The EF 70-300 DO IS USM diffractive optics flare rapidly with strong front lighting, using a UV filter significantly increases the problem.
I made a test in the following conditions :
- With and without my Hoya HMC (multi-coated) UV filter
- I have been using this very filter for 3 years on standard lenses (non DO) with no significant problem
- With a tripod and mirror lockup
- There was some wind and the branches moved between the 2 shots
- In manual mode ISO 100 - 300mm - f/5.6 - 1/30 s
- Manual focus on the tree trunk
- Rising sun at 30 degrees on the right
- With the hood on
- 37 seconds between the two shots
When you will roll your mouse over the following image, you will see the picture taken without any filter:
As the lighting could have noticeably changed in 37 seconds with the sun rising, I did another test:
- With and without my Hoya HMC (multi-coated) UV filter
- With a tripod and mirror lockup
- In manual mode ISO 400 - 300mm - f/5.6 - 0.6 s
- Manual focus on the carpet
- Desk light towards the camera at 30 degrees on the right
- With the hood on
When you will roll your mouse over the following image, you will see the picture taken without any filter:
Fortunately the result is not always that dramatic. This
photo was taken with the filter (and handheld at 1/13 s with Image Stabilization).
With the high grade B&W MRC filter I get similar though slightly better results. Therefore, I decided to completely remove the filter as the front element of this lens is well protected by the large hood.
