Pro video blog…Produced by Philip Johnston DoP/Editor


The JVC GY-LS300 will be on show at the Glasgow Science centre on Tuesday the 17th March at the Visual Impact, Look Listen Experience show.

I am a tad busy at the moment and can’t give this camcorder my full attention but hope JVC can lend it to me for a few more days. As it happens I am off to Edinburgh filming on Tuesday so can only attend the show till about 12pm.

Here are some of my findings so far…


This is a stroke of genius by JVC, we have a camera that takes a far wider range of lenses with the appropriate lens adapter, JVC sent me a Metabones Canon to MTF Speed Booster. With a full frame Canon 50mm f1.4 lens you can access all of the Super 35mm sensor.


Low light testing…the LS300 can easily use 12dBs of gain without compromising your picture, I will go into this in more detail on the video review.


When I first added my Panasonic 12-35 f2.8 MTF lens I was horrified to find vignetting at the top of frame, a call to Mike Turner soon had me into the VSM mode. The LS300 gives you full access to your MTF lenses from auto focus to full aperture control.


You get HD-SDI and HDMI sockets at the hand grip side of the camera and a zoom rocker switch, I tested my Panasonic 45-175 power zoom lens and it works a treat, this once again will be shown on the video review.

Did I find any negatives about the camera…that will have to wait for the video. Please remember the version I have is an engineering sample so any negatives may be sorted out by firmware.

So far I am very impressed with JVCs LS300, out of the box glorious rich natural colours a common feature with JVC camcorders, having interchangeable lenses and a servo zoom rocker switch helps sell this camera and Variable Scan Mapping is just pure genius.

UPDATE : JVC have recalled the camera for other commitments so the video review will be delayed till I get it back at the end of this month.


Having been working in the video business since 1988 I have amassed a great amount of knowledge of both the kit and production values over the last 30 years.

17 thoughts on “JVC GY-LS300 4K Super 35mm camcorder “First Thoughts”

  1. Did JVC really sent you a Metabones EF to MFT “Speed Booster” or was it a non optical “smart adapter”?
    Mounting an EF lens to the LS300 via an EF-MFT Speed Booster appears to me contra productive.
    The SB does what it is built for. It reduces the native field of view of the bigger EF lens to the native field of view of the smaller sensor. But the LS 300 has (!) a 35 mm sensor! Why deteriorate the native view of an EF lens to MFT size though the LS300 has a 35mm sensor?
    It appears to me that only a non-optical 1:1 EF to MFT adapter is the right choice when adapting an EF lens.

    Aside this I am also looking
    forward to your findings in the LS300 Review.

    HDW : Yip its a Speed Booster, but using the Canon 50mm f1.4 lens I am able to use the whole Super 35mm sensor area with no vignetting.

  2. sure, you could use a Speed Booster with an EF lens. But why? If doing so you will not be able to cover the whole 35mm sensor area but the MFT sensor area only. The Speed Booster’s optics has been per se designed to focus (reduce) the bigger native field of view (image circle) of the EF lens to the smaller image circle of the MFT sensor. How can then the MFT fousing optics of the SB spread the light so that whole area of the 35mm sensor is covered?
    An EF lens with a non optical adapter covers the whole 35mm sensor area. Fine. If a MFT lens
    is mounted the genius VSM technique scans and images only the MFT sized area of the sensor. This is the charm of JVS’s unique LS300 solution. Truly genius.

    Is there any error in my reasoning?

  3. As usual JVC give us interesting cameras. Now lets wait for a new FW which will enable 4K and UHD 50p, 10bit as the AltaSens S35 sensor is capable of.

  4. Canon new 4k fixed lens camcorder is rumored to be called the XC10.

    Canon XC10 Rumored Features

    Direct competition to Sony’s PXW-X70
    Sensor size will be about 1 inch
    Form factor will resemble the Canon EOS C100 on a smaller scale
    Priced around the Sony’s PXW-X70
    It will definitely be 4K

  5. Wolfgang, the JVC GY-LS300 doesn’t have a ’35mm sensor’ …it has a ‘Super 35mm’ sensor (not the same thing).
    It appears you are confusing the ’35mm Full Frame Format’ (36x24mm with 3:2 aspect ratio as used originally in stills cameras which transported the [35mm wide] film horizontally [and now by ‘Full Frame’ digital sensor cameras]) with ‘Super 35mm’ motion picture film format (up to 24.89mm horizontal with variable height according to aspect ratio, as used originally in cine cameras which transported the same [35mm wide] film vertically).
    Hence, the maximum size of a true 16:9 format ‘Super 35mm’ frame on film would be 24.89x14mm giving a diagonal of 28.56mm and therefore a (frame diagonal) crop factor of 1.52x.
    Unfortunately the term ‘Super 35mm’ is not an exact size standard and is now used to describe video camera sensors which can be anything from ~1.4x to ~1.7x in terms of crop factor (in frame diagonal terms relative to the 36x24mm format).
    I don’t yet know the exact dimensions of the ‘Super 35mm’ sensor in the JVC GY-LS300 but if (for example) we assume a crop factor figure of ~1.5x then the use of a ‘Speed Booster’ with its 0.71x optics would allow the, above example, Canon 50mm f1.4 EF lens (designed to cover the 36x24mm Full Frame Format for stills) to give an angle of view equivalence of ~53mm (50 x 0.71 x 1.5 = 53.25) whilst gaining 1 stop in effective aperture (in this case going from f1.4 to f1 maximum). Of course the Speed Booster ONLY works with lenses which are designed to cover a larger format than the sensor in actual use as the image is effectively ‘squeezed’ down to 0.71x the original coverage.
    In your case of using a “non-optical 1:1 EF to MFT adapter” you would have to apply the appropriate crop factor of the ‘Super 35mm’ (or smaller sensor area if using the other ‘Variable Scan Mapping’ settings of the JVC) which would mean the Canon 50mm f1.4 EF lens would produce a field of view similar (at assumed 1.5x crop factor) to a ~75mm f1.4 lens on ’35mm Full Frame format’ (effective aperture unchanged).
    I hope this clarifies some of the confusion surrounding the use of similar-sounding but imprecise generic terminology that now applies to sensor formats …it would make life so much simpler if manufacturers would publish exact sensor imaging-area dimensions rather than vague terms such as ‘Super 35mm’ which now covers all sorts of different sizes.

  6. Peter, thanks for your helpful explanations. Yes, the term “35mm sensor” is used for a full frame sensor. Just to avoid confusion (for myself) I’m not using this term but “FF” (24x36mm) only. When I skipped the “super” I was s assuming that the reader would understand that the LS300 doesn’t have a FF sensor. Having a super 35 mm sensor is a sensation by itself.

    My misunderstanding was based on the initial (short) thinking that nobody would use a Speed Booster when mounting Canon EF or EF-S lenses e.g. on the C100, which has also a super 35mm sensor. Because there is no Speed Booster EF to EF mount which could reduce crop factor and gaining 1 stop in aperture.

  7. The reason there’s no EF-EF booster is because there’s just no space for it. EF is a long mount, designed for SLRs (with a mirror). The C-series may not have mirrors but their mount is still the same. Boosters fit between a mirrorless body (short flange distance) and a lens made for a mirrored body (long flange distance).

  8. How about the HDMI out?

    What are the specs? 10bit or 8bit?

    HDW : Will find out

  9. It’s 10 bit, just fyi.
    I’m anxious to see the review. I’ve just purchased one and the 4k images are fantastic. But as far as I can see there is no OSI (it appears in the menu but it’s grayed out as an option), there is no histogram (the absence of which profoundly cripples your ability to get good exposure), and a number of small issues that are really frustrating (like the impossibly difficult f stop adjustment, and white balance issues, and the shitty EVF). In my view, JVC has just GOT to fix the no OSI and Histogram issues in a firmware up date. It’s absurd to omit the histogram.
    But, the super 35 sensor gives beautiful imagery, lovely DOF, creamy and soft, with most lenses, and you can use a speed booster on ff lenses with no worries about vignetting. Pretty cool. All my Canon FD lenses work very well, w/or without speed booster. My Rokinon 85mm ff lens works great as well. I get great DOF shooting wide open out of doors with a variable range ND filter on the lens.
    The internal ND filters work well, but I hate step filters, and use variables on lenses whenever I can.

  10. Any idea WHEN this camera will be released in Australia? Hopefully sometime before 2020.

    HDW : JVC told me it should be available now

  11. The big Question for me is:
    Why use the LS300 not immediately a MFT Sensor?

    HDW : No its better than an MTF sensor its a Super 35mm sensor which will give you far better shallow depth of field.

  12. I have had the LS300 for 4 months and am having horrific audio problems. Either in “auto” mode or “manuel” mode, the audio seems to be under the control of a terrible AGC. IE: during the presence of loud music from a DJ (weddings), the audio is constantly dipping then coming back up. A disaster. Would love a call from JVC on this one. Soon!

    HDW : Hey Ron I have just been given a JVC LS300 for the next 2 weeks I will look into this for you.

  13. Thank you!
    One question: you wrote “With a full frame Canon 50mm f1.4 lens you can access all of the Super 35mm sensor”.
    I was assuming the Ef-Mft speedbooster covers only the mft sensor area. You are saying it covers the s35 area without vignetting? its confirmed?

    HDW : I will confirm this at BVE next week but I think I am wrong.

  14. When using VSM on a micro 4/3 lens, do you get the advantage of the 35mm sensor (eg big sensor ‘look’)? Or is it similar to aps-c with the crop factor (1.7??). What are the effects compared to using full frame (canon) lenses with appropriate adapter?

    HDW : Will come back to you on this one

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