James Ritson

Hi @Steve143, here's a rough breakdown: Luma+Chroma Denoise (on the linear data) Colour Preserving Tone Stretch Live Background Subtraction to remove a red-ish colour cast Star Eater at 50% opacity to reduce star intensity Enhance Structure masked to bring out dust detail around the main stars RGB Luminosity—green and blue contribution brought up, red contribution all the way down Curves adjustment for a tone curve to boost the mid-tone detail Enhance Blue Signal for a richer blue colour around the stars Boost Red/Yellow detail to bring out very subtle colours in the surrounding stars Extract Inferred Ha Luminance to create a stretched luminosity layer based on red channel data—this helped bring out the dust and trail detail and also made the fainter stars more visible Reduce Harsh Noise (+) to tame some of the blocky noise at this point Soft Star Glow for some nice glow around the stars Diffuse Glow to bring in some deeper colour diffusion around the star detail Brightness & Contrast adjustment masked to exclude the bright star detail—this was to bring up the background tones Another Curves adjustment for a contrast tone curve Brightness & Contrast adjustment to increase general contrast Reduce Star Luminosity to dampen the bright star detail Another Curves adjustment to control tones Background Sharpening to sharpen detail whilst avoiding panda eyes Final tone adjustments (Curves, Brightness & Contrast etc) So it's quite an iterative process. Some of my experimentation involved moving layers around in the layer stack Z-order, as this can affect the rendering. I've actually made some of my acquired data sets available for download on my website (https://jamesritson.co.uk/resources.html) including the Pleiades data—again, as it's via Gumroad and the download sizes vary from 1-5GB, I've added an arbitrary fee of £1 as I can't list them for free. They are hopefully good value for money, however, as they also include a finished .afphoto document with all the non-destructive edits, so you can stack the data yourself then follow along (or deviate!). Thanks, James

Hi, I've just seen this post, apologies for bumping the thread—are you referring to sigma clipping for outlier pixels, e.g. rejecting hot pixels, light trails, inconsistent response pixels? Affinity Photo does indeed do this, it's under the Stacking Options panel, you can set the Threshold and Clipping iterations: Thanks, James

Hi all, I've taken the above feedback into account: @jjosefsen, I will check with the developer how best light frame selection is actually implemented so I can give you an accurate answer. @powerlord that's interesting about the Align Layers by Stars feature, usually it works flawlessly unless one of the images has significant star bloat. For example, I tried to align two stacks of M42, one with 180s subs, the other with 15s subs, and because the stars were overexposed with the longer exposure stack it failed to align. Generally, though, outside of exposure merging, it should be fine–what are you using it with? Have you tried using file groups within the stacking workspace? It aligns different data groups during the actual registration process, therefore it avoids resampling (higher quality) and will likely be more successful with alignment as well. I also just wanted to let you all know that I've released version 10 of the macros today: you can grab them for free directly on Gumroad or via my website. Alternatively, if you had already downloaded them previously, you can find the email with the download link and follow that again to re-download them. Here is the change list for v10: Fixed issue with Normalised Tone Stretch where NaN (not a number) pixels could be created during tone stretching. Improved Soft Star Glow macro: completely changed implementation for a smoother appearance. New macro: Live Channel Mask, to easily mask based on channel contribution. New macro: Channel Masked White Balance, enabling you to change white balance and blackbody tint whilst masking to a specific RGB channel contribution. New macro: Average Neutralisation, useful for balancing out images that have strong colour casts. New macro: Diffuse Glow, renders a pleasing diffuse lighting effect on brighter areas of the image. New macro: Background Sharpening, which applies sharpening based on a non-destructive weighted intensity mask, avoiding bright areas such as star detail. Very useful for minimising black star halos around stars. New macros: Boost Red/Yellow Detail and Boost Blue/Green Detail. Compared to the Enhance Signal macros, these focus more on colour intensity as opposed to luminosity. New macro: Luma Denoise, for reducing luma noise independently of chroma noise. New macro: RGB + HOS (Mixed Luminance). Sets up RGB layers as colour data, then averages between Ha, OIII and SII data layers for luminance enhancement. New macro: Ha Luminosity Setup, to quickly take an additional Ha data layer and use it for luminance enhancement. New macro: Extract Inferred Ha Luminance, which extracts red channel data from your composition, tone stretches it and applies it non-destructively as a luminosity layer. I haven't been shooting much over the holiday period as we ended up getting Covid and spending Christmas and New Year in isolation! It completely knocked us out, so I didn't even have the energy to jump on remote telescoping much, but I managed to produce a couple of results, mainly using the macros to achieve the majority of the editing: I could have cropped Pleiades a bit more, but I'm quite fond of the detail on the outer parts of the image...

Aha, not too far away then I take it? I used to live in Woodhall Spa, moved to Newark, then to Boughton (near Ollerton) which had some great skies for seeing around the pit wood, then finally moved back to Newark this year. Hi, the deconvolution would certainly be useful. May I ask what local histogram equalisation does? Is it similar to the tone stretching macros in my macro pack? (They will perform various nonlinear transforms such as log2, sqrt then do histogram equalisation). Frame weighting: is that evaluating the quality of frames? Photo has the "Select best light frames" percentage option when stacking which might be useful? I did also read somewhere—I can't remember whether it was here or another forum—that someone passed on using Photo because the stacking did not offer kappa sigma clipping. This confused me because it's the default option in Photo and is pretty much essential for removing outlier hot pixels and inconsistent pixels. I can't say whether any new features will make it into the next version, as the dev team are all hard at work and need to focus on other longstanding features that have not yet been implemented. We did talk about the possibility of guided star removal in the future, however.

Hello all, I hope it's OK to post this thread (and that I'm using the correct forum). I wanted to introduce myself: I'm the Affinity Photo product expert and I work for Serif who are responsible for the Affinity range of software. I've already seen a couple of threads and posts here about Affinity Photo and its usefulness for astrophotography image editing. As it has been noted previously, version 1.9 launched with a dedicated workspace for stacking astrophotography data—this came about because one of the developers and myself are keen astrophotographers, and seeing as Affinity Photo has other advantages for astrophotography retouching it made sense to put the effort in so that people could stack in the software as well and therefore have an all-in-one solution. Basically, I'm a huge astrophotography geek, especially when it comes to the retouching aspect of the genre: I've been producing a variety of official video tutorials and providing macros (essentially the equivalent of 'actions') and example documents to try and make it as accessible as possible for people. I wanted to raise awareness about all this material that is available for people to take advantage of, and also to offer support on this forum if people had any questions about Affinity Photo for astrophotography. Video tutorials I've produced an array of video tutorials that cover stacking and subsequent editing techniques for various composition setups (e.g. one shot colour, LRGB, SHO, bi-colour, greyscale colour mapping), as well as some shorter videos that demonstrate how to use certain features like the background colour removal filter, file groups, sigma clipping etc. The best place to see them all is on YouTube with the Astrophotography playlist: https://youtube.com/playlist?list=PLjZ7Y0kROWit-4cZY2A-tiEsYaWzWQoIC Macros Since the release of version 1.9, I've been releasing and updating macros to support the software. As well as being a workflow aid to speed up the editing process, I also wanted to highlight the various non-destructive functionality that Photo offers, as the natural tendency is to try and recreate equivalent workflows from Photoshop which are not always the most efficient. The macro functionality includes: Automated tone stretching: normalised, logarithmic, colour preserving options. Composition setups: designed for greyscale data, these will quickly set up the appropriate layer structure, blend modes and colour mapping for combinations such as RGB, LRGB, SHO, HSO, HOO and many other variations, including more exotic combinations like HORGB-L and HaRGB-L. Structure enhancement, local contrast enhancement, structure softening, highlight brilliance enhancement Live luminosity masks that allow you to reduce background or star luminosity, produce weighted saturation masks etc Star reduction and fringing removal Star motion deconvolution Colour signal options including selective luminosity and saturation enhancement Noise reduction: luma and chroma, just chroma, structure denoising and harsh/blocky noise removal RGB and Min/Max calculation live luminosity options, to alter brightness and contribution of colour channel data Monochrome colour mapping for single greyscale data compositions Merge to 16-bit sRGB/wide gamut options (after tone stretching) to improve compositing performance on older/weaker machines. A separate 16-bit category with most macro behaviours tweaked to compensate for the difference in gamma compositing (32-bit uses linear compositing, 16-bit uses gamma transformed non-linear compositing). I tend to add to these macros and improve them quite regularly, and they are now on version 9! Alongside this latest release, I have finally managed to plan, record and edit a comprehensive video tutorial that covers how to use each macro in detail, and it's 41 minutes long! The tutorial can be viewed on YouTube here: https://youtu.be/s2vVO9WoDC0 I provide the macros as a free download, available on Gumroad (https://jamesritson.gumroad.com/l/jr_astrophotography_macros) and my website (https://jamesritson.co.uk/resources.html) Example documents I have started compiling finished example .afphoto document files and providing them so that people can explore the layer structure and see how various non-destructive retouching can be achieved. The documents are produced from a combination of my own data and from remote imaging services. The layers are all colour-coded (the key is provided in the readme PDF) and you are free to experiment with the layers to gain insight into how they are all being used to reach the final result. I provide these with an arbitrary £1 (GBP) fee, as Gumroad does not allow free downloads over a certain file size, and these documents are fairly large! Download link: https://jamesritson.gumroad.com/l/jr_astrophotography_example_documents There are currently 16 example documents featuring a variety of composition setups, and they are: California Nebula HOS Cone Nebula Ha Heart Nebula Ha Helix Nebula HORGB-L Orion Nebula OSC Rosette Nebula SHO Sculptor Galaxy LRGB Tarantula Nebula HaOIII Tarantula Nebula LRGB Crescent Nebula OHS Pleiades RGB Squid Nebula OSH Thor's Helmet HSO North America Nebula OSC Witch Head Nebula LRGB Rho Ophiuchi LRGB (OSC stands for one-shot-colour imagery from bayer sensors). Data sets and finished documents More recently, I have also been providing downloadable data sets along with a finished .afphoto example document. The idea is that you can stack the data yourself in Affinity Photo and learn what its stacking functionality is capable of (e.g. sigma clipping to reject outlier pixels, file groups to quickly stack multiple data sets), then follow along with the finished document to see which macros and techniques have been used to achieve the end result. All data is provided as calibrated FIT files, so there is no need to lengthen the stacking process with calibration frames. Like the example documents, I provide these with an arbitrary £1 (GBP) fee, as Gumroad does not allow free downloads over a certain file size, and the data sets are typically quite large. So far I have made available: Pleiades (M45) one shot colour bayer sensor: https://jamesritson.gumroad.com/l/pleiades Triangulum Galaxy (M33) monochrome LRGB: https://jamesritson.gumroad.com/l/triangulum_galaxy Orion Nebula (M42) bi-colour HOO: https://jamesritson.gumroad.com/l/orion_nebula I hope all the above material is of interest to fellow astrophotographers—we're always keen to find out if people are having a good experience with Affinity Photo for editing, and what the current frustrations or issues are. If anyone has any queries or feedback I've made sure to follow this thread so I can be notified. Thank you for your time!