Sigma 18-35/ Viltrox Adapter/ GH5 Parafocal Issue

[Karl Miller]

Using the non-speed-booster Viltrox adapter with a Sigma 18-35 on a GH5; the lens works great. But its not acting like a parafocal. That is, if I zoom in and focus, and then zoom out, the focus point changes… Shouldn’t I be getting a constant focal point across the entire zoom range (assumming that I focus while zoomed all the way in)?

thanks-