u/JustSomeDumbassGirl

Hi, is there an archive of older firmwares available for the ef-m adapters? I have an ef-m1 and the ef-m2ii adapters that I’m using with my Olympus em1ii and sigma art DC HSM 30mm f1.4 and Canon USM 50mm f1.4. And get very different results for each lens depending on the firmware.

I have firmware 5 on the ef-m2ii
It works extremely well with the sigma in AF-S mode and is quick and very accurate to focus (no af-c at all, it just hunts and gives up sadly). If I use this adapter and firmware on my canon lens it wildly overshoots autofocus and virtually never lands accurately, it can only really be manually focused.

I have firmware 3.6 on the ef-m1
It works extremely well on the Canon, locking on fast and accurately, it even seems to operate with af-c and tracking. But sadly it works horribly on the sigma, it will not jump far enough when corse focusing and then will very slowly creep toward focus but not fully arrive before the camera gives up, sometimes it will require 3+ focusing operations to achieve a lock.

I’m happy I currently have a really good working solution for both lenses and am super satisfied with the adapters but I would really like to be able to switch lenses between adapters to either speed boost or not. Unfortunately there is only firmware 5 available on the website and I’d like to try different options out to see if there’s a solution that works for both (or at least change the firmware over so I can use the speed booster with the canon occasionally). I also don’t want to update my ef-m1 to an unusable firmware for the canon and not be able to go back.

If there’s an archive of the older firmwares somewhere to allow me to trial different options and switch back and forth when required I’d be super grateful. I’m assuming downgrading firmware is possible?

Otherwise if anyone from viltrox is looking at this could you please consider for the next firmware update to use the 5.0 behaviour for the sigma and 3.6 behaviour for the canon because that would be absolutely perfect :)