don4l

SH2-161, or Lowers Nebula.   Here it is in Ha.

Very nice.

This is what I was hoping to achieve when I attempted this recently.

43 minutes ago, JSeaman said:

The O3 was without moon, the Ha and SII were with

The results I'm chasing are the clarity of detail, nothing to do with the black point, that's the very last thing I tweak

There is indeed drift and I have been working on PA - see other thread for the drift alignment I did the next time I went out!

As long as you are happy to gather lots of exposure, then there is no reason that you cannot shoot a galaxy in narrowband.  You will get different results, but that shouldn't make them any the less interesting.

I think that there are two problems with the above image.  The first is focus.  It looks a bit off to me.  Do you have any software that can measure the FWHM, or HFD?  I find this very useful.

The second issue is that the stars look a bit elongated.  A good PA will help of course, but I feel that people spend too much time getting the error down to 6".  If you have a flexure problem, then accurate PA won't fix it.  You could experiment with using shorter Ha subs, and then using the Ha stack as a Luminance on the colour image.  Another approach would be to remove the stars altogether (Starnet+ for example) and then replace them with stars made from shorter subs.

Thanks Geof.  That was a very clear and informative post.

I'd like to do more visual observation,  but there is always another image that needs finishing, so I never seem to get around to it.

Your combination of binos, mount and suitable seat seems to be very practical, and importantly, easy to use.

On 15/02/2020 at 09:56, Skyline said:

I have 4 renditions of this. I found the decreasing the stretch to reduce the red blotches also the faint stuff would be faint as well. I did use a noise reduction filter but not aggressively. 

Even though it would have giving a slight better balance of colours. I do wonder are the blotches are more apparent due to the length of subs taken, as the noise levels on coloured cmos cameras to be much more then a conventional ccd sensors.

Maybe someone with more knowledge then I can comment.

N.

I've recently taken a similar image and found the same thing.  The first exposures show lots of lovely detail, and it looked like it wasn't going to need a lot to produce a decent image.

However, I think that there is a huge range of brightness and the faint stull really needs lots of exposure.

So, I think that there is a choice between showing the faint stuff and having everything looking smooth.

It's a lovely image either way, so it isn't really very important.

Lovely image.  As already said, very natural looking.

That's looking lovely and smooth.

I think that as ones's imaging improves, the impact of the Moon increases.  A year ago I felt that I could almost ignore the Moon when imaging in Ha.  Recently, I have become more fussy.  I'm not sure that I am pleased, or not.

15 hours ago, DaveS said:

Wow, whata lota images! I thought I did well to get eight, but your haul is something else.

I was very surprised too!    I hadn't realised how efficient that my setup had become.

This year I hope to go for some longer exposures, and fewer images.

I've just tidied up my hard disk and was astonished to discover that I have done much more imaging than I thought!  The last 6 month has seen dreadful weather for astronomy, and at times it was almost depressing.

I've been wondering where this huge increase in productivity has come from, and the answer is CCDCiel, ASTAP, and Indi.  They just seem to work.  I used to spend an hour, or more just finding, focusing and rotating the camera.  Now, all these tasks are completed in about 10 minutes - long before the camera has reached temperature.

This is a collection of the images, all of which were taken during 2019.

This year, I will have to concentrate on getting more exposure time on individual targets, and maybe  go for fewer images.  Time will tell - I'm not sure that I have the patience.

22 minutes ago, han59 said:

Thanks again Don. The  new ASTAP version 3.19 with asteroid annotation is available to play with.

Han

Very neat.  I've just tried it and it works just fine!  It will certainly make finding asteroids much quicker and easier.  Thank you.

You might as well have the last one.  This is Bellona.

Glad I could help.

Belona_LPR_60s_008.fits

7 minutes ago, han59 said:

No binned 2x2 is fine. Yes please some more for testing. No need for applying darks or flats.

It is very stormy here but the sky is now partly clear. But very risky with my flap-open roof. And still some rain is coming....

Han

No rain here, but windy and lots of cloud around.  I wouldn't be able to do 10m exposures anyway, so this is a good exercise for me.

This is Althaeia and Aspasia.  There is a bit of cloud around, but I can make both of them out, and Astap solves it instantly.

AsteAlth_LPR_60s_015.fits

5 minutes ago, han59 said:

Hello Don,

This one matches also well. Took some time to prove but looks all good!

I'm only a little puzzled by the two dates in the FITS header:

DATE    = '2020-02-11T19:45:42'                                                 
DATE-OBS= '2020-02-11T19:10:42' 

What is the Windows file time of the original file?

Thanks for providing the image!

Han

 

 

The original file shows 19:11.  The Calibrated file shows 19:45.  I can post up the original if you want.

It has cleared up and I am currently having a go at Althaea and Aspasia.  Would you like thesee also?  I've been binning them 2x2,  if unbinned would be better, then I can do that too.

14 minutes ago, han59 said:

No, but if possible try to set it correct

It looks like it is indeed correct.  It agrees with my mobile phone.

The fits image is in the post above.  Here is a gif in case you have any problems.  This is a crop of the centre of the fits file above, and another taken 66m later.

Do you want more images?  It has gone cloudy now, so I don't think that I can get any more tonight, but I am happy to collect more if they would be useful.

Here is Hygiea.  It is more or less in the centre of the image.

60s,  2x2  FSQ106 at F3,6  (387// I think).  I've dark and flat fielded it, but nothing else..  If you prefer the file straight from the camera, I can put it up.

Astap solves it in 0.2s.

Aste_LPR_60s_003-16.FIT

16 minutes ago, han59 said:

Hello Don,

More then 3 month back will most likely  give a too large offset.  The program uses the MPCORB.dat file from the minor planet center. Unfortunately you can only download the latest MPCORB.dat version, not one from 3 months ago. My intention is to check the rather complex calculation. The annotation should be spot on.  You can just load a FITS file (or raw) in the program (astap) , press solve button, press annotate asteroids en it should work. The UTC observation time and location on Earth is read from the FITS header or has to be entered manually.

Yes a new image Vesta or Metis will do. 😀  If you can make a second one some time later then the movement will prove which object is an asteroid.

Han

 

  

 

Is it a problem if the time in the fits header is a couple of minutes out?

I prefer the reworked version.  However, I prefer the stars in the original.

Both versions are lovely, and I haven't seen it presented like this before, so I'd say it doesn't really matter.

4 hours ago, han59 said:

For the testing new software to annotate asteroids on images, I'm looking for recent images containing asteroid(s) tracks.  Preferably in FITS format (with start exposure date)  or  with the original file time.

Is there anybody who can assist?

Han

Hi Han,

I can provide the original files with fits headers for the images that I used for this if it is what you are looking for:-

I can post up, or e-mail, the original files with their fits headers.

If they are not recent enough, then I would be quite happy to try for Vesta or Metis tonight.  The forecast is looking OK at the moment, and my current target is behind a tree until 8pm.

This shot was taken on Friday (under an 86% moon).  Given the circumstances I'm very pleased with how it turned out.  I was surprised with how slowly the comet is moving.  I haven't bothered doing any special alignment or trickery for the comet.  The "L" was a bit off from the colour subs, but I couldn't see any noticeable problem from this.

Due to light pollution, I had given up on LRGB imaging, but I've recently come back to it.  Lots of practice with layer masks in the Gimp have made it possible to work wonders with the uneven filthy gradients that are produced.

Exposure:  L = 3 x 300s  1x1,   R = 5 x 180s 2x2,  G=3 x 180s 2x2,  B= 6 x 180s 2x2.    Total 57m

Equipment:  G3 16200,  EQ6,

Software:  CCDCiel, CCDStack, Gimp.

Thanks for looking.  Advice and comments very welcome.

Just watched the 7s version.  Lovely presentation, and  7s was just right.

Excellent job.  Lovely processing.

Wow!

Agree that it is lovely.  Colours and framing are just right.

10 hours ago, ollypenrice said:

There are three fundamental problems with using Ha as red. 1) the signal from the stars is tiny in Ha so red is under represented. 2) The background is held down by the NB filter so it's hard to get a balanced background sky. 3) The red you have is highly selective, coming only from only one source of emission and it's almost monochromatic. While you have a broad blue spectrum and a broad green one you have only a highly restricted red one.

For all that, the image is attractive and it would be easy to reduce saturation in red if you wanted to. However, I think it would work even better if the Ha were applied to the red channel in blend mode Lighten.

There is a blue reflection nebula in the middle part of the cone which has little or no signal in Ha. This means that if you use Ha to illuminate the image you'll kill it.

Olly

I think that the weak Ha stars are compensated by the different stretches that I apply to the Ha and G/B.  Each are stretched by eye in CCDStack.  The RGB combination seems to produce a balance similar to what I see in other images.

The background is a real issue, and I do not really like the plasticy look that results.  My processing method makes the problem much worse.  I duplicate the final image and blend it with itself using "overlay" mode.  This seems to highlight areas of interest (eg the tadpoles) but it does suppress the background.

I've looked at my blue data, and I cannot see any discernable signal in the middle of the cone.  There is a small bit just below the tip of the cone, and I have added this to the Lum layer.  When the moon goes away, I will try to get another hour of Blue which will be much easier to use.

This is what I got by adding the blue and reducing the saturation a bit:-

8 hours ago, carastro said:

I think this has worked very well.  Sometimes I wonder why I bother to capture Red when I am adding Ha as the Ha quite overwhelms the Red.

I also add Ha as Luminance, there is sometimes some adjustment to be made to the colour to prevent it coming out Salmon pink, but I really like this idea even if as Olly says the sky background might be a bit difficult to achieve. 

Carole 

I'm wondering if it something to do with light pollution.  On the other hand,  I've had some surprising success with galaxies recently where the  gradients didn't seem too awful.