GH4 Finally Picked up a AF lens..but need help

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Darktide Media

Active member
After using older Contax Zeiss lens on our GH4 for the past few weeks we have chosen to go the M43 route and pick up some native glass so we can have AF and smaller weight when needed. I have never used any AF lens on a M43 camera before but after reading all the good things on them, I said heck its time to pick some up for filming this year. I really like the 12-40 and now word of the 40-150 is really making me happy and the 300 will be great for wildlife and surfing, but our first lens is the Lumix 20mm 1.7 that I picked up this weekend for $250 after reading some good things on it. I dont know if its me but I really dont like this one. Its AF is really really slow compared to what I have seen the other lens do and its not that sharp really, its good but but not great. Also I dont know if Im messing up or just wont but the GH4 will not track on AFS, Like I have to repress the shutter to get it refocus on something. Here are some photos, mabye Im just to picky. The top two are the 20mm and the other is the Zeiss I focus by hand.


20 mm 1.7.jpg
20 mm.jpg
Test Fox.jpg
 
Yes, the Panny 20mm auto focus is slow. The X lenses, 12-35 and 35-100, are good though. The Oly M43 lenses are the fastest, IMO.
 
You're not going to get the fastest AF performance out of most mid-range M43 lenses. Lenses like Panasonic's 25mm f/1.4 or 12-35mm f/2.8 will have very fast AF performance. Olympus lenses are also fast (45mm f/1.8, 12-40mm f/2.8, etc.).
 
I'm sorry to say but the 20mm was probably the worst lens to chose to introduce yourself to m4/3 AF lenses. It has always been known to be a pig at AF but people love it because of its sharp image. the first two images seem to be shot wide open and the third is not so shallow?
 
Just to add, the 20mm also cannot be used in AF-C mode. It's really not a great lens for video.
 
The 20mm takes some getting used to. The field of view is kind of "wide normal" and this is very useful if trying to work "in close" to small groups, a couple of people, or in slightly confined quarters. Slow autofocus never bothered me, I never even noticed it. As already pointed out it does not work with AFC, but then AFC does not work reliably enough with other lenses for me to trust it.

But I find the 20mm useful. Small, a bit inconspicuous (people don't notice it like they would a large zoom or telephoto. Where you might need moderate to deep DOF, it may be easier to achieve with this lens and there is no disputing it's low light value.

Even though I have the Pan/Leica 25mm f1.4, I chose to keep the 20. I use it quite a bit.
 
Thank you for getting back to me on this, kinda happy to hear to it was a bad choice to start with that means it only gets better. I will sell it hopefully and just pick up the 12-40 lens, I keep hearing its amazing and Im really excited for the 40-150
 
Consider keeping it. It's marginal and low light performance is something you'll miss once you do some of that. Try some night street scene location video with it. When you need something like that it can save yer bacon.

You've already paid for it, it only takes up bit of room in the corner of your bag.
 
Bruce Foreman said:
The 20mm takes some getting used to. The field of view is kind of "wide normal" and this is very useful if trying to work "in close" to small groups, a couple of people, or in slightly confined quarters. Slow autofocus never bothered me, I never even noticed it. As already pointed out it does not work with AFC, but then AFC does not work reliably enough with other lenses for me to trust it.

But I find the 20mm useful. Small, a bit inconspicuous (people don't notice it like they would a large zoom or telephoto. Where you might need moderate to deep DOF, it may be easier to achieve with this lens and there is no disputing it's low light value.

Even though I have the Pan/Leica 25mm f1.4, I chose to keep the 20. I use it quite a bit.
Click to expand...

Agreed. Love the lens. Fast... somewhat wide, super small, which keeps the camera compact.
 
Im trying to see if I should just stick with the Panasonic glass due to the DFD in the GH4, shooting action I would think it would help out a good amount. Thoughts?
 
Sol M. said:
Lenses like Panasonic's 25mm f/1.4 or 12-35mm f/2.8 will have very fast AF performance.
Click to expand...

I too like the topic creator picked the 20mm 1,7 as the first lens since the store did not have 12-35mm at the store and I just did not have patience to wait for it and wanted to test out GH4 soon as possible.
Now my idea is to return it and try out the 25mm f1,4 , does it have AFC and does it really stand up to the 12-35 focusing?
 
I have both the 20mm and that Panasonic Leica DG Summilux 25mm f1.4. Yes, it does work with the body's AFC, however even in the GH4 that AFC is not fully reliable. Focus shifts and hunts a bit as things in the background may begin to "compete" with the subject for "focus". It all depends on the "environment" you are shooting in.

The color and detail, sharpness and contrast of the Pan/Leica are all excellent.

But with either of these lenses you have to get to "know" them well and work within the limitations of what they will do. This is true of any lens or gear. These things are easy for me to say because I worked professionally with photo gear for decades before autofocus or IS came along.
 
I have an Olympus 17mm f/1.8 that I've used extensively over the last week with on a GH4 and it is instantaneous focus with a touch of the shutter button or tap on the screen, but completely useless for action sports in auto focus. I have tried every combo of settings and it just won't move quick enough to be reliable for anything. It nearly always focuses perfectly on the background and rarely will pick up the subject even when it takes up more than 2/3rds of the frame. Hoping that native Panasonic lenses might work at least somewhat.

Cheers,
Pete
 
I doubt it'll be great for sports, despite the hoo-ha by m4/3s fans over the GH4's DFD. The E-M1 barely can keep up (it's 50-50 or worse). It's good for more static or predictable situations, which makes it ok for most situations. Just not... sport. Or small birds in flight.
 
Really sucks to hear this, but I have talked to a few people who say its working for sports like we shoot, I will rent and see. We love our GH4 for video when we do the focus so that doesnt matter.
 
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