« on: January 06, 2013, 05:21:04 PM »
This thread has been stagnant for a while, but Drizzt321 asked about my test set up. I haven’t answered because my 5D3 arrived a few days ago and I’ve been busy shooting the newness off of it.
I have to do my testing at my office after hours or during the weekend. It’s the only place I have access to with enough space to let me test at 131 feet (40 meters). When I start with tele-convertors or lenses longer than 200mm I will have to move to the parking garage in the basement. Besides the available space, the office building has much more rigid floors to minimize vibration, but even so, I sit down and don't move while the tests are running.
I enlarged the standard FoCal 50FL target 2x, 3x and 4x to be appropriate with the 100FL, 150FL and 200FL test distances. The targets are mounted on pieces of foam-core board, with the center of each target located at the same place on each board. I made a target stand that lets me quickly change the targets without disturbing the stand or the lights. After a target change only slight adjustments must be made to where the camera is aimed.
The camera is mounted on a tripod with the legs at their shortest length. The tripod is anchored using a very taunt bungee cord running from the hook on the tripod to a 40 lb (18.2 kg) weight resting on the floor.
I use two 1000 watt halogen lights to illuminate the target. These are construction lights so I have to use my Expodisc to correct white balance. It seems to work OK. I get between 9.0 and 10.0 EV on the target, depending on how I can arrange the lights. The office furniture limits me sometimes. Mostly, I can get between 9.5 and 10.0 EV.
The following is an example of the process I use:
1. Set up target stand and lights at 16.5 feet (5 meters) from the camera. This is approximately 200FL for 24mm, 100FL for 50mm and 50FL for 105mm.
2. Slid 200FL target into stand and run AFMA tests, autofocus consistency test and aperture sharpness test for EF 24 F1.4L II.
3. Mount EF 24-105 F4.0 on camera and test 24mm focal length.
4. Change to 50FL target and test 105mm focal length.
5. Mount Sigma 50 F1.4 on camera, change to 100FL target and run tests.
6. At this point, if I have enough time I will change the distance and run another series of tests; or if I have another camera body available I will rerun the tests using the second body.
This may all seem like overkill, but I am interested to see if I can find any pattern to how the autofocus setting will vary with a change in distance.
Also I wonder if some lens manufacturers are optimizing their lens designs to perform well at the standard test distances, but at the cost of performance at other distances.