As Sir John says, the light tent packs easily to travel as per photo. Hand held led lights can be used to augment as needed but I have seldom used them at the FEGA show.
You need to learn to position/tilt the engraved piece until you see no shadows on the metal and the engraving stands out. Also you may need more lights.
I don't know what kind of vision support you use...at 77 I still find an optivisor more than adequate for my engraving which is fairly detailed. I find a 'scope too confining as I like to put a little body English into the cutting.
While I do use an airgraver classic from Steve, I have used...
Here is the light tent I use at the FEGA show. I set it up on one of the unused tables and just use the ambient room lighting.
The sheet has a hole in it for the camera screen and for me to reach controls...part of the sheet drapes down between the tripod and the table and then there is a...
Michael, one of the more well known American engravers of years gone by was E.C. (Jack) Prudhomme from Shreveport. Jack authored the book Gun Engraving Review in 1960. I believe some of his work was/is at the Norton Museum in Shreveport. You might want to check that out.
Here is a snapshot to show just how much curvature the cartridge trap has which can be very difficult to get a good photo...it is propped on a penny for comparison.
No cell phone...my "smart" phone stays home on the wall where it belongs!
I use a Canon G9 point and shoot camera that I have had for years...same one I use to take photos of the contest winners at the FEGA show for The Engraver Magazine.
I have seen some really nice photos taken with cell...
Here is the kind of photo you can get with such a simple setup. The cartridge trap cover is highly curved, about the shape of a 1" pipe sliced in half lengthwise.
For your item, hold it in a candle flame to get some lamp black on it, rub off the excess and then position you eye where the item...
Here is a very simple light diffuser that I use made from two clothes hangers spread out with wood dowels across the ends and covered with freezer paper held on with tape. Here you see it hung over my vise and under a three bulb light fixture (led bulbs).
It can be just set on a table over...
If I remember right, remove the friction set screw on the side of the lower half and lift the upper out. Clean the bearings and surfaces, lube with a light grease, re-assemble and good to go.