G9 compared to E-M1 continuous focus while zooming

I'm coming from a Fuji X-H1 and 50-140 2.8 zoom lens.  When continuously focusing WHILE zooming in burst mode (mechanical shutter, not electronic shutter)--say continuously focusing on a runner coming toward me starting out at the long end of the zoom and then widening as the runner gets closer--my X-H1 does a pretty good job maintaining focus WHILE zooming.

I recently tried a Panasonic G9 with the Olympus 40-150 2.8 doing the same thing, and the camera simply cannot maintain focus at all while zooming (this is actually mentioned in the instruction manual I think).  It's fine otherwise, just not WHILE zooming at the same time.

Is the Olympus E-M1 II any better at this than the G9? I'm wondering if it might be since like the X-H1 it uses PDAF instead of the contrast system of the G9.  Anybody got any experience with this combo?

Well, it's a difficult thing to do while zooming with a lens that changes its focus as you zoom.

Even so I think the EM1 MkII with its new firmware should do better. It has phase detect cells on its sensor, it really might do better.

By the way, I own a G9. But I've never tried your experiment.

A little bit better, but all the m43 bodies are awful at maintaining C-AF while racking zoom. I know for sure the X-T3 does this quite well and I've heard the latest Sony bodies handle it well but I've only shot the A9/A7III with primes so can't really comment from personal experience. Also, pretty much any DSLR will do this without blinking.

Xbot wrote:

whumber wrote:

A little bit better, but all the m43 bodies are awful at maintaining C-AF while racking zoom.

Thanks. Are you saying this from experience with m43 bodies?

Yes, I currently own the G9, E-M1ii, and E-M1X. None of them can maintain accurate C-AF while racking zoom; at best I see something like a 20% hit rate when racking zoom. Most of my experience in this regard is with the 40-150 PRO, I don't have any meaningful experience with the 100-400 PL or any of the other tele zoom lenses other than the Panasonic 35-100. On the Fuji side, OTH, I spent some time with the X-T3 plus the cheapo 50-230 and it had no issues maintaining good focus while racking zoom.

whumber wrote:

Xbot wrote:

whumber wrote:

A little bit better, but all the m43 bodies are awful at maintaining C-AF while racking zoom.

Thanks. Are you saying this from experience with m43 bodies?

Yes, I currently own the G9, E-M1ii, and E-M1X. None of them can maintain accurate C-AF while racking zoom; at best I see something like a 20% hit rate when racking zoom. Most of my experience in this regard is with the 40-150 PRO, I don't have any meaningful experience with the 100-400 PL or any of the other tele zoom lenses other than the Panasonic 35-100. On the Fuji side, OTH, I spent some time with the X-T3 plus the cheapo 50-230 and it had no issues maintaining good focus while racking zoom.

The PL50-200mm is apparently parfocal (or nearly so), which would presumably help significantly with this process.

I've owned both and agree with the comments that neither is that good but the EM-1mk2 + v3.1 is better

If I need to maintain focus whilst zooming I find constantly half-pressing the shutter button does a pretty good job as the speed of refocus is near instantaneous.

(My best experience of maintaining zoom focus was with my 7Dmk2 + lenses such as the 400 f5.6L and 70-300LIS)

Donald B wrote:

Brian Wadie wrote:

I've owned both and agree with the comments that neither is that good but the EM-1mk2 + v3.1 is better

If I need to maintain focus whilst zooming I find constantly half-pressing the shutter button does a pretty good job as the speed of refocus is near instantaneous.

(My best experience of maintaining zoom focus was with my 7Dmk2 + lenses such as the 400 f5.6L and 70-300LIS)

zoom focus with the 400 5.6 that would be a leejay answer

Don

thanks Don, old age and stupidity again, should have read 100-400 f4-5.6 L - how embarrassing

Donald B wrote:

Brian Wadie wrote:

Donald B wrote:

Brian Wadie wrote:

I've owned both and agree with the comments that neither is that good but the EM-1mk2 + v3.1 is better

If I need to maintain focus whilst zooming I find constantly half-pressing the shutter button does a pretty good job as the speed of refocus is near instantaneous.

(My best experience of maintaining zoom focus was with my 7Dmk2 + lenses such as the 400 f5.6L and 70-300LIS)

zoom focus with the 400 5.6 that would be a leejay answer

Don

thanks Don, old age and stupidity again, should have read 100-400 f4-5.6 L - how embarrassing

I have a new phone and I'm so tired of it puting words in My sentence after I have hit the go button

Don

I can't even claim that Don, I'm prone to forgetting what I writing half way through, it always makes sense when I check before posting (I guess because I knew what I meant to say )

I even have to check in the mirror in the morning to make sure I woke the right person up! 

I think they should add this in reviews actually. When you have a zoom and bikers come towards you, it is a very handy feature. Here also Fuji not so long ago known for pretty lousy AF has suprassed mFTs it seems. Well done!

I only have the E-M1 mark 1 and 40-150 pro for experience, but I've not had any real issues zooming whilst maintaining CAF+TR, whilst taking a high speed burst.

Out of a burst of around 8 frames and zooming out, 2 frames will be out of focus. This will be with a total of 2 short bursts either side of zooming, whilst panning and holding the shutter half way to keep focusing. The sequence is only 6mm but I was holding focus and zooming out as they approached ahead of the jump.

Not sure if that helps in any way, but I hope it does.