Shutter Speed Adjustment On TVI Cameras?

That's a good question. In the models I've tested (nearly all Hikvision), it's been an option. 

We show it in this video from our Hikvision HDTVI Camera Test (about halfway through).

What manufacturers/models are you using that you don't see it on?

We’ve been trying a Hik OEM LTS and virtually none of these have the shutter option. Get what you pay for I guess. Strange that this would be missing on what are essentially Hik clones. 

Thanks Ethan