I have this picture I took with my Fuji X-T1 in JPEG Fine. I wanted to print it for a relatively big frame in black and white, so I converted it to B&W in Lightroom, exported it and sent it to a printing lab.
I got a call from them saying that when they try to print it, their software gives a maximum print size of 20cm wide, if they go larger it gets "pixellized" (their words). I looked at the file again (the exported one, outside of Lightroom) and it's 4896x3264 pixels. When I zoom in at 100% the details are crisp and the image is more than four times the size of my screen.
We tried to share the file through a bunch of different platforms to eliminate any unwanted compression - same. I eventually sent the lab the original color JPEG which they converted themselves to black and white and it suddenly worked for them.
The only setting I had specified when exporting was the resolution of 300 that was already there. When looking at the image details on a Mac, it says resolution 72x72 for the non-exported straight out of camera image and 300x300 for the exported one... Makes sense for the 300x300 but rather counter-intuitive int terms of what they could or could not print - until I came across an explanation of the Resolution setting in Lightroom which only seems to be indicative metadata. So probably their software didn't pick that up.
Is there an implicit export setting in Lightroom that could cause that type of problem?