The EQ3 DSO Challenge

[Stub Mandrel]

1 hour ago, wimvb said:

For an alternative to the lrgb method that I suggested earlier, here is one that may be more suited for photoshop and gimp. The blending methods may have different names (value instead of color?)

As always, DO try this at home. (As opposed to what they say on tv shows)

I use this method a lot on the RGB version of my DSLR data, I've set it up as an 'action'. I find it works best if you tweak the saturation up very slightly in C,M,Y & B but not R or G first. You can repeat it but watch out for any colour channel that is getting ahead of the others - you can pull its saturation back a bit before repeating.

Another 'trick' that works well for brining faint nebulosity out of data from a DSLR is described at length in a 1 1/32 hour tutorial somewhere but the basic technique (for photoshop) is:

• Create a copy of your image called 'LUM'.
• Set the black point as high as you can without clipping the black, then back off a smidgin.
• <option at this point you may want to run a make stars smaller routine a few times>
• <option it can also be worth using curves at this point to help emphasise any nebulosity>
• Duplicate as a new layer.
• Use dust and scratches filter with a radius of 10-15 to remove most stars
• Use the 'heal' or 'clone stamp' tools to remove any large stars that remain so you just have the 'background' with any nebulosity.
• Check the black point again and move if required
• <option at this point it can be worth blurring the image slightly or running noise reduction if required>
• Now set the mode for this star-free layer to 'screen' - the image will lighten considerably, but the stars won't blow out.
• Add a levels adjustment layer as you will now almost certainly need to adjust the black point
• Also add a curves layer and add a slight upwards  curve, starting just above the black background level to help further emphasise the nebulosity.
• If you keep layers separate you can go back an do further noise reduction etc. as required.

I also sharpen/contrast enhance and noise-reduce my 'LUM' version in Astra Image.

My RGB version , I normally blur slightly to reduce colour noise and bring colour into brighter stars

I combine teh RGB and LUM versions by dropping the LUM version onto the RGB one as a layer and setting its mode to luminosity.

 

[Peco4321]

Here's my  latest effort, Orion Nebula and Running Man Nebula, 43 x 30sec ISO 800, plus 20 x Darks plus 20 x Bias and for the first time, plus 10 x Flats.  Now I may be opening myself up for being told I did it all wrong, but the results are the best I have got so far.  For the flats, I was just experimenting and I simply took the lens off the camera this morning, set it to AV and took 10 pictures pointing at the bright Sun - I know this is not the correct way, but I think it sort of worked, please tell my why this is wrong?

Stacked in DSS, processed in PS free version.  My next learning curve will focus on getting rid of the blown out core of Orion by layering etc.

 

[Stub Mandrel]

24 minutes ago, Peco4321 said:

Here's my  latest effort, Orion Nebula and Running Man Nebula, 43 x 30sec ISO 800, plus 20 x Darks plus 20 x Bias and for the first time, plus 10 x Flats.  Now I may be opening myself up for being told I did it all wrong, but the results are the best I have got so far.  For the flats, I was just experimenting and I simply took the lens off the camera this morning, set it to AV and took 10 pictures pointing at the bright Sun - I know this is not the correct way, but I think it sort of worked, please tell my why this is wrong?

The pictures are good.

I'm worried about pointing the scope at the sun, it doesn't take long to burn out a sensor or worse, plus you really want an image with no features in it at all. For easy flats, just either point the scope at a featureless sky or a flat plain surface or even a hanging sheet - it must be evenly illuminated with no marks that will come out on the image. I use a flat painted wall indoors and rotate the scope between shots - the wall is so close that any marks on it will be so out of focus they don't show.

[Peco4321]

9 minutes ago, Stub Mandrel said:

I'm worried about pointing the scope at the sun

I did not have the camera on the scope at the time I took the flats, just the body of the camera in my hands. Also I do not look through the view finder, just pointed in the general direction. 

[Stub Mandrel]

5 minutes ago, Peco4321 said:

I did not have the camera on the scope at the time I took the flats, just the body of the camera in my hands. Also I do not look through the view finder, just pointed in the general direction. 

Ah. the aim of flats is to correct for things like vignetting (dark corners) as well as dust on the sensor. You need to take them with the scope attached to do this, also this affects how dust throws a shadow so basically always take them before removing the camera from the scope, even if you leave it there until morning.

[Peco4321]

Thanks @Stub Mandrel, I'll try that next time. 

[wimvb]

Here's an image I took last April, and which I hope to revisit in March or April.

NGC 2903 is a barred spiral galaxy in Leo. It is sometimes called the galaxy that Messier missed, since it is as large and bright as certain Messier objects.

This image was captured with my 150PDS on the EQ3 Pro, unguided 80 and 120 seconds exposures at ISO 1600, 24 subs in total. 120 seconds means that this target is underexposed, but in this case the mount was the limiting factor. Processed in PixInsight. The fuzzy on the left is another NGC object.

Next time I gather data on this target will be with my AZ EQ6 and guiding. That will make for a nice comparison.

[Nigel G]

For my flats I just aim the scope close to and at my pc screen with a blank white screen,  this seems to work well,  you could put a white t shirt over the scope end too.

Nige

[Stub Mandrel]

48 minutes ago, wimvb said:

This image was captured with my 150PDS on the EQ3 Pro, unguided 80 and 120 seconds exposures at ISO 1600, 24 subs in total. 120 seconds means that this target is underexposed, but in this case the mount was the limiting factor. Processed in PixInsight. The fuzzy on the left is another NGC object.

is there a touch of uncorrected coma there? Stars near the corners seem to be 'stretched' outwards a bit.

[wimvb]

2 hours ago, Stub Mandrel said:

is there a touch of uncorrected coma there? Stars near the corners seem to be 'stretched' outwards a bit.

You are too modest. It's not just a touch. Besides a new mount, I also invested in a coma corrector last summer, after this image. Next major investment will be a camera to replace my box brownie (aka Pentax).

[Galactic Wanderer]

Some amazing images. Still wrapping my head round about how good these are. I still find it awe inspiring that we can take such images from our backgarden with relatively modest scopes Some top space telescopes 25 years ago  would have had the same results, if not worse. Imaging in London has been challenging but I've improved with every image I've taken. Here is my latest - Lots of grainy background (still don't know how to get rid of this). 35mins of exposure with no flats, no bias, no darks with a CLS filter.  stacked in DSS and processed in Pixinsight.

Thanks, Seb

Edited January 29, 2017 by Galactic Wanderer

[mikey2000]

Keen eyed members will have noticed me posting about my struggles with an EQ3Pro mount since Jan this year.   I managed this on the Flame Nebula in Orion and my optimistic composition was unexpectedly rewarded with a view of the Horse Head!!!  It's a crop of the full shot so there is some clear star stretching but I hope my new coma corrector can fix that.

 

I'm just amazed what can be pulled out of that humble 150mm mirror.....  I look up at Alnitak since then and I can see these clouds in my minds eye.  Hubble can do better, but Hubble isn't in my back garden in Leighton Buzzard :-)

[mikey2000]

2 minutes ago, Galactic Wanderer said:

 Lots of grainy background (still don't know how to get rid of this).

 

 

Have you tried a free trial of Astro Tools?  It seems to do a rather good job of pulling details out of nothingness and cleaning up background....

[Galactic Wanderer]

Just now, mikey2000 said:

Keen eyed members will have noticed me posting about my struggles with an EQ3Pro mount since Jan this year.   I managed this on the Flame Nebula in Orion and my optimistic composition was unexpectedly rewarded with a view of the Horse Head!!!  It's a crop of the full shot so there is some clear star stretching but I hope my new coma corrector can fix that.

 

I'm just amazed what can be pulled out of that humble 150mm mirror.....  I look up at Alnitak since then and I can see these clouds in my minds eye.  Hubble can do better, but Hubble isn't in my back garden in Leighton Buzzard :-)

Wow, brilliant image. I'm thinking about the horsehead and definitely will have a go! Have a go at toning down Altinak, it slightly overpowers the image but apart from that well done!

[Galactic Wanderer]

1 minute ago, mikey2000 said:

Have you tried a free trial of Astro Tools?  It seems to do a rather good job of pulling details out of nothingness and cleaning up background....

Will have a go. Thanks

[mikey2000]

2 minutes ago, Galactic Wanderer said:

Wow, brilliant image. I'm thinking about the horsehead and definitely will have a go! Have a go at toning down Altinak, it slightly overpowers the image but apart from that well done!

Thanks!  I did try overlaying a dimmer exposure from a different night but the diffraction spikes were at different angles.  I could try something in photoshop maybe....

 

I'm waiting for a clear night to try again with my new coma corrector and light pollution filter to see how that goes.  And hoping to extend to 90s subs....

[mikey2000]

Here's M108 Surfboard Galaxy.  Heavily cropped, 26x 85s, DSS 2xDrizzle then pulled apart in startools.exe

[wimvb]

37 minutes ago, Galactic Wanderer said:

Here is my latest - Lots of grainy background (still don't know how to get rid of this). 35mins of exposure with no flats, no bias, no darks with a CLS filter.  stacked in DSS and processed in Pixinsight.

Thanks, Seb

 

Since you already have PixInsight, why not use its noise reduction methods. They do wonders with most images, and retain detail.

Here's my noise reduction recipe

http://wimvberlo.blogspot.se/2016/07/noise-reduction-for-dslr-astroimages.html?m=1

If you have Warren Kellers book, he describes his method in detail. I've tried it, and it works just as well.

[Victor Boesen]

9 hours ago, Galactic Wanderer said:

Lots of grainy background (still don't know how to get rid of this)

If you use a nikon dslr, then you have to turn off noise reduction in settings, and shoot in raw. i have the d3300 and when i have noise reduction on, i get the same grainy astro pics.

[Stub Mandrel]

12 hours ago, mikey2000 said:

I'm just amazed what can be pulled out of that humble 150mm mirror.....  I look up at Alnitak since then and I can see these clouds in my minds eye.  Hubble can do better, but Hubble isn't in my back garden in Leighton Buzzard :-)

Me too, I look at the night sky and wonder what it would look at if all the faint nebulosity was visible to the naked eye.

[Stub Mandrel]

12 hours ago, mikey2000 said:

Thanks!  I did try overlaying a dimmer exposure from a different night but the diffraction spikes were at different angles.  I could try something in photoshop maybe....

If you use dust and scratches then the heal tool to get rid of the stars you could then add in the extra nebulosity as another layer

[Galactic Wanderer]

21 hours ago, wimvb said:

Since you already have PixInsight, why not use its noise reduction methods. They do wonders with most images, and retain detail.

Here's my noise reduction recipe

http://wimvberlo.blogspot.se/2016/07/noise-reduction-for-dslr-astroimages.html?m=1

If you have Warren Kellers book, he describes his method in detail. I've tried it, and it works just as well.

Hey Wim,

Tried TGVdenoise - and it seemed to work when I zoomed in. Here is the result

[wormix]

This is a really inspiring thread with some amazing pictures - I feel inspired to do some more research into Astro photography after seeing what is possible with smaller setups. 

[Markh68]

I have just got a 150pds and having a look at some of the great photos.

Hopefully will try it out myself soon.

[Nova2000]

I think this is a good place to post my question. 

To start with I have  a eq 3 mount with ra motor drive and no polar scope. I got 3mins exposure with a 50mm lense. 

I am thinking of using a Astele 95mm makustove for lunar, solar and hopefully some bright dso. 

I know that f ratio is too much. 

I may use a 150/1200 reflector. 

Question 

1- how can I improve the polar alignment without a polar scope 

2- with the 150/1200 scope how much second exposure can I expect. 

3- have I provided the necessary details? 

Thankyou 

Raj£$#