Recently we’ve had feedback from clients using both their own and rental Canon 5DS/R cameras, with regards to the accuracy of focusing. This has led us to create this piece on possible ways to improve tack sharp images every time…
Often the camera is actually ‘focusing’ but sometimes this is slightly off the intended focus plane - Often referred to as ‘Back-Focusing’ The New Canon’s 5Dmk3, 5DS, 5DSR, 1DX, 1DXmk2, 1DmkIV.
When AF does not focus on the targeted position, it’s possible to change the plane of sharpest focus by performing AF Microadjustment.
You can select from two types, "Adjust by lens" and "All by the same amount"
Adjustments for up to 40 individual lenses can be entered and stored in-camera. When a recognised lens is mounted, those stored AF adjustments will automatically be applied to AF.
It’s even possible to make adjustments to both the wide-angle (W) and telephoto (T) ends of a zoom lens.
- Shoot a couple of (say 5) frames using single AF, of for example a newspaper (distance will depend on the focal length of the lens you are testing)
- Download images to your editing software and zoom into 100% to check focus.
- Check all five images to see if they have a tendency to focus slightly in front of the newspaper, slightly behind or if you're lucky, all perfectly in focus (no adjustment needed)
- Select AF micro adjustment
- Press Set and select Adjust by lens, then press info
- In the adjustment screen, make a relevant adjustment on the scale (this is trial and error, but you should know which way once you found if it’s front or back focusing) It’s recommended to shift two points with each try until you obtain accurate focus.
- Press Info and it will bring up the screen asking you to put the serial number of the lens in, press ok once done.
If you're still having focusing issues, this may be due to one of the following:
- Low contrast subject.
- Very low light
- Strong backlighting
- Near and Far subjects both in the frame (Lion in a cage)
- Specular highlights
- Subject having repetitive patterns
- Objects that are smaller in the frame than the AF point.