B4 lenses and mounting solutions

qwerty123

Canon lenses

Fujinon lenses

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The only adapter I've seen is this one: http://bit.ly/obeiGG

Looks nice, but it costs $320!!!!! (seems very over-priced)

Anyone know of alternatives?

stoney

Don't do it. Those B4 lenses are not made for CMOS sensors. Just buy fast primes.

qwerty123

There are some nice examples of these lenses working well on gh1 (and maybe gh2).

The advantages of using these lenses are:

1. much *more DOF* (b/c of tele-option on gh2);
2. many b4 lenses are parifocal;
3. lenses have constant (stepless) wide aperatures (f1.8) throughout the zoom range.

These lenses would be great for documentary or event shooting work.

Vitaliy_Kiselev

@qwerty123

You can mount B4 lens using this thing (see my posts)
http://www.personal-view.com/talks/discussion/52/how-to-fix-lens-to-adapter-looseness/p1

You'll need to remove rear bayonet mount, most probably.
But it looks like throw is not enough (you need longer threads).

Contact sellers, they wanted to make version suitable for B4 and similar stuff.
Talk to them.

Vitaliy_Kiselev

Btw, cheaper B4 adapters also exist on ebay, they are just not so easy to find.

qwerty123

Hmmm. I'll look around ebay a bit more. Perhaps an alternative would be finding a cheap b4 to nikon (or canon) mount, and then double mounting onto gh2.

BTW, you thought $320 was a lot? Looks at this thing: http://www.abelcine.com/store/HDx2-MFT-B4-MFT-Optical-Adapter/
For that amount of money you also loose a wonderful 2 stops of light!
This is why the extended tele mode on the gh2 rocks.

stoney

Aren't those B4 lenses designed for 3 chip cameras? http://en.m.wikipedia.org/wiki/Three-CCD_camera

Are you sure B4 lens will give good sharpness and good color tone on single chip CMOS camera?

fchris

Check out this link: http://www.componentgeek.com/lenses-micro-four-thirds/b4-lens/canon-j8x6b-6-48mm-gh1/ There are also some links to more footage towards the end of the article.

ed_lee83

I found a broadcast lens in rare c-mount before, a Fujinon 7.5-105mm f1.4. I've seen many of them in B4 so was lucky to pick it up. Hence I was able to modify it for GH2 to use with ETC mode:

andres

I spoke with the guy at www.leitax.com and ask him if he could make an adapter that would screw over the current bayonet and we could end up with something like a canon ef mount.

He told me he could give it a try and that sounds like a good idea.
He needs a lens to make a prototype. If someone is interested email him.
info@leitax.com.

Grunf

I use Canon B4 ENG lens on my GH2 with B4 -> FD -> M43 adapter. It's made for 2/3 inch sensors and it fills whole GH2 CCD correctly when I enable built-in 2x extender.

It's somewhat soft when open fully wide, but it's plenty sharp when zoomed in, despite being built for Betacam SP.

Rumors of "being built for three chip CCD's and thus unusable for single CCD" are untrue. Three chip or not, all ENG lenses have same chromatic focal point, thus will focus all colors in the same plane. Back-focus needs to be adjusted though.

bubba

Is there a way to correct the slight chromo in post?
There is some skew there. I get more in J lenses than in "YJ" B4 mount lenses.

x_worpig_x

@ed_lee83 Not to change the subject... but that was probably the most awkward wedding video i've seen. The bride wasn't looking at the groom at all, she didn't seem interested, and the kiss was really awkward.

bubba

@x_worpig_x
No problem. You are right, though....

Figured out why chromo was better in the "non B" lenses,
The B in Canon's naming system is for adjustment for the 3 ccd prism.
Evidently, this feature loses that adjustment after a while.
Which correlates with a main varible on how well an individual ENG B4 lens works with the GH2... It's overall condition.

I am testing for other features which are especially helpful in a GH2 system. Anyone know what the suffex's IX12, SX12, PX12 refer to?

oneday

@bubba

I am having the B4 J with 2x extender built-in lens and it is behaving wonderful, the resolution is great, I have no CA issue just some edge blur on wide open aperture, and it is first time that I heard that the YJ lens is better than the J lens, can you post some footage I would like to see the performance of the YJ lens, since the YJ lenses are a lot cheaper the the J series, I might consider of buying one.

Roberto

@ed_lee83
Well you showed off your ENG technique! Fast focal-length changes and *that look* you only get with ENG lenses. Great video. Did you use a 2nd camera at all? Did you have to ask the talent to repeat anything for the camera? If not, extraordinary coverage for a 1-camera shoot!

bubba

@oneday

I figured it out... See my post following the one you responded to.
A newish YJ easily outperforms a worn out, maladjusted J.
The B prism adjust feature is just another thing that can go wrong with an ENG lens. Not having a feature means that it can't go bad.
BTW, these are great lenses...all of them!

bubba

@oneday
If they're cheap, buy a good YJ.
These really are great lenses...all of them!!

oneday

@bubba
>Anyone know what the suffex's IX12, SX12, PX12 refer to?

the X is optical " X -Element" which corrects colour aberration to a much lower level than with conventional optical elements and layouts. Using these innovative technologies, the length is 13.3mm shorter and the weight is 70g lighter than the previous models, M.O.D. is 0.6m. = from Canon brochure

see more variations on link below

http://www.canon.com/bctv/products/lens_no.html

ed_lee83

@x_worpig_x haha very true. The bride was rather nervous and jittery. This wasn't a paid gig so it wasn't really my concern.

@Roberto thanks man, one-man shoot it was. Had to ask someone to cover me with an umbrella though, haha.

Roberto

Somebody in China has started making B4 adapters at less than half the price of the European machined ones.
Any test results welcome. See http://www.ebay.com.au/itm/360416729005?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_3655wt_1274

Vitaliy_Kiselev

@Roberto

Good find.

oneday

looks like the canons are jealous, they will get their B4 optical adapter that spreads the lens to fit APS-C sensor

qwerty123

Anybody tried the jinfinance b4 to micro 4/3 adapter? Feedback / thoughts?

greeches

Canon B4 on GH2 w/ ceico7 adapter.

bubba

@querty123
I just got one of Jin's original versions
through Vitaliy.
@Vitaliy_Kiselev
Thanks!
@Greeches
cold hearty palms?
I've seen that video before.
Are you in Raleigh?

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