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!

2. Sigma 150 mm f/2.8 APO (f/4):

I bought this Sigma 150 mm APO lens about 3 years ago. I wanted to have something with less chromatic problem compare to my older lenses. I'm very satisfied with this lens, but don't use it at full aperture, I set it to f/4 to get it sharper and less vignetting.

In center the signal is about 66'000 and at the corners about 33'000. The signal drop 50 % at the corners which is pretty much. It's is the same as if you only have half the exposure in the corners and then more noise at corners.

Signal drop at corners relative center = 50 % or 1 EV (full frame sensor).

Sigma 150 mm f/2.8 APO:

• https://www.the-digital-picture.com/ Reviews/ Sigma-150mm-f-2.8-EX-DG-HSM-Macro-Lens-Review.aspx

Even if the vignetting is high it's one of the better lenses I have. See my astrophotos I have of M45, taken with both Sigma APO 150mm and Pentax 67 165 mm.