Registar Help Please

[Knight of Clear Skies]

I'm trying to use Registar to combine RGB and Ha images. (For the mono Ha I've converted it into an RGB image by pasting the RGB channel into the red channel and clearing the green and blue channels, giving me an all red image.) I'm following the tutorial here, Registar is aligning the two images fine but the colours are messed up. Here's a screen grab.

Looks like it's doing something strange with the channels. Looking at the title bar of the aligned image it's put the same data in the blue and green channels without adding the Ha (but the black frame around it is in the correct orientation).

Save is disabled in the evaluation edition so I can't see what what this would actually give me. Can anyone help please? I'd like to have some confidence it will work with my data before I spend £150 on it.

[Knight of Clear Skies]

Just to add, 'combine images' does work but I need to get the original images in the same orientation so I can blend them together properly in PS.

Edited April 21, 2020 by Knight of Clear Skies

[Davey-T]

Do you mean combine or align, I do have it n my laptop but haven't used it for a while, I've only used it to align images not combine them.

Dave

[Knight of Clear Skies]

1 minute ago, Davey-T said:

Do you mean combine or align, I do have it n my laptop but haven't used it for a while, I've only used it to align images not combine them.

Dave

Align is what I want but I can't see a menu item for that. 'Register' is what i used in the first post, 'Combine' in the second. I think it's working OK but I'm confused by it and various searches haven't helped.

[Knight of Clear Skies]

I suppose I should also ask, are there any viable alternatives to Registar these days? I have lots of data taken with different focal length lenses and telescopes I'd like to combine.

[Davey-T]

Most of the programs have something similar but Registar always works.

Dave

[ollypenrice]

35 minutes ago, Knight of Clear Skies said:

I'm trying to use Registar to combine RGB and Ha images. 

Don't do that. That is not what Registar is for. How you choose to combine Ha and (L)RGB is a subtle business about which not all imagers agree but don't ask Registar to make this decision for you. It is a stunningly good program which I use repeatedly on every image I make but it is not your Artistic Director regarding how to combine Ha!

No,  just ask Registar to align and crop/pad your Ha to your (L)RGB image and save the result. Export this aligned and cropped image into whatever program you are using to construct your final image. In my case that would be Photoshop. I will then process the post-Registar Ha in a way which bears in mind how I'm going to use it to make an Ha(L)RGB image. This will not be quite the same processing as I'd use to make a nice standalone Ha image. Why not? Because I can push the 'Ha to be added to LRGB' far harder than I can push the 'Standalone Ha.' I'm going to add it to the red channel in Photoshop's Blend Mode Lighten which means it will only appear in the red channel where it is brighter than the red channel. If the dark parts of my Ha image are stretched beyond the noise limit (as they will be) it doesn't matter so long as they are still darker than the dark parts of the red channel. They won't be applied.

In my post-processing workflow my software priorities are 1) Photoshop 2) Registar 3) Pixinsight. I don't doubt that those who can fathom the autistic mysteries of Pixinsight will say that it can do the lot. They may be right but it doesn't communicate with me well enough for us to come to an understanding...

Olly

[Knight of Clear Skies]

18 minutes ago, ollypenrice said:

No,  just ask Registar to align and crop/pad your Ha to your (L)RGB image and save the result. Export this aligned and cropped image into whatever program you are using to construct your final image.

Yes, that's what I'm trying to do thanks. Sorry, wasn't clear enough in my original post. I used 'combine' to prove the software was working after I got the strange colours.

[Knight of Clear Skies]

To rephrase my questions:

- What's going on in this screen grab, why has Registar given me a teal image? In the title bar it says G=<image name>, B= <image name>. Is Registar confused or am I?

- Will the above problem stop me from saving aligned versions of the original images, which is what I need to blend the Ha data in properly using Photoshop?

Edited April 21, 2020 by Knight of Clear Skies

[ollypenrice]

31 minutes ago, Knight of Clear Skies said:

To rephrase my questions:

- What's going on in this screen grab, why has Registar given me a teal image? In the title bar it says G=<image name>, B= <image name>. Is Registar confused or am I?

- Will the above problem stop me from saving aligned versions of the original images, which is what I need to blend the Ha data in properly using Photoshop?

Let's start from the beginning.

1) Open your RGB image in Registar. (Make sure it has nothing 'funny' about it. You can sometimes end up with an invisible extra channel created in Ps so check it in Ps channels to ensure it really is just RGB.)

2) Open your Ha. Go to Register Images icon and register Ha to RGB. This will throw up a screen-only image like the one on the right of your post. It's a screen rendition. Don't save it and don't worry about its colour.

3) Go to Crop and Pad icon and select 'Just this image' and 'Match.' This will crop off the registered Ha image where there is no RGB underneath it and fill in the Ha with black where the Ha fails to cover the RGB. Save this. It will be something like Ha_reg_crop.

Now you can open Ha_reg_crop in Ps, split the channels of your RGB, paste Ha_reg_crop on top of it and choose blend mode lighten. The dark corners won't be  visible or applied in this blend mode. Your main concerns will be twofold. Ensure that the background sky is not being lightened by the Ha. Adjust the black point or the bottom of the Curve if it is. Then ensure that the Ha is suffiently effective in bringing out the nebulae. If it isn't you can pin the bottom of the Curve and lift it higher up to get it to do more.  Flatten and merge channels in RGB.

Olly

Edited April 21, 2020 by ollypenrice
Typo

[Knight of Clear Skies]

18 minutes ago, ollypenrice said:

This will throw up a screen-only image like the one on the right of your post. It's a screen rendition. Don't save it and don't worry about its colour.

Thanks Olly, that's the crucial bit of information I needed to know. The title bar threw me, I wondered if something had gone wrong with the colour channels. Think I'll go ahead with buying Registar later this week, when I've got a bit more time to use it.

[ollypenrice]

Just now, Knight of Clear Skies said:

Thanks Olly, that's the crucial bit of information I needed to know. The title bar threw me, I wondered if something had gone wrong with the colour channels. Think I'll go ahead with buying Registar later this week, when I've got a bit more time to use it.

It is my right hand any number of times during a processing job. You never have to worry about cropping one channel of an image because you can just register-crop-pad the rest to it an any time.

I wouldn't be without it.

Olly

[Knight of Clear Skies]

Thanks for the help. I've splashed out on Registar and had a very quick go at blending in my Ha data.

I should be able to get a bit more detail in the nebulosity with more care.

Think this tool is going to transform my imaging. I've been shooting a lot of Ha recently and can blend it in with colour images I took a few years ago. (When shooting widefields my 1960s Takumar lens might be my best bit of kit for RGB imaging, while I can use the Samyang f2 to go deep in Ha quickly.)

Edited May 5, 2020 by Knight of Clear Skies

[ollypenrice]

11 minutes ago, Knight of Clear Skies said:

Thanks for the help. I've splashed out on Registar and had a very quick go at blending in my Ha data.

I should be able to get a bit more detail in the nebulosity with more care.

Think this tool is going to transform my imaging. I've been shooting a lot of Ha recently and can blend it in with colour images I took a few years ago. (When shooting widefields my 1960s Takumar lens might be my best bit of kit for RGB imaging, while I can use the Samyang f2 to go deep in Ha quickly.)

That's very good. People say Registar is a one trick pony but it's a damned good trick.

Olly