# Hyperbolic Arcsine Curve

The hyperbolic arcsine adjustment (also known as ArcSinH) is a powerful tool for revealing faint details, especially in astronomical images. It is good at preserving the color of both faint and bright objects.

<div align="left"><figure><img src="https://642819126-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FLBlqtJBdFJ4rkIvhdwcZ%2Fuploads%2FqF3MWCDthGR0iHefAEc2%2Farcsinh.png?alt=media&#x26;token=f1195ce0-7583-481e-887f-8767f82d6216" alt="The Hyperbolic Arcsine Curve tool."><figcaption><p>The Hyperbolic Arcsine Curve tool.</p></figcaption></figure></div>

**ArcSinH Strength**\
Sets the strength of the overall adjustment. Higher values will lead to brighter images.

**Background Level**\
As the level of the Strength setting is increased, the background level of the image will also increase. To correct for this, use this setting to subtract a background value from the image. Very small changes are sometimes required to achieve the best results.

**Black Level**\
Sets the black point. Used in tandem with the Background Level setting, this can assist in creating an image with a dark background.

**Weighted luminance calculation**\
When calculating the new pixel values, the luminance of each pixel is used. When this option is not checked, the mean of the red, green and blue channels is used for the luminance calculation. When checked, a more advanced method is used. Experimentation may be required to find out which method works best for your image.