Calibration

[ChrisLumix]

Let me begin by shocking BP - by agreeing with him. Yes, calibration IS important .. as a starting point. If the white point and black point are way out, for example, then everything will just look wrong. So let’s start by agreeing on that. Now I'm going to invoke three other things to explain what I meant in the other topic : exposure, car tuning, and film.

 

Exposure.

Yes, there is such a thing as ‘the correct exposure’, as long as we understand what that means : it means the exposure is correct for a 50% grey card. However, there is a lot of variance from that mid point. Someone may choose to massively under-expose (for only the highlights, say) to create a ‘noir’ effect. Someone else might choose to only hint at shadows by massively over-exposing, and thereby create a ‘high key’ effect, or achieve the same thing in post-process. ‘Correct’ exposure is an average, using an industry standard measuring tool. We don't have to stick to it.

 

Car tuning.

I don't know if any of you are old enough or experienced enough to have done this? Back in those primitive days before computers, you would rotate your crankshaft until the pistons were at Top Dead Centre (TDC) then set the distributor a few degrees away from that. At that point, the car was ‘correctly’ tuned. However, that was a compromise, albeit one that non-mechanical minded car owners were happy to abide by. It provided the best balance between economy and performance. 

However, you could - if experienced! - adjust the distributor more, in either direction. One adjustment delivered better economy but worse performance, the other delivered the opposite. But too much adjustment either way meant the car wouldn't run properly at all. The main point though, is that ‘correctly tuned’ was - like calibration - a midway compromise between a range of options, though the range itself had to be respected.

Which leads me on to the most important point :

 

Film.

Were films calibrated for ‘correct’ colour? Manifestly not, as BP has demonstrated in his topic ‘Pick a colour’. Each manufacturer had a different bias : Ilford were often regarded as too blue, Fuji as too green, Agfa as too red, and Kodak somewhere in the middle (though there were those who said Kodak’s greens weren't true enough). And that’s the point. Films would deliver good results within a certain range. The film you went with depended on what your own bias (or even eyesight) was; I tended to favour Kodak until Fuji brought out Reala, but for transparencies it was Kodachrome all the way. None of these films were ‘correct’ - how could they be? all being different, even within one manufacturer - but they all delivered within an industry-defined range.

And those who processed in black and white as I did for a few years, had even more latitude. The different qualities of different papers, not to mention films and developers, was staggering. Take contrast as one variant : you could pick from very low contrast which gave highest detail in both shadows and highlights, all the way up to strong contrast, where detail was lost in shadows and highlights, but a lot of drama was added. None of this was ‘correct’ : there was simply a mid-point and you could vary away from that in either direction, sometimes to dramatic effect.

 

So to summarise : calibration is important especially for displays that are way out. But having calibrated to the industry standard median, it’s then perfectly acceptable to vary away from that, as long as it’s within a certain range. In other words, too much variance will produce ever more distorted visuals, but within that range there is no ‘correct’ or ‘incorrect’, merely subjective personal taste.

[ChrisLumix]

bump

[Craftysnapper]

Chris strangley enough you have hit on a pet subject orf mine.

Humans do not see colours correctly,why, because we have a utomatic wb in our brain,our brain filters out colour casts. When there is a warm light from a sunset we do not see those very warm orange hues in a white shirt but a white shirt,thats the auto wb working just as ity does in the cameras we have built to mimic what we wrongly see.

And then you have to ask yourself do we all have the same auto WB in our heads?

Edited January 11, 2016 by OlympusPaul

[ChrisLumix]

10 hours ago, OlympusPaul said:

 

And then you have to ask yourself do we all have the same auto WB in our heads?

I would say no! We're all different - physically, mentally, emotionally. But for most of us it's within the range that the film manufacturers encompassed with their different biases.