3

Many advices say RAW files are not affected by picture control.

However, when shooting, LCD shows preview according to picture control selected.

So, in practice, when I shoot with flat mode set, histogram will be somewhat shrinked. Afterwards, when post-processing, if I change to Neutral mode, histogram will be extended in both directions. Than, I can find that shadows or highlights are lost.

The problem is even more emphasised by switching to Standard mode.

So, after I expose according to histogram that reflects Flat mode, often, I won't be able to switch to Neutral or Standard without lifting shadows/reducing highlights much.

Therefore I decided to shoot in Neutral mode, but now I'm thinking about eventually switching to Standard mode.

Exposing according to Standard mode will give me most of flexibility in post-processing, because other histograms are more shrinked than Standard (save Landscapes), but during shooting, it is harder to find exposition with Standard.

What are experiences/advices? Thanks in advance.

5

Many advices say RAW files are not affected by picture control.

However, when shooting, LCD shows preview according to picture control selected.

The "many advices" are precisely correct, so I think you maybe are not getting the meaning. The raw data in the raw file is Not affected by the camera settings (other than exposure). However, raw files also include an embedded JPG file which is affected by the camera settings. This JPG data is used to show the rear LCD preview and the histogram (which raw cannot show), but the raw data is not affected by it. The raw file is only affected by whatever settings you apply later in the raw editor. This makes them be rather different pictures, controlled in very different ways.

One complication about understanding this is if you might be use a simplest photo editor (like Irfanview or Faststone), these will OPEN raw files, but they are NOT raw editors, and they ignore the raw data and simply use the JPG data, which just means you wasted the effort and bytes of selecting to shoot in raw. That offers NONE of the many advantages of raw, so if you want to shoot JPG, then just shoot JPG.

  • ...but I'm talking exactly about exposure! – DrazenC Feb 9 '20 at 22:28
  • 1
    I read it as about the histogram, and Neutral and Standard mode, all of which applies only to the embedded JPG image in the raw file. The raw image data is something different and unaffected. You didn't say, but if possibly you might be in fact processing raw, and do plan to make exactly similar settings in the raw processing, then the early JPG histogram could be a guide (for making those exact same setting again later processing the raw). But if you're interested in the JPG data, it still seems like you should be shooting JPG. Or maybe set to output BOTH a real JPG and a raw file, if wanted. – WayneF Feb 10 '20 at 3:50
  • I'm interested to get exposure that will give me the most of opportunities in post-process, as I never shoot JPG, and exposure is based on histogram of JPG preview. – DrazenC Feb 10 '20 at 23:49
  • Shooting in flat mode is good when I know that there will not be much light, as flat histogram will show me how much I can push RAW file, to the limit. In a bright day, thing are very different, flat histogram will show me perfect exposure, but later, no matter would I change picture control or raise contrast, darks will be blown, and the only thing I can do is to raise exposure, which is very impractical if I was shooting in bright day – DrazenC Feb 10 '20 at 23:53
0

I don't really see your issue... switching to a different camera profile in post (i.e. standard) is really just a bunch of image adjustments that don't move the sliders (i.e. in lightroom).

It is beneficial to have the camera preview/review show a (more) accurate histogram/highlight warnings for the raw data; but that can largely be achieved by modifying the picture control settings. I.e. instead of just selecting the standard picture control in the camera, go in one step farther and reduce the contrast setting to the minimum.

But when you apply the standard camera profile in Lightroom the histogram will still shift; because it assumes the contrast setting was left at the default. If you want to avoid that you need to use Nikon's software which can read the actual picture control settings from the proprietary exif tags.

  • That's really not my experience. The reason for probing different picture controls in PP is my finding that picture controls act differently compared to sliders. – DrazenC Feb 8 '20 at 16:36
  • It's still just manipulating the raw data... you're not loosing anything. – Steven Kersting Feb 8 '20 at 18:10
  • When I base my exposure on flat mode, and later find that standard mode would be better, my shadows and darks fall so deep that I need to raise exposure by 0,7 or even one full stop, which is really depressing if I took picture on bright day and carefully exposed, as that will introduce noise that was not inevitable. – DrazenC Feb 8 '20 at 18:16
0

I concur with Wayne. You are making this more complex than it is. RAW files are unprocessed. Every image is flat. Even neutral is not actually flat, it is just less dynamic than other settings. Different shooting modes alter the histogram and change image paramaters automatically by applying a preset affect. There is no nuance. Editing software processes those files according to how you make corrections and/or how the preferences are set. If you are shooting RAW, simply use a RAW editor like the one that came with your camera or a PS type program and change the image by adjusting individual sliders. It sounds to me like you are putting the cart before the horse and you need to practice image manipulation in your software.

You didn't mention your camera so I am assuming it has a proper RAW mode but some cameras say they shoot RAW and they actually don't. It would help to know what you are shooting with.

0

Use a Lightmeter for Exposure

That is not meant to come across as cheeky or snobby at all, that is not my intent — but the histogram does not (necessarily) tell you if you are "filling the buckets" and really does not tell you your "exposure" relative to the RAW data.

When you change "picture settings" the RAW data is not at all affected (assuming real RAW). What IS affected is the jpeg preview, and that is what the histogram is calculated from. Thus that only shows you the exposure relative to the preview settings, not relative to the RAW data.

Buckets (simplified)

On the sensor, think of each RAW pixel as a bucket that can hold a certain number of photons of light1. Once the bucket is full of electrons, it can not take any more photons (clipping) and when the bucket is empty or close to it, it has a random number of electrons which is never exactly zero (noise). Your useable image data is between these two extremes of clipping and noise.

The way the buckets 'fill up" is linear relative to the light hitting it. Twice as much light means twice as many photons hitting the sensor and thus twice as many electrons in the bucket are stored.

Film is decidedly NOT linear in response to light, and neither is human vision, nor jpeg image data.

  • Film is essentially logarithmic over much of its range, but at the high and low ends tapers so there is a very soft clip at which and black.
  • In contrast, RAW sensor data is linear and when it gets to the clip point, it rather abruptly stops.
  • JPEG image data is usually stored with a transfer curve such as sRGB, which is approximately a power curve with a 0.4545 exponent.
  • Human vision is way outside the scope of this post, but for the sake of discussion let's say photopic vision is approx. a power curve with a 0.43 exponent.

Exposures Exposed

There are plenty of theories on exposure best practices. Ansel Adam's zone theory suggested Zone 5 (middle, 18% grey card) be exposed to 50% density, i.e. right in the middle of the exposure/density curve. This allows for the highlights to gracefully blow out with film's extended high end/soft clip, and also retain enough density in the negative for the dark areas of the image.

But zone 5 should definitely not be at the 50% point of "buckets full" on a CCD, as the "data in the bucket" is linear to light. A 1:1 relationship would mean an 18% luminance would be a bucket that is 18% full (or 82% empty for the pessimists... 😆)

But setting the 18% grey card so that it is 18% in RAW data may be correct, as that can still result in poorly clipped highlights depending on the subject matter, or the corollary of too much noise for the darker areas of the image it that is more important than highlights for the given subject.

Picture Settings

The various preset picture settings are just ways the manufacturer to debayer the RAW data into a useable image, weighting the highlights and shadows differently. None of these affect the RAW data, but the settings do affect the histogram, and how highlights are clipped/rolled off and black is handled.

The distance between where the white level soft clipping starts, and the hard clip of the sensor (full bucket) is a headroom the manufacturer chose based on their ideas of how an image should look and feel (i.e. Nikon, Canon, Sony all have different ideas here — Nikon seems to under-expose the sensor to preserve more highlight data, and as Nikon sensors are excellent in low noise they have plenty of room to do so).

The implication here is that the histogram is not necessarily telling you exactly how full the buckets are. Thus, their utility as an exposure reference may not be ideal.

So with RAW it comes down to:

  • At what point can you tolerate the hard clip of highlights.
    • Consider how much headroom you want above where you'd like to start rolling off highlights, to the "brick wall" of "full".
  • How much noise can you accept in the darker areas.

If you can make a custom "picture setting" so the histogram shows you this information in a way that's valuable to you in your workflow, that might work. But I'd be cautious of "standard" or other presets.

Meter Reader

Personally, I much prefer to use a Sekonic and meter to find the exposure the old fashioned way. If you are going to use a meter, I do recommend finding how the meter correlates to the camera's brick wall highlight clipping point — meter and shoot a white card increasing the camera's exposure in 1/3rd stops till you find the point the RAW data clips at least one of the channels.

Then make a note as to how the camera exposure settings at that clipping point relate to the reading on the meter. A useful target setting for shooting then is a nominal exposure with an 18% grey card at least five stops lower than that clipping point. Seven stops is probably better if you have highlight details you want to preserve.

I find I shoot about a stop darker per the camera's standard preview image so I boost exposure in post in Lightroom — I prefer this as it gives better control for how highlights are handled, and I hate losing highlight detail if I can avoid it.

Footnotes:
1) The "bucket" does not actually hold photons, but when the sensor's pixel is hit with a photon, it creates a charge by knocking free one or more electrons. The "bucket" can hold a certain number of electrons.

0

The processed JPEG is produced from the RAW data, so whatever settings you use that manage to produce a good JPEG will retain the necessary data in the raw file for producing a similar-quality JPEG in a raw processor. Not necessarily with default settings, but shooting raw with the intent to only use default settings does not make a whole lot of sense.

With regard to getting best results, the main idea would be to maximise exposure without blowing highlights. At different ISO settings, the relation between a JPEG file blowing highlights and a raw file blowing highlights will tend to be different, so it makes sense to experiment. With some sensors (like the Sony Exmor family), most ISO settings (apart from extended ISO) don't actually influence absolute noise levels in the raw file but instead only affect the metered exposure and its compensation in camera JPEG processing. If you are using the raw file anyway, the ISO setting is almost exclusively about your comfort level when metering on such cameras.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.