First impression:
Second Test (1 month later):
Reference scales - The top scale is gray, the bottom one is how this company reproduced it in our test.
Color plot - Red, Green and Blue should be close together, and not be very far from zero.
Image samples - These are just an example based on our testing with this company.
Illumination and Dust - this is a scan from a solid gray test image.
The image should be evenly illuminated with no black dust spots.
Dust Highlighted - Red circles indicate dust in the camera system, usually on the CRT itself.
These spots show up in every slide, and there is no way to clean them.
Illumination - This is an enhanced gray scale image made from the scan above.
This image highlights the uneven lighting in the CRT. The uneven pattern, depending on the image,
may result in an unsatisfactory slide.
How we tested
We created 3 very simple digital files and submitted them to various service bureaus to have standard 35mm slides produced. These tests were run at the end of January and the beginning of February 2009, and a second test was run in Mid March 2009.
The first image consisted of a neutral gray scale so we could test color reproduction. Gray is very difficult to reproduce on color film and allows accurate density readings using an industry standard densitometer. The results from each bureau are plotted in the graph above. The results were used to compute color curves which were then applied to digital files to show fairly accurate expected results.
The second image we sent for testing was a solid gray image. The purpose of this image was to look for dust, and to check the evenness of illumination. The slides were scanned at high resolution with Digital ICE turned on. (Dust spots on the surface of the film would be removed by Digital ICE, but dust in the film recorder would become part of the image, and thus would not be removed by Digital ICE.) Dust spots on the CRT are easy to find. If the spot has film grain in it, then it is part of the image, and caused in-camera. Any spots were then verified using a 30x magnifier on all the test images. The scanned images are reproduced here. To see illumination on the CRT we batch processed all the companies' gray frame scans together to be fair. We converted them to grayscale, increased the brightness and lowered the black point to enhance the image.
The third image was for resolution and image verification. This was to test for other potential film recorder problems such as flare or blooming, resolution and linearity. Two images, one color and one grayscale were added to the file for verification that our sample images would be visually accurate.