Personal View site logo
Make sure to join PV on Telegram or Facebook! Perfect to keep up with community on your smartphone.
B4 lenses and mounting solutions
  • 147 Replies sorted by
  • qwerty123 January 3 "Anybody tried the jinfinance b4 to micro 4/3 adapter? Feedback / thoughts?"

    Yes I ordered some. The notch is not at the top where it's supposed to be but at an angle. It's fine for lenses without a zoom servo / handgrip, but if you're planning on keeping the servo / handgrip on then it's no good because it points down at a 45 degree angle.

    I bought more than I need and because of this I would like to sell some of mine. I don't know the protocol for listing "for sale" items in this forum but I will sell them at a $10 discount through PayPal so the cost is $110 shipped within the U.S. for forum members. I haven't gotten around to listing them on eBay yet.

    I also have some B4 lenses, the Polish adapters, and a Hirose cable / battery system to power the lenses. I would like to start a new thread to list what I have for sale but I'm not sure what's allowable / not allowable in this forum as far as listing "for sale" items goes. Thanks.

  • @oneday That's very pricey, plus there's the 2.5 f-stop drop. The GH2 plus its Ex Tele function is simply the best cam to use with these broadcast zooms

  • @ed_lee83 "The GH2 plus its Ex Tele function is simply the best cam to use with these broadcast zooms" 2.6x crop means 2.6x more visible noise and 2.6x deeper depth of field. It's very washed out and milky wide open in Ex Tele mode. It's better down to about f/4 but in low light it's better to use the built-in 2x extender. I shot this wide open with a 14x B4 lens and the built-in 2x extender, wide open.

  • @Turbodog Are u using that 800 pound MTF adapter? I agree ETC makes more noise but it's only evident for me past 400 ISO. Ok not the greatest for dark situations. Deeper DOF? Subjective and preferential. Milky wide open? Depends on the lens. Fortunately some of my broadcast lenses are mint so they're sharp wide open. But 800 pounds for that adapter, damn. I guess i'm really saying is that GH2 owners already have a good solution without buying that.

  • @ed_lee83 No, I'm using the $300 Polish adapter on the GH2. The $800 one is to spread the image across the Canon APS-C sensor and even then you still need to engage the 2x adapter. I don't think it's even for sale to the public yet.

    I don't know the ISO on this footage because I was using Auto ISO but I know it went pretty high at times.

    The depth of field is 2x and with 1:1 crop mode it's 2.6x -- so yeah not that different. (Actually compared to 2/3" camcorders, the depth of field is actually the same on full sensor and 1.3x with ETC !)

    I not been able to use the B4 lenses wide open in 1:1 crop mode myself, mine all look washed out, especially bad at wide angles. Which broadcast lens models do you find to be the sharpest wide open in 1x / ETC ? Do you have any wide open footage to share?

  • @Turbodog I currently have Fujinon 7.5-105 f1.4, 10-140 f1.8 and 7.3-88 f1.4, all c-mount. The latter two have not been modified yet so I'm just waiting till they're all prepped for GH2 usage before I do test footage. I'm also still figuring out which hack is best for ETC. So far I'm eyeing Driftwood's Aquamotion. Watch this space!

  • @ed_lee83 OK I thought we were discussing B4 2/3" lenses. The ones I've tested, Fujinon, Canon, Nikon, all look milky at f/1.7 in the ETC mode. I'm not sure what the deal is because they were obviously intended to be usable wide open originally. The Fujinon 7.5-105 f1.4 sounds like a 1/2" lens. I bought one on eBay in B4 mount, a Canon 7-105mm 1.4, but the backfocus was wrong. It had a shorter flange distance than the 2/3" lenses & it didn't focus at all using the MFT adapter. I didn't think I could modify it so I sold it. I pretty much gave up on searching for the holy grail in c-mount lenses because almost all of them vignette on the full sensor. ETC mode is a nice feature but only the full sensor gives you the full latitude of dynamic range that the camera is capable of.

    My goal right now is to find someone to produce a B4 to Canon EF adapter. Then I can use a Canon 2x tele-converter to provide full coverage of the 4/3 sensor. My tests have shown that a Canon 2x tele-converter improves the edge sharpness over the built-in 2x extender which wasn't originally designed to cover such a large sensor.

    Of course it would have to be designed with precision accuracy to get the back-focus correct for infinity focus. If you know anyone who might have this capability please put them in touch with me via pm. Thanks

  • @Turbodog Damn you're right, everyone here's talking about B4 mounts, not broadcast zoom lenses in general. Sorry.

  • @ed_lee83 That's exactly what I was looking for. Same supplier as the MFT one. Thanks.

  • This video, shot with a Fujinon 14x 8.5-119mm f/1.7 lens was embedded in an eBay listing. Cameras used were the GH2 and AF100. It's sharp, and with the 2x extender engaged, it covers the entire sensor.

  • @balazer Yeah, that's me... my cover's been blown!! :-)

  • Then I am curious to know why you would sell such a supposedly nice lens. ;)

    Actually the sharpness looks good to me, but I don't care for the overall look. I can't put my finger on why. Maybe the contrast is too low or there are aberations. I take it these lenses were for SD cameras.

  • @balazer Looks like he's got a mess of them! Probably duplicates....

  • Yes I have a number of them, plus the MFT adapters -- something I buy and sell. They were for SD video cameras but it is professional grade glass that still holds up quite well. With fixed aperture, parfocal zoom (stays in focus across the whole zoom range), step-less iris (no click stops) and macro. Plus you can power the zoom servo with the cable I made & the battery doubles as a 6400mAh external battery for the GH2. Not as sharp or with bokeh as nice as an SLR lens, but still you get a lot of versatility with these lenses. Sharpens up as you stop it down.

    A nice solution to the problem of slow variable aperture, varifocus zooms without smooth mechanical zooming or step-less iris for shooting video.

  • My Chinese adapter just arrived. Tried some shots with my Fujinon B4-mount 10-120mm. Quite impressed. Easy to manipulate even though the servo does indeed sit at the bottom. [not unusably though, the W -T rocker switch is at the side; power the thing up with 12V and you could put your hand in from the top then under the strap, rocking the zoom with your thumb]. For some reason I have to use the back-focus ring with the ꝈMacro on it; I'm guessing the lens just needs to be collimated. Overall, I was struck more by its sharpness when compared to my Zenit C-mount 17-70 zoom.

  • @Roberto: I am interested in getting the same adapter do you have any pics of how your's mounted with the lens? Do you have any focusing issue with this adapter?


  • @spcamno No focusing issues other than mentioned. I'm quite happy to focus shots using the back ring for now; the quality is very good and I've also given a new lease of life to this lens just by adding a $100 adapter.

    600 x 451 - 44K
  • @Turbodog did you already try the B4 to Canon EOS adapter with your Canon extender? I'm very curious as I read that the adapter is a replacement for the EOS mount. I am really looking for a B4 to Canon FD mount adapter like the Bumki version from 2010. Do you know where to get it?

  • This was my solution. I started with an old broken Sony BVP-90. I modified the CCD assembly with a M4/3 adapter.. Since the CCD assembly is attached to the body it means that the camera only has to hold itself up, the lens is held up by the body. This was the cheapest way for me, especially since that HK adapter has the lens mounted sideways which makes it almost useless for handheld camera..

  • @FW200 wow.. off topic: how did you connect the viewfinder. Is it the HDMI output of the GH2?

  • Since its a SD Digibeta viewer I used a HDMI > Y/C converter and used the Y part to go into the viewfinder. Not the best solution available (would offcourse like a HD viewfinder) but I was on a budget :)

  • @FW200 what a gr8 setup you have, on the other side is there a sound recorder or what?

    too bad that gh2 hdmi does not have output on other modes, just 24p

    also you could connect the eng lens REC button from the hirose connector to the GH2 remote jack

  • Ive been very tempted to get a B4 ENG lens, the biggest draw back fro me is im always using faster lenses than a ENG in 2x can provide.. There arr adapters on ebay that are less than the 320 dolar blue ringed one that do provide adjustable rings so that the lens can remain level so you can use the zoom controls etc. and plenty of ways to power the zoom control also.. seems like a very good setup if you can deal with a f3.8 lens.. the parafocal and constant f stop are the good points however.. one other thing is I've seen some sample clips that the corners of the image were distorted to some extent,... seemed to be defendant on the model lens used.. I think this is a great setup, just can't justify 400+ or so for a old used lens and 200-250 for a adapter on something that some say the result is not so sharp images and limit me to f3.8 when I can get a ton of older faster primes that are tack sharp for less. But I'm still tempted to get a setup like this .. if I can score a cheap b4 lens I may spring for the adapter just for messing around, I have seen some footage from this setup that looked pretty good.. also I noted in a diffrent thread that the GFx sensors are slightly smaller than the GH2 and could make any slight corner image distortion more minimal and look good on GFx cameras since they arn't quite as sharp anyway.. If some ones looking for a full auto run and gun solution a eng b4 lens with doubler may be perfect combined with a GFx body.. but until we get full manual controls I'm not going to buy a b4 lens and the expensive adapter to try it. with that kind of money I can buy a couple nice fast primes.. maybe once I have my primes in order I'll venture down this ENG B4 road. but I would consider it a experiment and nothing more.

  • @Ebacherville

     im always using faster lenses than a ENG in 2x can provide

    A lot of ENG lenses are fast. My Fujinon is f1.7.