Can I create a color image only for O3

@mo-mo If you only use the OIII channel then the data by definition is mono. The pass band of the OIII filter is so small that is effectively eliminates any color information. In order to get a color image you need to at least combine OIII with an Ha (or R) image.

The lack of color in the LRGBHOO image may be due to the contribution of L. Adding that generally tends to wash out colors. Do you get colors if you create an RGBHOO image instead? If it does then we can help you add L as well while maintaining color.

HTH, Wouter

@wvreeven 

Thanks for the answer.

I tried RGBHOO.
Compared to LRGBHOO, the color of O3 is better, certainly.
And then I realized that I had encountered a new challenge. In other words, the entire image is biased toward bluish-green because the color of O3 is strong in all regions.

I think this is correct in principle, but I don't know how to emphasize only the squid nebula. It would be nice if the APP had a function for this.

thanks in advance

@mo-mo I am not sure what you mean with "emphasize" but if you mean "use a mask" then this is not possible (yet, I think) in APP. If you upload your L, R, G, B, Ha and OIII images then we can try and help you get the most out of it. Without any example it is hard to give you advice.

Wouter

@wvreeven Thank you. I'm glad if you specify where I upload.

@mo-mo Please upload to

@wvreeven

hello
I uploaded six files to the folder.
I would be very grateful if you could give me some advice.

Thank you

@mo-mo Thanks for uploading the images.

The signal of the Bat Nebula in L is very low and the Squid is completely absent, which is why the colors become very pale when you use it. The signal of the Bat Nebula and particularly the Squid are very low in R, G and B, which is why they don't become very visible when combining all RGBHaOIII images. So you probably get the best result by

• Combining the R, G and B images into an RGB image.
• Combining the Ha and OIII images into an HOO image.
• Reducing the size of the stars in the HOO image.
• Combine the RGB and HOO images such that the star colors of the RGB image and the nebulae of the HOO image are used.

There are several posts on this forum that explain how to do that.

Wouter

@wvreeven 

Thank you for the advice.
I will search for the forum and try it.