Adapting PENTACON AV 80mm F/2.8 projector lens to digital camera (ASMR-ish)

In this video I show my method for adapting Pentacon AV 80mm F/2.8 projector lens to modern digital camera.
There are many ways to do this, I just went for something compact, handy and versatile.
The idea is not completely new, of course - please also check the video I was inspired by (   • 【自作レンズ】PENTACON AV 2.8/80 M42マウント改造方法。  ) and show Hiron some love too.

Pentacon AV 80mm F/2.8 lens was used in vintage German Pentacon AV 100 Auto and AV 150 Auto (and maybe some others) slide projectors.
This is a simple triplet design with no aperture control (it is always wide open at F/2.8).
The Pentacon itself is the successor to the Meyer-Optic company, and this lens shares a lot with the famous Meyer Trioplan 100mm F/2.8 lens - in particular its "soap bubble" bokeh style.
Pentacon AV lenses are often called "budget Trioplans", which is a bit of an overstatement, but for the 1/10 of the current price of the original Trioplan you can't really complain.

The adapted lens uses M42 mount to make it easy to use with different DSLR and mirrorless cameras - you just need to change one part (well, actually two parts for Nikon DSLRs). The 46mm "front thread" was added to attach MC UV lens filter and/or lens hood - the original AR coating on the lens itself is basically useless.

Most parts are widely available and very easy to find on eBay, Amazon or AliExpress. However, below are the links for some parts you may have trouble finding:

Pixco 25-55mm (25-57mm actually) M42 focusing helicoid:
eBay: https://www.ebay.com/itm/383050711121
AliExpress: https://www.aliexpress.com/item/32674...

M42x1.0 to M52x0.75 step-up ring:
eBay: https://www.ebay.com/itm/283108687026
AliExpress: https://www.aliexpress.com/item/32881...

Set of M52 extension tubes (you will need tube #2 for this build - you can buy it separately, but this kit is cheaper and you can use tubes #1 and #3 as "macro tubes")
eBay: https://www.ebay.com/itm/263614816352
AliExpress: https://www.aliexpress.com/item/32652...

Enjoy and thanks for watching!