Another Take on the 7D with Firmware V2 and MFA
On the various Canon Forums, some people are complaining about the Micro-Focus-Adjustment (MFA) and the new firmware v2.0. Many people have reported that their MFA has changed from +something to 0. How could that be?
- The camera has a database of most Canon lenses in each dSLR camera. The data is mostly used for illumination correction to make sure that the illumination is the same across the whole photo.
- The Canon 7D is old enough that Canon has accumulated enough data over the last 2½ years to know most of the MFA for most of the Canon lenses. This data is included in the new firmware. That's one of the reasons that you should redo your MFA for all of your lenses.
- The MFA changes all the time! The Micro-Focus-Adjustment is to compensate for the physical variations of the lens/camera combination against the theoretical manufacturing. The problem is that both the camera and the lenses contract and expand depending on the temperature variations. I mentioned it before at: Micro Focus Adjustment Revisited

Canon 7D: C.Fn III -5 - AF Micro Adjustment
New firmware, new MFA, let get “moooving”. Here are the results for some of my more common lenses. I haven't finished all the lenses. I'm going along as I need them.
BTW, I'm not using the FoCal, a software that does the calculations for you. When I tried it, compared it to my manual system, sometimes it was better, sometimes it was worst but it was always faster and me being a cheapskate I couldn't justify it.
| Lens | Firmware v1.2.5 | Firmware v2.0 |
|---|---|---|
| Canon 70-200L f/4 IS | -1 | +9 |
| Canon 17-55 f/2.8 IS | +4 | +10 |
| Sigma 120-400 f/4.5-5.6 | -1 | +4 |
Big differences. Three weeks ago, I did a “big” photo session with the 17-55 when it was at +4 and it was in “perfect” focus. I use the 70-200 almost daily and did many large prints with it in perfect focus, see: Canon 7D: The Perfect Focus

Eepeebee carving a drum dancer, Iqaluit, Nunavut, Canada
As many other people have reported, upgrading to v2 is a good time to recalibrate your Canon's MFA from the start.
