@Roberto with 2x extender (to fill the sensor) enabled it loses two stops and it goes to f3.4

@Ebacherville well the B4 setup is the ideal Run and Gun solution for the gh2, and we are all using the cheap old SD lenses and we hope that soon the second hand HD lenses will drop prices (something must happend, like TV broadcast standard goes to 2k or even more, I don't know),

soft corner issue is coming from that gh2 has the multi aspect sensor, so in the 16:9 modes the crop is actually 1.86 not 2, so we use the portions from the lens that are ment to be cropped, on the GF1 that is not an issue

http://www.bmupix.com/display/ShowImage?imageUrl=/storage/post-images/GH2_sensor_aspect_ratios_1920_1.jpg?__SQUARESPACE_CACHEVERSION=1287002123798

the crossover eng lens will be the solution for the soft corners issue, but anyhow if you stop down a little bit the lens it goes away

http://www.canon.com/bctv/faq/cross.html

As for the crop and corner issues, yeah the GF2 GF3 have a smaller sensor size also, they have a bit softer sensor anyway, I feel the GF line would pair well. IF VK gets manual controls figured out these would make a great body for a B4 SD lens. I brought this up and have some sample images with a Cmount lens showing the difference of the crop on GF2 vs GH2 http://www.personal-view.com/talks/discussion/2710/gf2-sensor-is-slightly-smaller..-could-be-really-good-paired-with-a-b4-23-eng-with-doubler-lens.

I have been following this thread for a while and finally bought a Fuji b4 lens from ebay for my GH1. I still need an adapter, and @Ebacherville looks to have found the best one so far. Having a mount on the adapter is probably important if you don't have a rail system for support, which I don't. I was a local tv photographer for over 10 years, so I am looking forward to using one of these lenses again!

@DirkVoorhoeve my 8x5,5 Funijon Argus wide-angle lens gives me only the same FOV as a 7,3 'normal' lens

Yes, you got it. You may find you can use your lens in non-ETC mode at some focal lengths, too. And yes, it has also occurred to me that ETC mode uses the sweetest spot at the centre of a lens - (like when we use f8).

@DirkVoorhoeve I am saying that GH2 produce the 16:9 image from the different parts of the sensor rather than cutting upper and lower part of the 4:3 area, and the lenses without crossover on 2/3 sensors do not goes outside of the 4:3 borders, in this case we have the gh2 forcing the crossover but we do not have crossover lens, so the 16:9 image on 2/3 sensor will have the diameter of 9.9mm and with the doubler you have 19.8mm instead of 21.6mm needed for the gh2

that is how I figure it out, maybe I am wrong

I don't think that the tripod mount from funkykoval2001 adapter looks as strong as the one from ciecio7. I have the ciecio7 mount in stock and will sell for $275 shipped within the U.S. If anyone is interested send me a PM.

As I said, my Fujinon 10-120 can be used without ETC, doubler or vignetting, at some of its longer focal lengths only. Not that it's of much use - it's there if you want it, using the rear macro-ring to adjust focus.

oneday: The camera has been modified since then. I recently added a Zoom H4 recorder to the mix as well, I will be running my audio through that and powering that from the anton bauer as well. Looking into an adapter cable from 3.5mm line to 2.5mm mic for the GH2. Sadly I didn't get the H4N model, just the two channel H4..

I might be able to get the lens remote for the camera working.. however I am allready using the port for the mic input.. Another option I've been thinking about is attaching some sort of headphone speakers on top of the GH2 so it captures the audio from the Zoom H4 for reference in the edit set. That would free up the mic/remote port so I could see if remote starting works..

The GH2 itself is powered by it's own battery (I could convert it with the DC thingie but I prefer to keep it under it's own power.. That way I can also shoot without powering on the rig..

The reason why B4 lenses appear quite soft in the corners is because those lenses are made to focus the light rays passing through the beam split filter on fron of the 3 CCD's block. On the oter hand, GH2 and all the other DSLR's use a single focal plane sensor. Using the ETC mode a B4 lens becomes parctically unusable wide open, you need to close down a couple of stops to get acceptable results. Engaging the 2X externder you get the same effect because the 2 stops loosing, however the extender adds some softness and makes CA look worst.

Mounting a B4 lens on a 4/3 camera is a compromise and has its downsides, but also some advantages, parafocal characteristics, usable ring for manual focusing, build quality, stepless aperture ring etc.

@FW200 very good picture! it would also be nice to have the same picture with ETC (no extender) so it's clear to all what the ETC crop-factor effect is on the field of view..

I prefer not to solder directly onto the GH2.. Everything I have done so far does not affect the operation of the GH2 in any way. I can take it out of the rig and throw on a kitlens and I have a normal GH2 again.

I will see about making some pictures with the ETC mode, I kinda forgot about that one..

@Turbodog I am interested to hear that the B4 to EOS adapter didn't work out for you with the Kenko 2x adapter. It sounds like there must have been an issue with the flange depth. Perhaps the Kenko ES mount on the extender is a different thickness to the camera one, in that case maybe it would work with shims or on a Canon extender?? I presume you tried playing with the backfocus adjustment on the lens.

Even though you couldn't get it focussing to infinity at the long end, did you get it working well enough to determine if the corner image quality was improved over using an internal 2x teleconverter in the B4 lens? I would imagine it should be

@DirkVoorhoeve do you use lens with built in extender?