When introducing the EYV Project 4 Ex nihilo, the OCA manual states ‘ Studio work is highly technical and you really need to know your equipment inside out…’. How very true this proved to be.
Before starting this exercise I considered myself to be reasonably proficient in the use of my camera. But the exacting nature of studio photography, which I’ve never properly tried before, exposed my technical shortcomings. I have learnt so much!
I have a high-quality camera, great lenses and a sturdy tripod but despite that I struggled to get sharp images at slow shutter speeds in the studio setting.
After some reading I identified three settings that seem to have varying impacts on image sharpness. Mirror lockup and long exposure noise reduction apply in long exposure shots. Aperture settings have a marked effect on the sharpness of all images.
The DSLR that I use is a Canon 5DSR which uses a mirror and prism system. When taking a photograph the mirror’s reflex action causes camera vibration known as ‘mirror shock’. This shock has no noticeable effect at fast shutter speeds but during long exposures the mirror shock causes the camera to move and blur the image. To overcome this problem there is a camera setting called mirror lock up which does what it says on the tin. It locks the mirror up so that when the shutter is released there is no vibration from a moving mirror. This seems to have quite significant effect.
Long exposure noise reduction (LENR)
In simple terms (it’s a long since I studied physics) when taking a long exposure photograph the electronic film sensor in the camera gets hot. Sounds logical to me so far. The effect of the heat on the sensor creates hot spots that appear in the image as dots. This is also known as thermal noise.
I have now set the camera to automatically enable LENR for exposures over 1 second. The feature works by taking a second image with the shutter closed ie totally dark. The camera senses the thermal noice and attempts to correct in camera. I believe that with my Canon the in camera LENR does effect the RAW file. I can’t say yet whether the effect is significant and in any event I could correct in post processing. Certainly the biggest downside is that each image takes twice as long to shoot.
Each lens has what is known as a sweet spot. That is to say an aperture setting where the image is at its sharpest. Wide apertures can create chromatic aberration. Small apertures increase diffraction. So somewhere in the mid range is likely to yield an image with the greatest sharpness.
To test this I took a series of images with different lens/camera combinations and spent a day staring at blown up Lightroom images. Here are my findings. The result are pretty amazing!
|Canon 5DSR||24-70 f2.8||f6.3|
|100-400 with 2x||f14|