Panasonic GH4 4K Video Crop vs 1080p Ex Tele Mode

While Full Frame DSLR cameras have the advantage on the wide shot, these mirrorless cameras have advantages for distant shots due to it's crop factor. As an added bonus, the Ex Tele Conversion mode in these Panasonic cameras switch to using pixels in the center of the sensor creating a further cropped view (I believe an additional 2.6x crop). Since it's still using a 1:1 pixel readout, there is no loss in resolution for full 1080p video.

GH4 tele mode sample review demo video 4K

This is extremely handy as you can easily more than double the focal length of any lens. With this mode, my Lumix 12-35mm F/2.8 (24-70mm equivalent) quickly turns into something like a 31mm-90mm F/2.8 [60-180mm 35mm equivalent], and all without losing a stop.

lumix 12-35mm gh4 vario ois
find-price-button Lumix 12-35mm F/2.8 OIS Lens

Having so many options in a single camera is new to me, so i'm still learning the best ways to use the GH4. Knowing that I can crop in on a 4K video file is a great option, but is it better than using the EX Tele Mode at 1080p? I shot this very short clip to test this out, let me know what you think.

Certainly cropping from 4K still retains plenty of details. To the average viewer, they may not pick up on such subtle differences, but judging from my eyes I think the Ext Tele Mode in 1080p is better. If i'm considering my final output to be 1080p, I can use this mode with the 35-100mm F/2.8 (70-200mm equivalent) essentially giving me something around a 90-260mm F/2.8. Remember that if you compare this to 35mm equiv it's like shooting with a 180-520mm F/2.8 on a Canon 5D (but for a lot less money).

35-100mm lumix lens
find-price-button Lumix 35-100mm F/2.8 OIS Lens

Keeping in mind that you double the focal distance on an M43 lens to get that 35mm equivalent, I decided to grab some samples from my new Lumix 100-300mm OIS which is 35mm equivalent to a 200-600mm. With Ex Tele Mode this lens should be around 260mm-780mm which should be like working with a view similar to a 520mm-780mm - again without reducing the amount of light like a teleconverter extension would on a Canon 5D.

Here's another short clip testing out cropping from 4K as opposed to using EX Tele Mode in 1080p with my Lumix 100-300mm OIS lens.

panasonic lumix vario 100-300 ois
find-price-button Lumix 100-300mm F/4.0-5.6 OIS Lens

Here's a few other GH4 clips from my trip to the Academy of Science in San Francisco yesterday. Nothing special, just me learning.

16 thoughts on “Panasonic GH4 4K Video Crop vs 1080p Ex Tele Mode

  1. Jay Huron

    So what's the crop/magnification factor from cropping 4k video to a 1080p size? 2.6x? So if I'm shooting my Panasonic 100-300 at 300mm (600 eq) at 4K, is that 1,560mm (eq) if I put it in a 1080 video?!

  2. kawika

    Thank you for very good coverage of a good topic. Pretty much answers the question for me; there is a slight difference, with maybe an edge to 1080p and Extended Tele function.

    One other advantage to 1080p + "ETC": you can shoot at 60p and really stop anything you want to stop. I just tried this with a GX7, 100-300mm lens, "ETC" mode at 300mm. Got great frame grabs from clip of a hummingbird diving from a twig about 30 yards away.

    You can't use ETC while shooting 4K--which means I can hang onto my GH3 and GX7 a bit longer. (The GH3 doesn't use sensor crop to get ETC; instead the footage is downgraded to HD Lite and lower res.)

    According to the GX7 manual, ETC gives 2.4x (approx) in video; you also can shoot 8mp stills and get 1.4x, or shoot 5mp stills and get 2x.

  3. Rene

    There a small error in this post. You state:

    Lumix 100-300mm OIS which is 35mm equivalent to a 200-600mm. With Ex Tele Mode this lens should be around 260mm-780mm which should be like working with a view similar to a 520mm-780mm .

    It should be " working with a view similar to a 520-1560".

    You forgot to double the 780mm like you did the 260mm.

    That's a crazy focal length for just under $600 dollars. I bought one last night for my new GH4, and I have to say it's incredibly sharp when shooting video - even on the long end. I would never handhold it for any serious work - but you really can. It's a good lens.

  4. This seems to make sense since it's not just resolution that matters, but bitrate. With the tele mode you're making the most of the data the camera can spit out.

  5. Emm

    Post author

    @carl - I used the 200Mbs All-I, but I don't think that would make a difference in sharpness. You can test this with other rates.

  6. carl

    Hi Emm,
    Great review - as always. Can I ask what 1080 mode and bit rate you were using. It does seem the 1080 with ex tele mode is sharper but wasn't sure how much space saving I would be doing with shooting high bit rate over 4K.

  7. Emm

    Post author

    @j - I shot two different clips and still 1080p seems to be sharper. The 300mm lens is not a very sharp lens to begin with, but I can see advantages to using both 4K crop and Ex Tele Mode.

  8. EricSF

    The butterfly example is hard to tell the diff but with the cars, I agree, ex-tele mode in a little cleaner but the heat waves might be affecting this. If it's as close as the butterfly example in most cases, 4K to 1080p will give more flexibility because you can choose to scale it as big or small in that range to suit composition. With ex-tele, what you see is what you get...

    The same comparison in low light would be interesting indeed to see how things differ at higher ISO's...

  9. No difference in my mind, on the first clip. The second clip though has a difference. I'm not sure it's because of the crop, i think it more because of the atmosphere and the temperature - Though i'm not sure!

    and i would prefer the 4K crop instead of Tele mode, because then i can also stabiliz the footage - i can't do this in tele mode without going under 1080p.

    Just my thoughts.

  10. Emm

    Post author

    @kai - I actually thought about that, but in this situation if you zoom in post, you will also zoom into the noise at 4K. Thinking about this, the results may actually be the same. You increase the noise with Ex Tele because you are zoomed in on those pixels, but cropping in 4K is also zooming in on those same pixels. Maybe there is a slight difference, but I think noise will still have to be considered either way.

    4K will actually benefit more when downscaling to 1080p because it is downscaling the noise (maybe not technically correct, but you get the idea).

  11. Emm

    Post author

    @Giovanni - If you're simply talking about depth of field, of course you cannot compare a full frame DOF to M43 DOF at F/2.8. Here we are simply talking about the amount of incoming light and using the sensor to crop rather to crop in post. The amount of light available through the lens should not change in EX Tele Mode.

  12. kai

    Should do a test compare high ISO. The drawback to use ETC is at high ISO. I tried that on gh3. ETC with ISO 800 is like I am shooting at ISO 3200 in normal mode. The noise is crazy above ISO 800 in ETC mode. So in this case. would crop 4k be a better option in high ISO???

  13. Giovanni

    There is a big discussion out there about that we have to apply crop factor in the aperture value. Se basically they said that 13-35 f2.8 is not equivalent to a 24-70 f2.8. In terms of DOP the smaller form factor lens need a bigger aperture to achieve the same DOP of an f2.8 lens on FF. Metabones understand this and this is why speedbooster exists. There is no excuse, you always need a better lens instead of a better camera.

  14. Bob

    Great work Emm -

    For the flags one, Tele mode CLEARLY is sharper with a higher apparent resolution. The butterfly is closer between the two.

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