Black and white and rendering intents

[Majohnson]

Hello

I currently use Lightroom and have a few questions regarding rendering intents, black point compensation and black and white photos.

Is the rendering intent (perceptual or relative) relevant for printing in black and white when printing with a paper profile. I assume it is not relevant when using the Epson ABW driver.

I notice that with the majority of my prints when soft proofing with perceptual rendering intent appear brighter and often slightly warmer for black and white prints.

I appears that when soft proofing unlike in the develop module, the histogram shows the colour break down. Does this mean that the rendering intent is still applied to the underlying colours even thou we are processing the photo as a black and white.

With regards to black point compensation, if yo are printing on a matte paper for instance that can only print a certain black level say L = 14, is there any benefit in adjusting your tone curve to reflect that achievable black point with a certain type of paper or will black point compensation just take care of everything? Would the answer differ if using the Epson ABW driver instead of a paper profile?

Hopefully I am explains myself correctly. I'm just trying to understand how all of this works. I know I probably don't need to but I find it fascinating.

Regards
Mark

[Mark D Segal]

There are several ways of getting to B&W within LR. What specific conversion approach are you using?

[Majohnson]

Hi Mark

I am selecting Black and White in Lightroom so I can adjust the colour channels in the HSL / Color / B&W section. I do not de-saturate my images.

I am happy with how I process my black and whites, it is just i didn't expect there to be any change when changing the rendering intent when printing as I was wanting to print Black and White.

I understand the difference between perceptual and relative rendering and how it handles out of gamut colour, i just didn't expect the black and white preview to change in soft proofing. The fact that things did change might suggest that I may not know exactly how the rendering intents function with regard black and white.

I typically print using the Epson ABW driver but have been testing printing to matte paper using paper profiles in lightroom

Regards
Mark

[Mark D Segal]

I think all that's happening is that the underlying colours affect the B&W tonal rendition, so to the extent the choice between Relative and Perceptual changes the manner in which in-gamut and OOG colours are handled relative to each other and from there the appearance of the underlying colours, the B&W tones corresponding with those colours would also be modified, accounting for the differences you are seeing.

[Majohnson]

Thanks Mark. That makes sense.