Ultra-wide prime · Full frame

Pentax 01 Standard Prime 8.5mm f/1.9 AL [IF]

The Pentax 01 Standard Prime 8.5mm f/1.9 AL [IF] is a full frame prime lens (8.5 mm, f/1.9) for Pentax Q. It belongs to the ultra-wide prime class — ideal for astrophotography, landscapes and dramatic perspectives.

8.5 mmf/1.9Pentax Q
8.5 mm
Focal length
f/1.9
Maximum aperture
137°
Diagonal angle of view (Full frame)
Full frame
Designed for

Specifications#

Brand
Pentax
Model
01 Standard Prime 8.5mm f/1.9 AL [IF]
Lens type
Ultra-wide prime
Focal length
8.5 mm
Maximum aperture
f/1.9
Image circle
Full frame (36×24 mm)
Mount(s)
Pentax Q
Projection
Rectilinear
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 8.5 mmEquiv. aperture (DoF)
Full frame8 mm · 137°f/1.9
APS-C13 mm · 118°f/2.8
APS-C (Canon)14 mm · 115°f/3.0
Micro Four Thirds17 mm · 104°f/3.8

Depth of field & background blur#

Computed on its native Full frame format (CoC 30 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 on full frame.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
8.5 mmf/1.94.03 m∞∞∞1.28 m0.1%
8.5 mmf/4∞∞∞∞61.1 cm0.0%
8.5 mmf/8∞∞∞∞31.0 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 8.5 mmNPF at 8.5 mm, f/1.9
Full frame1/8 s59 s29 s
APS-C1/13 s39 s22 s
APS-C (Canon)1/13 s37 s21 s
Micro Four Thirds1/15 s29 s19 s

Frequently asked questions#

Is the Pentax 01 Standard Prime 8.5mm f/1.9 AL [IF] full frame?

Yes — it covers the full 36 × 24 mm frame.

What is the Pentax 01 Standard Prime 8.5mm f/1.9 AL [IF] equivalent to on APS-C?

On a 1.5× APS-C body it frames like 13 mm, and like 14 mm on Canon APS-C.

What is the Pentax 01 Standard Prime 8.5mm f/1.9 AL [IF] good for?

As a ultra-wide prime it suits astrophotography, landscapes and dramatic perspectives.

Sources & licences#

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