Sony Alpha 99: Crop Factor, NPF Rule & Hyperfocal Chart

Name: Sony Alpha 99
Brand: Sony

The Sony Alpha 99 uses the Sony Alpha mount with a 1.00× crop factor (about 35.8 × 23.9 mm sensor), 24.3 megapixels, announced in 2012. Below: equivalent focal lengths, maximum shutter speeds for sharp stars, a hyperfocal distance chart, compatible lenses and how to check the shutter count.

Mount

Sony Alpha

Crop factor

1.00×

Sensor (approx.)

35.8 × 23.9 mm

Resolution

24.3 MP

pixel pitch ≈ 5.93 µm

Announced

2012

Circle of confusion

0.0299 mm

Equivalent focal length & field of view

Lens focal length	Full-frame equivalent	Diagonal FOV	Horizontal FOV
10 mm	10 mm	130.2°	121.6°
12 mm	12 mm	121.7°	112.3°
14 mm	14 mm	113.9°	103.9°
16 mm	16 mm	106.7°	96.4°
18 mm	18 mm	100.2°	89.7°
20 mm	20 mm	94.2°	83.7°
24 mm	24 mm	83.8°	73.4°
28 mm	28 mm	75.1°	65.2°
35 mm	35 mm	63.2°	54.2°
50 mm	50 mm	46.6°	39.4°
85 mm	85 mm	28.4°	23.8°
135 mm	136 mm	18.1°	15.1°
200 mm	201 mm	12.3°	10.2°
300 mm	301 mm	8.2°	6.8°
400 mm	402 mm	6.2°	5.1°
600 mm	603 mm	4.1°	3.4°

Multiply by the 1.00× crop factor for the full-frame equivalent field of view.

Milky Way exposure: NPF and 500 rule

Focal length	NPF @ f/1.8	NPF @ f/2.8	Strict NPF @ f/2.8	500 rule
10 mm	24.1 s	27.6 s	14.8 s	49.8 s
12 mm	20.1 s	23.0 s	12.4 s	41.5 s
14 mm	17.2 s	19.7 s	10.6 s	35.5 s
16 mm	15.1 s	17.2 s	9.3 s	31.1 s
18 mm	13.4 s	15.3 s	8.3 s	27.6 s
20 mm	12.0 s	13.8 s	7.5 s	24.9 s
24 mm	10.0 s	11.5 s	6.2 s	20.7 s
28 mm	8.6 s	9.9 s	5.4 s	17.8 s
35 mm	6.9 s	7.9 s	4.3 s	14.2 s
50 mm	4.8 s	5.5 s	3.1 s	10.0 s

NPF = (35 × f-number + 30 × pixel pitch) ÷ focal length, with a pixel pitch of 5.93 µm (from 24.3 MP). The strict version (Michaud's detailed NPF for the galactic core) gives pin-point stars at 100% view; the 500 rule is a loose rule of thumb that shows trailing on modern sensors.

Hyperfocal distance chart

Focal length	f/2.8	f/5.6	f/8	f/11	f/16
14 mm	2.4 m	1.2 m	0.8 m	0.6 m	0.4 m
16 mm	3.1 m	1.5 m	1.1 m	0.8 m	0.6 m
18 mm	3.9 m	2.0 m	1.4 m	1.0 m	0.7 m
20 mm	4.8 m	2.4 m	1.7 m	1.2 m	0.9 m
24 mm	6.9 m	3.5 m	2.4 m	1.8 m	1.2 m
28 mm	9.4 m	4.7 m	3.3 m	2.4 m	1.7 m
35 mm	15 m	7.4 m	5.2 m	3.8 m	2.6 m
50 mm	30 m	15 m	11 m	7.7 m	5.3 m

Focus at the hyperfocal distance and everything from half that distance to infinity is acceptably sharp (circle of confusion 0.0299 mm). Use the hyperfocal calculator for other settings.

Maximum print size

Print resolution	Inches	Centimeters
150 ppi	40.2 × 26.8 in	102 × 68 cm
200 ppi	30.2 × 20.1 in	77 × 51 cm
240 ppi	25.2 × 16.8 in	64 × 43 cm
300 ppi	20.1 × 13.4 in	51 × 34 cm

300 ppi suits close viewing; 150–200 ppi is plenty for large prints viewed from a distance.

Compatible lenses (147 in our database)

Lens	Focal length	Max aperture	Mount
Sony AF DT 16-105mm f/3.5-5.6	16–105 mm	f/3.5	Sony Alpha
Sony DT 16-50mm f/2.8 SSM	16–50 mm	f/2.8	Sony Alpha
Sony Zeiss Vario-Sonnar T* 16-35mm f/2.8 ZA SSM II	16–35 mm	f/2.8	Sony Alpha
Sony DT 18-55mm f/3.5-5.6 SAM	18–55 mm	f/3.5	Sony Alpha
Sony Minolta/Sony AF DT 18-70mm f/3.5-5.6 (D)	18–70 mm	f/3.5	Sony Alpha
Sony DT 18-135mm f/3.5-5.6 SAM	18–135 mm	f/3.5	Sony Alpha
Sony AF DT 18-250mm f/3.5-6.3	18–250 mm	f/3.5	Sony Alpha
Sony Zeiss Vario-Sonnar T* 24-70mm f/2.8 ZA SSM II	24–70 mm	f/2.8	Sony Alpha
Sony Carl Zeiss Distagon T* 24mm F2 ZA SSM (SAL24F20Z)	24 mm	f/2	Sony Alpha
Sony 28-75mm F2.8 SAM	28–75 mm	f/2.8	Sony Alpha
Sony AF DT 30mm f/2.8 SAM Macro	30 mm	f/2.8	Sony Alpha
Sony DT 35mm f/1.8 SAM	35 mm	f/1.8	Sony Alpha
Sony 35mm f/1.4 G	35 mm	f/1.4	Sony Alpha
Sony 50mm f/1.4	50 mm	f/1.4	Sony Alpha
Sony DT 50mm f/1.8 SAM	50 mm	f/1.8	Sony Alpha
Sony Zeiss Planar T* 50mm f/1.4 ZA SSM	50 mm	f/1.4	Sony Alpha
Sony AF DT 55-200mm f/4-5.6 SAM	55–200 mm	f/4	Sony Alpha
Sony DT 55-300mm f/4.5-5.6 SAM	55–300 mm	f/4.5	Sony Alpha
Sony 70-300mm f/4.5-5.6 G SSM II	70–300 mm	f/4.5	Sony Alpha
Sony 85mm F2.8 SAM (SAL85F28)	85 mm	f/2.8	Sony Alpha
Sony AF 100mm F2.8 Macro	100 mm	f/100	Sony Alpha
Sony Carl Zeiss Sonnar T* 135mm F1.8 ZA (SAL135F18Z)	135 mm	f/1.8	Sony Alpha
Sony AF 500mm F8 Reflex	500 mm	f/500	Sony Alpha
Sigma 4.5mm f/2.8 EX DC HSM circular fisheye	4 mm	f/2.8	Canon EF, Nikon F AF
Samyang 8mm f/3.5 Fish-Eye CS	8 mm	f/3.5	Pentax KAF, Canon EF
Sigma 8-16mm f/4.5-5.6 DC HSM	8–16 mm	f/4.5	Sigma SA, Canon EF
Samyang 10mm f/2.8 ED AS NCS CS	10 mm	f/2.8	Canon EF, Canon EF-M
Sigma 10-20mm f/4-5.6 EX DC	10–20 mm	f/4	Nikon F AF, Sigma SA
Sigma 10-20mm f/3.5 EX DC HSM	10–20 mm	f/3.5	Nikon F AF, Sigma SA
Sigma 10mm f/2.8 EX DC Fisheye HSM	10 mm	f/2.8	Sigma SA, Nikon F AF
Tamron SP AF 10-24mm f/3.5-4.5 Di II LD Aspherical (IF)	10–24 mm	f/10	Canon EF, Nikon F AF
Tamron SP AF 11-18mm f/4.5-5.6 Di-II LD Aspherical (IF)	11–18 mm	f/11	Canon EF, Nikon F AF
Tokina AF 11-16mm f/2.8 AT-X Pro DX	11–16 mm	f/2.8	Canon EF, Nikon F AF
Tokina AT-X 116 PRO DX II (11-16mm f/2.8)	11–16 mm	f/2.8	Canon EF, Nikon F AF
Venus Laowa 12mm f/2.8 Zero-D	12 mm	f/2.8	Canon EF, Nikon F
Sigma 12-24mm F4.5-5.6 II DG HSM	12–24 mm	f/4.5	Nikon F AF, Canon EF
Sigma 14mm f/2.8 EX	14 mm	f/2.8	Sigma SA, Canon EF
Sigma 14mm f/3.5 EX	14 mm	f/3.5	Sigma SA, Canon EF
Samyang 14mm f/2.8 AE ED AS IF UMC	14 mm	f/2.8	Pentax KAF, Canon EF
Sigma 14mm f/2.8 EX Aspherical HSM	14 mm	f/2.8	Canon EF, Nikon F

Native and adapter-free compatible lenses from the Lensfun database. Third-party and adapted lenses may also work.

How to check the Sony Alpha 99 shutter count

Most Sony Alpha bodies record the count in MakerNotes. Use `exiftool -ShutterCount -ShutterCount2 image.arw` on an unedited file.

ExifTool tag: ShutterCount / ShutterCount2. Always test an original, unedited file straight from the card.

Where to buy

Compare new and used prices at these retailers:

B&H Photo Amazon KEH (used)MPB (used)

Other Sony Alpha cameras

FAQ

What is the crop factor of the Sony Alpha 99?

1.00×. A 24 mm lens frames like a 24 mm lens on full frame.

What shutter speed should I use for the Milky Way with the Sony Alpha 99?

With a 10 mm lens at f/2.8, about 28 seconds keeps stars sharp (NPF rule).

How do I check the shutter count on the Sony Alpha 99?

Most Sony Alpha bodies record the count in MakerNotes. Use `exiftool -ShutterCount -ShutterCount2 image.arw` on an unedited file.

Which lenses fit the Sony Alpha 99?

Lenses for the Sony Alpha mount and compatible mounts (Minolta AF, Tamron Adaptall) — 147 are listed above.