Fisheye · APS-C

Sigma 4.5mm f/2.8 EX DC HSM circular fisheye

The Sigma 4.5mm f/2.8 EX DC HSM circular fisheye is a APS-C prime lens (4.5 mm, f/2.8) for Canon EF, Nikon F, Sony / Minolta A-mount, Pentax K and Sigma SA. It belongs to the fisheye class — ideal for creative ultra-wide views, skateboarding, interiors and all-sky astro.

4.5 mmf/2.8Canon EFNikon FSony / Minolta A-mount
4.5 mm
Focal length
f/2.8
Maximum aperture
145°
Diagonal angle of view (APS-C)
APS-C
Designed for

Specifications#

Brand
Sigma
Model
4.5mm f/2.8 EX DC HSM circular fisheye
Lens type
Fisheye
Focal length
4.5 mm
Maximum aperture
f/2.8
Image circle
APS-C (23.5×15.6 mm)
Projection
Fisheye
Autofocus motor
hypersonic (HSM)
Lensfun correction profile
Yes — distortion/vignetting/TCA

Equivalent focal length on different cameras#

Field of view and depth-of-field equivalence when this lens is used on bodies with different sensor sizes (natively or via an adapter).

Camera formatAt 4.5 mmEquiv. aperture (DoF)
APS-C7 mm · 145°f/4.2
APS-C (Canon)7 mm · 143°f/4.5
Micro Four Thirds9 mm · 135°f/5.6

Depth of field & background blur#

Computed on its native APS-C format (CoC 20 µm). “Blur @2 m” is the size of an out-of-focus point at infinity, as a percentage of frame width, with the subject at 2 m — a simple bokeh index. Full table: 14 mm f/2.8 on aps-c.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
4.5 mmf/2.8∞∞∞∞37.4 cm0.0%
4.5 mmf/4∞∞∞∞26.3 cm0.0%
4.5 mmf/8∞∞∞∞13.4 cm0.0%

Handheld & night-sky limits#

NPF assumes typical 20–24 MP sensors (≈6 µm pixels on full frame, ≈3.9 µm on APS-C, ≈3.3 µm on Micro Four Thirds).

BodyMin. handheld shutter (longest focal)500 rule at 4.5 mmNPF at 4.5 mm, f/2.8
APS-C1/6 s74 s48 s
APS-C (Canon)1/8 s69 s46 s
Micro Four Thirds1/10 s56 s44 s

Adapt it to other systems#

Frequently asked questions#

Is the Sigma 4.5mm f/2.8 EX DC HSM circular fisheye full frame?

No — it is designed for APS-C sensors. On a full-frame body it vignettes or triggers crop mode.

What is the Sigma 4.5mm f/2.8 EX DC HSM circular fisheye equivalent to on APS-C?

Its focal length is already the real value for APS-C: 4.5 mm frames like 7 mm on full frame.

What is the Sigma 4.5mm f/2.8 EX DC HSM circular fisheye good for?

As a fisheye it suits creative ultra-wide views, skateboarding, interiors and all-sky astro.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources

Last posts

  1. Delivering Wedding Photos on USB Drives Pros and Cons
  2. Why Lenses Cost More Than Camera Bodies
  3. Why Used Camera Gear Holds Value So Well
  4. Best Surge Protectors for Photography Editing Workstations
  5. Can Cheap Flash Triggers Damage Your Camera
  6. Do You Need a UPS for Your NAS and Why It Matters
  7. Best NAS for Photography Teams and How to Choose One
  8. Why Photos Look the Same After Buying Expensive Lenses
  9. Choosing NAS Drive Size for Growing Photo Archives
  10. Is an LTO Tape Drive Overkill for a Small Photography Studio