msycamore said:

Some bad news... I wanted to use a median script in AviSynth for all the different LD-captures in order to remove all the random noise and dropouts etc. but it proved to be impossible to align them for some reason, the frame count differ slightly between them in different parts of the video (mostly just 1 frame difference) which I found weird, even between the three captures of the same LD. Could this have something to do with me IVTC'ing them before attempting this? (I've heard this shouldn't be a problem) or does it have something to do with how these LD's were captured in the first place?

Please help me out here if you have any idea what's causing this frame count difference.

It is quite normal for framecounts to be different between versions. However, three different captures of the same LD should line up frame-for-frame.

It may be caused by the IVTC process if you are using an automatic field-matching filter, that may give different results for the different captures. If so, do the multi-cap median before the IVTC stage.

It could also be caused by dropped frames in the capture. More common with VHS than LD, but I suppose could still be a possibility.

If you're using AviSynth, AvsPmod is good for lining up different files and finding where they differ. You can have three scripts open in three tabs and scan through the timeline of all 3 together.