Light.dat file in t...
Clear all

31 July 2020 - Comet Registration video tutorial using APP 1.083-beta1 released.

30 July 2020 - APP 1.083-beta1 has been released introducing Comet processing! This 1st beta has comet registration. The stable release will also include special comet integration modes.

9 July 2020 - New and updated video tutorial using APP 1.081: Complete LRGB Tutorial of NGC292, The Small Magellanic Cloud by Christian Sasse ( and Mabula Haverkamp

2019 September: Astro Pixel Processor and celebrate a new Partnership!

Light.dat file in the working folder is 128GB is this normal?  


White Dwarf Customer
Joined: 1 year ago
Posts: 20
September 27, 2020 23:09  


Tonight I processed 400 Canon 5d MKIV RAW light frames of M31 in APP with ~ 84 darks, 33 bias, and 33 flat frames. While processing I watched the "Available HDD" drop from 294GB to ~164GB.

In the APP folder there was a .dat file that was a HUGE 128GB.

Just wanted to ask if this is normal?

As soon as processing finished the file disappeared and available HDD went back up to 294GB

I have 32GB ram, 16GB allocated to APP but my RAM usage went from 27% to 87% during processing which I thought was odd.

Is there a tool or calculation I can use to make sure I have enough free HDD space for processing if using lots of frames, per the above?

Many thanks,




Quasar Admin
Joined: 3 years ago
Posts: 2469
September 28, 2020 12:10  

Usually APP tells you if you have enough space left for processing, but it does use quite a bit for processing especially with higher resolutions etc. You can divide the data up in smaller chunks if you want to limit the resources more, like doing 4x100 frames at a time and combining those 4 later.