How to Process Glass Plate Negatives in CaptureOne Cultural Heritage. From .iiq RAW format to workable inverted TIF.

Hi there!

This may be a really rudimentary question for a lot of people so I'm sorry in advance! but I wanted to make sure I was following the best process I could with these images. 

We have been given the chance to start working with .iiq files directly as opposed to being sent TIF files from the archive we work with, however, when I invert the images are coming out incredibly washed out. The images we are working with are from the late 1800's/early 1900's can sometimes have that quality until they are edited in post, but they seem... worse than usual?

Request:
Would someone familiar with the software be able to give me a brief run down on the process of inverting, and processing to .TIF a .iiq file taken from a glass plate?

Material: .iiq RAW files of glass plate negatives taken with a Phase One camera system.

Outcome: Editable TIF files. Inverted from negative to positive in black and white.

Additional Question:
The images have a purple cast (a product of the camera I imagine) Being these are black and white images, is there a best practice for conversion?

Thank you so much, and I will keep an eye out for your replies!