NEX-FS100 demo footage shot for NAB

[Doug Jensen]

Liam,

The main thing that Mr. Moritz's blog proves is that he does not know how to use an ND polarizer properly. Yeah, I can show a lot of vignetting too -- if I misuse the filter. In the proper hands, the vignetting is neglible and would only be a problem in the most extreme examples.

You seem to think that a DX lens is going to reveal all kinds of problems, so I pulled out a 18-105 DX lens that I have never used before and would never use under ordinary circumstances. It came as a kit lens on a D700O I own. Can we agree that the sensor size of the Nikon D7000 is approximately the same as the FS100? It would be nice to have an FS100 for a test, but since we don't, I've used a Nikon D7000.

Here's series of three shots, all taken at 18mm within seconds of each other -- as you can see from the cloud pattern. The only thing that has changed was the rotation of the filter and the shutter speed that the camera chose to compensate for the exposure change. There approximately a 4-stop difference between A and C.

Yes, there is some vignetting, but keep in mind that this is a worst case example. White clouds on a flat sky. If this was typical video/photo of a person, landscape, etc. with shadows, shapes, etc. the vignetting would not even be noticable. As the video I posted at the start of this thread supports.

I can live with these results. But if it bothers someone else, then they should look into using real ND filters or find another camera to buy. The polarizer is not perfect, but it is a quick and easy way to adjust the exposure in most common shooting situations. Anyone who says an ND polarizer is unusable is dead wrong. And the Genus I have is the cheapest one you can buy. I wonder if a more expensive filter would look even better?

Whether or not this lens or filter would show vignetting on a full-size sensor camera is irrelevant, since the FS100 is not full-size sensor. This is an FS100 forum.

[Liam Hall]

Doug, it has nothing to do with user operation. It's simple physics.

The reason you don't see vignetting on your 18-105 is because it is not wide enough. Please read my earlier post carefully. I mention 12mm for APS-C and 24mm for Full-Frame.

The issue here is the image circle produced by different lenses. I'm sure you understand that a lens designed for full frame camera produces a larger image circle than a lens designed for a crop sensor camera at the same focal length and that the image circle will differ between manufacturers at the same focal length for the same format.

As far as I understand it, and please correct me if I'm wrong, but the FS100 sensor is S35 sized, so if I can see vignetting on on a 7D at 12mm with a Tokina 11-16mm lens then it stands to reason that I will see even more vignetting on the FS100 because the sensor is bigger.

The reason variable NDs suffer particularly badly from vignetting on wides is because they are effectively two filters. Any stills photographer used to working with filters will know that stacking filters can be problematic with some lenses at certain focal lengths. In fact you can see the rim of some variable ND filters with some lenses at certain focal lengths. The new Tiffen variable ND looks promising because it has a lower profile than most of the others and is certainly worth a try.

The work around is simple enough - use a larger filter with a step down ring, but that can be a pain too, bringing more flares and ghosting issues into the equation.

Anyway, I don't want to derail your thread further, I've only answered this again because I think it's important that people make the right lens/filter choices with this camera. I think I've said all I can on this matter, you can choose to disagree, so be it, no hard feelings:)


Here's a useful chart for comparing sensor sizes (it doesn't have FS100, but does have F3 - which is the same size):
http://www.creativevideo.co.uk/image...nsor_table.gif

[Doug Jensen]

Liam,

No hard feelings at all. I enjoy the debate, and you have not derailed the thread. Topics weave and evolve all on their own.

As for me, I won't ever be using a lens wider than 17mm on my FS100 (when I get it) and my filter is 77mm, so I have already established to my satisfaction that the ND polarizer will work just fine for controlling exposure while keeping the lens wide open and the shutter speed right where I want it. Naturally, other people have their own unique needs and expectations. I think we have both given people some food for thought. Thanks.

[Steve Mullen]

Originally Posted by Doug Jensen

Can we agree that the sensor size of the Nikon D7000 is approximately the same as the FS100?

I will agree 100% because the F3/FS100 is an Super 35 version of the 16.2 million photosite APS-C chip used in the A55, the D7000, and the re-spin of the NEX cameras,

Other than SHAPE, the chip is the same.

What's different -- and is key -- is the way the F3/FS100 DSP groups 16 photosites into one of 3.7 million "pixels." This is HOW the 2-stops of sensitivity is obtained. The DSP, not the chip is the magic part!

But, the difference in DSP goes further. The F3 has 10-bit processing that works in 4:4:4 space.

The FS100 uses standard consumer/prosumer DSP that works in 8-bit 4:2:2 color space. This is why power consumption is so much less.

[Alister Chapman]

Steve, can I ask you to state when you are speculating about camera details rather than just simply presenting them as known and proven facts? You know how the internet goes, one person says something and it then gets picked up and spread as a solid fact, when it may be incorrect.

BTW the F3's processing is 12 bit, the same as all the other EX cameras.

I also believe that the F3 and FS100 sensors active imaging area to be larger than that of most APS-C cameras including the VG10, Canon's and Nikons. In my recent camera evaluations using the same lens on both APS-C cameras and the F3 the F3 presented a significantly wider FOV which is a sure sign of a larger active area.

The Canon is supposed to be 22.3 x 14.9mm, the VG10 is supposed to be 23.4 X 15.6mm the F3 is supposed to be 23.6 x 13.3mm but the images I get with the same lens indicate that the VG10's sensor (or at least the active area) is smaller than the Canon which is smaller than the F3, this is not what I was expecting, but that's what I am seeing.

[Liam Hall]

Alister,

The F3/FS100 image sensor is larger than APS-C. It is an S35 sized sensor measuring 31.1 on the diagonal, as opposed to 26.7 on APS-C.

(Figures courtesy of Creative Video)

[Steve Mullen]

OK -- I believe you are correct the F3 uses 12-bit processing. :)

I believe someone else posted the FS100 DSP was 8-bit and 4:2:2 when they were explaining the lower power consumption.

I also believe that Super 35 is 23.6mmx15.8mm and the VG10 uses a Sony APS-HD (23.4x15.6mm) sensor because these are what the Sony Japan specs say.

The VG10 has a 3:2 aspect-ratio APS-HD chip in which video is obtained by placing a 16:9 window within the sensor. I have assumed the window is the full 23.4 um wide, but it may not be which would explain your results.

There is another question about the APS-HD chip.

I have read that when you switch the 18200 lens to ACTIVE Steadyshot, EIS is added to OIS. If so, then the actual useable pixel area MAY be smaller than 23.4x15.6mm aperture in both photo and video modes. I have no confirmation of the rumor!

Do the F3 and FS100 offer ACTIVE steadyshot?

[Alister Chapman]

The FS100 has active steadyshot when used with an E-Mount lens. The F3 has no form of image stabilisation at this time. The 18-252mm F3 mount lens will have OiS. There is no mention of image cropping when using active steadyshot in the FS100 manual.

The sensor dimensions of 23.6 x 13.3mm for the F3 are taken from Sony literature and have often caused confusion as this is somewhat smaller than super35 which should be 24.89mm x 18.67mm (24.89 x 13.95 16:9) I believe.

Taking a 16:9 crop from the published sensor sizes would yield:

VG10 23.4 x 13.16mm
7D/550D 22.3 x 12.54mm
F3 publish 16:9 23.6 x 13.3mm

The Canon and F3 results fit my test results but the VG10 does not as it shows a considerably narrower FoV than both the F3 and Canon. I'll have to check to see if it's due to active steadyshot cropping the image in my test shots, I need to get the camera back out and have a look in the menu.

[Sam Renkin]

Hi Doug,

I'm coming to this thread a little late but you wrote something in the first post that caught my eye:

The camera arrived on a Saturday morning. I set it up on my DSC test chart and created a custom Picture Profile that looked good to me. Please keep in mind that you should never judge a Sony camera right out of the box. You MUST create (or get) a Picture Profile or Scene File with a Sony camera if you expect the camera to perform at its best. That's the way Sony designs them, and it is the right way to do it.

I have a Sony Z5U and would like to get my hands on some scene files or picture profiles that improve the image, as I've been using it now for a year and have never been happy with the black levels. Any advice is appreciated - thanks!

Sam

[Doug Jensen]

I'll have specific recommendations when my FS100 training DVD is released in late July, but I have not fine-tuned them yet. I was still not pleased with the results I got from the FS100 when I had it. I see a lot of flaws in the footage. It is hard to dial in the settings perfectly with a prototype camera that Sony warns is not running properly!

Anyway, I doubt my FS100 settings would translate to the Z5U. I recommend getting a copy of my Z7U training DVD since the Z5U is basically identical to a Z7U. I can't tell you what settings I recommend in that DVD because I don't remember off the top of my head what they are -- but more importantly, the DVD explains the reasons for the settings and how to set exposure for them, etc. I am not a proponent of just giving some settings, or having PP files for downloading, without the proper training to go with them. Good luck. I think you'd like the DVD.

Vortex Media: VIDEO & PHOTO Tools and Training

As I said, none of the Sony cameras look good right out of the box. As you have seen, that is also true for the Z5U.

[Galen Rath]

Doug, someone on another forum is questioning that the FS-100 doesn't have manual white balance/incremental Kelvin temp settings, but only:

Auto, Outdoor (5800K), indoor(3200K), One-push (Touch panel)

I don't believe it.

Can you comment?

Thanks.

[Doug Jensen]

Galen,

You're smart not to believe it. Total crappola.

Just like any other professional video camcorder from Sony, it has a standard white balance memory A/B switch for storing two custom white balances. Also there is a customizable preset setting, and the ability to dial-in a custom color temperature from 2300K to 15000K in 100K increments.

[Piotr Wozniacki]

Originally Posted by Doug Jensen

Just like any other professional video camcorder from Sony, it has a stadarnd white balance memory A/B switch for storing two custom white balances, a customizable preset setting, and the ability to dial-in a custom color temperature from 2300K to 15000K in 100K increments.

Dear Doug,

Of course you're one of the few to have actually used the camera, but are you 100% positive the CT can be dialed-in, other than through PP's WB offset?

Cause you see it's not quite true that "any other professional video camcorder from Sony" is capable of that; the EX1/3 being the most important example... Also, when you look up the specs on Sony sites, they say:

White Balance
Auto, Outdoor (5800K), indoor(3200K), One-push (Touch panel)

So, I guess we'll need to see the actual production units, I guess.

[Doug Jensen]

Piotr,

I'm sorry I wasn't clear in my post yesterday. I have edited that post this morning to phrase it differently. When I said that the FS100 was like any other Sony professional camcorder, I was only referring to the A/B memory switch. Sorry if that wasn't clear.

Anyway, regarding the ability to dial-in a white balance setting, this comes straight out of the FS100 operation manual:

You can set the color temperature when you
set [WB PRESET] to [MANU WB TEMP].
Temperature range: 2300K to 15000K in
100K increments.

[Piotr Wozniacki]

Thanks Doug for the quick reply.

BTW, is the user manual already available to the public?