In astrophotography, using thousands of dollars of equipment to capture images of deep sky objects as you carefully track them across the sky is only part of the imaging process. Equally important is the task of combining and processing the captured images to produce your final astrophotograph. That’s where tools like Photoshop, PixInsight, Astro Pixel Processor, Siril, and even the Gimp would traditionally be put to work. But a new tool is gaining a foothold in the astrophotography world–Affinity Photo. Affinity Photo is just as capable as Photoshop for a fraction of the price. If that doesn’t make it attractive enough, the latest version (1.9) has added some astrophotography-specific capabilities, including the ability to stack astro exposures–a very important task in astro image processing.
Affinity Photo is a general-purpose image editor, very much like Photoshop in its layout and features. I purchased it directly from the Affinity website for $50 early in 2020. Right now (February 2021) Affinity is selling Affinity Photo for half price–only $25! Additionally, Affinity is currently offering a 90-day free trial. If you’re in the market for an image processing tool (or getting sick of paying by the month for Photoshop), you really can’t go wrong with Affinity Photo. In the rest of this article, I’ll share with you some resources and information I’ve come across that will help you get started with using Affinity Photo for astro image processing.
Before I go any further, two disclaimers. First, my interest in Affinity Photo is only as a happy customer–I have no relation to nor affiliation with Affinity. Second, I am by no means an expert in either the use of Affinity Photo or in astro image processing in general. I’m not even sure I’m competent at this point, but I’m at least gaining ground. Here’s an example from my gallery of some of my recent work, stacked and processed using Affinity Photo. Judge for yourself.
Useful Resources for Affinity Photo Astro Image Processing
The first resource I found that helped me get started with processing astro images was a book by Dave Eagle: The Stargazing Guide to Affinity Photo Astrophotography Image Processing.
This book is also available from Amazon. Dave Eagle’s book is fairly brief but provides a few concrete easy-to-follow examples of how to process images. It was worth the modest cost to me because it helped me get started. At the time, there wasn’t a whole lot else to be found.
One thing I learned from Dave Eagle’s book was that Affinity Photo is capable of using some of the available astro image processing plug-ins that had been created for Photoshop. His book specifically mentioned two:
- AstroFlat Pro, by ProDigital Software, is an effective tool for removing background gradients and sky glow from your images.
- GradientXTerminator, by Russell Crowman, also addresses unwanted gradients in astro images.
Both of these are known as “8BF” plug-ins, and Affinity Photo is able to directly use both of these as well as other 8BF plug-ins. I have personally found AstroFlat Pro to be particularly useful.
Topaz Labs also produces some image processing plug-ins that can be valuable for improving astro images as well as regular photographs. Both of these tools purport to use artificial intelligence to accomplish their jobs, and they can be launched as stand-alone applications as well as be accessed as plug-ins from within Affinity Photo:
- DeNoise AI is a powerful tool for removing noise from images. Noise is a perpetual challenge for anyone shooting images in low light conditions, and it can be especially challenging for astro imaging. I’ve been pretty impressed with how well DeNoise AI works. I posted a quick before-and-after example a few weeks ago.
- Sharpen AI is another useful too. This one does exactly what its name says–it sharpens images. I don’t find myself using this as often as DeNoise, but it does come in handy when an image could use a little help.
The Topaz Labs tools are pretty heavily advertised, and DeNoise AI seems to have a pretty good reputation among astro imagers. They can be a bit pricey but Topaz Labs frequently offers discounts, so keep an eye out.
Affinity Photo 1.9
While I felt pretty good about using earlier versions of Affinity Photo for astro image processing, the release of version 1.9 really brought Affinity Photo into the spotlight for the astrophotography world. The two new features I’ve used (and liked) so far are the ability to do stacking right in Affinity Photo (rather than having to use another tool like Deep Sky Stacker) and a killer astrophotography filter for reducing backgrounds and gradients. Here’s the announcement:
James Ritson is a member of the Affinity team and appears frequently in the video tutorials on the Affinity website. He’s also an accomplished astrophotographer and I suspect is one of the driving forces within Affinity for adding tools specifically for astrophotographers. James created several video tutorials specifically addressing the new capabilities within Affinity, demonstrating an end-to-end workflow for a number of different astro image processing scenarios. You can find his videos on this page. They’re pretty comprehensive–give them a look.
James has also written a pretty lengthy article that discusses the advantages of using the new astro image stacking capabilities added to version 1.9, but also demonstrates how to use Affinity Photo to address common tasks in astro image processing.
Finally, James has also put together quite a set of macros for Affinity Photo for quickly performing common astro image processing tasks, like tone stretching and star reduction. Here’s a video he put together as a teaser:
You can download the macros from his website. They’re free, but you’ll be given an opportunity to offer James a donation for his effort.
The bottom line is that Affinity appears to be committed to serving the needs not only of the general image processing community but also specifically astrophotographers, and Affinity Photo version 1.9 is an excellent step forward in that direction. Even at its regular price of $50, my opinion is that Affinity Photo is a huge value for that price. With Adobe moving to a subscription pricing model for its products in order to extract more money from its users, Affinity Photo’s modest one-time price seems like a bargain.