The OP also wants to handle one so as to see what feels best in his opinion...Can't touch them when you shop on Amazon...

There is no software that can't be defeated. There are several programs for watermaking photos (I use Picasa since it's free), but it's best to put reduced resolution copies out on the web (800 pixels on the long side max)

As the title says , I just joined & have posted on a few topics. Been shootin for 40+ years, currently using Nikon. I moderate on several other forums, mostly on using older MF lenses on Nikon DSLR's. I've got well over 100 lenses in AF & MF iterations (mostly Nikon but also Yashica,Minolta,Konica & M42) as well as older film cameras...Live in North Georgia. Soon to retire from my day job

I used to be in the Paulding County Photo Club & when we went to the North Georgia "Shootout", there were vendors on site that had their latest & greatest gear for everyone to see (& buy)...Depending on what brand you want to buy, you might contact Nikon, Cann or whomever else & ask them what local stores would have whichever DSLR it is that you want ,in stock, for you to look at...BTW, Stores likle Best Buy & Brandsmart do have some DSLR's on display

I've found that all of them affect the sharpness in the image after being applied. I try to get the exposure right to avoid having to use one...

I use many old lenses on my Nikon DSLR. I've got well over 100 lenses in several mounts (mostly Nikon though) in both AF & MF iterations.My favorite is my Lester A Dine 105mm F2.8 macro, it rarely leaves my camera. The older lenses are an inexpensive way to acquire different focal lengths without breaking the bank...BTW, Vivitar did not manufacture anything. They were an importer/distributor & had other s make their products (still do). It's likely the serial # will give an indication of who made the lens for Vivitar

You need to use a Linear polarizer in conjuction with a Circular polarizer to do this & IMHO, you are better off with a variable ND filter.