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Old January 28th, 2020, 10:52 PM   #1
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Which 2/3 B4 lens for FS7?

Hi everyone. I'm looking to get a HD 2/3 b4 lens with 2x extender for Sony FS7. Any recommendation for a reasonable price fujinon/canon lens with min focal length of about 900mm-1000mm (35mm equivalent) There are so many lens on fujinon website and is pretty confusing. Will be using mainly for stage performance such as mini concerts and conference etc. Looking more for the zoom rather than wide. I'm also considering MTF adapter to fit the s35 sensor.
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Old January 29th, 2020, 07:14 AM   #2
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Re: Which 2/3 B4 lens for FS7?

Does your budget run to service focus, or will you be using the cheaper mechanical systems, which are still quite expensive?

EDIT I just checked and you can get the remote kit - so electronic servo zoom and mechanical focus for just over a grand if you look at the Fujinon XA20sx8.5BERM, which is the lens on the cameras we hire in for our theatre work when we need HD and ⅔" cameras. We actually own 700 series JVC ⅓" cameras for our theatre work because the DoF is a bit deeper. The spec on the XA20 is wide is 58 degrees horizontal, and the zoomed in 3.2 degrees which is pretty tight. It's also quite speedy getting from end to end, which helps enormously in events work. The Bowden cable operated focus is fine, but there's a little resistance as you focus, which isn't there on servo zooms. It does use the smaller zoom connector, which also saves you money as the larger connector uses zoom demands that cost a lot more money. I've got the older SD version from an older camera which does work, but you get colour fringing at the extreme end of the zoom, and of course it's a little softer. If we need to work to a budget and use it on stage on an older camera, or for reverse angle stuff, we get away with it. If you need to use the handgrip, ENG style, it's great with my quite large hands, but my colleague struggles a bit with his smaller hands - you need to have your palm opened wider with smaller hands.
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Old January 29th, 2020, 09:47 AM   #3
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Re: Which 2/3 B4 lens for FS7?

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Originally Posted by Kenny Shem View Post
Hi everyone. I'm looking to get a HD 2/3 b4 lens with 2x extender for Sony FS7. Any recommendation for a reasonable price fujinon/canon lens with min focal length of about 900mm-1000mm (35mm equivalent) There are so many lens on fujinon website and is pretty confusing. Will be using mainly for stage performance such as mini concerts and conference etc. Looking more for the zoom rather than wide. I'm also considering MTF adapter to fit the s35 sensor.
Forget about it. You'd be better off taking the money you'd spend on a lens and getting a Z280. It would cost less and be a far, far, superior solution. The Z280 would kick ass over a B4 on a FS7. Better low-light, better AF, 17x zoom in 4K or 34x in HD. Trust me, I own both cameras and B4 lenses.
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Old January 29th, 2020, 01:30 PM   #4
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Re: Which 2/3 B4 lens for FS7?

Considering that camera with the integral lens is less than many B4 lenses alone - how does this work?
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Old January 29th, 2020, 02:23 PM   #5
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Re: Which 2/3 B4 lens for FS7?

What do you mean, how does it work? You don't think that a $6500 camcorder can beat a $7500 camera being used with a B4 2/3" lens that was never designed to be used on it? The Z280's lens is part of the camera and so they perform flawlessly together.
Is the FS7 a better camera than the Z280? Maybe. Is a $25,000 B4 ENG lens better than the lens on the Z280? Absolutely. But i fyou put the FS7 and that lens together -- the sum is less than the parts. It is a poor match, both visually and features-wise. Not to mention a huge waste of money.
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Old January 29th, 2020, 04:44 PM   #6
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Re: Which 2/3 B4 lens for FS7?

What do I mean? well - I'm just wondering how they make a good quality lens for the kind of money it is? If the glass in a branded lens is worth the price tag, then what corners have been cut optically with an integral lens? I have a real issue with servo lenses with not direct connection as these rarely behave like a broadcast lens, in fell, speed or accuracy.

At my local venue we look after we provide a host of technical facilities, including video, but are quite happy with clients using their own favourite video firms. I see them fight and squirm with cameras of all kinds and price tickets. I'm a firm believer in standing behind the camera wherever I can. Side operation using the lens focus, and pan handle zoom is the most tiring way to operate a camera, with two 60 minute continuous sections. Now I'm getting older, it actually hurts. Standing behind, broadcast fashion is much more human.

My own experience with B4 lenses is a good one. In fact, when you need the long end of the lenses, we can mount a B4 on our JVCs with a picture subjectively very, very similar to the stock lens that lives on them. An old SD lens is a bit soft, but an HD B4 looks damn good to me. A second hand lens is easy to source as people migrate to 4K, so I think they can be good value. Feature wise, I'm a little lost. Focus, zoom, extender, maybe macro - what more do you want? If the lens adaptor crops or has vignetted edges, then I agree - a bad choice but if the lens works properly, I just don't see why its bad.

If you hate the idea, I understand and it's a personal choice, but that doesn't mean its a bad idea. Me, I just hate integral servo controlled zooms that lack what I want in a lens - which is proper demands, and good glass. Stabilisers and gadgetry I can do without. A lens scale that is marked is for me, essential. Others probably don't need it. I've never had an autofocus lens and don't intend looking for one now.
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Old January 29th, 2020, 05:25 PM   #7
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Re: Which 2/3 B4 lens for FS7?

I agree with most of what you're saying, but I still contend that the OP's idea is a bad one.
If he want's all the bells and whistles of a ENG lens, then he ought to get a 2/3" camera and put the lens on it instead of a super35 camera.
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Old January 29th, 2020, 05:27 PM   #8
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Re: Which 2/3 B4 lens for FS7?

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I've never had an autofocus lens and don't intend looking for one now.
I used to make narrow minded statements like that too. And then I actually tried the features I was crapping on and found that technology has advanced quite a bit. I guarantee you that the Z280 will track focus on human faces better than you, or anyone else, can do manually. It's not meant to be an insult, just a fact.
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Old January 30th, 2020, 02:32 AM   #9
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Re: Which 2/3 B4 lens for FS7?

The OP is into events and theatre, as we are. Very often the subject centre frame is NOT what you are looking for, or vice versa, or you have things like mic stands that autofocus thinks is the subject, when you need to focus 2m upstage where the singer is standing on a drum riser. Worse is with backcloths that have very hard edges to the painting and there's so much of it, the camera want's to treat that as the subject, ignoring the dancer on the left side of the frame. I get it all the time on stills, where autofocus guesses wrong - and the bits of the screen it selects as the focus areas of interest are just in the wrong place. For what we do, autofocus is tricky - which also explains our need for focus from the rear, because for anything other than wide, focus can be troublesome and require continual attention. If you are in the pit at a music event, the microphone stand is such a common autofocus wrecker. It's also a pain for people using non-parfocal zooms on nice lager format cameras, where the same problem arises when you zoom, and touching the focus button takes it the wrong way. Not even large format cameras really - I had to use an EX3 for 74 onstage, 'pointed' by one of the cast at the audience. He was a totally un-technical person, and managed to treat the audience on the big screen to a blurring mess on 10% of the shows when he zoomed in too fast, autofocus went the wrong way and by the time it realised and fixed it the moment was gone. We lost 4 shows totally as autofocus went so wrong, and he zoomed in too far that it never found focus and we lifted the flown in screen, and scrapped the sequence. On manual, the suggestion that we simply put marks on the focus ring fell flat when I explained servo focus didn't work like that. This scenario was a no win one. I swapped the Sony for my JVC on show 3, but without autofocus it was worse because he couldn't manual focus, and the marked ring didn't cater for the people being different distances away. I went back to the EX3 on auto, which was 90% OK. It was better than manual, but still not right for 100% of the sequence. A real camera op would have sorted this silly problem easily. Lowish light levels and shallow DoF make focus critical. For the show recordings, I found a mark on the stage floor the same distance as the first actors position, so while the audience were coming in I could focus on that, zoomed right in, then pan right to an empty space the first person would walk into. Just how it is. Autofocus is just unacceptable for what we do with cameras.
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Old January 30th, 2020, 08:17 AM   #10
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Re: Which 2/3 B4 lens for FS7?

All good points. But if I was in the OP's shoes, and even having used ENG lenses for almost 40 years, so I understand perfectly well how they are used, I still stand by my earlier comments. Get a Z280 and be done with it. AF on the Z280 ain't your daddy's AF and the lack of performance on previous cameras shouldn't be grounds for dismissing AF on newer, better engineered cameras. Technology marches forward.
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Old January 30th, 2020, 10:47 AM   #11
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Re: Which 2/3 B4 lens for FS7?

I do a lot of stage performance, mostly dance recitals, musicals and plays. I never use auto focus, I set it to at the middle of the stage and leave it. I've used 1/3" sensors that have such a large dof there's never a focus issue and I use 1" sensor and for the most part the dof is still large enough for wide shots. Of course the closer you zoom in the shallower the dof. I don't zoom in past full body shot so focus isn't a problem if it is I'll press auto focus button to over ride manual until its sharp. But if you do feel the need to adjust focus, a large, high resolution monitor is must. You can't judge focus using the camera's lcd. Focus becomes more difficult the closer you get to the stage, the tighter the shot, and if you're shooting at diagonal. In higher end productions they have dedicated cameras the cover a smaller portion of the stage.

With all that being said I'm frequently frustrated by these built in servo lenses. The sensitivity of the focus ring is terrible. If the subject is a few feet away you can make subtle adjustments, but if you're 90ft away, if you turn the ring a hair it will jump to infinity then back to 50ft. Often it's impossible to get it back to it's original setting. You can temporarily turn auto focus on but that's also risky because in low contrast situations the camera can start hunting and there's no easy way to recover to the original setting. For one or two camera live shots you can't afford to be messing with the focus.

The other issue with these servo lenses is the zoom, particularly when attached to a remote lanc isn't very smooth. Again when you're close to the subject they are fine, but at a large distance its tricky to pull off smooth zooms. Given the budget I work at I have to accept the short comings of servo lenses.
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Old January 30th, 2020, 07:11 PM   #12
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Re: Which 2/3 B4 lens for FS7?

Quote:
Originally Posted by Doug Jensen View Post
Forget about it. You'd be better off taking the money you'd spend on a lens and getting a Z280. It would cost less and be a far, far, superior solution. The Z280 would kick ass over a B4 on a FS7. Better low-light, better AF, 17x zoom in 4K or 34x in HD. Trust me, I own both cameras and B4 lenses.
Hi Doug, thank you for your comment. I've heard that z280 does not have clear image zoom for the extra reach. Want to clarify if that is really the case?
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Old January 30th, 2020, 08:02 PM   #13
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Re: Which 2/3 B4 lens for FS7?

You're absolutely right that the Z280 does not have Clear Image Zoom. Clear Image Zoom is a consumer-oriented zoom that digitally magnifies the image. What the Z280 has instead is Digital Extender which is a 1920x1080 crop mode from the center of the 4K sensor. it gives you the functional equivalent of a 2x optical teleconverter with no loss of light and no loss of sharpness – for free when you are shooting in HD. Andobviously you don't care about shooting in 4K or you wouldn't be considering a B4 lens for your FS7.

Unlike Digital Extender or center scan on other cameras, you can actually turn Digital Extender on and off while you’re recording. A 34x zoom range at the touch of a button. All at f/1.9.
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Old January 30th, 2020, 09:05 PM   #14
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Re: Which 2/3 B4 lens for FS7?

Is it called center scan? It seems to be a much better option than clear image zoom which actually does degrade the image, although many people say it doesnt.
Yes 4K is not important as we are normally recording and live feed/live stream in HD.
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Old January 31st, 2020, 02:09 AM   #15
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Re: Which 2/3 B4 lens for FS7?

Clear image zoom on my Sony Z90 degrades the image for sure, handy feature if you do need the extra reach though.
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