Regardless, being still a linear image, it appears really dark in our screen. Of course, since we've integrated two linear images, our resulting image is also linear, which can be very handy if we would like to do some processes that work much better with linear images, such as deconvolution, etc. You could tweak the parameters, but really, the only things to adjust would be the parameters that define the mask creation: threshold, smoothness and growth, and as we shall see, the default values already work pretty well. Considering all we've done is to open the HDRComposition tool, feed it the files and click "Apply", that's pretty amazing! With that done, we simply apply (click on the round blue sphere), and we're done creating the HDR composition. The first step then, once we have our set of images with different exposures nicely registered (just two in this example), is to add them to the list of Input Images: In fact, if you feed it linear images, it will also return a linear image - a very useful feature, as you can create the HDR composition and then start processing the image as if the already composed HDR image is what came out of your calibration steps. HDRComposition works really well with linear images. Now that we have our two master luminance images nicely aligned, let's get to the bottom of it.
#Pixinsight core settings registration#
The calibration/stacking process can be done with the ImageCalibration and ImageIntegration modules in PixInsight, the registration can easily be done with the StarAlignment tool, and the gradient removal (don't forget to crop "bad" edges first, due to dithering or misalignment) with the DBE tool.
![pixinsight core settings pixinsight core settings](http://www.lightvortexastronomy.com/uploads/6/4/9/7/64970217/pi_eg_m31_andromeda_galaxy_dslr_-_4.1.png)
Of course, before we can integrate the two luminance images, all the subframes for each image need to be registered/calibrated/stacked, and once we have the two master luminance images, we should remove gradients, and register them so they align nicely. I only spent about one hour capturing all the data (both luminance sets and all the RGB data) in the middle of one imaging session, just for the purpose of writing these articles. As I also mention in my last article, this is clearly NOT high quality data.
![pixinsight core settings pixinsight core settings](http://bf-astro.com/ngc4725/ngc4725-hdr1.jpg)
The two luminance sets is where we'll be doing the HDR composition.
![pixinsight core settings pixinsight core settings](https://i.ytimg.com/vi/CAehUD-Kv9s/maxresdefault.jpg)
#Pixinsight core settings plus#
The data is the same I used in my previous article, plus some color data to make it "pretty": As I anticipated in my previous article, I'm going to explain one easy way to generate an HDR composition with the HDRComposition tool in PixInsight.