These test were made from series of 5 minutes exposures, using the Canon lens that i have, from the diafragm wide open, closing it one step each shoot, until i reached a minimun of 4 pics. Althrough the illumination isn't the same for every photo, it helps to evaluate the optical quality of stellar images, and gives and idea of the vigneting. Notice that there is and extra gradient of luinosity from the light pollution coming from Santiago. The photographies were made with a Canon F1, the mirror raised and with self-timer, mounted over the NASA Astrograph located in Observatorio Cerro Pochoco, Santiago, Chile (sky magnitude ~17.7). The film used was Kodak Ektachrome 200, pushed two steps.

The scanning process were made using a Polaroid SprintScan 35, with the software PolaColor Insight. The images are "raw" except the first three images with de 50mm lens, wich were diminished in 50 the luminosity, since the images were too much overexposed.

These images represent cuts made from the original image, at maxima
resolution (2700dpi), as shown in the pic.

See the images and the particular conclusion:

Canon nFD 50mm f/1.4
Canon FD 135mm f/2.5 S.C.

Final Conclusion: I'll repeat the test with greater times of exhibition for f/4.0 and f/5.6 for both lenses, and thus to obtain a more critical measurement. Also, the complete test could be repeated to measure this time the vigneting in similar conditions of light.

PD: Your commentaries and critics are very well received to enrich this test.