).

However, focusing is going to be a chore. At f1.4 there is no forgiveness! I just tried my first RGB daytime photo (just what was in view from the desk) and I'm really going to have to work on refining my movement of the focus ring.

Here's a small crop of the full image (there was a lot of reflection in other parts of the image and I haven't adjusted the white balance for the indoor lighting. I thought I had this in focus and maybe I do for the picture but the frame is out of focus. Thankfully, this is a close shot where that's going to have a bigger impact. I'm hoping infinity will be easier.

Now I just need another clear night to properly test this and use the HFW measure from SGPro to refine the focus more precisely.

An on that note, my new autofocuser for the refractor should be arriving soon so I can automate focusing between filter changes and every 5-10 minutes depending on temperatures, etc.

[Nigel G]

6 hours ago, happy-kat said:

The first image has nice stars, tight.

Is the last image unmodded?

First orion- flame is modded, second is unmodded H&S is modded.

[SteveNickolls]

Lovely images Nige, well done indeed. So looking forward to doing some wide field of Orion later this month (weather permitting). Amazing what can be obtained using quite few exposures-that's great!

Thanks for posting,
Steve

[Nigel G]

6 hours ago, Filroden said:

I love the colour and sharpness of the modded Orion. The Ha really comes through and you can see it extend into the region to the right of the Horsehead. And the stars are perfect. I love their subdued feel. There are signs of hollow stars again so I think one of the StarTools processes is eating them. 

I need to check the original subs to see if its the lens or a processing step causing the star problem. It looks like its there when first stretch is applied.

With the modded camera I have used shorter subs, 30s on orion and 60s unmodded, I think this is why the modded images are sharper, the H&S has just 58 x 20s subs and is a ton better than my first effort.

The CLS CCD filter seems to dim the stars compared to no filter and give them a blue tint, I'm reducing the colour saturation by around 75% with the modified camera.

It is without a doubt gathering much more Ha.... With the original Orion I had to mask all the nebula's and isolate them in ST, but with the modified, no mask is needed.

Cheers

Nige.

[Stub Mandrel]

4 hours ago, Nigel G said:

First orion- flame is modded, second is unmodded H&S is modded.

Keep playing with the processing then, the detail of the first shouldn't stop you being able to tease out the colours from it by holding back the reds.

I got good colours for the same target out of my modded 450D here:

Do you have photoshop or gimp? If so you can use (1) as your LUM and belnd in some of (2) as RGB,

[Nigel G]

1 hour ago, Stub Mandrel said:

Keep playing with the processing then, the detail of the first shouldn't stop you being able to tease out the colours from it by holding back the reds.

I got good colours for the same target out of my modded 450D here:

Do you have photoshop or gimp? If so you can use (1) as your LUM and belnd in some of (2) as RGB,

I have gimp which I have never used, also have PS 2 old version which I have limited knowledge of. 

A good time to learn ☺

Cheers 

Nige. 

[Nigel G]

I have reprocessed Rosette taking a bit more time.

Found quite a bit more detail and better colour.

The hollow stars seem to be coming from either my lens or during stacking ?

Repairing the stars then tightening in the magic module  gave this result, a vast improvement on the first process.

As theres only 30 minutes of data I also got almost full frame image.

I have posted both for comparison.

Cheers

Nige.

[Filroden]

DSS can create hollow stars. I found this thread

Your stars are tighter and more subdued so the nebula really stands out and you can see a lot of detail in the nebula now. There's also more tone in the nebula. It was good before but now it's great!

[alacant]

8 hours ago, Nigel G said:

tightening in the magic

StarTools Magic. It's magic:)

[Nigel G]

2 hours ago, Filroden said:

DSS can create hollow stars. I found this thread

Your stars are tighter and more subdued so the nebula really stands out and you can see a lot of detail in the nebula now. There's also more tone in the nebula. It was good before but now it's great!

Thanks Ken.

Funnily enough I had upped the hot and cold pixel detection in DSS, that's got to be the answer.

Cheers.

Nige.

[Stub Mandrel]

10 hours ago, Nigel G said:

The hollow stars seem to be coming from either my lens or during stacking ?

I get hollow stars if I move the bottom slider too far to the right in DSS. If you look carefully at the graph the top of the curve bends down once the slider is past about 80%. This means if any star has a blown out core, it darkens! In this example it doesn't create the effect because the histogram is far to the left:

The solution is simple, check a bright star before saving your DSS picture, and if tit is hollow, move the slider left a bit and try again.

I'm sure this is  related to how the bezier curve controls have been implemented as the top right of the curve should be fixed to the top right of the graph regardless of slider postions

[Nigel G]

4 minutes ago, Stub Mandrel said:

I get hollow stars if I move the bottom slider too far to the right in DSS. If you look carefully at the graph the top of the curve bends down once the slider is past about 80%. This means if any star has a blown out core, it darkens! In this example it doesn't create the effect because the histogram is far to the left:

The solution is simple, check a bright star before saving your DSS picture, and if tit is hollow, move the slider left a bit and try again.

I'm sure this is  related to how the bezier curve controls have been implemented as the top right of the curve should be fixed to the top right of the graph regardless of slider postions

Thanks for that , I was wondering how to approach the issue

I'll have a look.

Nige.

[The Admiral]

Interesting aspect. I guess that the "Detect and Clean Remaining Hot Pixels" thniks the bright star centres are hot pixels then! I must say that in the short time I've been using Astroart for stacking, I've noticed that my 'bright' stars just look 'different'. I've not done any close analysis though.

Mind you, and perhaps I'm showing my ignorance here, if you use the autosave in DSS I thought it didn't apply any curves to the stacked image. Most of us who use StarTools I guess are taking the output of DSS without using DSS to pre-condition the file presented to ST. So I'm not sure how relevant the dip in the transfer curve is here.

Ian

Edited December 16, 2016 by The Admiral
Further thoughts!

[Herzy]

I have a modified T3i shipping to me right now!  can't wait to try it out at a dark site.

[Filroden]

Just got set up, aligned and camera cooled then the high clouds come over

[Nigel G]

I had a similar episode last night although I managed 15 minutes before the cloud came.

I used the 150p, modded camera with LP filter, then took a couple without the filter when I saw the clouds arriving just to see the difference.

NGC 6888, Crescent Nebula, 30 x 30s Canon 1200D modified & CLS CCD filter, ISO 1600, bias . no dark or flat as I packed away before remembering to take any. I need to and will be adding more to this.

I have posted the single 30s subs with and without. The better one is with LP.

Nige.

[The Admiral]

9 hours ago, Nigel G said:

I had a similar episode last night although I managed 15 minutes before the cloud came.

That's an amazing image for just 15 minutes Nige, just shows how much the red sensitivity has been improved. I must look again at my crescent neb image and perhaps rein back my stretching to a more comparable image.

Ian

[parallaxerr]

Which LP filter are you using Nige?

[The Admiral]

I had another quick attempt at processing my crescent  neb, but without the, perhaps excessive, stretching I used before. It's OK, but I can't say it fills me with great pleasure, and this was from a couple of hours exposure! As I said previously, I think that this is on the limit of what might be achievable with my set-up.

Stacked in AA, processed in ST, and tweaked in LR.

Ian

[Nigel G]

1 hour ago, parallaxerr said:

Which LP filter are you using Nige?

CLS CCD clip in filter for canon cameras 

Nige. 

[Filroden]

2 hours ago, The Admiral said:

Stacked in AA, processed in ST, and tweaked in LR.

Have you tried the processing in AstroArt yet? How does it compare to StarTools?

[The Admiral]

55 minutes ago, Filroden said:

Have you tried the processing in AstroArt yet? How does it compare to StarTools?

Well, let's just say I've dabbled. I did a straightforward process on my M45 and there wasn't a lot of difference between that and a ST processed one. However, other things I've tried haven't been very successful. To be fair though, I've not studied it, particularly as there isn't as much teaching material around that one can dip into, as there is for ST. The modus operandum is I think more like PI, with operations needing to be performed in a certain sequence. It does seem to have a multiplicity of 'filters', most of which I haven't a clue about what benefit they bring to the table. As I found during a brief acquaintance with PI, getting colour into the image seems to be difficult. I am sure that it is fine for good subs, but when things get marginal I do find ST gives me more for less effort. At least, with my limited expertise.

Ian

[alacant]

13 hours ago, Nigel G said:

NGC 6888, Crescent Nebula

Brilliant. There are some really awful foreground stars which ruin lesser photographer's efforts. You've got them under control. I reckon a 1-pixel shrink with 2 pixel fuzz Magic under a fat-star -save the mask before you denoise- ST mask would really nail it:)

[Filroden]

It's arrived and now fitted...for someone as mechanically incompetent as me, that's a real achievement!

Now I just need a clear night to finish setting up auto-focus in SGPro and I can now stay in the warmth for most of the night. Now if only I could extend the cables so it reached my armchair in the sitting room  I'm hoping to see an improvement in my focusing now. Particularly as I can now focus for each filter. My next thing to solve is the correct spacing for my camera. Until know I've just suffered the poor stars in the corners since I usually crop quite a lot because of rotation, but I'd like to get it right!

[SteveNickolls]

35 minutes ago, Filroden said:

Now I just need a clear night

Excellent piece of equipment there Ken. I heartily concur regarding the need for some clear night skies. Getting stir crazy watching those clouds. 

Cheers,
Steve