Thread: Pocket 4K / Metabones Ultra / Viltrox EF-M2

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  1. #1 Pocket 4K / Metabones Ultra / Viltrox EF-M2 
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    Hi guys !
    Just a message to sum up all the shortcomings I encountered so far with the camera and the adapters as well as a few questions for you !

    So I tried the Pocket 4K with numerous third party focal reducers, including the Viltrox EF-M2. I have to say that the Viltrox doesn't support IS on my canon 24-105 L IS for now. I emailed Viltrox, they answered me quickly and told me they would pass my message on the engineering team. So we can hope they'll fix it in future firmware (if they can get a p4K somehow). Also the trick that I read that it works if you turn on IS and the camera beforehand, doesn't do it for me... I don't know if it's actually a thing. (It was the other way around when the bmpcc had this IS issue with metabones at the begining).

    The other thing is, as discussed in an other thread, more important and I feel nobody's taking this very seriously. I haven't been able to achieve focus on wide angle lenses weither it was with the Viltrox EF-M2 or the other focal reducers, granted I don't have a metabones ULTRA nor native lenses. But for instance, at 24mm with the 24-105 mm on the Viltrox, there's some field curvature or something else that prevents me from reaching perfect focus across the image ! Also at infinity focus. The same holds true with a 28mm Contax Zeiss on a Kipon focal reducer.

    Is it the quality of the glass inside those adapters ? Is it a problem with the thickness of the glass in front of the sensor ? Is it because of the slightly larger sensor size of the pocket 4k compared to a regluar m43 sensor ?

    Can someone with the speedbooster Ultra + moderately wide lens chime in and try to achieve focus all across the image ? Or someone with the Viltrox and a GH5s for instance ? Or someone with a native wide angle lens. Because for now I can't get a landscape shot for instance, wide angle, sharp corner to corner. I can tell you right away it's not about stoping down the aperture or the softness of the lens. I used those lenses on full frame cameras and never had those problems. I think it really needs to be investigate and addressed as it has quietly begun in another thread. Maybe it's just the sensor size and the quality of the adapter. Maybe it's not on blackmagic's side but it needs to be solved anyway !

    It would also be great to hear from someone at Blackmagic ! Like the very wise CaptainHook !

    Have a good day !
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  2. #2  
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    I'm also experiencing strange issues. I have the Metabones XL. I have severe coma issues with my P4K and XL combo and I've had issues with getting everything in focus with a 14mm lens. I'm suspecting is the adapter but will take your post into account when looking at what's going on with my setup.
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  3. #3  
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    Quote Originally Posted by papiskokuji View Post
    The other thing is, as discussed in an other thread, more important and I feel nobody's taking this very seriously. I haven't been able to achieve focus on wide angle lenses weither it was with the Viltrox EF-M2 or the other focal reducers, granted I don't have a metabones ULTRA nor native lenses. But for instance, at 24mm with the 24-105 mm on the Viltrox, there's some field curvature or something else that prevents me from reaching perfect focus across the image ! Also at infinity focus. The same holds true with a 28mm Contax Zeiss on a Kipon focal reducer.

    Is it the quality of the glass inside those adapters ? Is it a problem with the thickness of the glass in front of the sensor ? Is it because of the slightly larger sensor size of the pocket 4k compared to a regluar m43 sensor ?
    Just wanted to chime in that I'm the OP in the other thread you're talking about, I have 2 native MFT wide angle lenses (Laowa 7.5mm and Samyang 12mm) that can't achieve total focus through the entire frame. Either the center or the edges of the frame can be in focus but not at the same time. This does not happen with my Panasonic GX85 and Panasonic GH2. I've also rented a GH5s and used those lenses before without any issues.
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  4. #4  
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    GH4 uses software to correct distortion of wide angle lenses on MFT sensor. Any 'Focal Reducer" has essentially an effect of a magnifying glass behind back element= amplification of any lens distortion and focus. Even on FF camera anything below 12mm will have softening around the edges, add magnifying glass and it will bet worse. Plenty of footage showing good results with 12-35 from Panasonic and 12-40 Olympus at 12mm. Laowa and Samyang are very mediocre lenses, the question would be if you still have focus issues at say F5.6?
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  5. #5  
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    Quote Originally Posted by Robert Rogoz View Post
    GH4 uses software to correct distortion of wide angle lenses on MFT sensor.
    Only for native lenses that have electronic communication. The lenses I used do not have electronic contacts.

    Quote Originally Posted by Robert Rogoz View Post
    Even on FF camera anything below 12mm will have softening around the edges, add magnifying glass and it will bet worse.
    The edges aren't just soft, they're actually out of focus. I can get the edges of the frame to be in focus, at the expense of center sharpness. It looks as if the center and the edges are on different focal planes.

    Quote Originally Posted by Robert Rogoz View Post
    Plenty of footage showing good results with 12-35 from Panasonic and 12-40 Olympus at 12mm. Plenty of footage showing good results with 12-35 from Panasonic and 12-40 Olympus at 12mm. Laowa and Samyang are very mediocre lenses, the question would be if you still have focus issues at say F5.6?
    Those lenses you mentioned are pretty slow, this issue seems most prominent with faster wide angle lenses. Of course stopping down will help, but that seems like a bandage to the problem. Again, this problem does not appear when I'm shooting on Panasonic cameras with those same lenses. Also, there are other people who have reproduced this problem with their BMP4K, so I don't think I have a bad sample (I hope).

    I don't want to derail this thread, but a lot of the issues you've brought up have already been discussed in a previous thread.
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  6. #6  
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    Hey,
    In the other thread I had promised to do a better edge to edge test. I forgot until now...


    Rokinon Cine 14mm @ f5.8 mounted with a Metabones 0.71x F-mount Speedbooster.
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  7. #7  
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    This is the widest non-fisheye lens that I own. It's pretty damn wide, but I don't see any difference in the edge-to-edge sharpness from what I see on my GH5.
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  8. #8  
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    Quote Originally Posted by joe12south View Post
    This is the widest non-fisheye lens that I own. It's pretty damn wide, but I don't see any difference in the edge-to-edge sharpness from what I see on my GH5.
    Could you try it again with the lens wide open, focused on something at infinity? I know shooting wide open isn't ideal, but it's the easiest way to see the problem.
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  9. #9  
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    Im using the viltrox with the 18-35. There's an ever so slight vignetting in the corners at 18mm shooting 4K DCI.

    I also have a samyang 10mm which cuts off the side of the fram at 4K DCI with its non-removable hood wings.

    Initially the inifinity focus was WAY off, but after a bit of tweaking and trial and error, I got it pretty sharp (the lens is never pin sharp in the corners anyway).
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  10. #10  
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    14mm @ f3.1

    Focus set as close to infinity as it will focus. (This combo has never had accurate infinity focus on any camera.)
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