EPIC and Alexa...

[Eki Halkka]

Just look at the chart at the beginning of this thread. The Red low end is much less blocky and more smooth. The Alexa runs into the whites better.

Rolling of the highlights is a total non-issue: both cameras have linear sensors, as far as i know, so half of the values the cameras gather are in the highest stop. That means, Red has 2048 brightness values between the two brightest wedges in that chart, assuming the brightest wedge is exactly at the brink of overexposure (which it seems to be: examining the jpegs, some pixels are clipped 255,255,255, but some pixels have some variation, so it must be almost exactly at the brink).

Same goes to Alexa - the brightest wedge is at 240, and there's very little variation. I assume that it too is (correctly) exposed to the brink of overexposure, and the lower white level is simply the result of conversion to the jpeg we saw.

In other words, there's always more than plenty of information in the highlights, unless they are clipped.

How the transition to whites is performed, is a color correction issue, not a camera issue. What we are interested in is the shadows: how much we can underexpose to protect the highlights.

 

[Wolf]

On-camera de-bayer - yes

On-camera de-bayer - yes

Was this test done with Arri Alexa's on-camera de-bayer? And recorded to ProRes? If yes, which flavor? Or recorded to something else? If yes, what else?

Poked around other cinematography forums. Somebody else had posted a similar question which was answered by Jim Jannard:

Arri Alexa was feeding RGB directly into a Pablo.

So On-Camera debayer yes, ProRes no. Compression: Uncompressed.

If I somehow got that wrong please feel free to correct.

Thanks,

 

[Brook Willard]

Rolling of the highlights is a total non-issue: both cameras have linear sensors, as far as i know, so half of the values the cameras gather are in the highest stop. That means, Red has 2048 brightness values between the two brightest wedges in that chart, assuming the brightest wedge is exactly at the brink of overexposure (which it seems to be: examining the jpegs, some pixels are clipped 255,255,255, but some pixels have some variation, so it must be almost exactly at the brink).

Same goes to Alexa - the brightest wedge is at 240, and there's very little variation. I assume that it too is (correctly) exposed to the brink of overexposure, and the lower white level is simply the result of conversion to the jpeg we saw.

In other words, there's always more than plenty of information in the highlights, unless they are clipped.

How the transition to whites is performed, is a color correction issue, not a camera issue. What we are interested in is the shadows: how much we can underexpose to protect the highlights.

While this is all true, what ultimately matters is how these data are presented to the colorist. If they are presented in a way with a harsh shoulder [not suggesting either camera does this], there is only so much that a colorist can smooth out.

The Log C curve Arri has built for the Alexa is pretty fantastic. That's not me saying it's better or worse than the MX and how the data is presented to a colorist... just an observation.

 

[Sanjin Jukic]

While I don't agree with Sanjin, who says you can't put Alexa on your shoulder at all, I really wouldn't want to do it for any extended time periods. I often have a RED One rig on my shoulder that is 35 lbs or more. A similarly configured Alexa will always have that extra 6 lbs or so difference in the body weight. Neither are fun for extended periods like all day I've done it. It sucks.

He, he, he, Jeff but I never said that you can't put Alexa on shoulder at all, but what I've said is that you can shoot with Alexa on shouder but very short time otherwise you gonna finish in a sort of orthopedic clinic sooner or later.

Why?

Alexa is heavier than RED1 (already I showed the figures before here above) and it's good to have accessories like an ET Mantis and EasyRig 3 Cine 700 if you want to keep Alexa 15 minutes up on a shoulder...

Alexa's built in body shoulder pad and handle are pretty uncomfortable for longer use.

BTW, I had about 500 hours experience of handheld shooting with my RED1.

 

[Andy Jarosz]

Jarred - was the Epic seriously able to stand on the table by itself like that? I'd expect it to be very front-heavy with the RPPs on.

At RED Day, with a new 17-50, that exact setup (and camera actually) did indeed tip onto the lens. However, it's not like it's falling 5 inches and denting the barrel.

 

[Rob Ruffo]

Following up on the HD-SDI monitor output discussion:

EPIC brains allows the HD-SDI, Viewfinder and HDMI outputs to operate at independent resolutions, frame rates and gamma.

EPIC offers REDcolor or REDlog gamma at 720p, 1080p or 2K, with LOOK AROUND and graphics, or as a clean PROGRAM feed.


Details:

EPIC supports 1.5GHz HD-SDI (as used on RED ONE), plus 3GHz HD-SDI. The latter replaces "dual link" with a single BNC cable.

1.5GHz mode allows 1280 x 720p 4:2:2 at 50 or 60 fps, or 1920 x 1080p 4:2:2 at 24, 25 or 30 fps, both in record and playback.

3GHz mode adds 1920 x 1080p 4:4:4 (RGB) at 24, 25 or 30 fps and 1920 x 1080p 4:2:2 at 50 or 60 fps, both in record and playback.

EPIC can also support 2048 x 1080p 4:4:4 (RGB) at 24 or 25 fps, and 2048 x 1080p 4:2:2 at 50 or 60 fps, but as yet there may be little you can connect to.

So for 3K I get a Nanoflash and who needs a prores module - if I have a job that has to leave with the producer, on snaps the Nanoflash - and now I have DUAL recording, if I want.

 

[Ed Carlton]

He, he, he, Jeff but I never said that you can't put Alexa on shoulder at all, but what I've said is that you can shoot with Alexa on shouder but very short time otherwise you gonna finish in a sort of orthopedic clinic sooner or later.

Why?

Alexa is heavier than RED1 (already I showed the figures before here above) and it's good to have accessories like an ET Mantis and EasyRig 3 Cine 700 if you want to keep Alexa 15 minutes up on a shoulder...

Alexa's built in body shoulder pad and handle are pretty uncomfortable for longer use.

BTW, I had about 500 hours experience of handheld shooting with my RED1.

As the expert here on Alexa I'm curious as to how much time you have spent with an Alexa on or off your shoulder?

 

[Jannard]

If this keeps up I'm going to close the thread.

Jim

 

[Sanjin Jukic]

As the expert here on Alexa I'm curious as to how much time you have spent with an Alexa on or off your shoulder?

As I said already here if Alexa would cost 25,000.00 Euro I can have it in on my shoulder in two days.

 

[mike ogden]

If this keeps up I'm going to close the thread.

Jim

Please do. It's tedious beyond belief.

 

[David Rasberry]

Ahhhhhhhh......The Alexa has more than 1920x1080 as its native
pixel count.

I'm talking about the final output. It doesn't matter how you scale it. Any fixed pattern digital image is going to show aliasing as you approach the Nyquist limit. A smooth alias free image won't optically resolve beyond about 80% of pixel resolution. Regardless of what you start with, a finished 1080p HD image is still in the end only 1920 pixels wide.

 

[Rick Darge]

One thing I do wonder about his the Epic being too light? There is a certain fluidity you get with the Red One and other cinema cameras in its weight class when you're doing handheld. Lighter cameras are more prone to hand shake/vibrations and with CMOS, well, this could get ugly. Heavier cameras make you think different and vice versa with lighter cameras. I guess the brilliant thing about the Epic is that it's modular and I can just snap on my 'workout module' if I need that extra weight.

 

[Martin Stevens]

I'm talking about the final output. It doesn't matter how you scale it. Any fixed pattern digital image is going to show aliasing as you approach the Nyquist limit. A smooth alias free image won't optically resolve beyond about 80% of pixel resolution. Regardless of what you start with, a finished 1080p HD image is still in the end only 1920 pixels wide.

I disagree with this on the grounds that you can take a 2K crop
out of a 4K image and it will resolve the full 2K.
:001_cool:

 

[Jan Reiff]

epic on steadicam

epic on steadicam

first thing i buy me for my epic is ... a light and cheap steadicam system ...
i love it already.

 

[Jeff Kilgroe]

As the expert here on Alexa I'm curious as to how much time you have spent with an Alexa on or off your shoulder?

Somewhere close to an hour total, in segments of 10 minutes or so spread out over a few hours. Yeah, it has the curved shoulder bumpers or whatever, but it's still a brick in the middle of that shoulder arc. Maybe it works for some, but it didn't do it for me... I wouldn't want it on my shoulders for more than 10 to 15 minutes without a good shoulder pad. In that respect, and in terms of its size, weight and mounting or handle options, I didn't see where it was so fantastic compared to the RED One, which has several shoulder-mount options too, which can go direct from tripod to shoulder in a matter of a few seconds.

Anyway, Jim's threatening to close this down, and he probably should. I'm not exactly setting a good example as a moderator here anyway, so I'll leave it at that.

 

[Rick Burnett]

I disagree with this on the grounds that you can take a 2K crop
out of a 4K image and it will resolve the full 2K.
:001_cool:

You are joking right?

And pertaining to camera weight, I can tell you this, you can always add weight to the EPIC. I do this with some lighter cameras for specific conditions where I need the weight to help me with using it hand held to be smoother. However, you cannot take weight off of a heavier camera. Something to think about.

 

[Jannard]

I think we have all had a good run at this topic. Let's now move over to another. Might I suggest the JJ Abrams thread where he raves about the dynamic range of the RED ONE M-X?

Jim