Polarized light and retardation plates doubt

[martinprieto]

Hello,
I've been wondering if there is any difference between placing retardation plates between polarizer and condenser or between the objective and the analyzer, so I tried both and I have not seen a difference.
I've seen that they are usually placed between the objective and the analyzer but my logic tells me that it should be better for image quality not to place it there. So, Does anyone know the reason to use this setup? I'm sure there must be some...
Thanks in advance for your answers.

[wstenberg]

OK, I don't know the answer, but at least one of my Zeiss condensers has a slot for a retardation plate. I have never actually tried to use it. Maybe I will experiment with it.
I think image quality would be the same, as long as the plate is not coincident with the specimen conjugate plane. I'm interested to hear what others have to say.