EPIC Native ISO

[John Smyrnios]

Hi guys,

I'm a new member and new RED user and really excited about this powerhouse of a camera!

From reading around the forum its my understanding that the EPIC has a native ISO of 800 http://reduser.net/forum/showthread.php?36340-Mysterium-X...

Gathering information over the past few days, it seems to me that correct usage of the EPIC can be achieved by proper exposure as No.1 priority, since all else is just META-DATA.

This relies mainly on correct aperture and shutter speed, as ISO, White Balance, and Colour Profiles are all things that can be done in post.


And the question: Can shooting at ISO800 and keeping an eye on the histogram reliably give me a good indication through my monitor of what the sensor is actually picking up?



(it appears new users can be fooled into thinking they have correct exposure because they lowered the ISO setting and looked at a correctly exposed image through the monitor when in fact the sensor was being over exposed therefore killing the highlights)


Thanks,

I hope I'm not asking a very silly question

 

[David Battistella]

And the question: Can shooting at ISO800 and keeping an eye on the histogram reliably give me a good indication through my monitor of what the sensor is actually picking up?

THis is sure to be a hot thread.

Since I was just asked this about an article I wrote on R1 MX exposure over a year ago. I will post the same asnwer here:

"how does that (ISO vs. EXPOSURE) pan out exactly related to your base stop?"

This depends on where you set your mid grey but as a rule when highlights clip they are gone, there is much more DR in the blacks than in the top end (though I am hearing that on EPIC the TOP END has MORE thatn the R1 MX.

"is it best to set it at 800 for both int and ext and just ND it to hell or adjust accordingly?"

Red recomends that the the ISO be set to 800.

I tend to do the following.

-I always set the ISO to 320 and light accordingly looking at the histogram for cliping, etc. I always rate the camera at 320. M, MX, or also EPIC (when I get it)

-If i want to protect highlights on exteriors then I set the ISO to 500.
-By doing this you are effectively "stopping down" to ensure that you do not over expose the shot and protect highlights.
-It depends on your level of comfort, if you know the sensor and the camera and you expose to the right you get great shots at 320, but you leave little room for margin of error.
-I always monitor the RAW file and I set the Color temperature to 5000 (the sensors native setting) so I see exactly what the sensor is seeing.
-I find the the sensor likes more light so I expose to the right.
-When exposed properly with a lot of light it looks best.
-Starve it from light and you can count on more noise.
-I try to stay away from noise.

The only other person I know who leaves teh camera a 320 all the time and monitors RAW is MArk Toia.
800 ISO is the safe way to preotect highlights.
I think the sensor perfroms better when you hit it with more light and expose to the right as much as possible, giving you the most amount of play in post.

I equate it to recording a low audio signal, the more you boost it the more noise you also boost.

Let the games begin...

David

 

[Adam Eden]

Hey don't forget about me David. I only ever shoot 320 ISO also!

At 320 you can push the hell out of it if need be.

 

[David Battistella]

Hey don't forget about me David. I only ever shoot 320 ISO also!

At 320 you can push the hell out of it if need be.

Plus 1 for the 320 ISO crowd. Let's face it. More light makes better images and usually sharper. Rating at 800 means less light on the sensor.

David

 

[Damien Molineaux]

Plus 1 for the 320 ISO crowd. Let's face it. More light makes better images and usually sharper. Rating at 800 means less light on the sensor.

David

+1 for ISO 800, as that means protecting your highlights, and the darks are so clean, this gives you the most latitude, er oops I mean dynamic ;-) !

Cheers,
Damien

 

[John Smyrnios]

Plus 1 for the 320 ISO crowd. Let's face it. More light makes better images and usually sharper. Rating at 800 means less light on the sensor.

David

Thanks David, are you still talking about the Red One sensor or the New M-X on the EPIC? I'm currently working on the EPIC and it appears to be more sensitive than the old sensor of the Red One.

 

[David Battistella]

RED MX and EPIC share the exact same sensor.

I am refereing to the MX sensor.

RED reccomends ISO 800 but there are a few people (like myself) who like to rate it at 320 whenver possible. This will carry over to EPIC for me and I base that only on trusting TOIA becuase I do not have mine yet.

Also, I hihgly reccomend shooting some stuff and running iit right through post.

There are other consuderations. 320 will almost always mean short focus, getting F4 at 320 is a lot of light. F4 at 800 less light, so it might let you go to F85.6 or F8 for deeper focus.

It depends on the situation. I'm talking optimal here.

There is always plently of room for creative choice, budget consideration, speed of set-ups, size of crew, etc.

320 is fine, 500 is fine, 800 is (can also be) fine. Just know the tool going in. The MX chip (RED ONE MX AND EPIC) is much cleaner in the blacks over the original RED ONE M.

David

 

[John Marchant]

I tend to shoot at 320 as I usually judge exposure visually rather than technically. Rating at 800 I find I tend to watch highlights like normal and consequently waste latitude on highlight safety I needn't have worried about, at the expense of shadows that could have been better...

My business partner shoots 800, but exposes more like video... (He's from a video background, I'm from a 35mm stills background) I usually do the grade, and knock his stuff back to 320 as a starting point for an easier curve. Everyone has their own style

 

[Brook Willard]

I leave the camera at 800 ASA 100% of the time. I feel that it gives you the most balanced readings of what your image is actually going to look like.

Here's the thing - all cameras have a "native ASA" that differs from the settings we choose. Whether it's an HVX or a DLSR [stills or otherwise] or an F35 or an Alexa. The cameras all have a native ASA that is lower than what we see.

On all of those cameras when you select an ASA [or equivalent setting] you are essentially choosing which LUT to view. It's an oversimplified description but that's what it is. Even when you choose 100 ASA on a still camera you take the shot and end up with a picture that is "meant for human consumption". It looks good. Lots of math has gone on behind the scenes to make sure that the image you see looks as a human might expect it to.

The same thing happens in the Epic. When you turn the camera on... you see a pretty picture. It's based on the math that happens in between the sensor and your eyeballs.

The difference with the Epic [and R1] is that you can essentially turn all of this off. You can choose a LUT that is not "meant for human consumption" but is instead more appropriate for robots. You could take all settings back to their defaults and load your data in linear. Or any number of other LUTs.

I view this as an enormous advantage. On a whim I can pull back the curtain on my footage and see the wizard hiding behind it. Properly understanding the relationship between RAW data [and proper exposure of a RAW camera] and the infinite number of ways by which you can process footage is key to getting the most out of your camera and footage.

Many people take this in the opposite way. "Well, the R1/Epic isn't really 800, it's actually 320. They just boost it to 800." In many ways that is true. The thing that people skip over is that EVERY camera does this. Every camera has an inherent sensitivity which is modified into a functional sensitivity via math that happens behind the curtain. The reason that people often brush over this point is because they don't realize that to be true. No other camera [in my hands-on experience] has the ability to strip back the inherent math/LUTs to see what the image "really" looks like.

Unfortunately the knowledge that the sensor is "really" 320 [just as the M sensor was "really" 160] is a dangerous fact without a greater understanding of the RED/Epic system and RAW capture in general. It's a flash headline on a low-rent blog that is hunting for traffic. The functional ASA is what people should compare between systems.

I interpret the Epic's functional sensitivity to be 800 ASA.

 

[Jeff Kilgroe]

+1 to everything Brook said.

I also leave the EPIC at 800 all the time. You can shoot 320 with it, and some people do, but I've found ISO 800 to give the most balanced response. And I suppose that's why RED has picked it as the target sensitivity. If you can over-light a scene and not blow your highlights when rating at 320, then good for you... However, there's a good chance you're crushing out some potential DR in that scenario. But this really comes down to each shot and lighting setup.

 

[jimhare]

Also, even though it's the same sensor on the MX and Epic, the Epic has new advanced space-age guts that create an even cleaner image, so those basing all of this on MX may need to test and possibly rethink their stance when they have the EPIC.

In the end, you can't go past what experts like Brook and Jeff say about 800, and I have never been more consistently impressed then Mark Toia's 320 work so it's clear both 320 and 800 work damn well in capable hands! :coolgleamA:

 

[Jeff Kilgroe]

Also, even though it's the same sensor on the MX and Epic, the Epic has new advanced space-age guts that create an even cleaner image, so those basing all of this on MX may need to test and possibly rethink their stance when they have the EPIC.

Quite true. Epic captures 16bit data from the sensor, vs. the 12bit on RED One. And there's a lot of other deeper things going on in the EPIC as well... Images from it look to be on a whole new level.

 

[Ryan E. Walters]

Well put Brook.

I haven't landed on where I'm going to rate the Epic yet. I may end up rating the EI higher then 800 (Possibly 1000). Since it records 5k, and the deliverables could be in 4k or smaller, some of the noise that might be there in the 5k image will get hidden in the down sample to 4k or smaller, so I might be able to get away with more.

Here is the way I see the EI of the MX chip- in the Red One MX, for sure, (Still testing with the Epic). The "native" EI of the chip is 320. A simple way to check is to turn the camera to 320 and then switch to RAW view, not much changes. (The RedColor view has it's own LUT which does make things "brighter", but not by much on the Red One MX.) This is even more clear on the Epic, as almost nothing changes. The catch being at least on the Red One MX, the sensor is VERY, VERY, VERY clean and there is a lot of room for under exposure. At EI 320, the sensor is not very balanced in terms of DR. There is MUCH more under exposure latitude then over exposure latitude. By bumping it up to EI 800 the over and under exposure latitude is much more balanced, and is most similar to how I am used to working with my light meter. And since I know the sensor is VERY clean, I can comfortably "underexpose" it and know that I have solid highlight protection so that it rolls of nicely, and I have clean details in the shadows. So even though the "native" EI is 320, the effective working EI for myself ends up being around EI 800.

As the Red One MX has the same chip as the EPIC, my hunch is that it is the same here too. Although I'm still testing and playing around with it to see where I am comfortable rating it. I think I can "get away" with more on the EPIC due to the increase of resolution, and also the processing in camera of the RAW data feels cleaner to be then on the Red One MX (that may just be me) - so I think I can push it harder then the Red One MX if I need to.

Native ISO is a VERY tricky / touchy subject, as too many people just read the headlines and do not bother with the details and implications of what that means. I highly suggest that you do some testing of your own, figure out what your on set working method is, and what your post workflow is going to be, and then develop a rating based off of that. Something that is KEY to working with the Red RAW data is what / how you process it in post. I've seen some MX footage shot at EI 320 that was processed nicely, and EI 800 footage that was processed horribly. But they both were shot correctly. The is the same when working with film. Just because Kodak or Fuji says their film is EI 500, or 250, that doesn't mean that it is EI 500 or EI 250- how you shoot it and then develop it can significantly change that rating depending on your needs. Treat RAW data the same way.

 

[Mike McEntire]

I am in the middle. For exterior daylight shots I rate the camera at 500. In exterior day with low light and under artificial light I use 800. The highest I rate it in extreme low light is 2000.
In my tests on my epic it seems like 400 is the native speed of the sensor so 500 gives me a little wiggle room with ultra clean images.

 

[David Battistella]

Also, even though it's the same sensor on the MX and Epic, the Epic has new advanced space-age guts that create an even cleaner image, so those basing all of this on MX may need to test and possibly rethink their stance when they have the EPIC.

In the end, you can't go past what experts like Brook and Jeff say about 800, and I have never been more consistently impressed then Mark Toia's 320 work so it's clear both 320 and 800 work damn well in capable hands! :coolgleamA:

That's a pretty sweet backhanded slap. Thanks Jim!

 

[soren k jensen]

At the recent Reducation UK, Ted said that Epic is technically measuring to 320, but in the real world 800 works at least as well, and Red prefers to shoot it at 800. Of course you can do whatever you want, depending on needs and aesthetics. Just test...

 

[Patrick Tresch]

Quite true. Epic captures 16bit data from the sensor, vs. the 12bit on RED One. And there's a lot of other deeper things going on in the EPIC as well... Images from it look to be on a whole new level.

Hello Jeff,

Very interested about where did you get this info about 16bit data captured from the Epic sensor?

Thanks a lot.

Patrick

+1 on 800 asa with the Epic. Much cleaner blacks than with te One MX.

 

[Eric Haase]

I rate the camera at 800. Rating at 320 sacrifices highlight detail. 320 would work well for a scene that has all it's values one or two stops over key and the rest under. Turn on your internal spot meter on the camera, break out your minolta F, and shoot a bracketed greyscale. Plot the IRE of the internal spot meter against how many stops under or over the grey value is based on your minolta F spot meter. Do this at 320, 800, 1200, etc. You'll find that at 320 you get a very unbalanced distribution of the dynamic range- it mostly resides in the shadows. Rating 800 improves the distribution to a bit more even for over/under. There is no wrong way to shoot but I think it's good to be aware that even at 800 you do not have an even distribution of under and over key values.

I've shot scenes for episodic television at 1000 and they looked super clean on air. As many have discussed the noise floor on the MX and Epic is so low.

 

[Billy Summers]

I also leave the EPIC at 800 all the time. You can shoot 320 with it, and some people do, but I've found ISO 800 to give the most balanced response. And I suppose that's why RED has picked it as the target sensitivity. If you can over-light a scene and not blow your highlights when rating at 320, then good for you... However, there's a good chance you're crushing out some potential DR in that scenario. But this really comes down to each shot and lighting setup.

I think this was even more true before REDfilmlog curve was added to the mix

 

[Ian Laurie]

I tend to stick to monitoring the RAW data, I like to see exactly what the sensor is getting. so +1 to the 320 crowd. Though The mx does make me less worried about allowing it to be viewed in REDcolor rather than raw.