[HELP] Filter Order

[Selur]

Is the order of filters applied in the order I select the filters, or is it set within the application itself?

The order in select stuff does not matter.
Hybrid does use a 'default filter order', but you can can change the filter order of both Vapoursynth and Avisynth filters.

• Filtering->Vapoursynth->Misc->Filter Order/Queue (see: also [INFO] About Vapoursynth Filter Order/Queue)
  
• Filtering->Avisynth->Misc->Filter Order
  

There you can also see the default order Hybrid uses.

How important is the filter order when de-interlacing and upscaling etc?

Filter order gets more and more important the more filters you add.
Note that for Vapoursynth you can even add most of the filters more than once with different settings (filter settings, or on regions etc.)
The default filter order is a good start, usually I would recommend to deinterlace as one of the first filters.
Whether upscaling should be done before or after other filters strongly depends a lot on the source and the used filters.

When should I change the filter order?

Whenever you think it makes sense for the source.
Most of the filters can make sense before or after another filter.
DeNoising, DeHalo,... for example can make sense before and/or after sharpening depending on the source.
In general, the default filter order is okay and should be considered a good starting point.
Normally you would use a deblocker, before applying other filters, assuming the blocking was introduced through the last compression of the source. Sometimes you want to remove blocking that was already in the source that before its last recompression, during which the source was also resized. In such a case, deblocking after resizing might make sense too.
The more you understand what a specific filter does, the better you can decide where it should be placed.
-> Probably any filter combination can make sense depending on the source and what you aim for.

Cu Selur