I just bought a Samyang 135mm f/2 and I'm looking to use it with my ASI533MC camera. I will be replacing its bayonet with the M48 adapter sold by Astro Essentials. From my research online, this lens requires a 44mm backfocus. My camera comes with the necessary adapters for 55mm backfocus (top picture of this). My thought is that by replacing the 21-mm T2 extender in that schematic with a 10-mm T2 extender, I should be able to achieve the 44-mm backfocus.
Does this sound like a good plan or am I missing anything here?
Thank you for your inputs!