Vignetting flaw BMP 4K Lumix Vario 12-35

Hi everybody,

that's my first post and I have bought a second-hand Black Magic Pocket 4k, including a lents Panasonic Lumix G X Vario 12-35 f2.8. I just started to test my camera and I really trust the guy who sold it to me. He used it very few times, so he didn't realize about the following.

I shot in 4K at maximum resolution and I noted that if I have a light background (the sky i.e.) I can see a vignetting "effect" (I would call it flaw) at the four corner, when the lents zoom is at 12mm.

Sorry for my bad technical English, that's not my native language.

Could someone tell me if noted the same? Is it "normal", a flaw or what...?
Isn't mine one of the lents suggested for BMP 4K?
Can I fix this problem or not?

I couldn't find a way to upload a screenshot of my shooting here as example. It might have helped to understand my issue, if I was not enough clear. But I didn't understand how the button work.
Thank you for any help or suggestion!

Nobody can help me?

I did more trials and the problems is still there...
I'm in Italy where actually there is a lockdown, I cannot even go to an assistance centre.
If anyone could give me some feedback, it would be really welcome!

Uhm I had pocket but not 12-35 Panasonic. I used 14-45 and no vignette, but 12 could vignette.
Remember that 12-35 is a m43 lens and pocket had a little bigger sensor, a 4/3 sensor.

Just to check, have you some lenshood or filter on this lens?

I had a 17-55 Efs which cover correctly s35 sensor on bigger cameras, but I cannot use threaded filter be cause it vignette


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Also, the 12-35 like most ultra WA lenses have some image fall off with darkened edges, on a sensor that the lens image circle just barely covers. The wider the lens focal length, especially zooms, the more pronounced this will be. Panasonic Cameras can correct for this vignetting in Camera, the Pocket 4K does not.

Also, the older Pana Zoom was designed for Micro Four Thirds smaller sensor cameras, like the GH3/4. As previously pointed out, the Pocket 4 K sensor in full 17:9 gate size (4K) has a wider sensor than MFT still cameras like the GH4. UWA lenses designed for S16 has the same issue on the original Pocket camera with its larger diagonal image gate size. So this is not a flaw, but more of a design issue between older lenses and the newer cameras.
Cheers

Remember the area covered by the BMPCC4K sensor when recording DCI 4K may be larger than a traditional mirrorless camera. Crop BMD 1.9x versus crop more than 2x for most mFT cameras.

Normal for a M43 lens on the P4k as on native M43 cameras this is corrected in-body via a lens profile. Did you also notice the huge barrel distortion at 12mm as well?

I couldn't find a way to upload a screenshot of my shooting here as example. It might have helped to understand my issue, if I was not enough clear. But I didn't understand how the button work.
Thank you for any help or suggestion!

As a new user here there are a few restrictions what you are allowed to do in the forum. After a few posts (5, I think) you can post links and images. This is to prevent spammers.

I shot in 4K at maximum resolution and I noted that if I have a light background (the sky i.e.) I can see a vignetting "effect" (I would call it flaw) at the four corner, when the lents zoom is at 12mm.

Sorry for my bad technical English, that's not my native language.

Could someone tell me if noted the same? Is it "normal", a flaw or what...?
Isn't mine one of the lents suggested for BMP 4K?
Can I fix this problem or not?

That strong vignetting is a technical shortcoming of this lens. Because it is quite small (only 58mm diameter)
See this test: https://www.lenstip.com/367.8-Lens_revi ... tting.html

The test is for the older model of this lens, but vignetting is quite similar on version II.

What you can do is to close the aperture from 2.8 to 4.0 which does reduce the vignetting effect as shown in the test from lenstip.com

JB posted this wide lens comparison on bmcuser back in the day. Cool to see how all these lenses play out on the mft+ sized P4k sensor.

Good Luck

http://www.bmcuser.com/forum/blackmagic ... on-the-p4k

Because of your technical explanations in English, I need to read some of your posts again, then I will come back to you with my comments.

I'll also have a look at your suggested review/links and let you know.
Since I posted, I had some more tests on my BMPC. What I could see is that, even changing the iris stops or other values, the problem is still there every time I use the focus at 12mm...

I'll check your links and keep you updated. Thanks everybody for your help!