A great astrophotography image is very subjective. What some people would consider to be the ‘perfect’ image, is a complete mess to others. While there are some core aesthetics that I think most people can agree on (nobody likes a noisy image), other aspects have vastly different opinions depending on who you ask.
If I consider the image of the Western Veil Nebula shown below to be one of my best images yet, I think it would be helpful for beginners to understand why. You can learn from the key steps I took in the image acquisition and processing stages to create an astrophoto like this, or you can take your images in a different direction to tell the story of the object you want to tell.
I sent the following tweet to a massive list of astrophotographers to get their opinion on what makes a great astrophotography image. It is interesting to see what aspects of an astrophotography image are important to some and ruin the image for others.
This is (IMO) one of the best astrophotos I’ve ever taken. So I can get better, please tell me what you like/dislike about it: pic.twitter.com/n6XoGk2mwf
— 🔭AstroBackyard (@AstroBackyard) November 1, 2023
I encourage you to comment on this article with your ideas of what makes a great image, and if I have left anything important out. While I do have a lot of experience with deep-sky astrophotography, I have plenty of room to improve in terms of technique, and image processing.
Before we go any further, I have a few disclaimers. The image traits I mention below are highly subjective, and that is the point. You may disagree with my logic, and I welcome your constructive criticism in the comments.
This article refers to deep-sky astrophotography images taken with a camera and telescope. While many of the same key strategies apply to Nightscape and Milky Way Photography, this article is geared toward pictures of nebulae and galaxies through a telescope.
The Western Veil Nebula. 5 Hours of Total Exposure Time. ZWO ASI2600MM Pro Camera with Narrowband Filters.
- The subject is well-framed
- The filters used isolate key wavelengths of light
- Depth is achieved by reducing star size
- The image is large and looks sharp at full resolution
- Dynamic color enhancements help create a dynamic scene
What Could Be Improved:
- More exposure time would help create a cleaner image
- The image is cropped from a larger field of view
- Many consider the image to be oversaturated
- Natural star colors are lost due to narrowband imaging
The 7 Traits of a Great Astrophotography Image
Based on my own experience (for over a decade), I have a few secrets to a great image. However, these are subjective traits that some people may not consider to be aesthetic. For example, I prefer to leave the stars in my final images (always), while others seem to enjoy the look of a completely starless astrophotography image.
One of the best places to review quality astrophotos is AstroBin. This website hosts all types of astrophotography images (deep-sky, planetary, nightscapes, etc.) from around the world, in stunning high-resolution. If you are looking for the best astrophotos in the world, it is hard to top the examples found in the image of the day section of AstroBin.
Based on my research and personal expertise, I have put together the following list of key factors that go into a great deep-sky astrophoto. You’ll notice that I have not included ‘difficulty of target’ on the list, which could be considered an important factor for many astrophotography competitions.
- Large, High-Resolution Image Size: The image looks great at its native size captured, and details can be enjoyed up close.
- Composition and Framing: The deep-sky object is thoughtfully framed to showcase its unique beauty.
- Overall Exposure Time (& Calibration): The image has enough overall integration to reveal delicate details without over-stretching and introducing excess noise.
- Star Quality and Size: The stars are round, small, and not overly ‘crunchy’ or soft.
- Overall Sharpness: The image is crisp and clear, but not jagged or over-sharpened.
- Saturation and Color Balance: The colors are punchy and not washed out. The highlights and shadows are not clipped.
- Depth and Contrast: The deep-sky object is dynamic, with areas of light and darkness. It does not appear ‘flat’.
Above: I prefer a colorful (perhaps oversaturated) look to my images. These images look great to me right now, but I know that in a few years, I will see several ways to improve the images using new techniques.
When Does an Image Become ‘Over-Processed’?
This is an interesting discussion. 5 years ago, I would have considered my latest photo of the Veil Nebula to be over-processed and unnatural looking. If you ever want to see how your personal image processing tastes evolve, just look back through your Instagram gallery. I bet you will see that your processing style gradually changes over time.
Or maybe your images go the other direction, and you now produce more scientifically accurate astrophotos of a higher quality. There are no rules to follow when astrophotography is a hobby that is meant to be enjoyed. I have found that when I experience times of burnout or lack of motivation, it’s always because I am not making progress that excites me.
Several people who saw my latest version of the Veil Nebula considered it to be oversaturated and over-processed. I do not disagree with them, yet I was very intentional with the level of color and detail of this photo. By next month, I am sure I will have a new opinion on the quality of this image.
Above: The top version of the image has a more natural ‘out of the camera’ look, while the bottom version has been stretched and saturated much more.
Finding Inspiration from Others
All of my deep-sky astrophotography projects start the same way. I see a stunning deep-sky image shared online and am inspired to create my own version of the target using my telescope equipment in the backyard. The equipment and processing tools used are often very different than my inspiration image, but this helps me put my own unique spin on the target.
If you also operate this way, make sure you understand the amount of time, energy, and money that went into the image. If an image was taken through a 24″ telescope from a dark, remote observatory, you may be a little underwhelmed with how to object looks through your RedCat 51.
However, you can still learn from the processing style, framing, and color palette of your favorite astrophotographer and apply those techniques to your image. My latest version of the Veil Nebula was heavily influenced by the incredible version shared by Ken Crawford many years ago. To me, this is ‘what the Veil should look like’. This phrase always gives me a chuckle when I hear astrophotographers debating it in forums or the comments section.
No matter which image processing software you use, I hope you keep these 7 key traits in mind as you edit your images. As long as you feel that your images are gradually improving over time, you will be motivated to keep going.