Shift lever and rear derailleur compatibility I have got MTB with Shimano RD-M410 Alivio Rear Derailleur 8 speed. It has  brake/shift lever for it model ST-EF50-8R. I would like to move to disc brakes and therefore want to change to ST-EF505 shift/brake lever. Does anyone know if it is compatible with the Alivio RD-M410 rear derailleur?
Actually I plan on buying the 8 speed version of the st-ef505-r. https://bike.shimano.com/en-EU/product/component/acera-m3000/ST-EF505-8R.html Does it have the same cable pull as the st-ef50-8r?
Yes, you can use any Shimano 8 speed shifter with a Shimano 8 speed derailleur and cassette.
Generally Shimano (and SRAM) used the same sprocket spacing for all cassettes with the same number of sprockets (more sprockets means narrower spacing though). All MTB shifters up to 9 speed use the same cable actuation ratio (ratio of cable pulled to cage movement), and all shifters pull the right amount of cable per shift for the number of speeds they are for.