The more powerful the light, or ability to see long distances in dim light, the better. Had a cheap one at the previous job and it was just about useless after a few feet in the dark even with the 4 LEDs on full brightness.

If there was some feature to tell orientation that would be useful, but not necessary.

Professional and Structural Engineer (ME, NH, MA)
American Concrete Industries
www.americanconcrete.com

SLTA....since you would be using this yourself and can control the care of the equipment, you could consider a higher end videoscope, but the entry level of same. A FLIR VS70 or Extech HDV600 are two pretty good ones. Those will run you somewhere around $2000 for the entry level.

If you want to go a lot cheaper, Extech has one for $275 or so (BR-250), that will probably do the trick for your applications. We have several different borescopes....all are difficult to use! We have a couple of Olympus Industrial Borescopes which are very good for looking at things, but they don't have video capability and the cost to adapt them for that is astronomical! We have a little cheapy General Instruments scope but no recording capability. We have the BR-250 and that one seems to have the greater application flexibility but as TME noted, the lighting is limited. The video records OK in low light though.

Good luck.

Ryobi has one for about $100 that attaches to a smartphone. Dunno if it is worth a damn, however. Has anyone tried it?

In 2015 I purchased a very INexpensive endoscope to trial some video/photo inside unbonded PT sheaths (after the strand was removed).

I purchased a $20 one from Amazon. Link

It has a 15' cable with USB that connects to your computer and uses the Windows video/photo software to capture the images. The endoscope has 6 small LED's that are brightness adjustable. The diameter the camera head is about 6mm.



Here is an image inside the stressing-end anchorage of the tendon, about 12" inside the transition sleeve. The RED circular object is the PT HDPE sheath of about 1/2" ID. The hazy substance is grease. The image quality was as good as I expected for $20!

I attached the cable/head to a small 3mm dia steel wire to have control on the camera direction/location.

Do I hear cheap colonoscopy?