PhotonsToPhotos does the Canon EOS R5 Mark II and it’s good
- Thread starter Richard CR
- Start date
That’s not really how it works. To achieve what you have just described you’d need a scene with a large EV range, let’s say 12 from the brightest highlight to the lowest lowlight. Assuming both cameras are 14 bit digital and you have taken a spot meter reading from the brightest point, overexposing from the meter reading of say 3.5 stops - the highest highlight your two cameras can record. (Aka the zone system principle).
The recording of black or grey would depend on the profile curve applied to the converted image, and if the black point on one is raised to hide electronic noise. Without that profile they’d both record the grey, but the one with “lower DR” ( think say Canon 5DII vs Sony A7) would include some rather unpleasant blotchy colour noise. The higher DR camera would also include colour noise, but it would be finer and less obvious, and so people shout hallelujah and claim greater dynamic range. Also that kind of noise is easier to eliminate with NR and so some people said, in 2012, we’re all going to switch to Sony and Canon will never sell another camera.
So all these cameras have the same dynamic range, it just depends on where you draw the line with acceptable shadow noise, and how much that can be cleaned up - look at Canon now applying subtle NR to deep lowlights to gain a higher “DR rating” and everyone is over the moon.
If you want to see real dramatic dynamic range try shooting modern negative film. Here you can correctly expose for the shadows, and so keep optimal tonality, and allow the highest highlights to be 8 stops over a reflected 18% meter reading ! Now that is a significant increase in dynamic range.
So to go back to your original piece; if the limitations of a sensor means that the black point has to be lifted to hide colour noise then assuming the brightest highlights are in the image too, you’re going to have full white to black contrast in a more compressed range, and tonality may suffer compared with a sensor where the black point can be much further down the range of the 14 bit sensor.
I should add; all these DR arguments have been basically over lifting black, hence the craze around 2012 for taking pictures with the lens cap on, and then lifting the image to see what it looked like. So pretty much any camera I can think of from the past and present would be able to define your grey, unless you were taking a purposely underexposed image, and even then the points I made above would be relevant.
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I believe you are asserting more DR = less contrast because you are not considering HDR displays but only standard displays with a limited dynamic range.
If you want to show all of the detail in a high contrast and high dynamic range scene on a standard 8 bit display… In that scenario yes, the overall image will have less contrast if you tone map the details to the standard 255 brightness points of an 8-bit display. In this scenario, the brightest whites and darkest shadows will be reduced to fit within this tonal range. The high DR of the sensor will just allow those details to be enhanced, mapped and displayed cleanly for that limited brightness range. Ultimately the display has become the limiting factor for the level of ‘contrast’ that can be displayed - not the sensor.
Now once you factor in a proper HDR display with a correctly processed HDR image or footage, the dynamic range of the original scene could be captured and then displayed with the same high contrast between dark and light brightness values but with the detail maintained cleanly.
As HDR screens and camera sensors get better and better we will be able to display higher dynamic range scenes in a more ‘lifelike’ way and with much higher contrast between light and shadow areas.
Example - a patch of sunlight on the grass in a landscape photo could be displayed 10x brighter than the shadow areas of the grass, but both would still have a level of detail more similar to what we see with our eyes in real life. A great, high DR sensor would be able display these details cleanly / minimal introduced noise.
The DR of a sensor is really how much of the extreme brights and extreme darks can be captured in a single exposure cleanly. The way you then display them then ultimately determines the contrast ratio between those bright and dark values.
It would be more accurate to say more DR = a more flexible raw file. A higher DR sensor captures more detail in a scene with a higher contrast ratio in brightness values.
It is never a negative to have more flexible files.
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