Improving on the Veil

[Craig123]

42 minutes ago, carastro said:

You don't use the two methods simultaneously.  

I find you need a steady sky to use FWHM, my experience has been it jumping all over the place and not knowing which reading to take, so I went back to using a Bahtinov mask which I find very reliable.  I use Artemis as well and for narrowband you need to lengthen the exposure slightly and loop x 3 (for faster download) to use the mask, probably 3 secs binned x 3 will do it.

You should add some Oiii to this when you get a chance, combined with the Ha makes a lovely coloured image.

Carole

Thanks Carole...i think I have spoken to you before about Artemis and markers.

Do you use the subframe button to zoom in on a bright star while looping the exposures?

I don't have a Oiii filter yet but I think I'm going to try again with ha and work on focus some more.

 

[Craig123]

17 minutes ago, tooth_dr said:

I hope you don’t me posting this here. My image looks so very similar to yours, it is also around 3 hours exposure but in 5 minute subs, with an Atik mono CCD.

Mine top image

Craigs bottom image

 

Nice one.Looking at various ha images has made me realise how much detail you can pick up with a ccd.I think I'm going to have another go with 20 mins or even try 30 if there's no clouds around.Plate solving was my aim for this week but I'm going to look at Bhatinov focus instead as I never felt confident i was nailing focus with Fwhm .

[carastro]

Quote

Thanks Carole...i think I have spoken to you before about Artemis and markers.

Do you use the subframe button to zoom in on a bright star while looping the exposures?

Yes we have spoken about Markers and I am using them now (when I remember, lol), very useful.

No I don't use the subframe button, I just zoom in using the zoom slider in the "display" window.

Carole 

[Tim]

3 hours ago, Craig123 said:

Hi Tim.I had a look at a Bhatinov video on YouTube and I agree..it looks a great method and something of a contrast to all the other stuff you have to do in set up so I will try it tonight if clear.I had a look through the other shots on the link above.Is that your work?.Very nice and inspiring as I hope to go for Elephants trunk when I need a break from the Veil. What is the site the pictures are on..is there info about how they were done ?

Thanks

Great, just be sure to be particularly particular about centralising the middle spike. You'll need a good few seconds of exposure to get a decent pattern, even when you use a good, high, bright star to set focus. You will get a line of dots with the Ha filter, if you can watch the screen as you focus and defocus you will see which way you need to turn the focus knob to achieve perfection. When happy, lock it, and then ALWAYS re-check after locking, just in case it gets budged by the locking mechanism.

Thanks for the compliment about those images in the link, but they are not mine   Very nice work though. I don't get to do many of my own images these days, but the Veil has always been one of my favourite targets, both photographically, and at the eyepiece. A million years ago we had "Picture of the Week" on here, and tons of photos posted, and a dodgy Veil nebula with a DSLR was my first POTW, and it kind of inspired me to get into AP a bit more. Here's the last photo I took of it, a few years back. Note that the sharpest, and brightest details are via the Oiii filter. It is a bi-colour image. You can see the difference on Tooth_Dr's picture between your soft focus and his. In his case, the tight focus has made the most of the shorter subs. Faster telescopes and darker skies all play their part in improving the overall image, but really, narrowband imaging is a great playing field leveller, where we who are blighted by poor seeing and light pollution stand a chance of taking decent photos that compare with those taken under better conditions.

Cheers

Tim

[newbie alert]

Fantastic image Tim

[ollypenrice]

If using FWHM it's much quicker to draw a box round the star and read only that bit. (Our full frame cameras take 15 seconds to download a full frame so this matters for us!) Just be sure to hit the Full Frame button and remember that the Artemis sequencer does not over-rule the subframe! It over-rules everything else on the capture window so I think this is a bit daft.

Also with FWHM be sure not to use brightnesses too close to 65000. Once at 65K you are chopping the top off the brightness bell curve so the 'Maximum' bit in FWHM becomes a false reading.

While the image to which Tim linked is remarkably and admirably deep I do have a beef with it: the brightest parts of the nebulae have very dark background around them and I see no evidence of this in my own data. I think it's a processing artefact arising from over-use of something like Noel's Local Contrast Enhancement or PI's Local Histogram Equalization. But it certainly shows where the faint stuff is!

Olly

[Craig123]

2 hours ago, Tim said:

Great, just be sure to be particularly particular about centralising the middle spike. You'll need a good few seconds of exposure to get a decent pattern, even when you use a good, high, bright star to set focus. You will get a line of dots with the Ha filter, if you can watch the screen as you focus and defocus you will see which way you need to turn the focus knob to achieve perfection. When happy, lock it, and then ALWAYS re-check after locking, just in case it gets budged by the locking mechanism.

Thanks for the compliment about those images in the link, but they are not mine   Very nice work though. I don't get to do many of my own images these days, but the Veil has always been one of my favourite targets, both photographically, and at the eyepiece. A million years ago we had "Picture of the Week" on here, and tons of photos posted, and a dodgy Veil nebula with a DSLR was my first POTW, and it kind of inspired me to get into AP a bit more. Here's the last photo I took of it, a few years back. Note that the sharpest, and brightest details are via the Oiii filter. It is a bi-colour image. You can see the difference on Tooth_Dr's picture between your soft focus and his. In his case, the tight focus has made the most of the shorter subs. Faster telescopes and darker skies all play their part in improving the overall image, but really, narrowband imaging is a great playing field leveller, where we who are blighted by poor seeing and light pollution stand a chance of taking decent photos that compare with those taken under better conditions.

Cheers

Tim

 

[Craig123]

Yes..thats a great shot Tim , very inspiring and probably means I will have to fork out for an Oiii filter aswell sometime.I'm glad I posted a thread   as I can now see what I need to do with it ( start again lol )  rather than just keep going hoping definition will come with more subs and that is nice to know and gives more confidence.Much appreciated.

Craig

[Craig123]

3 hours ago, carastro said:

Yes we have spoken about Markers and I am using them now (when I remember, lol), very useful.

No I don't use the subframe button, I just zoom in using the zoom slider in the "display" window.

Carole 

Nice one.I will look out for the zoom slider.Its supposed to be clear later here so I have quite a few things to work on.

Craig

[Craig123]

44 minutes ago, ollypenrice said:

Just be sure to hit the Full Frame button and remember that the Artemis sequencer does not over-rule the subframe! It over-rules everything else on the capture window so I think this is a bit daft.

Also with FWHM be sure not to use brightnesses too close to 65000. 

Thanks Olly.Two more things to add to the must/must not do list.I need more note paper.?