6k footage in 4k timeline

sorry all quick questions

i am shooting on the 6k pro - at 2.4:1 (6144 x2560)

I want to edit this in a resolve 4k timeline - to make sure the image fits 100% whats the correct aspect ration /resolution need to be ?

2.39 4096x1716

or

2.40 4096x1706

If you're going for the DCI standard it should be 2.39.

Image scaling should be set to 'Scale full frame with crop'.

If you have playback issues due to system limitations, you could make your timeline 2.39 at 2k or even HD and go back to 4k for your deliverables.

Sorry, I just re read your post and saw that you're shooting at 6144 x2560, which comes out to 2.4:1

Does the camera actually shoots at this aspect ratio or are these just guides on a bigger container?

If it's just guides, you can just go normally as I described before.

If that's the actual size of the image and you wanted to conform for the standard, like for example if you plan to make a DCP down the line, you might have to choose "Scale entire image to fill" to get rid of the thin black lines on top and bottom.

The DCI spec is 4096 x 1716.

The DCI spec is 4096 x 1716.

Thanks- i have used this aspect ration but when i pull in my 6k footage and set the input scaling to "scale entire image to fit" their still seems to be tiny black bars at the top and bottom - as if the 6k footage does not confirm 100% to this resolution?

It's very likely it doesn't. Even the Pocket 4K records at 4096 x 1720, four more lines than DCI spec.

Normally, you just Crop those lines out. Use Scale full frame with crop.

nowadays iss not uncommon to have out of aspect masters anymore.
the container is the same (4096x1716) bu tthe actuve image can be slightly different.

you have three choices:

1) 2.40 4096x1706 for the timeline and you will fit that in export to a 4096x1716 with few lines of black. the master will be flagged and you will kick back "intended photography".
2) DCI spec 40961716, instead of "fit" you "crop" the original material losing few lines left right (the safer option)
3) DCI spec 40961716, "fit" but then you stretch 1.01 vertically to fit. while this looks strange, i saw it done successfully on some movies to make everybody look "slimmer". (see "the great gatsby" for example, we stretched between 3 and 7% the trailer...)