Rheumatoid factor (RF) levels above a normal range can indicate autoimmune conditions, such as rheumatoid arthritis (RA). Rheumatoid factor (RF) is an immune system protein that attacks healthy cells.

Do you use a Canon EOS R mirrorless camera? From wide-angle to telephoto, these are the best lenses we've tested for the platform. Images, and the devices that capture them, are my focus. I've ...

With the advent of this RF 16-28mm, there are no less than five full-frame options plus an RF-S wide-angle zoom for APS-C format cameras, and that’s not counting all of the back-catalog EF mount zooms ...

It's an ultra-wide zoom lens designed for full-frame cameras like the Canon EOS R8 Its design is practically identical to that of the RF 28-70mm F2.8 IS STM It costs $1,149 / £1,249 / AU$1,879 ...