is the LUmix 12-35mm parfocal?
- Thread starter cathstrat
- Start date
little bobby
Member
The Lumix 12-35 is parfocal, at least mine seems to be. The Lumix 35-100 is definitely not.
These lenses are not parfocal mechanically. However, when used on a camera with an active mount, the system "remembers" focua and resets it as you change focal length. It can take a second or two for the lens to catch up. It's not perfect, but it works, and considering the small size, weight and constant f2.8 maximum aperture of these things they are very useful lenses on the AF100.
I might add that they are very sharp at f2.8 - 5.6, better than many lenses I've adapted from still cameras, including Leica-R. The 35-100 is slightly soft in the corners at about 70-100, but in most cases that's more of a problem with stills than video. my only complaint is the manual focus and iris adjustment on the 35-100 is more spongy feeling than the 12-35, which is pretty responsive. With AF, which I seldom use but have tested, both lenses work well.
I might add that they are very sharp at f2.8 - 5.6, better than many lenses I've adapted from still cameras, including Leica-R. The 35-100 is slightly soft in the corners at about 70-100, but in most cases that's more of a problem with stills than video. my only complaint is the manual focus and iris adjustment on the 35-100 is more spongy feeling than the 12-35, which is pretty responsive. With AF, which I seldom use but have tested, both lenses work well.
I should mention, although it's obvious, that these two lenses together cost nearly as much as the current bargain prices on the AF100. And unfortunately they're not useable on other cameras except the GHs... If you have a BMDCC in your future, they won't work with the current model (which no one can get yet anyway) becuase it's passive. I invested in them along with two Noktons hoping for a significant update to the Panasonic MFT line.
STOP, I'm not starting another bitch session about the AF!... but it important to know the limitations.
STOP, I'm not starting another bitch session about the AF!... but it important to know the limitations.
*** Remember : Panasonic released a firmware update for both the 12-35mm and the 35-100mm lenses in December 2012 ***
Lumix Customer Support ( links to firmware udpates on this page )
Lumix Customer Support ( links to firmware udpates on this page )
Erik Naso
New member
Has anyone done the update? I didn't hear about the firmware update before now. Add this to the weekend to do list.
I love both of these lenses a lot. But then I also have a GH3 so I get more use from them. It would have been great if they made these with video in mind more but I guess you cant have it all.
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Bern Caughey
New member
Does this firmware fix the exposure stutter upon zooming in the 12-35? That's the one thing that kills it for me on this lens - I very much need to do slow zooms for a project, and with the flicker I can't use the 12-35. Also, I assume that the 14-35 f/2 Olympus doesn't have such a flicker - I may have to go for it, even though I lose 2mm on the wide end.
Officially the firmware updates are for improvements with the AF speed, but sometimes other things get bundled in too.
...For the exposure stutter problem, what's the simplest way to reproduce this?
i.e. Just zoom at any aperture and it should show up? ( I haven't spent much time using the zoom while filming, so I haven't noticed exposure stutter yet )
Erik Naso describes it here, including a video of the test - basically, just slow zoom:
Lumix 12-35 G X Vario F2.8 OIS Lens Review.
groveChuck
U-matic Member
Mac (and Catherine)-food for thought regarding purchasing Lumix (or any M4/3) lenses---
Even if these lenses don't work for your (or others) post-AF100 future, just in the sheer numbers of GH1/2/3s sold, there should be great resale value in M4/3 glass, even if there's not a vast array of cameras using them.
It is my understanding that the 12-35 and the 35-100 are parafocal, meaning that once you focus on the telephoto end of the lens that it will stay in focus at any focal length as you zoom back out. I know they can briefly lose focus on a whip zoom but otherwise the focus will hold. If anyone can clarify please do so.
Yeah, I described the way it works earlier, not true parfocal, but good enough for most purposes. In my case I seldom use a zoom in a shot, I zoom in to focus and then pull back to frame. If I zoom back slowly the lens keeps up, but not with a snap.. takes a second or so. There is a momentary variation in exposure too, but I haven't found it to be a problem in documentaries.
Again, given the other qualities of these lenses, (size, weight, 2.8 thru the range) and the lack of alternatives, they are worth it to me... I know many will point to Sigmas and Nikkors as an option, but they are bigger by nature, and if you ever need OIS, the Lumix lenses work well with the AF100 (including showing the "shaky-Hand" icon in the finder) and are easy to switch on and off...
One feature I've adapted to my shooting (keeping in mind that I'm basically old-school film) is using the function button to select a point in the frame and push-to-focus on that spot.. works with exposure as well..
I also was unaware of the firmware update.. does it do anything worth trying on the AF100? Sorry Eric, I guess you're the goat again...
Again, given the other qualities of these lenses, (size, weight, 2.8 thru the range) and the lack of alternatives, they are worth it to me... I know many will point to Sigmas and Nikkors as an option, but they are bigger by nature, and if you ever need OIS, the Lumix lenses work well with the AF100 (including showing the "shaky-Hand" icon in the finder) and are easy to switch on and off...
One feature I've adapted to my shooting (keeping in mind that I'm basically old-school film) is using the function button to select a point in the frame and push-to-focus on that spot.. works with exposure as well..
I also was unaware of the firmware update.. does it do anything worth trying on the AF100? Sorry Eric, I guess you're the goat again...
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Eric doesn't have to do everything
Just installed the firmware upgrade. It does make autofocus during video more responsive, and hunt less (in situations where it would normally hunt), both on my GH2 and AF100. Doesn't appear to have changed anything else. No downside I can see.
Just played around with a few snap-zooms and noticed the lens seemed to pick up its focus point much quicker... seems to reduce that minimal "out of focus" time on quick zooms. I may hork up a vid sample in a bit to see if this is truly the case
Just installed the firmware upgrade. It does make autofocus during video more responsive, and hunt less (in situations where it would normally hunt), both on my GH2 and AF100. Doesn't appear to have changed anything else. No downside I can see.
Just played around with a few snap-zooms and noticed the lens seemed to pick up its focus point much quicker... seems to reduce that minimal "out of focus" time on quick zooms. I may hork up a vid sample in a bit to see if this is truly the case
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