Not sure about this statement. Isn't a screen with high max brightness more likely to use panel blocking at the lower end than lower "max brightness" screens? If so than it'd be the other way around.
Its at least my impression that black level will always be linear to the intensity of the backlight, such as you have 0.15 black point @ 100CD/m2 max you'll usually have 0.30 black point at 200CD/m2 max, contrast remains the same unless there's some "cheating" involved. This is true for all the reviews I've read anyways, expect those that use panel blocking to reduce brightness, but those are very obvious and usually commented.
Unless you're taking ambient lighting into consideration ofc, then brightness obviously becomes a factor.
i can see your point, i should have taken a bit longer to elaborate on my reply yesterday really
yes, in theory the contrast of a screen
should remain pretty constant while you adjust the brightness from 100 to 0%, and this is where "contrast stability" measurements come into play in reviews. Some screens (eg the Hazro models) are different though as they have no way of regulating the backlight intensity, and so contrast varies massively as you adjust the so called brightness control.
I suppose in a way, maximum brightness makes little difference to contrast since you are probably going to want to calibrate the screen to a decent level anyway and contrast should remain static hopefully once you've done this.
what i meant from the previous reply was that manufacturers often have higher max brightness in order to produce a higher contrast ratio. ie, if you have a screen with 250 cd/m2 (like the Samsung 971P for instance), you have to have a very decent low black point (0.16) to be able to offer a contrast ratio of 1500:1 as advertised. Other manufacturers get away with having worse black depths, but are able to offer high contrast ratios by having a high max brightness. for the Samsung 971P, if they'd had a max brightness of 500 cd/m2, they could have gotten away with having a panel which didnt need to show as low a black depth (in fact twice the value it needed to be) but still offer 1500:1 contrast ratio.
yes, the black depth is linked to brightness and backlight intensity anyway, but panel technologies and other electronics also reach their limits in many cases so this is a way of offering a higher contrast ratio, especially when it comes to advertising the screen. hard to explain it, hope you see what i mean