Specifications#
- Brand
- Petri
- Model
- TTL
- Camera type
- Digital camera
- Lens mount
- M42 screw mount
- Sensor size
- 53.0 × 51.0 mm (Medium format 53.4 × 40 mm)
- Crop factor
- 0.59×
- ISO range
- 25 – 1,600
- Weight
- 700 g (24.7 oz)
- Focus
- Manual
- Metering
- EV3 to EV18 @ ASA 100 / DIN 21
- Exposure modes
- Manual
- Flash
- Hot shoe, PC socket
- Battery
- PX-625
- Dimensions
- 93 × 151 × 53 mm (house only)
- Made in
- Japan
Specifications merged from Wikipedia. Spot an error? Tell us.
Sensor size compared#
Focal length equivalents & field of view#
Multiply any focal length by 0.59 to get the full-frame field of view. Angles are for a rectilinear lens focused at infinity.
| Lens on this camera | Full-frame equivalent | Horizontal | Vertical | Diagonal |
|---|---|---|---|---|
| 21 mm | 12 mm | 103.2° | 101.1° | 120.5° |
| 23 mm | 14 mm | 98.1° | 95.9° | 116.0° |
| 28 mm | 16 mm | 86.8° | 84.6° | 105.4° |
| 32 mm | 19 mm | 79.3° | 77.1° | 97.9° |
| 35 mm | 21 mm | 74.3° | 72.2° | 92.8° |
| 45 mm | 26 mm | 61.0° | 59.1° | 78.5° |
| 55 mm | 32 mm | 51.5° | 49.7° | 67.5° |
| 63 mm | 37 mm | 45.6° | 44.1° | 60.5° |
| 80 mm | 47 mm | 36.7° | 35.4° | 49.4° |
| 90 mm | 53 mm | 32.8° | 31.6° | 44.5° |
| 110 mm | 65 mm | 27.1° | 26.1° | 37.0° |
| 120 mm | 71 mm | 24.9° | 24.0° | 34.1° |
| 150 mm | 88 mm | 20.0° | 19.3° | 27.6° |
| 180 mm | 106 mm | 16.8° | 16.1° | 23.1° |
| 250 mm | 147 mm | 12.1° | 11.6° | 16.7° |
| 350 mm | 206 mm | 8.7° | 8.3° | 12.0° |
Depth of field table#
Total depth of field at each subject distance, using a circle of confusion of 51.0 µm (the 0.030 mm full-frame standard scaled by the crop factor).
| Focal | Aperture | 50.0 cm | 1.00 m | 2.00 m | 3.00 m | 5.00 m | 10.0 m | Hyperfocal |
|---|---|---|---|---|---|---|---|---|
| 37 mm | f/1.8 | 3.1 cm | 13.0 cm | 53.6 cm | 1.24 m | 3.74 m | 24.1 m | 14.9 m |
| 37 mm | f/2.8 | 4.8 cm | 20.3 cm | 85.5 cm | 2.05 m | 7.07 m | ∞ | 9.62 m |
| 37 mm | f/4 | 6.9 cm | 29.3 cm | 1.28 m | 3.29 m | 16.3 m | ∞ | 6.75 m |
| 37 mm | f/8 | 14.1 cm | 62.6 cm | 3.56 m | 24.1 m | ∞ | ∞ | 3.39 m |
| 74 mm | f/1.8 | 0.7 cm | 3.1 cm | 12.9 cm | 29.5 cm | 83.1 cm | 3.42 m | 59.7 m |
| 74 mm | f/2.8 | 1.1 cm | 4.8 cm | 20.1 cm | 46.0 cm | 1.31 m | 5.55 m | 38.4 m |
| 74 mm | f/4 | 1.6 cm | 6.9 cm | 28.8 cm | 66.2 cm | 1.90 m | 8.57 m | 26.9 m |
| 74 mm | f/8 | 3.2 cm | 13.9 cm | 58.6 cm | 1.37 m | 4.24 m | 32.6 m | 13.5 m |
| 126 mm | f/1.8 | 0.2 cm | 1.0 cm | 4.3 cm | 10.0 cm | 28.2 cm | 1.15 m | 173 m |
| 126 mm | f/2.8 | 0.3 cm | 1.6 cm | 6.7 cm | 15.5 cm | 43.9 cm | 1.79 m | 111 m |
| 126 mm | f/4 | 0.5 cm | 2.2 cm | 9.6 cm | 22.2 cm | 62.9 cm | 2.58 m | 78.0 m |
| 126 mm | f/8 | 1.0 cm | 4.5 cm | 19.3 cm | 44.6 cm | 1.27 m | 5.42 m | 39.0 m |
| 207 mm | f/1.8 | 0.1 cm | 0.3 cm | 1.5 cm | 3.6 cm | 10.3 cm | 42.0 cm | 467 m |
| 207 mm | f/2.8 | 0.1 cm | 0.5 cm | 2.4 cm | 5.6 cm | 16.0 cm | 65.3 cm | 300 m |
| 207 mm | f/4 | 0.1 cm | 0.8 cm | 3.4 cm | 8.0 cm | 22.8 cm | 93.4 cm | 210 m |
| 207 mm | f/8 | 0.3 cm | 1.5 cm | 6.8 cm | 16.0 cm | 45.7 cm | 1.88 m | 105 m |
Equivalent aperture#
Exposure is identical at the same f-number on any format; equivalence only describes depth of field and total light.
Night-sky exposure limits#
Longest exposure before stars trail. The NPF rule accounts for pixel pitch and is stricter than the classic 500 rule — use it for pin-sharp stars on high-resolution sensors. (NPF needs a known resolution and is omitted here.)
| Focal length | 500 rule |
|---|---|
| 24 mm (14 mm eq.) | 35.4 s |
| 34 mm (20 mm eq.) | 25.0 s |
| 41 mm (24 mm eq.) | 20.7 s |
| 59 mm (35 mm eq.) | 14.4 s |
| 85 mm (50 mm eq.) | 10.0 s |
Handheld shutter speed guide#
The reciprocal rule uses the equivalent focal length. High-resolution sensors may need one stop faster than this for pixel-sharp results.
| Focal length | No stabilisation (1/equiv. focal) | With 3-stop IS | With 5-stop IBIS |
|---|---|---|---|
| 41 mm | 1/25 s | 0.3 s | 1.3 s |
| 85 mm | 1/50 s | 1/6 s | 0.6 s |
| 170 mm | 1/100 s | 1/13 s | 0.3 s |
| 340 mm | 1/200 s | 1/25 s | 1/6 s |
Lenses for the Petri TTL#
Native M42 screw mount lenses in our database (17 total). Also adaptable: Tamron Adaptall.
- Laowa 15mm F/4 Wide Angle Macro 15 mm
- Pentax SMC Takumar 50mm f/1.4 50 mm
- Zeiss Carl Zeiss Jena Flektogon 20mm f/4 20 mm
- Tokina RMC Tokina 28mm f/2.8 28 mm
- Zeiss Carl Zeiss Jena Flektogon 35mm f/2.4 35 mm
- Pentax Super-Takumar 50mm f/1.4 50 mm
- Voigtländer Color-Ultron 50mm f/1.8 50 mm
- Zeiss Carl Zeiss Jena Pancolar 50mm f/1.8 50 mm
- Zeiss Carl Zeiss Jena Tessar 50mm f/2.8 50 mm
- Pentax Super-Takumar 55mm f/1.8 55 mm
- Zeiss Carl Zeiss Jena 1Q Biotar 1:2 f=58mm T 58 mm
- Zeiss Carl Zeiss Jena Biotar 58mm f/2 58 mm
- Pentax smc Pentax Takumar 135mm f/2.5 (V2/43812) 135 mm
- Tokina TELE-AUTO 135mm f/2.8 135 mm
- Zeiss Carl Zeiss Jena Sonnar 135mm f/3.5 135 mm
- Zeiss Carl Zeiss Jena Triotar-v2 135mm f/4 135 mm
- Pentax Super-Multi-Coated Takumar 400mm f/5.6 400 mm
Similar cameras#
Other Medium format 53.4 × 40 mm cameras from around the same time.
Frequently asked questions#
What is the crop factor of the Petri TTL?
The Petri TTL has a crop factor of 0.59× relative to 35 mm full frame (diagonal 73.6 mm vs 43.3 mm).
What size is the Petri TTL sensor?
53.0 × 51.0 mm (Medium format 53.4 × 40 mm), an area of 2703 mm² — 313% of full frame.
Is the Petri TTL full frame?
No — its sensor is larger than full frame (medium format).
What lens mount does the Petri TTL use?
The Petri TTL uses the M42 screw mount (flange distance 45.46 mm).
How long can I expose the night sky with the Petri TTL?
With a 34 mm lens (20 mm equivalent) the 500 rule gives 25 s.
Sources & licences#
- Wikipedia: Petri TTL — CC BY-SA 4.0
- Wikidata Q7178773 — CC0
Last updated October 03, 2026 · How we calculate · Sources