What EF lens for taking pictures inside a railcar?

[strantor]

Hello, first post here. I am building an automated inspection camera around a Canon EOS 5D MK IV. This is what it looks like:



It will be used to take pictures inside of bulk tank railcars. The environment where pictures will be taken looks like this:



In the first video, the camera is resting in a display stand that simulates the hatch openings that are seen in the second video. The camera will be used to take pictures of the inside of the railcar to document the presence or absence of dust which you can (hopefully) see being blown off the walls in the second video. The dust can be very fine, so a good camera is required. That is why I'm using the camera that I'm using instead of one that might seem more suited to the task (go pro, industrial camera, PTZ camera, etc.).

The camera will need to look up at the ceiling of the tank, along the walls, and all the way down at the bottom. Nearest target might be 2ft away and furthest might be 10ft away. What lens do you recommend for this application?

Or any other advice that I don't know enough to ask about is welcome. I am a photography noob. Maybe I'm barking up the wrong tree entirely. Don't hesitate to set me straight.

Thanks!

 

[ac12]

The autofocus may not work in that situation.
Usually, autofocus needs something of contrast to focus on. Example, my cameras won't focus on a plain mono-color shirt.

 

[strantor]

The autofocus may not work in that situation.
Usually, autofocus needs something of contrast to focus on. Example, my cameras won't focus on a plain mono-color shirt.

Does that go for any camera or just the one I've chosen?

 

[ac12]

Does that go for any camera or just the one I've chosen?

I have not used MANY cameras, so I can't say for certain.
But I have run into it enough that you better TEST it.
dSLRs use optical focusing, not a laser rangefinder.

Maybe you can project a grid, then focus on the projected grid.