A few months ago, I ran a blog post about how important it is to do camera tests. It was part one in a four part series. It discussed the fact that you should not just surf the web for forums and camera review blogs, but go out there yourself and test your camera. I will provide the playbook so that you can understand my methodology when I test new film stocks and new digital cameras for my features.
I treat each new digital camera that comes out as a new film emulsion, one that needs to be tested before I can use it to help tell my stories. Finding out its strengths and its weaknesses is all part of the process. There are three parts to the process. The first is to find the sensitivity of the sensor. Part two is the latitude of the sensor. Part three is taking your camera on location to put it through the paces in different lighting scenarios, both day and night.
You should do this even if you have been shooting with a camera that you have owned or rented for some time. If you have not done these tests, please do the diligence to test it because you will learn something new.
Preparing a Slate
I prefer to use a large whiteboard. Put all of the info necessary to educate you, your crew and your director on it. We were shooting four cameras on this test, so we divided our whiteboard into four sections.
Whiteboard slate with four sections
Slate information for the ISO test
This is something you do not want to rush. Plan carefully because this is your roadmap. Without good notes and driving directions, you are going to get lost.
Understanding the Power of Your Sensor
ISO lens cap tests are the best way to understand how far you can push your sensor and how much noise your camera exhibits at each ISO. It will also show whether there is a native ISO, which means the camera’s lowest noise ratio. The Canon 5D had a native ISO at 160, 320, 640,1250. These specific ISOs should contain the lowest noise.
5D Mark II ISO menu
Rolling Your Camera in the Darkness of a Lens Cap
Derek Johnson and Laura Murphy will take you through how to perform these tests. Accuracy is paramount, so take your time so that you do not make mistakes.
Setting the ISO on the Canon 1DC
Adding ISO information onto slate
Recording five seconds of slate
Putting lens cap on and recording 20 seconds of black
After shooting the all the ISO’s on black. Take the footage into after effects to push the footage to bring out the Noise. We have had the best results by using the Exposure Effect in Adobe After Effects CS6. Adjust the Exposure level and offset to where the grain starts to colorize and you can recognize the patterns.
Screen grab of 1DC Canon log ISOs
Screen grab of 1DC neutral picture style
Adding Skin Tone to Your ISO Tests
It is so important to not just shoot these lens cap tests but to add a model to showcase skin tones and illustrate how the noise reacts to shadow areas of the face, etc. Using a grey card is essential as well because this shows noise very well. A color chart is good too. I try to put them on the same focal plane as our model so that focus is good across everyone.
Example of key and fill ratio
Part three next week will show the latitude tests which are not about charts, waveform monitors and vector scopes. Stay tuned!