Jump to content
Andrew Reid

Fujifilm hint at 44x33 large format "GFX-H100" filmmaker's camera / open gate 4K3K

Recommended Posts

Some calculations.

A "pixel-to-pixel" 3840x2160 crop from 3882x2912 yields a 0.87x crop factor. Good news for owners of native G lens; much less so for owners of full frame lenses. But I guess most FF lenses except super-wides should cover it in practice, i.e. wide open at portrait distance or stopped down at infinity.

For those looking for the MF look: 0.87x0.71 roughly yields a 0.62x crop factor, i.e. 6x6 and 645 lenses with one-stop speedboosters should all have image circles big enough to cover it.

The Cooke Anamorphic/i Full Frame Plus Series has the following focal lengths (all in mm): 32, 40, 50, 75, 100, 135, 180. Putting them on the anticipated new "GFX 100 H" would yield the equivalent angles-of-view of 16, 21, 25, 38, 51, 68, 91 (all in mm) lenses. Someone would surely do an image circle test soon after this open gate anamorphic mode has become a reality. My guess is that the four at the tele end (75, 100, 135, 180) should comfortably cover.

.

Share this post


Link to post
Share on other sites
EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs
2 hours ago, androidlad said:

You are talking about encoding bitdepth, 8bit H.264, 10bit ProRes etc.

I am talking about everything that involves converting an analog signal to a digital signal, including the signal going into a camera sensor's ADC and the signal coming out of that ADC.

 

By the way, there are zillions of machine vision camera that offer selectable bit depths.  There is no encoding nor compression nor codec.  The bit depth changes, but the dynamic range doesn't change.

 

 

2 hours ago, androidlad said:

Sensor ADC readout precision dictates the upper limit of the total DR the sensor can output.

No.  It doesn't.

 

Barring any artificial signal processing, the max limit of dynamic range is dictated by the analog stage of the sensor.  Dynamic range is essentially (originally) a property of analog signals notated in decibels, regarding the maximum signal amplitude relative to its noise level.

 

An ADC merely maps some number of digital increments to an analog signal's amplitude range (not to the signal's dynamic range).  Regardless of how many digital increments the ADC maps, the relationship between max amplitude and noise level remains the same.

 

 

3 hours ago, androidlad said:

Do you know what ADC is? It's absolutely linear.

Analog to Digital Converter.

 

Most ADCs for camera sensors are linear.   Certainly, other ADCs exist that don't make a linear conversion.

 

 

3 hours ago, androidlad said:

12bit ADC theoretically offers 12 stops maximum DR, and BMPC6K does 11.8 in lab test.

10bit ADC = max 10 stops, as demonstrated by the noisy shadows in ZCAM E2 4K 120p footage.

Alexa uses dual 14bit ADCs, it's one of the reasons why it's capable of 14 stops of DR (then stored logarithmically in 10bit ProRes)

Most stills cameras use 14bit ADC for stills and that's why A7 III achieves 13.9 stops DR in stills mode.

First of all, a lot of folks who have tested Alexas would disagree with you and and say that it's dynamic range (in stops) is greater than it's bit depth -- 15+ stops of DR.

 

However, the manufacturer Blackmagic's sensor could integrate an 8-bit ADC with the same analog stage of their 12-bit sensor and also make another sensor with a 16-bit ADC to go with the same analog stage, and the dynamic range would not differ one iota between the 8-bit version, the 12-bit version and the 16-bit version.

 

The reason why the dynamic range (in stops) in CMOS sensors often approximates the bit depth of the ADC is because it is usually the most optimal/efficient balance between bandwidth and color depth.  Mapping 16-bits to a sensor with 12 stops of dynamic range probably wouldn't improve the look much, but it would significantly increase bandwidth.   Similarly, mapping only 8-bits to a sensor with 12 stops of dynamic range would severely limit the potential color depth and might make the images susceptible to banding.

 

There are camera sensors that have outboard ADCs (not built into the sensor), and, changing the bit depth of the ADC has no effect on the DR.

 

Share this post


Link to post
Share on other sites
On 9/5/2019 at 11:07 PM, Eugenia said:

My husband's GFX100 arrived yesterday for his studio. In a very short test I did, I found it to be sharper than my BMPCC 4k (its native Fuji lenses are very sharp, they resolve a lot of detail). I honestly don't think I need even sharper or whatever "better" Fuji thinks it can give us (better color/midtone detail sure, but even sharper details heck no). I had to soften the image in post by a lot to make it look anywhere near cinematic. There was a reason why Alexa was sitting at 2.8k resolution for the longest time before Netflix forced them to make a 4k camera. For true traditional cine stuff, 4k is enough. I personally have no plans on updating on 6k/8k any time soon, not even when 8k TVs might be commonplace. I end up softening my 4k clips in post by either Panasonic or BMD, but the GFX100 required a lot more (f-log). If you're after super crisp, commercial style look, that's your camera.

Indeed. Hybrid usage to include large formats as for instance can require it though : -)

Share this post


Link to post
Share on other sites
On 9/5/2019 at 4:16 PM, Eugenia said:

Panasonic's CineLike D and a rather soft, low contrast lens: https://imgur.com/a/FZoTc8j (open image in its own tab to look at full 4k size).

Nice work. Good to know these kind of results are possible. Have you guys used/considered vintage cinema lenses to get a vintage cinema look, rather than softening in post or adding texture?

As sensors get larger and sharper, especially those that support 4x3 anamorphic, I'm curious, if not excited what the images will look like with vintage anamorphic glass. I'm hoping 1, that vintage glass with a PL mount with cover an LF sensor, and 2, that a LF sensor will help compensate for how slow (~T4) vintage glass often is.

Share this post


Link to post
Share on other sites
Quote

Nice work. Good to know these kind of results are possible. Have you guys used/considered vintage cinema lenses to get a vintage cinema look, rather than softening in post or adding texture?

For that sample I used a manual 7Artisans lens which has vintage characteristics. Except the Sigma 18-35 and some Tokina zooms for their versatility, I avoid modern lens designs (like the ultra sharp Panasonic/Leicas, for example).

Regarding GFX 100's sharpness btw, here's a test I did yesterday comparing it to the BMPCC4k (more information on its youtube page, not via the video itself): https://www.youtube.com/watch?v=Efx6i5LMPK4&t=2s

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...