GX80 but with Phase detect af?

Ru55 wrote:

Hi Sion,

thanks for for the reply. I’m guessing it’s the contrast detection. Let me give you a scenario. I have focus, then the subject (young child) moves closer to the camera (more sort of back and forth movement) . I half press to lock focus and the lens will move through the full range and not lock. I sort of feel it’s not getting a constant amount of contrast in the scene to decide what to do - if that makes sense.

yes I have to use a slow-ish shutter speed because when I do lock focus I like to take a high amount of quickly successive photos due to the “action” and expressions that are rapidly changing!

Has anyone moved to an em1 and noticed a significant difference in focus of moving subjects, particularly subjects moving towards the camera?

Are you talking about video here or stills? In my experience for stills, AFS with the GX85 is super quick even in lower light and I doubt even a PDAF system can really match it. That said, I have the 12-32mm and 14-140 II which are newer than your 14-42 I.

If for video, half pressing is similarly fast, but slows down in 4K mode.

In my experience if it can't lock focus, it's either because there is not enough light/contrast in the focus point or the subject is closer than the minimum focus distance.

Anyways I would try out the various focus settings first of the GX80/GX85 before running out to buy a new camera (esp. given the lenses might be the issue).

Panasonic recommends AFF for unpredictable movement (p96 in advanced manual). You can also try the various focus modes (p97). Some people use 1 area in center and just do focus and recompose or they use the touch screen to move around focus point. This avoids camera trying to focus on background.

There is also a "Quick AF" setting p211 where the camera is constantly refocusing even before you half press the shutter button, which limits the distance the lens has to travel to refocus. This may drain the battery a lot more quickly though.

ftp://ftp.panasonic.com/camera/om/dmc-gx85_en_adv_om.pdf

1. Ru55 wrote:

Thanks for the reply. From what your saying the em1 wouldn’t give me any advantage but maybe a 15mm would.

Indeed. The 20mm focuses better on the gx80 than on the em1.1. Actually, any Panasonic lens does.

Any reason to keep the 20mm if I was to purchase a 15mm?

Different focal lengths. I have been using the 20 basically since I bought into the micro43 system. And I love it, the rendering, the fast aperture, the size, and the focal length. But recently, I've been trying to capture my running toddler with the same combo as you with no luck. So I finally decided to try the 15mm. Glad I did : the lens has a very similar rendering but it's even sharper corner to corner. And it's in another universe regarding focusing speed.

Since I got it about a month ago, the 20 didn't get much use, but I don't think I'll part with it. I'll Probably keep it for static subjects as the focal length is quite different from the 15.

Maybe this is the wrong forum but what about if I sold everything and started with a new system, body plus two primes in similar focal length. Does another system offer far superior focus speeds of subjects with the movement I describe?

You could do that, but remember the grass is not always greener on the other side. You'll discover other shortcomings. I for one wouldn't ever go back to DSLR. They might focus quicker in c-af in some cases, but I'll never forget how bad focus accuracy can be with fast lenses. When I got my em5 with the 45 1.8 and could get almost 100% accuracy, I understood I would never go back to dslr dinosaurs.

You might be more lucky with Sony mirrorless system though. I can't tell as I only use manual focusing lenses on my a7 (I'm probably going to sell that one too by the way, as I don't use it).

Ru55 wrote:

Yes it might be my experience and expectations. In the situation I describe I normally set the aperture to 1.7/1.8, iso to 800, single small box focus area in the middle of the screen, no flash. Normally this gives a shutter in the region of 120/160+.

Any advice on this?

If you are thinking that faster CAF will help capture moving children at those light levels, you will be disappointed. Even if you nail focus, they will have motion blur. You should be looking for shutter speeds in the 1/800 to 1/1000 range or use flash.

Ru55 wrote:

Sion H wrote:

Ru55 wrote:

Hopefully I can get someone’s advice here.

My current gear is as follows:

gx80

Panasonic 20mm 1.7

Olympus 45mm 1.8

Panasonic 14-42 first gen kit lens

I really enjoy my current setup. I like using prime lens for low light - being able to get a high FPS without needing a flash. I also like them for shallow dof sometimes.

However sometimes I just don’t get focus quick enough with moving subjects (young children) - because of the contrast detection system and end up losing out on a moment that I’d love to capture.

what I’d love to know is, what is the cheapest way to move to a phase detect camera with two equivalent prime lenses to what I already have.

I say cheap as the kits above cost approx £750 (not including the old kit lens). I’m looking for similar budget.

I shoot a mix of photo and video.

How do you know it's the lack of phase detection pixels?

You won't get a faster focussing camera in low light unless it's a g9. My gx80 focuses faster than my d750 in AFS. Tracking in AFC is where it is weak, but you don't need that for your use case.

Most likely it's your 20mm holding you back as it is the slowest focusing micro 4/3 lens. 15mm 1.7 works better for indoor candid family photos. Also your shutter speed is probably low - use a flash too.

Stick the 45mm on, put it in touch shutter release mode with the flash up and hit the screen when you want to grab a shot and it will capture it essentially instantly.

Hi Sion,

thanks for for the reply. I’m guessing it’s the contrast detection. Let me give you a scenario. I have focus, then the subject (young child) moves closer to the camera (more sort of back and forth movement) . I half press to lock focus and the lens will move through the full range and not lock. I sort of feel it’s not getting a constant amount of contrast in the scene to decide what to do - if that makes sense.

yes I have to use a slow-ish shutter speed because when I do lock focus I like to take a high amount of quickly successive photos due to the “action” and expressions that are rapidly changing!

Has anyone moved to an em1 and noticed a significant difference in focus of moving subjects, particularly subjects moving towards the camera?

The E-M1.1 is certainly fast enough to capture a moving child. Here is one of my "children" that is certainly faster that yours. I was able to get several shots in focus as he was running towards me.

Ru55 wrote:

Thanks photofan. I've had another recommendation for the 15mm. Sounds like a good solution for me - I'll just need to wait for a good deal on one though!

I just bought one for £299 from e-infinity.

Brand new boxed but not UK stock.  I'm loving it!!

Skeeterbytes wrote:

Ru55 wrote:

Thanks rsmithgi,

cracking photo. What lens was this with?

Not him but that's the mZD 40-150/2.8. Wonderful lens. Not small.

Cheers,

Rick

You are correct. I love that lens.

Ru55 wrote:

Thanks for the reply. Is that the main advantage then of the pdaf in Olympus em1 for legacy lenses?

No. The main advantage is much improved CAF. IMO, the support for legacy lenses is secondary. I'm sure many E-M1 and E-M1 Mark II owners don't own any legacy lenses.

Ru55 wrote:

Thanks for the reply. From what your saying the em1 wouldn’t give me any advantage but maybe a 15mm would. Any reason to keep the 20mm if I was to purchase a 15mm?

maybe this is the wrong forum but what about if I sold everything and started with a new system, body plus two primes in similar focal length. Does another system offer far superior focus speeds of subjects with the movement I describe?

Any time you have low enough light levels to make focusing difficult, you're not going to be able to capture clear shots of your children running at the camera anyway.

I think you've got two separate requirements:

1. Support for C-AF in good light that is fast enough to keep up with running children.

2. Good enough S-AF in low light to capture images.

I can assure you that requirement #1 is satisfied by the E-M1.1. I have shot HS soccer in light low enough to require ISO 6400 at F2.8 and 1/500.

I hear reports that Panasonic cameras are better at #2 than Olympus cameras, but for me I would not sacrifice requirement #1 for #2. I don't experience problems with my E-M1 or E-P5. It may just be that I don't shoot in low enough light.