Accuracy[]
The focus distance reported by the lens has fairly large steps and is typically only used for flash calibration, where a few cm of error are acceptable. Typically higher quality lenses have finer steps with more accurate measurements. Additionally, not all lenses support reporting the focus distance.
Tested lenses[]
| Lens | Focal length | Focus distance | Comments |
|---|---|---|---|
| Canon 15mm f/2.8 Fish-Eye (13) | Yes | No | |
| Canon 24mm f/1.4L | Yes | Yes | |
| Canon 28mm f/1.8 USM | Yes | Yes | |
| Canon 35mm f/2 (11) | Yes | No | |
| Canon 50 f/1.4 (?) | Yes | No | |
| Canon 50mm f/1.4 USM (198) | Yes | No | I think I read somewhere (DxO?) that reading the distance was "problematic" |
| Canon 50 f/1.8 (1 or 29?) | Yes | No | Rack focus works, but is noisy |
| Canon EF-S 60mm f2.8 Macro USM | Yes | Yes | |
| Canon 85mm f/1.8 USM (155) | Yes | Yes | Only 7 (apparently accurate) distances : infinity, 11.91m, 2.88m, 1.49m, 1.05m, 90cm, 85cm |
| Canon 100mm Macro f2.8 | Yes | Yes | Fixed Focal Length.
Accurate Focus Distance (20) 31cm, 32cm, 33cm, 34cm, 35cm, 36cm, 37cm, 39cm, 40cm, 42cm, 45cm, 50cm, 54cm, 61cm, 74cm, 1.170m, 1.310m, 1.570m, 2.160m, Infinity Lens S/N: 3600503D |
| Canon 200mm f/2.8L USM (151 or 162?) | Yes | Yes | Few (7) and apparently inaccurate distances (Mark I version of the lens). |
| Canon 15-85mm f/3.5-5.6 IS USM (488) | Yes | Yes | Lens is not Parfocal (focus changes extremely while zooming) |
| Canon 16-35mm f2.8L USM (229 or 246?) | Yes | Yes | |
| Canon 17-40mm f4L USM | Yes | Yes | |
| Canon EF-S 17-55mm f/2.8 IS USM (240) | Yes | Yes | |
| Canon 17-85mm f/4-5,6 USM | Yes | Yes | fairly good accuracy |
| Canon 18-55mm kit lens | Yes | Yes | |
| Canon 24-70mm f/2.8L (230) | Yes | Yes | |
|
Canon 18-135mm f/3.5-5.6 IS kit lens |
Yes | Yes |
In Video Mode ONLY, on two 60D's with ML v2.3 Lens is not Parfocal (focus changes extremely while zooming) |
| Canon 24-105mm f/4L IS USM (237) | Yes | Yes | http://www.dpreview.com/news/0508/05082207canonlenses.asp#specs24 |
| Canon 28-70mm f/2.8L (161) | Yes | No | |
| Canon 28-90mm f/4-5,6 (41 or 46?) | Yes | No | Old lens from film camera |
| Canon 28-135mm f/3.5-5.6 IS USM (178) | Yes | Yes | Fairly accurate for both. |
| Canon 55-250 f/4-5.6 IS (49) | Yes | Yes | |
| Canon 70-200mm f/4L (186) | Yes | Yes | fairly good accuracy |
| Canon 70-200mm f/4L IS USM (242) | Yes | Yes | "Accurate" reading of both. http://www.dpreview.com/news/0608/06082414canon70-200f4lens.asp |
| Canon 70-200mm f/2.8L IS USM (224) | Yes | Yes | http://www.dpreview.com/lensreviews/canon_70-200_2p8_is_usm_c16/ |
| Canon 70-300mm f/4-5.6 IS USM (238) | Yes | Yes | Fairly accurate for both. http://www.dpreview.com/news/0508/05082207canonlenses.asp#specs70 Accurate focal length in 1mm increments.Accurate Focus Distance (14) 28cm, 30cm, 31cm, 33cm, 35cm, 39cm, 43cm, 48cm, 56cm, 69cm, 94cm, 1.550m, 6.010m & InfinityLens S/N: 133111 |
| Canon 70-300mm f/4.5-5.6 DO IS USM (232) | Yes | Yes | |
| Sigma 30mm f/1.4 (150.2) | Yes | Yes | |
|
Sigma 50mm f/1.4 (169.4 ?) |
Yes | Yes | |
| Sigma 105mm f/2.8 Macro (10.3) | Yes | No | |
| Sigma 180mm f/3.5 Macro (173.1) | Yes | Yes | |
| Sigma 12-24mm f/4.5-5.6 (152.1) | Yes | No | |
| Sigma 17-50mm f/2.8 EX DC OS HSM | Yes | Yes | Fairly good accuracy on shorter distances in live view, but in photo modes ML says that "no distance reported". On longer distances my lens reports a bit too long. Approximately 29 distances. |
| Sigma 24-70mm f/2.8 (137.4 or 161.1 ?) | Yes | No | Accurate focal length |
| Sigma 70-300mm f/4-5,6 APO (8.1?) | Yes | No | Approximative focal length and no distance. |
|
Sigma 18-200mm f/3.5-6.3 |
Yes | Yes | Approximate distance not very accurate |
| Sigma 150-500 DG APO OS HSM | Yes | Yes | shows the zoom and distance values accurately. |
| Tamron 17-55mm f/2,8 VC | Yes | Yes | Shows the zoom accurately but inaccurate distance values (start from 33cm instead 29cm ) |
| Tokina 12-24mm f/4 DX (?) | Yes | Yes | shows the zoom accurately but inaccurate distance values (not enough steps, normal considering the focal length). |
| Tamron 28-75mm f/2,8 (?) | Yes | No | |
| Tamron SP 70-300mm f/4-5,6 | Yes | Yes | |
| Tamron 18-270mm F/3.5-6.3 Di II VC PZD | Yes | Yes | Works in live view, photo mode says "no distance reported". Have not measured accuracy yet. |
lenses type are in brackets and are taken from: http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Canon.html#LensType