Tuesday, 12 March 2013

Lens Testing

We were able to test two of our lenses in class and i choose to do my samyang 35 f1.4 and Helios 58 f2. They cost 350 and 50 respectively so i was not expecting big things from either lens. The Helios i was really impressed with, definitely usable by f2.8. The Samyang needs to be stopped down to f4 or even 5.6 for acceptably sharp results. However one must consider the uses of each lens when evaluation sharpness CA and distortion. The samyang was bought for photos of people in low light and i have been impressed with its real world sharpness and contrast. Rarely using the samyang of 1.4 i have found f2 to be quiet pleasing for an equivalent 50mm f2 portrait. Distortion is negligible on either lens as per the prime characteristics. Below are 100% centre crops from the samyang. Starting a f1.4 and finishing at f16 where diffraction is clearly visible.   
1.4

2



2.8

4

5.6

8

11

16



 Below are the Helios centre crops, from f2-f16.
2

2.8

4
5.6

8

11

16

Some Macro Work with the Blads and Own Camera

Experimented with the some very small objects to practice macro work, here are some examples.
Hasselblad 120mm at f4 .5 sec ISO 400. Macro 1:1

Hasselblad 120mm at f4 1/25 sec ISO 400. Macro 1:1. Two light sources, tungsten at front and iPhone LED through a glass brick from behind.

Hasselblad 120mm at f4 1/40 sec ISO 400. Macro 1:1. One tungsten light source with reflector.

Hasselblad 120mm at f4 1/25 sec ISO 400. Macro 1:1. Entirely Back light with a top reflector.

Canon 100mm at f7.1 1/8 ISO100. Macro 1:2. Two tungsten lighting.

Canon 100mm at f7.1 1/8 ISO100. Macro close to 1:2 but framed differently
Hasseblad 120mm at f4 1/6 ISO400. Macro 1:1. Lighting through a glass brick.


Canon 100mm at f7.1 1/8 ISO100. Macro 1:2. Two tungsten lights, glass brick behind.

Canon 100mm at f7.1 1/8 ISO100. Macro 1:2. Same set up but achieved a different background effect.