Vallerret Warmth Ratings
Extension tubes on FullFrame, what are the differences?
The Full Frame marking on the macro Extension tubes is not insignificant. If you are buying an intermediate ring for Sony cameras with the Sony E mount this is important information.
The aluminum as material is crap, but it's been experienced that way
We apologize to the professional society for mentioning aluminium as a material. It's obviously nonsense. You really wouldn't want anything aluminum in your home.