The digital revolution has brought with it an unprecedented number of formats and finite control over how an image is recorded in camera. While I appreciate the options and level of control, it has added some complications into the mix when it comes to creating camera profiles with the Sekonic DTS software. In an effort to clear up the confusion, I've updated the following information & camera profiles on my site.
Updated All Of The Camera Profiles
I think the major source of confusion around metering and exposing imagery with digital cameras today stems from the long held practices and assumptions of working with film. If we set our meters to the recommended film speed and expose the reading on our meter, we get consistent results - mid tone ends up where we expect it on the scale - thanks the standards developed for rating film from the ASA / ISO.
Digital cameras cannot be treated like film cameras, they are a separate beast entirely. Unfortunately, the "standards" by which digital cameras can be measured are to fluid and are up for to much interpretation by the manufacture and the end user to be very helpful in practice. Which is why we must spend the proper amount of time testing out each system before we use it on a production. "Test and verify" is my motto to working with any camera system.
When the DTS software creates a profile, it appears to me that it is assuming that the camera system is producing images that follow the Standard Output Sensitivity model. Due to this assumption, it is looking for an 8-bit middle tone value of 118. But this assumption does not hold true for all cameras. For example, the GH2, when shooting with the Nostalgic profile, places the middle tone value at 146, while the Epic, places it at 100. Neither of these values are anywhere close to 118*. When the software creates the profile based off of its default assumptions, it results in profiles that can vary by as much as 1 stop or more in-between the default profile or other custom profiles. I have suggested three ways of dealing with this under the Important Tips section of my Sekonic Profile Page. I have also taken the liberty of updating all of the camera profiles to include a modified profile that should bring all of the custom profiles into better alignment. (The modified profiles are for non-raw / log cameras only, as the raw / log based profiles have already taken this into account.)
*Placement of the IRE value for middle tone has the same amount of subjectivity to it as well. Middle tone can fall anywhere from 35 - 55 IRE. (Also see S-Log IRE.) Welcome to the digital age, where nothing is standard anymore ...
Updated The Important Tips
The Important Tips section contains updates to the conservative bias that the DTS program has when it creates a profile. I also have a detailed section on Using Multiple Profiles that goes hand in hand with the update I made to all of the camera profiles. Please read this section prior to using any of the modified profiles.
Updated The FAQs
The FAQ's section has been updated with step by step instructions for reseting the meter to its default settings as well as instructions for profiling a film camera. If you have any other questions, please consult the user manual, or shoot me an email, and I'll respond as quickly as possible.
Going Forward
I will be continuing to update and refine the camera profiles and information on my Sekonic Profile Page as my testing and experimenting continues. The page will be updated as soon as I have any new information to deliver to you. The updated sections will be noted in yellow with the date it was changed for easy reference.
Until Next Time - Get Out There And Shoot!
Ryan E. Walters, Cinematographer
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