CineEI is not the same as conventional shooting.

I’ve covered this many, many times before, but so many people still struggle to get their head around using the CineEI mode in a Sony camera.

Shooting using CineEI is a very different process to conventional shooting. The first thing to understand about CineEI and Log is that the number one objective is to get the best possible image quality and this can only be achieved by recording at the cameras base sensitivity. If you add in camera gain you add noise and reduce the dynamic range that can be recorded, so you always need to record at the cameras base sensitivity for the best possible “negative” or captured image.

Sony call their system CineEI. On an Arri camera the only way to shoot is using Exposure Indexes and it’s the same with Red, Canon and almost every other digital cinema camera. You record at the cameras base sensitivity.

It is assumed that when using CineEI that you will control the light levels in your shots to levels suitable for the recording ISO of the camera, again it’s all about getting the best possible image quality.

Then changing the EI allows you to tailor where the middle of your exposure range is and the balance between more highlight/less shadow or less highlight/more shadow detail in the captured image. On a bright high contrast exterior you might want more highlight range, while on a dark moody night scene you might want more shadow range.

EI is NOT the same as ISO.

ISO= The cameras sensitivity to light.
EI = Exposure Index.

Most cine film stocks had both an ISO rating, where the ISO was the laboratory measured sensitivity and an Exposure Index which was the recommended value to use in a light meter to obtain the best results in a typical practical filming situation. More often than not the ISO and EI values were slightly different.

EI is an exposure rating, not a sensitivity rating. EI is the number you would put into a light meter for the best exposure for the type of scene you are shooting or it is the exposure value of the LUT that you are monitoring with. The EI that you use depends on the desired shadow/highlight range and it is more often than not unwise to raise the EI in a low light situation.


A higher EI than the base ISO will result in images with less shadow range, more highlight range and more noise. This is not what you normally want when shooting darker scenes, you normally want less noise, more shadow range. So with CineEI, you would normally try to shoot a darker, moody scene with an EI lower than the base ISO.

Screenshot-2022-02-11-at-10.15.43-600x270 CineEI is not the same as conventional shooting.
In this chart we can see how at 800 EI there is 6 stops of over exposure range and 9 stops of under. At 1600 EI there will be 7 stops of over range and 8 stops of under and the image will also be twice as noisy. At 400 EI there are 5 stops over and 10 stops under and the noise will be halved.



This goes completely against most peoples conventional exposure thinking. But the CineEI mode and log are not conventional and require a completely different approach if you really want to achieve the best possible results. If you find the images are too dark when the EI value matches the recording base ISO, then you need to add light or use a faster lens. Raising the EI to compensate is likely to create more problems than it will fix. It might brighten the image in the viewfinder, making you think all is OK, but you won’t see the extra noise and grain that will be in the final images once you have raised your levels in post production on a small viewfinder screen. Using a higher EI and not paying attention could result in you stopping down a touch to protect some blown out highlight or to tweak the exposure when this is probably the last thing you want to do.

I’ve lost count of the number of times I have seen people cranking up the EI to a high value thinking this is how you should shoot a darker scene only to discover they can’t then make it look good in post production. The CineEI mode on these cameras is deliberately kept separate from the conventional “custom” or “SDR” mode to help people understand that this is something different. And it really does need to be treated differently and you really do need to re-learn how you think about exposure.

The CineEI mode in some regards emulates how you would shoot with a film camera. You have a single film stock with a fixed sensitivity (the base ISO). Then you have the option to expose that stock brighter (using a lower EI) for less grain, more shadow detail, less highlight range or expose darker (using a higher EI) more grain, less shadow detail, more highlight range. Just as you would do with a film camera.

13 thoughts on “CineEI is not the same as conventional shooting.”

  1. Dear Alister,

    Thanks for your article.
    I’ve been working with Cine EI for many years now and I think I’ve understood it, as you’re explaining it here.
    Just one thing though: I don’t get why you’[re talking about lower EI, say like 400, while when shootings in EI mode, (I’m using the FX6), there’s only two possible modes, right? 800 or 12600. Why one would use a different one also, as these are the only two native EI ?

    Thanks for this last clarification… but image wise, I’m very happy with Cine EI and use it all the times, without issues. I’m asking here to have a complete and crystal clear understanding. Yet never matching yours, obviously… 🙂

    Best regards,
    Federico

    1. I would respectfully suggest you don’t understand Exposure Index and CineEI.

      There are 2 base ISO’s 800 and 12,800 on the FX6. These are the base ISO, the base sensitivities.

      There are many different EI’s on the FX6. Depending on the highlight/shadow range you want you use a lower EI than the base when you want a greater shadow range and less noise and a higher EI when you want more highlight range but can accept more noise.

      EI and ISO are NOT the same thing.

      See: https://www.xdcam-user.com/2020/12/a-guide-the-the-fx6s-cineei-mode/

      1. Thanks for your swift and honest answer Allister.
        I recall you telling me about the fs7 once when we had a one to one chat in 2017, I was in Japan, that basically there were no points in playing with different iso settings (or EI now) as the sensitivity of the camera was 2000 and it was just the way images were recorded. Using different EI or ISO would only make the DOP adjust the light. You used the comparison of the radio receiver/sensitivity and volume change, I also recall. That made all sense then and since then
        I’m happy with all results I get, so in a way, all good here.
        But for the sake of theory:
        Basically what I understood from your explanation that day was that varying the iso or ei was only useful if shooting in custom mode. And also with the fx6 now, I’d say that if not using a LUT, then changing the ei has no effect whatsoever. If using a LUT, say in the VF only, then yea sure, one will add light to the scene to get the a correct lighting if switching from ei800 to ei 400. I get that. But if recording slog3, well.. what is recorded will be the same if it was correctly lit using slog3 as a reference and no LUT.
        That’s why I’ve now got used to expose my scenes in slog3 and rarely use a LUT.
        Does that makes sense..?

        Thanks!

        1. You cannot change the EI in custom mode, because in custom mode there are no LUT’s and EI only changes the LUT’s. EI is NOT ISO.

          EI is only applicable to the CineEI mode and changing the exposure Index alters the brightness of the LUTs. When you then put the new EI value into your light meter or expose via the EI adjusted LUT the brightness of the exposure will change according to the chosen EI. The brighter/darker recordings alters where the middle of your exposure range is and this allows you to carefully and precisely control the highlight range v the shadow range as well as how much noise you have in the final graded image. This is a very important part of working with log as different scenes will be best exposed with different highlight/shadow/noise priorities. A bright sunny scene will often benefit from a lower brightness exposure to allow for the greater highlight range, while a darker interior scene may benefit from a much brighter exposure to provide less noise and increased shadow range. While you can guess at this and assume that a higher or lower exposure may or may not work, CineEI allows you to see visually via the offset LUT how the higher or lower exposure is going to look.

          The big benefit of log is that you can expose it brighter or darker to suit the scene and how you want to distribute the data within the recorded image. Then in post you can compensate for the chosen offset exposure without impacting the contrast and desired look and you have the very best shadows or the very best highlights depending on what you need. EI is the tool you use to do this in a simple, efficient and repeatable manner and the viewfinder image, LUT’s and light meter will all be on the same page. Shooting every scene whether bright or dark, high contrast or low contrast at just one level with S-Log is not always going to deliver the optimum results. You need the flexibility to fine tune where the bottom/middle/top of the exposure range sits and this is what CineEI allows for.

          1. Yes, I actually think that’s what I liked the most ftom your article, firstly. -> the explanation about where the range of stops shifts according to the set ei.
            For the rest, I think that what you explained to me back in 2017 still makes sense and I’ve been using that knowledge proficiently until now. Maybe I’m just not able to describe it with the right words in theory but practically it works and I feel I know where I am.
            So thanks for that then and for thanks now for this new knowledge about the shifting stop range. I’ll use it in my next shoots. Since I’m now quite used to expose looking at the slog3 image and it’s my preference, I might actually not use a LUT but will expose a bit brighter to gain stops in the dark areas and oppositely.
            Thanks and happy weekend!

            Federico

  2. Hey Alister,

    So please correct me here. Looking at this from the film world. Shifting CineEI is just shifting middle grey. Placing it at a different place for a different look?

    So on my F35 18% grey is not actually where I want to place it the exposure.

    Using false colours.

    I place on SLOG 2 at 32%, but for Slog1, the same look is achieved at 45%. Yes this shifts my middle great, but base ISO is still the same?

    So for Slog1 to match Slog2 we can achieve same look, at different CineEIs.

    1. Yes, just middle grey up and down to alter the highlight and shadow range.

      But this isn’t really giving a different look, just shifting where the middle of the exposure range is. The “look”, if we consider the look to be skin tones, contrast, saturation etc remains the same, just with the bias towards highlights or shadows altered.

      1. Well, if we are trying to match cameras, it gives a different look, no?

        And vice versa, for the other camera to match, we would have the shift their CineEI to the same location?

        1. If the correct offset for each EI used is applied in post then clips shot at different EI’s will not look different other than the clip point and black point. This is the whole point of how this works.

  3. Hi Alister,

    I’m new to the F5 and just wanted to clarify something about the Cine EI mode.

    I understand that the camera is rated at 2000
    , and that’s fixed upon recording. The EI toggle is for monitoring purposes only.

    I’m recording internally only to SXS, with the MLUT internal ‘baking in’ set to off.

    If I wanted to rate the camera lower, so view with say the EI preview turned down to 800, and effectively overexpose the SLog recording, how would I be able to view the correctly adjusted footage in my NLE? Do I just need to use a specialised compensatory LUT?

    Is this practice of rating the camera lower something that’s an option when recording internally to SXS with Slog?

    I’m concerned that this may be something only achievable with a Raw file? I mention this as with RED footage (which I’ve had some experience with) in the past, this has been able to be achieved by simply sliding (what they call an) ISO slider in RED Cine X. I wondered if this was also the case with the Sony Raw workflow?

    Many thanks.

    1. You will often find LUT’s available with offsets for different over/under exposures. Otherwise you can alter the gain of the clip prior to the addition of the LUT. In Sony’s Content Browser software there is an ISO slider that you can use in exactly the same way as you would with a raw file.

  4. Greetings. Thanks for the articles, I recently purchased fx6 and thanks to you, I figured it out. Question – I understand how and why the lowering of EI relative to the base value of iso works – to make a study in the shadows. And for what purposes is it necessary to raise EI relative to the base iso? When shooting in sunny weather?

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