Never could read my negs - and still can't after all these years. My contacts are all done Grade 2, minimum exposure / maximum black and help me keep an eye on my entire process. I use a channel on my analyzer to meter between the frames and the enlarger set exactly the same each time - same lens, same aperture, same height and same lens extension. If there's a variation in the reading it gives me a heads up that something's changed. First thing I check on tee proof is the frame numbers and writing - the writing should be very clear and the clear film shouldn't be distinguishable from the black surround. If not there's something wrong with the process. Then the photos. Those negs that that are incorrectly exposed are really obvious and indicate a metering error. I can then work out what it was I did wrong. It works for me as a control over the entire process - in addition to seeing if there are frames worth pursuing.