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Winter 2024 Challenge Edition of JS9-4L: Crab Nebula

Welcome to NASA’s Astrophoto Challenge!

First, we’ll take you through the steps of using our JS9-4L image processing tool.

Then you can process your own astronomical images, which you can submit to NASA’s Astrophoto Challenge.

Start Guided Tour

Select an Image

Start by opening a sample image file to practice using JS9-4L. Click on the MicroObservatory Crab Nebula images in the Challenge Images dropdown.

Then choose one of the NASA image files here.


Adjust the Scale

Use these scales to highlight different regions of relative brightness in your image. Log scale works best for dim images.

Switch between the scales to see how regions that appear black suddenly reveal much greater detail.


Adjust the Controls

Use these sliders to fine-tune the contrast.

Pixel values below the Low Brightness Limit will be absolute black, values above the High Brightness Limit will be absolute white.


Advanced Controls

The Contrast and Bias sliders are advanced tools that allow you to stretch, squish and shift the pixel value range in which your colors are displayed.

Play with them as you like to enhance your image!


Adjust the Color

Choose from this list of colormaps to either
add beauty to your image, or highlight the
relative brightness of different regions in your image.

You can also make real-color images with
RGB mode, but you ought to watch a tutorial
on creating RGB images first.


Auto Align Images

When you want to blend multiple NASA images (or NASA images with MicroObservatory), you will need to use the Auto Align Images tool. Different telescopes come with different fields of view, so Auto Align Images will align all of the images to the same field of view.

Watch the tutorials on how to auto-align images and also how to blend images to learn more.


Save Your Image

When you’re done, don’t forget to save your image to your computer or device! You’ll need it when you submit your image to the Astrophoto Challenge.

And make sure to choose either PNG or JPEG format. (FITS format won’t save all the processing that you’ve done.)


Close the Image

At this point you know the main steps of processing images in JS9-4L, so you don’t need the Crab Nebula image that you opened at the beginning.

You can close any image by clicking the × next to the image filename in the My List dropdown.

**You can open your own image by using the Image dropdown**


Explore More

If you want more detailed help, Video Tutorials will take you to a collection of tutorials on processing images.

To learn more about this nebula, Hear from Experts opens a playlist of astronomy experts introducing you to Crab Nebula.


You’re All Set!

But if you would like to watch this Guided Tour again, just click this button above.

Finish Guided Tour



Back to NASA’s Astrophoto Challenge

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