Project:
Analyzes of vignetting from my
lenses and telescopes

Contents:

1. Introduction vignetting
2. Sigma 150 mm f/2.8 APO (f/4)
3. Pentax 67 165 mm f/2.8 (f/2.8)
4. Pentax 67 165 mm f/2.8 (f/4)
5. Canon 300 mm f/4 L (f/4)
6. Pentax 645 300 mm ED f/4 (f/4)
7. Pentax 500 mm f/4.5 (f/4.5)
8. TS130 2.5" x0.7 field flattener 684 mm f/5.3
9. TS130 3" x1.0 field flattener 910 mm f/7

Note:
I take no responsibility or liability for what are written here, you use the information on your own risk!

4. Pentax 67 165 mm f/2.8 (f/4):

If I stop down the aperture to f/4 I get this result:

It gave a bit asymmetric vignetting but this graph is heave expanded because of the low vignetting. What we see here can also partly be effect of uneven lit screen. In center the signal is about 66'000 and at the corners about 62'000. The signal drop at corners is almost nothing.

Signal drop at corners relative center = 7 % or 0.1 EV (full frame sensor).

Pentax 67 165 mm f/2.8:

• http://skrasnov.com/ pentax-67/ 165mm-f28/

My most low vignetting lens at full frame. See my astrophotographs I have of M45, taken with both Sigma APO 150mm and Pentax 67 165 mm . Even if the chromatic aberration is heavy on an old lens like this the result looks pleasent.