The Holding Tank

Hardware

Lens Tests

| EF 28mm f1.8 USM | EF 50mm f1.4 USM | EF 100mm f2.8 Macro USM |

| EF 180mm f3.5L Macro | EF 180mm f3.5L Macro + EF 1.4X II | EF 180mm f3.5L Macro + EF 2X II |

Flare Tests

| EF 28mm f1.8 USM | EF 50mm f1.4 USM | EF 100mm f2.8 Macro USM |

| EF 200mm f2.8L I| USM | EF 300mm f4L IS USM |

Serious Real World Flare Case

Introduction

Test Setup

Test Setup Validation

Results

Conclusions

Introduction

This test involves taking shots with the sun on the diagonal (centre to corner) both in and out of the APS-C frame with a shadow background.

As such this is very much a daylight worse case.

Test Setup

The camera was set on manual and the exposure set for the shadowed foreground, being f11. 1/4 or 0.3 sec ISO 100 for the EF 28mm f1.8 USM and EF 17-40mm f4L @ 28mm. The sun was low on the horizon maximizing the contrast available resulting in an extreme against the light situation.

The test was conducted handheld with no attempt to use the same sun locations for each lens, this was to minimize the duration of the test so the light conditions were as unchanged as possible.

An additional reference shot was taken with the sun's disk shaded by a hand.

The seen light by the sun had an evaluative exposure of 1/200 f4 ISO 100 resulting in a shadow to sunlight exposure difference of 8.6 stops.

In the case of the disk of the sun being in frame (or at least not shielded by the lens hood) the disk of the sun has a luminance of about 1,000,000,000 cd/m2 and that of a sunlit scene is around 100,000 cd/m2 [Ref]. This is a source to scene luminance ratio of 10000:1 or about 13.3 stops.

So in this test the luminance difference between the disk of the sun and the shadow scene is a total of about 22 stops.

This is much higher than the controlled test conditions difference of about 16 stops.

Results

The results are presented in tables for as shot (metered for shadow) and digitally reduced by 4 stops.

Firstly for the EF 28mm f1.8

As Shot	As Shot -4 Stops
Ref Shot

Secondly for the EF 17-40mm f4L @ 28mm

As Shot	As Shot -4 Stops
Ref Shot

Conclusions

Although the above lens tests can not be directly compared angle for angle, there seems to be a similar order-of-magnitude of flare for the two lenses with the EF 28mm f1.8 slightly worse than the EF 17-40mm f4L, this is probably to be expected of a fast wide angle.

The above test were conducted with Hoya SHMC Pro1 filters fitted. However the controlled experiments showed that in both cases (28mm and 17-40 @ 28mm) the lens flared before the filter and any filter flare was second order at least.

The above results also agree with the controlled case tests in that the zoom is somewhat better controlled than the prime.

It seems this case is extremely harsh, a full 6 stops worse than the controlled test case, and it seems unlikely any lens would not flare under these conditions.

Last Updated 05/06/2008

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All opinions stated are the authors own.

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