Tested Monstro vs. Helium

[Misha Engel]

The ALEV III is an amazing sensor, but 19 stops? Nope. It does deserve praise for its performance and longevity, but stating that it does 19 stops is way, way too far-fetched.

14+(14,8 color and 15,2 mono) stops latitude at 200, 400, 800, 1600 and 3200, makes a total dynamic range of ~14+(200iso) + 1(400iso) + 1(800iso) + 1(1600iso) + 1(3200iso) ~ 18+ ~ 19 stops.

 

[Hrvoje Simic]

14+(14,8 color and 15,2 mono) stops latitude at 200, 400, 800, 1600 and 3200, makes a total dynamic range of ~14+(200iso) + 1(400iso) + 1(800iso) + 1(1600iso) + 1(3200iso) ~ 18+ ~ 19 stops.

No it doesn't.
Different camera rating is just re-distribution of available DR. Which comes at a cost.

 

[Aris_Gavriilidis]

14+(14,8 color and 15,2 mono) stops latitude at 200, 400, 800, 1600 and 3200, makes a total dynamic range of ~14+(200iso) + 1(400iso) + 1(800iso) + 1(1600iso) + 1(3200iso) ~ 18+ ~ 19 stops.

Nope, that's not how it works, while you do get more highlight protection the higher you go, you also increase the noise at the same time, thus losing shadow stops, so really you're just re-distributing your DR. It's the same amount of stops at all ISO's, same goes for RED cameras.

 

[Eric Haase]

6.5 stops and 8 stops over - over what? Over itself? Over noise? Over ISO 100, 800...what?

over key. over an 18% grey card exposed at both the incident light meter and spot meter reading for a given rated ISO (they will be the same with an 18% grey card in even lighting). This is a "normal" exposure where the grey card will look grey if the aperture is set to the light meter reading. If you want another stop of highlights, rate the camera a stop more. The low noise floor and clean shadows give a lot of options on Monstro on where you can place the dynamic range. He's probably talking about ISO 800 for Monstro and Alexa in describing 6.5 vs 8 stops over key of highlight range. ISO 1600 on Monstro would give another stop of highlight range at the sacrifice of 1 stop of shadow range but it is so clean. We almost never encounter situations that break the entire dynamic range of an Alexa or Monstro so shifting the range is an effective way at getting the most out of any camera.

 

[Sabovic Adis]

over key. over an 18% grey card exposed at both the incident light meter and spot meter reading for a given rated ISO (they will be the same with an 18% grey card in even lighting). This is a "normal" exposure where the grey card will look grey if the aperture is set to the light meter reading. If you want another stop of highlights, rate the camera a stop more. The low noise floor and clean shadows give a lot of options on Monstro on where you can place the dynamic range. He's probably talking about ISO 800 for Monstro and Alexa in describing 6.5 vs 8 stops over key of highlight range. ISO 1600 on Monstro would give another stop of highlight range at the sacrifice of 1 stop of shadow range but it is so clean. We almost never encounter situations that break the entire dynamic range of an Alexa or Monstro so shifting the range is an effective way at getting the most out of any camera.

Ok.

And how do I chose my key - by setting ISO so the gray card looks gray, or setting ISO so the gray card sits in the middle of the total DR?

 

[Eric Haase]

Ok.

And how do I chose my key - by setting ISO so the gray card looks gray, or setting ISO so the gray card sits in the middle of the total DR?

Set your ISO based on how you want to shift the dynamic range. More highlight range = higher ISO. More shadow range = Lower ISO. It depends on where you want to place the values in the scene. Once you've chosen the ISO then key is a normally exposed grey card, which means when you expose for what it reflects it will look normal when developed at the ISO you have rated.

So saying "Alexa has more highlight range" isn't the whole story. If you rate Monstro higher it will have more highlight range than Alexa at 800. And it will still be clean. For awhile. Overall dynamic range is more important, BUT...

We are at the point where overall dynamic range on these cameras is largely sufficient and actually amazing. Sure it would be nice to have an overall stop or two more on ANY camera but it is almost always unnecessary with the latest sensors from Arri or RED. If you know how to shift the range for the image you intend to create you will find exceptional results with either and very rarely max out the total D.R. in an unpleasant way.

 

[Misha Engel]

Nope, that's not how it works, while you do get more highlight protection the higher you go, you also increase the noise at the same time, thus losing shadow stops, so really you're just re-distributing your DR. It's the same amount of stops at all ISO's, same goes for RED cameras.

With ARRI ALEV III it is, ALEV III has a native ISO of 200..3200. ARRI has, at all ISO's between 200 and 3200 a latitude of 14+(14.8 color, 15.2 mono) stops.

I think that RED Monstro also doesn't have a fixed (native or base) ISO anymore.

 

[Misha Engel]

No it doesn't.
Different camera rating is just re-distribution of available DR. Which comes at a cost.

Yes it does.
I think you mix up latitude and DR.

 

[Christoph Tilley]

With ARRI ALEV III it is, ALEV III has a native ISO of 200..3200. ARRI has, at all ISO's between 200 and 3200 a latitude of 14+(14.8 color, 15.2 mono) stops.

I think that RED Monstro also doesn't have a fixed (native or base) ISO anymore.

ALEV III has a base sensitivity of 800. Not 200 point point point 3200, or whatever.

 

[Christoph Tilley]

Here is a quick BTS shot I took while testing these monstros.

 

[Aris_Gavriilidis]

Yes it does.
I think you mix up latitude and DR.

Show me a Xyla chart of an Alexa then, doing 19 stops at 3200 ASA.

 

[Hrvoje Simic]

Yes it does.
I think you mix up latitude and DR.

You are wrong. On both accounts.

 

[Sabovic Adis]

Set your ISO based on how you want to shift the dynamic range.

This I don't know. I don't know how I want to shift the dynamic range, that's what I'm asking.

More highlight range = higher ISO. More shadow range = Lower ISO. It depends on where you want to place the values in the scene. Once you've chosen the ISO then key is a normally exposed grey card, which means when you expose for what it reflects it will look normal when developed at the ISO you have rated.

Higher ISO - I'm underexposing, lower ISO - I'm overexposing. I think both is wrong.
Is there no correct way of doing it? A number?

So saying "Alexa has more highlight range" isn't the whole story. If you rate Monstro higher it will have more highlight range than Alexa at 800. And it will still be clean. For awhile. Overall dynamic range is more important, BUT...

We are at the point where overall dynamic range on these cameras is largely sufficient and actually amazing. Sure it would be nice to have an overall stop or two more on ANY camera but it is almost always unnecessary with the latest sensors from Arri or RED. If you know how to shift the range for the image you intend to create you will find exceptional results with either and very rarely max out the total D.R. in an unpleasant way.

Yeah, Post has become very powerful these days...

 

[Misha Engel]

ALEV III has a base sensitivity of 800. Not 200 point point point 3200, or whatever.

From the Arri site http://www.arri.com/camera/alexa_mini/camera_details/alexa-mini/subsection/technical_data/

Exposure latitude 14+ stops over the entire sensitivity range from EI 160 to EI 3200 as measured with the ARRI Dynamic Range Test Chart (DRTC-1)
Exposure index EI 800 base sensitivity (800 must be the sweetspot with the dual sensor read-out).

 

[Misha Engel]

Show me a Xyla chart of an Alexa then, doing 19 stops at 3200 ASA.

Start with Alexa mini at 160 and shoot again at 3200 ad this up and you have the DR of the sensor/combined with the electronics and build in software/firmware.
From the darkest at 3200 to the lightest at 160, you will get 18+ stops (rounded to 19 stops).

The latitude stays at 14+ stops.

The mini can expand it's total dynamic range with the build in ND's just like a human would do with his sunglasses or welding cap when it gets really bright.

 

[Sabovic Adis]

From the Arri site http://www.arri.com/camera/alexa_mini/camera_details/alexa-mini/subsection/technical_data/

Exposure latitude 14+ stops over the entire sensitivity range from EI 160 to EI 3200 as measured with the ARRI Dynamic Range Test Chart (DRTC-1)
Exposure index EI 800 base sensitivity (800 must be the sweetspot with the dual sensor read-out).

Start with Alexa mini at 160 and shoot again at 3200 ad this up and you have the DR of the sensor/combined with the electronics and build in software/firmware.
From the darkest at 3200 to the lightest at 160, you will get 18+ stops (rounded to 19 stops).

The latitude stays at 14+ stops.

The mini can expand it's total dynamic range with the build in ND's just like a human would do with his sunglasses or welding cap when it gets really bright.

ARRI's applying gain prior to AD converter? So that only cca. 14 of cca. 19 stops get digitized/recorded, meaning ISO gets "baked in"? When recording ARRIraw?

 

[Misha Engel]

ARRI's applying gain prior to AD converter? So that only cca. 14 of cca. 19 stops get digitized/recorded, meaning ISO gets "baked in"? When recording ARRIraw?

I don't know how they do it, what I do know is that the latitude is bigger than the human eye (14+ vs. 13+) and that the DR is nowhere near the range of the human eye(18+ vs. 29+) when you let your eyes adept to the darkness or light.

 

[Björn Benckert]

Micha, Built in NDs does not count. It´s not part of the sensor its part of the lens / glas setup.

 

[Hrvoje Simic]

From the Arri site http://www.arri.com/camera/alexa_mini/camera_details/alexa-mini/subsection/technical_data/

Exposure latitude 14+ stops over the entire sensitivity range from EI 160 to EI 3200 as measured with the ARRI Dynamic Range Test Chart (DRTC-1)
Exposure index EI 800 base sensitivity (800 must be the sweetspot with the dual sensor read-out).

Yes, Arri says they have a 14 stop capable camera.

The rest is what you misinterpret from the ISO equivalent rating range.

Start with Alexa mini at 160 and shoot again at 3200 ad this up and you have the DR of the sensor/combined with the electronics and build in software/firmware.
From the darkest at 3200 to the lightest at 160, you will get 18+ stops (rounded to 19 stops).

The latitude stays at 14+ stops.

The mini can expand it's total dynamic range with the build in ND's just like a human would do with his sunglasses or welding cap when it gets really bright.

No, it doesn't work that way. Neither the ISO nor the ND.

You have a 14 stop camera regardless of the ISO or ND or if you stand on a chair.

 

[Sabovic Adis]

I don't know how they do it, what I do know is that the latitude is bigger than the human eye (14+ vs. 13+)

Well, it could be, given the dual gain architecture (switching between hi-gain and lo-gain mode?) and the 14 bit AD converter, so that latitude is around 14 stops, and total DR (which only partially gets recorded, depending on lo or hi mode, and never fully) is around 19.

and that the DR is nowhere near the range of the human eye(18+ vs. 29+) when you let your eyes adept to the darkness or light.

Eyes have pupils, lenses have apertures and its blades...plus NDs. What Björn says. :smile5: