Help combining Oiii and Ha data on Pacman

[tooth_dr]

I cant seem to manage to get them merged without creating a complete mess.  I've manage it before with DSLR data, but I 've been at this for several hours now and I cant do it!  I've tried the Cannistra method, as well as NC actions to create synth green.

Would anyone please be able to have a look at it and see if it can be merged to create something like the Hubble Palate images I see of the Pacman Nebula with the lovely blue centre and then green and the yellow/red outer edge.

 

TIA

Adam.

 

 

 

SGL_PACMAN_HA.tif

SGL_PACMAN_Oiii.tif

[Hallingskies]

I really like this as it is.  I don’t personally care too much for (what I consider to be) the bizarre psychedelia of the “Hubble Pallet” but it’s your show, of course!

[geordie85]

I used to use this method when creating bi colour images from HA and O111. 

http://www.starrywonders.com/bicolortechniquenew.html

[tooth_dr]

1 minute ago, geordie85 said:

I used to use this method when creating bi colour images from HA and O111. 

http://www.starrywonders.com/bicolortechniquenew.html

Thanks Geordie. I actually used that before with my DSLR using NB filters and got the lovely colours I wanted. I can’t get it to work with my mono data and the same filters. Something I’m doing wrong but I can’t work it out. 

[tooth_dr]

2 hours ago, Hallingskies said:

I really like this as it is.  I don’t personally care too much for (what I consider to be) the bizarre psychedelia of the “Hubble Pallet” but it’s your show, of course!

Thank-you. I was inspired by the process (and images) in Steve’s @steppenwolf book where he processed his PacMan data. 

[geordie85]

47 minutes ago, tooth_dr said:

Thanks Geordie. I actually used that before with my DSLR using NB filters and got the lovely colours I wanted. I can’t get it to work with my mono data and the same filters. Something I’m doing wrong but I can’t work it out. 

I've had that trouble before, I over came it by slightly tweaking the hue/ saturation 

[tooth_dr]

It's not right, but it's better.  I think it's something to do with the Oiii data and the amount of signal.

 

 

[tooth_dr]

Just bumping up here, bad weather and all that. Hopefully someone is bored enough to help me ? 

[tooth_dr]

Sean let me process some of his Oiii and Ha on the crescent nebula and I was able to get some nice colouration (Attached below).

I cannot muster anything from my pacman data or even my wizard neb data.

The two tiffs are in the first post if anyone would please have a look and see if data is bad or filter etc? It’s the first time I’m used this oiii filter.  

 

 

[wimvb]

Just out of curiosity, how much did you stretch the tifs in your original post? One common issue with nb is that Oiii (and Sii) is not just weaker, but underexposed, compared to Ha. Overstretching Oiii to compensate for this will then lead to bloated stars or blue "panda eyes".

I can have a look at it if you post the linear masters.

[tooth_dr]

42 minutes ago, wimvb said:

Just out of curiosity, how much did you stretch the tifs in your original post? One common issue with nb is that Oiii (and Sii) is not just weaker, but underexposed, compared to Ha. Overstretching Oiii to compensate for this will then lead to bloated stars or blue "panda eyes".

I can have a look at it if you post the linear masters.

Thanks Wim. They were stretched using DPP in APP. I’ll post linear stacks straight out off APP without any processing ??

[tooth_dr]

@wimvb Stacked Oiii data straight out of APP following stacking, no DPP etc.  And same for Ha data (used DSS for this, no particular reason) called Autosave002, unprocessed

 

Thanks!

Adam.

 

St-avg-5400.0s-LNMSC_1_2.0_none-x_1.0_LZ3-NS-full-qua-add-sc_BWMV_nor-OIII-RL-MBB5_2ndLNC_it1-St.tiff

Autosave002.tif

[gorann]

It is clear from the panda eyes that the stars are much wider in your Oiii data. In PS I would do the stretch of each filter manually as several small stretches where I protect the stars (especially in Oiii) by selecting them and masking them. I would near the end of the stretching compare the star sizes in Ha and Oiii to get them as similar as possible. You can even use some star shrinking method on the Oiii before combining the channels. When that is done I found that a very powerful way to fix colours is to work on the curves of each colour channel. However, this is what I do in PS and I expect it to be a quite different approach with PI.

[tooth_dr]

38 minutes ago, gorann said:

It is clear from the panda eyes that the stars are much wider in your Oiii data. In PS I would do the stretch of each filter manually as several small stretches where I protect the stars (especially in Oiii) by selecting them and masking them. I would near the end of the stretching compare the star sizes in Ha and Oiii to get them as similar as possible. You can even use some star shrinking method on the Oiii before combining the channels. When that is done I found that a very powerful way to fix colours is to work on the curves of each colour channel. However, this is what I do in PS and I expect it to be a quite different approach with PI.

Thanks Goran.  It feels like I have bitten off more that I can chew with the mono camera.  I didn't expect so many stars in my Oiii image, and I simply am struggling to deal with it.  I spent two hours on my Wizard neb data last night, and  I may as well not have bothered!  I used a selection of processes including those listed in Steves book, as well as NC actions and Annies actions, still got nowhere!  I don't use PI either, I use PS.  Are stars always an issue with Oiii, or was it my guiding or a bad night with high cloud?

 

All the best

Adam

[carastro]

I took a look at your data, and it seems to me that there is too much nebulosity in the oiii data it looks almost the same as the Ha.  But the stars in the oiii are larger than the Ha which is pretty normal I have found.  

I am just wondering whether you might have muddled some Ha subs into your Oiii stack as I can't get any difference in the colours at all.  As regards the larger stars in oiii I normally have to reduce the size of the stars otherwise the colour of the oiii will stick out.

Finally, you can't get a Hubble palette image out of only two channels.   

But take a look at the Oiii stack and make sure they are all Oiii subs. 

Carole 

 

[tooth_dr]

4 minutes ago, carastro said:

I took a look at your data, and it seems to me that there is too much nebulosity in the oiii data it looks almost the same as the Ha.  But the stars in the oiii are larger than the Ha which is pretty normal I have found.  

I am just wondering whether you might have muddled some Ha subs into your Oiii stack as I can't get any difference in the colours at all.  As regards the larger stars in oiii I normally have to reduce the size of the stars otherwise the colour of the oiii will stick out.

Finally, you can't get a Hubble palette image out of only two channels.   

But take a look at the Oiii stack and make sure they are all Oiii subs. 

Carole 

 

Thanks Carole for taking time to comment and assess the data. I took the oiii on a separate night, I took 9x600s, didn’t mix it up with Ha. I’m going to reprocess it in DSS and see if that makes any difference, I’ll post the stack when I get a chance. 

[carastro]

Ok

[tooth_dr]

@carastro

 

Definitely all Oiii subs Carole. I've attached output from DSS untouched.

 

Thanks!

Adam.

Autosave.tif

[AngryDonkey]

I'm just processing Pacman in Ha and OIII myself and comparing the OIII stacked image there are definitely a lot more and brighter stars. What kind of OIII filter are you using?

It actually looks a lot more like a luminance or RGB image than narrowband. Is there any chance that you used the wrong filter at all? I only mention this because this is exactly what happened to me a couple of trips back. Luckily I checked the first frame and it just looked off, turned out I was using the R filter instead of SII...

Edit: I've attached my stacked OIII for reference. This is with an Astrodon 5nm OIII filter.

[wimvb]

Here's my process of your data. As Carole already wrote, the Oiii and Ha are very similar, and won't make a good Hubble-like palette (for which you will also need Sii).

After @AngryDonkey's Oiii reference image, I'm also starting to believe that you may somehow have had a filter mixup. The only sure way to find out is to reshoot Oiii. A single sub may be enough.

Anyway, this is HOO with H also as luminance.

 

[tooth_dr]

36 minutes ago, wimvb said:

Here's my process of your data. As Carole already wrote, the Oiii and Ha are very similar, and won't make a good Hubble-like palette (for which you will also need Sii).

After @AngryDonkey's Oiii reference image, I'm also starting to believe that you may somehow have had a filter mixup. The only sure way to find out is to reshoot Oiii. A single sub may be enough.

Anyway, this is HOO with H also as luminance.

 

Thanks Wim!  I focused on Oiii in APT by selecting that filter, but it's possible when I programmed it to take the sequence of images I may have not selected the Oiii filter (default is Lum).   I'll try to see if that happened.

[tooth_dr]

So the subs are labelled Oiii so I did select the right filter for the imaging sequence. And I checked and Oiii is in the number slot I have labelled for Oiii so this was definitely Oiii!

[tooth_dr]

Does it look like duff focus?

[AngryDonkey]

5 hours ago, tooth_dr said:

Does it look like duff focus?

I don't think so. Can you tell us what filters you are using (brand and nm range)? Some filters seem to suffer from reflections more than others and produce halos (and anecdotally OIII seems to be a particularly problem child). Also some filters have a direction arrow on them to position the reflective coating on the correct side, might be worth checking if this is pointing the right way.

[tooth_dr]

1 hour ago, AngryDonkey said:

I don't think so. Can you tell us what filters you are using (brand and nm range)? Some filters seem to suffer from reflections more than others and produce halos (and anecdotally OIII seems to be a particularly problem child). Also some filters have a direction arrow on them to position the reflective coating on the correct side, might be worth checking if this is pointing the right way.

Thanks for your help!

This is my filter, it’s positioned in an Atik EFW2.

https://www.365astronomy.com/optolong-oiii-ccd-6.5nm-extra-narrow-band-deep-sky-imaging-filter-2-for-ccd-astro-photography.html