Panasonic G85 auto focus - help needed!

[goinggreynow]

new G80 owner and despite reading the (advanced) user manual twice, reading all I can & YouTube videos, I am still getting into a pickle with Auto Focus. My Canon 80D seems much easier but that's probably because I've used it (and the 70D) for so long!
Can anyone please explain or confirm my understanding of the following;

Video/movie mode - provided I have "Continuous AF" set to on in the movie settings menu, the camera will continually re-focus providing I have the rear switch (the one surrounding the AF/AE lock button) set to either AFS/AFF or AFC. Is this correct?
Does the video AF use the AF mode previously set. i.e. 49-area, custom, tracking, 1 area, pinpoint or does it "do its own thing"? I have tried my own tests but they have proved inconclusive.

Photo mode
If I set AFC on the rear dial and half press the shutter button, the camera attempts to refocus on objects according to how i've set the AF area, but in so doing, the image in the EVF and on the LCD can best be described as "jittery" even when the camera remains on a static object. Any idea why this happens? It rather puts me off using AFC in any circumstances!
If I set AFS/AFF on the rear dial and also have "Quick AF" set to on in the menu, the camera attempts to refocus (sometimes not very quickly or accurately) even when not pressing the shutter button. I don't undertsand why or perhaps just don't understand what "Quick AF" is doing and whether its best to leave it on or off by default.

Thanks in advance for any help with these issues.

 

[stevelmx5]

I haven't used a G80 but Sony use the same "Quick Af" function and t basically means that the camera constantly changes focus on whatever is within the selected focus points, even when you're not half-pressing the shutter. The idea behind it is that it's already focused before you press the shutter but in reality it just causes the battery to flatten more quickly so I've always switched it off.

 

[Nawty]

Photo mode
If I set AFC on the rear dial and half press the shutter button, the camera attempts to refocus on objects according to how i've set the AF area, but in so doing, the image in the EVF and on the LCD can best be described as "jittery" even when the camera remains on a static object. Any idea why this happens? It rather puts me off using AFC in any circumstances!

The reason is because the camera uses contrast detect for AF, this works well for SAF but is basically useless at CAF, as are pretty much all mirrorless cameras except a few that also include phase detect sensors, and they are typically very expensive. I'm afraid to say that if you've bought this camera with a view to using CAF you will be left constantly frustrated as your Canon's will be infinitely better.

 

[goinggreynow]

I haven't used a G80 but Sony use the same "Quick Af" function and t basically means that the camera constantly changes focus on whatever is within the selected focus points, even when you're not half-pressing the shutter. The idea behind it is that it's already focused before you press the shutter but in reality it just causes the battery to flatten more quickly so I've always switched it off.

Thanks for the reply Steve. i was wondering if to leave "Quick AF" turned off & think I will do so now.

The reason is because the camera uses contrast detect for AF, this works well for SAF but is basically useless at CAF, as are pretty much all mirrorless cameras except a few that also include phase detect sensors, and they are typically very expensive. I'm afraid to say that if you've bought this camera with a view to using CAF you will be left constantly frustrated as your Canon's will be infinitely better.

Thanks, Ned. I was very aware of the issues surrounding Contrast Detect AF on mirrorless before buying the G80 and although i would like to use it to track cars/panning at Silverstone, I wasn't holding out any hope that it would be in the same league as my Canon 80D. That said, i am planning to use it for Motorsport with an old 70-210 manual focus lens for a bit of fun! Incidentally do you know why the "Continuous AF" in video mode seems much smoother/less "jerky" than when in photo mode?
Thanks Stuart

 

[mikew]

The reason is because the camera uses contrast detect for AF, this works well for SAF but is basically useless at CAF, as are pretty much all mirrorless cameras except a few that also include phase detect sensors, and they are typically very expensive. I'm afraid to say that if you've bought this camera with a view to using CAF you will be left constantly frustrated as your Canon's will be infinitely better.

Not strictly speaking true any more cameras like the G80 have a very good CAF,not as good as top end DSLRs but far from basically useless.

Not the best images as i have taken them back from flickr as i have no files on my PC, taken using the G80 and 100-400 @ 400mm in CAF.

 

[goinggreynow]

Thanks for posting Mike. I would have been thrilled to have ended up with images of this quality.
Do you typically use multi point, single or pinpoint AF for BIF?
Thanks. Stuart

 

[srhmoto]

Not strictly speaking true any more cameras like the G80 have a very good CAF,not as good as top end DSLRs but far from basically useless.

Not the best images as i have taken them back from flickr as i have no files on my PC, taken using the G80 and 100-400 @ 400mm in CAF.

View attachment 102136

View attachment 102137

I have to say that my experience of m4/3 cameras in CAF backs up @Nawty's basically useless description, although I have never used a G80, GH5 or EM1 mk II. The examples posted Mike while good, aren't really a stern test of CAF either - subject moving from right to left across the frame at more or less a constant distance from the camera.

I have no doubt that things are constantly improving, but in my experience, Panasonic still lags the competition by some margin.

Simon.

 

[mikew]

I dont bother much with birds flying towards me as i dont find the subject angle that interesting,i have done a few tests just out of interest and these i had to pull back from another forum as i didnt keep the originals.

Now ime not talking image quality here correct exposure or anything apart from CAF, these are unprocessed raw images converted to jpeg just to see how well or not the focus would keep up,again i will repeat not as good as top end DSLRs but above basically useless IMO.

Looks like 5 images are the max per post so have split it into two posts.

 

[mikew]

The point it went wrong as i lost the focus point

 

[mikew]

Thanks for posting Mike. I would have been thrilled to have ended up with images of this quality.
Do you typically use multi point, single or pinpoint AF for BIF?
Thanks. Stuart

I use single point unless its against a clear sky and i dont use any form of tracking.