Astrophotography Stacking slow with large numbers of files

[Jerry B]

I was pleased to see the stacking feature and watched the youtube video.  I tried to stack a set of files I'd stacked using DSS and gave up after about 20 hours of waiting.  There were about 700 plus bias as well which processed in DSS in about 90 mins (I dont remember the exact time).  I ran a few quick and dirty tests using Affinity and time varied roughly linearly with number of files up to 250 lights (46 min) then at 350 shot up (151 mins).

If I use a tracking mount I wont need as many as 750 or I could just use DSS for the stack in that case but it would be nice to use Affinity start to finish.

 

Jerry

[Dan C]

Hi @Jerry B,

Welcome to the Affinity forums

My sincerest apologies for the delayed response here, we are extremely busy following our 1.9 update and working from home is unfortunately extending our response window to be longer than normal, many thanks for your continued patience and understanding here.

I have spoken with James Ritson, our resident Photo and Astrophotography expert, who has said the following -

"Affinity Photo may be slower at processing a large stack of RAW images in the Astrophotography Stacking feature than other apps. Not only are these RAW files using Bayer sensor (so have to go through debayering) but they're typically 20MP plus in resolution.

Affinity Photo uses 'bundle adjustment' for alignment, which is slower than other methods but much more accurate. We have had test cases where DSS has failed to correctly align the images, or requires manual intervention after stacking to re-align, whereas this is not the case in Affinity Photo.

My example that comes close is something like 580 light frames, at 24 megapixels each. For me this takes over an hour to stack, but it's shortened somewhat if I reject bad frames (use the Select Best Light Frames option and pick a percentage around 80). Alignment could actually be choking on bad frames with star trailing perhaps, which would delay the process further."

 

I will also discuss with our developers if we can offer options to help process such large stacks faster, perhaps with a compromise regarding our alignment options, where we could allow the user to choose a less guaranteed stacking method with the aim for this to speed up processing with large stacks.

I hope this helps!

[John Rostron]

@Jerry B,

What would make life easier was for Affinity Photo to batch convert your raw files to tiffs. As far as I am aware, it can not. However there are other batch converters out there, as downloads or online. Converting to tiffs, then stacking might speed up your overall workflow.

John

[Jerry B]

Thanks for the comments, I'll look at rejecting bad frames and suggestions.  Interesting that 580 frames took much less time than I experienced.  I'll have to check my PC out as its a reasonable spec though I did find apps were not using the NVIDIA GPU by default which may be relevant.

Jerry

[Dan C]

17 hours ago, John Rostron said:

What would make life easier was for Affinity Photo to batch convert your raw files to tiffs. As far as I am aware, it can not

You can use File > New Batch Job for this - We previously made changes to how the Batch processor in Affinity deals with RAW files, it won't use exactly the same development pipeline as loading a RAW file directly in Affinity Photo, however when processed using this method we work to provide the same visual appearance that the RAW would give if you opened this in the Develop Persona and selected 'develop' without making any changes.

If you do need to manually adjust the RAW settings for the batch conversion, such as white balance etc, then unfortunately Affinity does not support this currently.

14 hours ago, Jerry B said:

Thanks for the comments, I'll look at rejecting bad frames and suggestions.  Interesting that 580 frames took much less time than I experienced

No problem at all  James was likely using a Mac rather than a Windows PC - so the comparison may be slightly skewed due to this.

14 hours ago, Jerry B said:

I'll have to check my PC out as its a reasonable spec though I did find apps were not using the NVIDIA GPU by default which may be relevant

As far as I'm aware, Hardware acceleration should speed up this process, and I would recommend enabling this if available to you. The mac James was running would have been using Metal Hardware Acceleration, which would also explain the difference in stacking time observed!

[Domus]

As I'm stacking hundreds of files over six file groups, I'm still waiting for the very first "Astrophotography stack" trackbar pixel to appear, after over an hour. I'm afraid I won't be able to add more files beyond today's pile, unless I want to wait a full 24 hours for them to be processed (although, extrapolating from 1 pixel for one hour, I'm guessing ten days, but I'm sure it'll pick up pace after a while...).

AP does stack quite excellently, however. Ah well, maybe after a serious hardware upgrade.

[Delattre]

I'm using a Stellina telescope and it makes only exposures of 10 s each. So over successive days, I have several groups of fits files. I had 4 groups for M51 taken at different nights in May and June and the total of the 4 groups is 1110 individual images that I started to stack yesterday. 27 h later the computer is still working. Any idea on how long this will take ?