Import Settings

Side note…If the only reason the meetup required shooting a color digital camera with a red filter was to understand how black-and-white film is visualized and shot through the viewfinder with color filters, then OK, that can be an important exercise.

But just to make sure you know, if you shoot a color digital camera with the intention of having the most control over the B&W tones, it’s much better to shoot without a filter and apply B&W techniques in post. It’s like being able to try, and combine, different color filters on the image long after the shot is taken. And you also get to apply colors that you can’t buy as a filter. Some advanced B&W digital techniques are based on this, like in the following videos that take advantage of gradient maps and raw profiles. The only way to achieve the extreme control they show over B&W tones is if you record a full color image.

Of course if you shoot in color for B&W, the viewfinder shows color and that is a problem for B&W visualization. Some cameras have a preview mode where they show B&W on the camera while still recording a color raw image, and that is the best way to shoot for the advanced B&W techniques above. I don’t know what it’s called on a Canon, but my camera calls it Monochrome Preview.

I agree with Wobert's post, if you must have the Camera B&W rendition then shoot with your camera settings to capture Raw + Jpeg. So you will have two options your cameras and Adobe's.

In LrC-This setting "Treat JPEG files......." in General Preferences has to be checked 'on' for LrC to Import (and show) both the raws and jpgs in the Library.

If it has not been checked- you can make it checked, then you will need to Import the JPGs using the Import dialog (or the Folder 'Synchronize' function).

the RAW files were colour only

That is always normal!- The raw image files are the raw data from the camera sensor, and YOU then edit (in the Develop module) in LrC, to see the images as you intend, perhaps by a B&W Profile, etc.

with a red filter

So if you placed a 'Red' filter on the lens when shooting- then your raw image files would be shown as red only in the Library, and you only have the 'red' color channel to work with.

You will always have a greater range of B&W adjustments if you edit a raw image (that contains the three RGB channels- without the lens filter!). And you can replicate the red lens filter with development functions in LrC.