I’ve noticed an issue with Sony E-mount lenses on the Pixboom Spark.
I’m using Sony G Master lenses, mainly the 24-70mm, 16-35mm and 70-200mm.
Every time I turn the camera off, it loses the focus position I had set before.
But I’ve also noticed that even while the camera stays on, the focus sometimes changes or gets lost. Over the last three days we were filming a bike trick at the same spot, and I basically never touched the focus once it was set. Still, some clips ended up noticeably out of focus and I had to readjust it.
The only things I changed between shots were aperture and ISO, so I’m wondering if changing one of those settings could somehow affect the lens/focus position.
Or maybe switching from playback to live view is the reason for it to change.
Has anyone else noticed this or had the same issue with Sony E-mount lenses on the Spark?
aperture can change your focus depending on lens. it is one of the things that makes cinema lenses so expensive
Yeah, that’s true in general, but I’m using the GM II lenses, which are reported to have basically no noticeable focus shift when stopping down.
Also, I’m not changing the aperture from like f/2 to f/15. I was mostly working between around f/4 and f/7–8. We had a cloudy day with the light constantly changing between sun and shade, so I had to adjust the aperture back and forth quite often.
The focus shift I’m seeing is also pretty significant, not just a tiny change in the plane of focus. I’ve never had this issue before with these lenses on my Sony cameras either.
The sample images were back to back with not touching the focus once:Uploading: 4k.00_11_26_23.Standbild008.png…
Uploading: 4k.00_10_03_19.Standbild006.png…
I think this is normal for now as the Spark doesn’t actually have AF control built in currently. Since the lens is Focus by wire the set point would change when the camera / lens is powered down.
(There is no physical mechanical connection between the focus ring and the optical elements; the lens’s motors move them. The zoom ring, however, is mechanically coupled.)
This set point would likely only be remembered once they enable AF control in the camera as it does with a native Sony camera.
It’s nice call out for the future feature set but for now I think it’s just the limit of having no actual AF control at the moment.
