Canon ENG B4 Lens on GH1

Thanks a lot lvlinux! My lens is FUJINON TV Z 9.5-152 F/1.8. and have already tried it (sort of...) what you told me, but I am just worrying about this backfocus ring... It seems to turn with no effect, seems to be completely loose with no connection to anything! For example: if I turn the Macro ring clockwise (the direction pointed by an arrow on Macro ring, see my picture) there appears a space of 1-2mm between Macro and backfocus ring so I can turn backfocus ring left or right (after loosing its knob) as many times as I wish... When I tighten the Macro ring by turning it counter-clockwise until it stops tightened - then turning the backfocus ring clocklwise engages also the Macro ring. Is it how it should be???
 
I think I am getting closer on my Fujinon with bayonet removed... But would anybody tell me please the thickness of the "wings" on the B4 bayonet? That would help me a lot! Thanks on advance.
 
valdi99 said:
Thanks a lot lvlinux! My lens is FUJINON TV Z 9.5-152 F/1.8. and have already tried it (sort of...) what you told me, but I am just worrying about this backfocus ring... It seems to turn with no effect, seems to be completely loose with no connection to anything! For example: if I turn the Macro ring clockwise (the direction pointed by an arrow on Macro ring, see my picture) there appears a space of 1-2mm between Macro and backfocus ring so I can turn backfocus ring left or right (after loosing its knob) as many times as I wish... When I tighten the Macro ring by turning it counter-clockwise until it stops tightened - then turning the backfocus ring clocklwise engages also the Macro ring. Is it how it should be???
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I think that is normal - the macro and backfocus rings are interconnected, so if you have the backfocus lock screw loose and turn the macro then they will do all kinds of weird stuff. Just set the macro ring to the normal position and unlock the backfocus. If when you turn the backfocus, you can see the rear element moving a tiny bit in and out then it is operating normally.

valdi99 said:
I think I am getting closer on my Fujinon with bayonet removed... But would anybody tell me please the thickness of the "wings" on the B4 bayonet? That would help me a lot! Thanks on advance.
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I measured 2 lenses with a caliper - a Nikon and a Fujinon, and the "wings" on both of them were exactly 2mm thick.
 
Great thanks again lvlinux! Well, so my backfocus ring seems to work, but only when I do some trick - anyway, no matter right now, as I locked it at the dot mark together with macro ring. I still try to figure out the right distance between the lens and GH2, what is PAINFUL, as one hand holds the lens, second hand holds the camera, and I would need third hand to zoom and focus and fourth - to measure ;) Oh my God - without any mount it wobbles, get misaligned, goes out of axis etc. every time - arghrrrrrrrrrr!!!

One more question - do I have to measure only when focusing at infinity? Because it would be easier to do it on a table - focus set on lets say at 2m and put some object exactly 2m away off the focal plane. Should work..?
 
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Yes I know it's hard but it is doable. Try setting the GH2 on a table and put a towel or sock or something under the lens to hold it at the right spot so you can just move it in and out on the table like a dolly. That should make it easier.
 
valdi99 said:
Thank you, will do that. How about focusing on far object, versus only 2m away? Despite of this - shall I zoom in all the way or just mid-zoom around 70mm?
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The zoom is not really relevant, but you need to be zoomed in enough to properly judge focus _exactly_. Because of this, it's usually easier to be all the way in. You really probably need something further than 2m to do it correctly. You might be able to get it right with something that close, but maybe not. It depends on how accurate the distance markings are on the lens. You can set it at the 2m mark and then point at an object exactly 2m away, but usually it's easier to just point at something far off and set the focus at infinity - then you know it will be right.
 
lvlinux said:
usually it's easier to just point at something far off and set the focus at infinity
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All right, sounds logical. I think I owe you a beer or two ;)

I just wonder if CA is an issue? I would love to have such bright 16X zoom on my GH2, but if there will be noticeable c. aberrations - it might appear not worth of all the efforts...
 
Well, some more attempts were made today. It looks my Fujinon gives a sharp picture when the distance between the GH2 camera (from surface of the mount) and the lens (its back without B4 mount) is around 54.5mm. I am going to connect it somehow with Pentax PK to m4/3 adapter, as I have several of these. Or will use M42 to m4/3 adapter, because the same focal flange distance. It was a big pain to get an image in focus, especially with shallow DOF at F=1.8 but I wanted to be as precise as possible. Finally, following lvlinux advices, I was able to measure the distance I needed to make an adapter. So (correct me if I am wrong) measured distance 54.5mm minus 45.46mm (Pentax focal flange distance) makes it 9.04mm and this is the "spacer" I have to add. I have already ordered something suitable that will be machined on CNC and will have a threaded tube giving me about +/- 2mm for final adjustments. Hope its gonna work...
 
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If anyone is looking for a way to power the zoom on your b4 lens, I have a suggestion. I bought this: http://www.hawkwoods.com/products/d...1&mainMenuItemToSlide=7&asi=hc-1&asi2=dv-f970 along with a 12-pin to d-tap cable. Connect a Sony NP-F type battery for power and plug the d-tap cable from the lens to the front of the Hot-Blok and it works beautifully! Not to mention the three cold shoe mounts on the Hot-Blok for attaching other things like led lights or microphones.

The only weird thing to happen is that when I first connected everything up, the iris on the lens (a Fujinon) would keep moving back to the middle position of f8. It was like the auto-iris button was pushed in, but in this case f8 was way too dark so I doubt that was the case. Anyway, it only did it the one time and it hasn't happened again, which makes it even weirder, I guess. Also, if you leave the NP battery on the Hot-Blok it will continually drain the battery, which I wasn't expecting. But now I know. I bought the 700 series of NP battery, which is the middle size. I should have gone with the smaller size because it sticks out a bit too much and hits me in the forehead. The smaller size would work perfectly.

Hope this helps! The Hot-Blok only seems to be available from this website in England. I haven't found anything similar anywhere else. It also isn't actively for sale on the site. I had to email them directly, but they were very nice and helpful and happy to sell it to me.
 
Thanks for all the valuable info, reading here months after the thread died it's still useful as heck to some eng lens newbies. I looked for a long time to avoid reopening an old thread, but can't find the info i need. I spent a few days reading every message in this and other threads.. I do see pinouts for the motors on eng lenses, but there isn't much solid info on color codes. I bought a lens awhile back and kept it for when i had time, the hirose connector was cut off already so i don't see a way to correlate pin numbers with wires.

My lens is a Canon J13x9B3 II-A, does anyone know if there's a chart anywhere that details what the colors are?

Thanks,

Rob T.
 
Loomis2, i had a similar idea, when we first started shooting multicam in the late nineties, we used quite a few trv900 cams. We also used trv22's later for backups, great cams, given dv, even the 22's at one chip, great for low light having 1/4" sensor. Anyway we collected lots of extra batteries for both. We still use the trv900s for backups, but i was looking at using the batteries from the trv22s for the same thing.

The trv900 batteries i think are the same as you mention, np-f920 (same thing, these are just the biggest ones), they also work with some other sony cams. They're 7.2v. The trv22 batteries are model np-qm91d, also 7.4v. Far as i can tell from reading, the motors use 12v, but you said the np-f batteries work? Do you have to hook two together to increase voltage?
 
My lens is a Canon J13x9B3 II-A, does anyone know if there's a chart anywhere that details what the colors are?
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Hey Rob, I think that if you open up the lens control box, on that model you will find that the wires go to a single 12 pin connector, with all the connections in a row. The position of the pins on that connector should match up with the pin numberings in the 12 pin Hirose connector that plugs into the camera. You can find which side is pin 1 and which side is pin 12 by finding the ground wire. I think it is the black one, but I can't remember for sure. You can use an ohm meter to test the black wire (and any others) to see which are connected to a ground point on the circuit board (like a screw pad or similar). If there are only 6 wires in your cable, instead of 12, then they will probably run to the same 12 pin connector inside the control box, but the connector inside will have the last 6 blank---no wires connected to those positions.
Anyway, once you know the order of the wires, you can map that to any of the pinouts for the 12 pin connectors that you have already seen.

Have fun :-D
 
RobTrujillo said:
The trv900 batteries i think are the same as you mention, np-f920 (same thing, these are just the biggest ones), they also work with some other sony cams. They're 7.2v. The trv22 batteries are model np-qm91d, also 7.4v. Far as i can tell from reading, the motors use 12v, but you said the np-f batteries work? Do you have to hook two together to increase voltage?
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Actually I think he was referring to the big 12V NP style batteries, not the smaller NPF style that the consumer cameras use. The NP batteries are broadcast batteries about 8 or 10 inches long by 3 inches wide by an inch thick or so, and they run at 12 volts (or more).
 
I bought one that looks like it wasn't cared for much since it was cheaper, a good way to test.. And the screws are welded on by calcification or oxidation. But thanks for that info, with that and pinouts posted before i should have everything i need, thank you! At some point we'll be shooting video with these lenses, probably in the spring, and i'll be posting them in my thread at

http://www.dvxuser.com/V6/showthrea...shoot-using-HV30-a-mix-of-other-cameras/page3
 
Thanks for the info, i saw your last post and was looking at it. I was thinking that your battery was running at 12v, but from that link it's 7.2v, just like my np-f970 series for the trv900 cams, so it should work fine. Either way the batteries are pretty cheap. The main thing is the ballpark $200 price on the hot bloc. It looks like a nice, rugged piece of equipment, but the whole idea is to keep costs low, this is more than double the price of the lens (though i got a pretty good deal on ebay). Will have to figure out how to wire up something to convert the 7.2v to 12, i think a boost converter or similar should save $200..
 
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