Canon EOS-7D
Brief
Performance Test
The following images and data are from initial performance evaluation of the Canon EOS-7D. EOS-7D imaging quality was briefly compared to that of the EOS-40D and EOS-20D. Autofocus and video function were not evaluated.
Resolution and 50% MTF Performance
Methods
Used for Resolution and 50% MTF
Resolution using QA-77 target |
QA-77 Target Applied Imaging, Inc. |
|
Vertical resolution EOS-7D |
Parking Garage Target - Resolution detail
EF 35mm f/1.4L lens @ f/8 ISO 200. All images shot from same
location on tripod. All images processed in standard settings in Digital Photo Profesional v. 3.7.8 from RAW in 16 bit 300 dpi Tiff files. Files were enlarged to 12 x 18 inches and converted to 8 bit jpg's and cropped for web pages after processing. Slight unsharp mask was applied to all images. Cameras at default standard tone/color settings and automatic white balance. Image Detail Comparison: EOS-7D; EOS-40D; EOS-20D Comparison of image detail with EOS-7D using EF 35mm f/1.4L @ f/8 and EF-S 17-85mm f/4-5.6 @ 33mm f/8 |
Print Quality
Images
of the garage above from the EOS-7D have slightly better visible
resolution on screen than those from the EOS-40D and have noticeably
better detail than those from the EOS-20D. Also, images produced with the
EF 35mm f/1.4L on the 7D were compared with images produced with a EF-S
17-85. There was minimally better detail produced by the L lens.
Are
any of these differences in image quality between the EOS-7D and EOS-40D
visible in prints?
Images were printed at 12X18 inch print size and
sections were printed at total enlargement of 20X30 inches. At 12X18 print
size, print quality produced by the 7D with either lens was almost
indistinguishable from that produced by the 40D. At 20x30, small
improvements were noted in the prints examined by close inspection
produced by the 7D over those produced by the 40D.
High ISO Performance
Only
ISO 100 and 1600 were compared in this initial test. Image quality at ISO
1600 with the 7D is significantly better than that of the 40D. The EOS-20D
shows its age and has notably lower performance at both ISO 100 and ISO
1600.
ISO 100 ISO 1600 |
Conclusion
As
expected, image quality produced by the 18 MP EOS-7D is improved over that
of the 10MP EOS-40D. Major improvements of the EOS-7D over EOS-40D and
EOS-50D include: 1) 100% viewfinder; 2) better weather sealing; 3) higher
frame rate (8 fps); 4) higher iso performance; 5) video function; and 6)
better autofocus function. All of the preceeding are notable improvements.
If you use your APS-c camera to produce images for general photography in
good light at ISO 800 and below, the EOS-40D offers performance that will
meet most needs. If you are still shooting with an EOS-20D, acquisition of
an EOS-40D (50D) or EOS-7D is a major step up in image quality for general
photography.
Index
Posted
04 October 2009; revised 11 October 2009
©
2009, William L. Castleman