Using a value-finder for self-portraits?

[Minh Thong]

As a beginner, I have been trying to be as methodical and as precise as possible when choosing hue, value, and chroma of colors in a portrait. So I am trying to learn how to properly use a value finder. I have a laminated two-inch wide strip made from store-bought paint chips in grey-scale values 1 thu 9. Each value section - which is roughly 2" x 2" - has a hole punched in the center through which the subject is compared to the chip.

Typically, I am standing in front of a mirror with my easel and a table on my right, and I use my left hand to hold the scale up to specific planes of my face (in the mirror) to judge a value. Then, I refer to the appropriate hue-row of my homemade Munsell/Reilly color charts to find the value of the plane I am working on, which gives me a starting point to work from. The the next plane/feature and so on.

However, I am having a hard time viewing the subject thru the hole in the value card. There are all kinds of distortions due to the mirror which makes it difficult to judge the value.

I realize that most professional portraitists probably no longer use a value scale, having developed the ability over time to judge these things with the eye. But for novices, is there a trick to this?

Also, when using a value scale for a portrait other than a self-portrait, do you walk right up to the subject and hold it close to his or her skin, or view it from a distance?

Thanks for the assistance,

Minh Thong