QA-ing a mini-lab ...

[dmr]

These came from a FOAF by way of our mutual friend. The FOAF now runs the photo lab at a local Wally World, and I can imagine this guy as a real stickler for quality control. He did admit that he knows of other labs which are not very meticulous in the process.

They use Fuji Frontier equipment and do a daily QA on the machines to test the chemistry and the overall results of processing.

The one on the left is a pre-exposed negative control strip. This is run through the negative processor before any customer jobs are done each day and it's then checked with a densitometer. The D-min and D-max should be obvious as to purpose. The HD and LD are high and low test points to verify the linearity of the processing. I'm not real clear on the Y-patch. He said something about this showing residual silver and that chemistry that's going bad will show up on this one.

The one on the right is a paper control strip, and again it's (supposed to be) checked with a densitometer although he said that some labs just eyeball-check it. The "stain" square is supposed to be totally white and the D-max totally black, with LD and HD being certain shades of grey with no color cast. I'm not really sure about the Y-max, but it appears to be a solid yellow. (Anybody know? Class?) 🙂

I thought that the gang here would find this of interest. I did. 🙂

 

[Chriscrawfordphoto]

When I was in college over a decade ago I worked at a one-hour lab that used Fuji machines. We used the optical SFA printer rather than the Frontier, which was new at the time, but we had similar control strips. There's another control strip too, which is generated by the printing machine itself. That one is used to calibrate the machine to new paper batches. The machine exposes colored and grey squares on the paper you have in the machine, processes them, then reads them with a built in spectrophotometer and compares what really printed to the colors that should have printed and adjusts itself to compensate for the difference caused by paper characteristics!