ENG Style zoom lens for FS-100?

[Nicholas de Kock]

Originally Posted by Jean-Philippe Archibald

It's ok if the aperture is 3.5f-6.3f. With a base sensitivity of ISO 800, this is about the same thing as using the lens provided with the EX3.

This statement bothers me, I don't understand how you think F3.5-6.3 would be useful for ENG work? The EX1/3 also has a native ISO 800 sensor and both camera's come with F1.9 a lens at F3.5 you are looking at some bad low light performance.

The low light spec's according to B&H.

Sony EX1/3:
0.14 lux (Typical)
1920 x 1080/59.94i mode, f/1.9, +18 dB gain, with 64-Frame Accumulation

Sony FS-100:
0.28 lx (1/30 shutter, IRIS F1.4, Auto GAIN)

You get good low light performance at F2.8 & lower. F3.5 is a full stop darker than F2.8. At F6.3 you almost need to be outside in full daylight to get any good results. Correct me if I'm wrong?

[Alister Chapman]

I think one of the key issues everyone is forgetting here is that very, very few DSLR zooms are parfocal. As you zoom the focus changes, it may not be by much but it's enough to make the pictures go in and out of focus when you zoom. That's why DSLR zooms are cheap compared to professional video zooms.

There is also the issues associated with producing a lens with silky smooth zoom operation with no change in tension or friction throughout the range. If your going to motorise a lens then the mechanics of that lens need to be far superior to a DSLR zoom. A further issue is the way most DSLR zooms telescope. That makes them all but impossible to use with a matte box of any kind an in addition at the extended position there is often a lot of movement in the lens barrel. That doesn't hurt too much with a still photo but you try shooting on a windy day and the wind is going to wobble the end of the lens making it next to useless for video.

Creating a Parfocal lens with silky smooth mechanics is much tougher and more expensive than making a cheap varifocal stills zoom where it really doesn't matter how smooth the zoom action is. Sure it can be done, but it's not going to be cheap.

[Brian Drysdale]

Originally Posted by Nicholas de Kock

This statement bothers me, I don't understand how you think F3.5-6.3 would be useful for ENG work? The EX1/3 also has a native ISO 800 sensor and both camera's come with F1.9 a lens at F3.5 you are looking at some bad low light performance.

On EX1 the ISO varies depending on the settings Adam Wilt did some tests

ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews

The gamma settings can alter the ISO, some people are rating it at 320.

I'm not sure about the large sensor cameras as traditional ENG cameras, perhaps more for feature pieces rather than hard news. Although, there's nothing to stop people doing so, the traditional 2/3" ENG lens with a built in x 2 is extremely versatile for this work.

[Jean-Philippe Archibald]

Originally Posted by Nicholas de Kock

This statement bothers me, I don't understand how you think F3.5-6.3 would be useful for ENG work? The EX1/3 also has a native ISO 800 sensor and both camera's come with F1.9 a lens at F3.5 you are looking at some bad low light performance.

The low light spec's according to B&H.

Sony EX1/3:
0.14 lux (Typical)
1920 x 1080/59.94i mode, f/1.9, +18 dB gain, with 64-Frame Accumulation

Sony FS-100:
0.28 lx (1/30 shutter, IRIS F1.4, Auto GAIN)

You get good low light performance at F2.8 & lower. F3.5 is a full stop darker than F2.8. At F6.3 you almost need to be outside in full daylight to get any good results. Correct me if I'm wrong?

I keep reading that the EX1 is rated at ISO 320. FS100 is rated at iso 800. It's 1 1/3 stop faster. at f 3.5, the kit lens is about 1 2/3 slower than the EX1 lens. So the two cameras equiped with these lenses are about 1/3 stop from each other at 0db, the EX1 have the advantage. I can live with it.

[Jean-Philippe Archibald]

Originally Posted by Alister Chapman

I think one of the key issues everyone is forgetting here is that very, very few DSLR zooms are parfocal. As you zoom the focus changes, it may not be by much but it's enough to make the pictures go in and out of focus when you zoom. That's why DSLR zooms are cheap compared to professional video zooms.

There is also the issues associated with producing a lens with silky smooth zoom operation with no change in tension or friction throughout the range. If your going to motorise a lens then the mechanics of that lens need to be far superior to a DSLR zoom. A further issue is the way most DSLR zooms telescope. That makes them all but impossible to use with a matte box of any kind an in addition at the extended position there is often a lot of movement in the lens barrel. That doesn't hurt too much with a still photo but you try shooting on a windy day and the wind is going to wobble the end of the lens making it next to useless for video.

Creating a Parfocal lens with silky smooth mechanics is much tougher and more expensive than making a cheap varifocal stills zoom where it really doesn't matter how smooth the zoom action is. Sure it can be done, but it's not going to be cheap.

I understand that, but I assumed, perhaps badly, that you can "transform" a 700$ still lens in a proper ENG one for 2000-3000$.

Of course we can continue to have multiple cameras for multiple kind of scenarios. And the lack of such a lens is not a deal breaker for me. I already have one preordered. In the last two years, my 7D got a lot more work than my XLH1 and EX1.

But as a freelancer, I would have liked to get this camera to be super versatile and have only one workflow for all my work.

[Alister Chapman]

Perhaps AbelCine will make an adapter like the HDx35 one they do for the F3 that allows you to use 2/3" ENG zooms on the FS100. Only problem is the cost, $5,800 for the adapter plus a good HD zoom lens.

The extra engineering and lens sophistication required to make a Parfocal lens compared to a varifocal is significant. Just look at the price of the very cheapest 2/3" HD eng lenses and then consider it is much harder to make a zoom lens for a 35mm sensor than a 2/3" one.

[Jean-Philippe Archibald]

Originally Posted by Alister Chapman

The extra engineering and lens sophistication required to make a Parfocal lens compared to a varifocal is significant. Just look at the price of the very cheapest 2/3" HD eng lenses and then consider it is much harder to make a zoom lens for a 35mm sensor than a 2/3" one.

I totally agree and I am well aware for the cost of 2/3" lenses. But I assumed that making a slower one (broadcast lenses are usually pretty fast, f1.6, f1.8 is not uncommon) would render it easier and less expensive to build. I must be wrong.

[Andy Shipsides]

Our HDx35 optical adapter could be used on the FS100 with a PL adapter.. Of course the adapter costs more then the camera :) But you would be able to use an ENG style lens on the camera. Their are huge advantages to ENG style lenses, but I don't really believe this would be a popular combination.

[Glen Vandermolen]

Originally Posted by Jon Braeley

Actually there is a world of difference one is professional grade with Zeiss ED glass optics, image stabilization and host of other features. It may be twice the cost but it is five times the lens.

Well, you know your budget and I know mine. Sometimes "good enough" really is good enough.

[Bill Bruner]

I had an interesting fixed-lens Super 8 camera 35 years ago:

CHINON PACIFIC 12 SMR SUPER 8mm Movie Camera | eBay

As I recall, it had a 12:1 parfocal f/1.7 power zoom lens and cost less than $1000 1970s dollars.

The Beaulieus cost more (~$2000 in 1970s dollars), but they had very fast (e.g., f/1.2) interchangeable C-mount Angenieux and Schneider parfocal power zooms.

If there's a market for it, it can be manufactured at an affordable price.

Sadly, the mass market for interchangeable-lens power zooms pretty much disappeared with high-end Super 8.

[Brian Drysdale]

Doing a quick on-line inflation calculation, that's about $10,000 in today's money.

I imagine the Fujinon for the JVC might be a better model. Although I imagine you'd be talking about an f 4 ish max aperture for a Super 35 sensor and lesser build standard than the broadcast lenses.

http://www.bhphotovideo.com/c/product/401434-REG/Fujinon_TH13X3_5BRMU_TH13x3_5BRMU_13x_1_3_JVC.html
The larger glass for Super 35 would mean adding some more mechanical beef, making it closer to a 2/3" lens in size.

[Steve Mullen]

FYI: Minolta made a power zooms: "In terms of overall build quality, Minolta's xi power zoom lenses from the early 1990s may represent a high water mark."

IF an A-mount adaptor had power contacts -- and a source of power -- there are controls on the lenses to zoom.

There are six different Minolta Maxxum Power Zoom lenses:
35-80 f/4-5.6
28-80 f/4-5.6
28-105 f/3.5-4.5
80-200 f/4.5-5.6
35-200 f/4.5-5.6


THESE ARE IDEAL:
MINOLTA MOTORIZED 28-105 f/3.5-4.5 ZOOM Xi LENS MAXXUM SONY ALPHA $100

Minolta Maxxum 28-80mm f4-5.6 Zoom Xi AF Lens for Sony $80

[Matt Davis]

This should add a little substance to one's dreams:

http://www.angenieux.com/file/datash...talog_2011.pdf

Make that nightmares. 12Kg, almost half a meter long. £450 per day to rent. As the sensors get bigger, so does the glass...

[Jean-Philippe Archibald]

Of course it's big. 2.8 f constant aperture over 12x of zoom range... that's why I asked for something like the kit lens; 3.5-6.3, just repackaged to be more adapted to video work.

But it seems to be impossible...

[Brian Drysdale]

Your best bet might be a version of the servo zoom that Sony are bringing out for the F3, possibly being announced at IBC, but it'll probably cost more than the FS 100. Most stills zoom aren't parfocal, which restricts the options for adaptation as an ENG style lens