Roger at LensRentals.com has done a quick comparison of the EF 400 f/4 DO IS and EF 400 f/4 DO IS II as well as the EF 100-400 f/4.5-5.6L IS and EF 100-400 f/4.5-5.6L IS II.
From LensRentals.com on the EF 400 f/4 DO IS II
||400mm DO mtf50
||400mm DO II mtf50
“The difference in Canon’s computer-generated MTF charts for the 400mm DO and 400mm DO II is pretty striking, and I think our results confirm that difference shows up in actual optical testing as well as in the computer ray tracing. Canon also says the new design has much greater contrast, and I tend to believe that too, although we’ll all want to see images in a variety of lighting conditions.”
From LensRentals.com on the EF 100-400 f/4.5-5.6L IS II
||100-400 II mtf50
“The Canon computer-generated MTF charts suggest that the center of the image should be similar in both the old and new versions, but that the Mk II should be noticeably better off-axis and particularly in the corners. We do see that difference in the resolution tests, but I had expected the difference to be a bit larger. It’s certainly not nearly as dramatic as the DO difference.”
Read the full comparison at LensRentals.com
A patent for a new Canon EF 400 f/4 DO IS has appeared. The current lens has been around since December, 2001 and I think it’s a gem in the Canon lineup.
We’ve seen a lot of DO patents over the years, but no DO lens has been announced since June, 2004 when the EF 70-300 f/4.5-5.6 DO IS came to market.
Canon EF 400 f/4 DO IS
- Patent Publication No. 2014-109700
- Publication date 2014.6.12
- Filing date 2012.12.3
- Example 1
- Focal length f = 392.00-381.59-332.99mm
- Half angle ω = 3.16-3.10-2.81 °
- Image height Y = 21.64mm
- The overall length of the lens 292.02mm
- BF 105.64mm
Source: [EG] | Canon EF 400 f/4 DO IS at B&H Photo
DO appears to still be alive
More patents for large Canon DO lenses. The one of note is the 500 f/5.6, a lens that would be a very solid follow-up to the EF 400 f/4 DO IS.
We’ve seen a lot of these patents in the past, and none of them have ever come to market. It is good to see R&D is still going into DO technology, as I really enjoy the 400 DO.
Source: [EG] via [NL]
Another DO patent
We haven’t seen a new DO lens in a long time, but the patents haven’t stopped. It looks like Canon is continuing the R&D, I’d love to see it go somewhere.
Interpretation and self-description of the patent literature
- Patent Publication No. 2013-64858
- 2013.4.11 Release Date
- Filing date 2011.9.16
- Focal length f = 392.12mm
- Fno. 4.12
- Half angle of ω = 3.16 °
- Image height Y = 21.64mm
- 262.14mm length lens
- BF 69.97mm
- Two fluorite
- Materials and anomalous partial dispersion DOE to use, reduce the chromatic aberration
- Refractive power of the diffractive surface
- Strong, but can reduce the chromatic aberration of the element itself, flare increases
- The weaker, other optical element DOE play a role
- Refractive optical unit
- DOE anomalous partial dispersion and bonding materials
- DOE aspherical surface on the opposite side of the
- Vibration control
- Inner Focus
Source: [EG] | Canon EF 400 f/4 DO IS