Resolution and Sensitivity Tests



All crops represent a view of 230x300 actual pixels cropped from the larger 12.2, 10.1, or 14.2MP images. The crop area on the 1.5X multiplier Sony and Nikon are represented by the red rectangle on the full image above. The Canon XSi is a 1.6x sensor so the coverage is slightly less than the 1.5X sensors at the same resolution.

Since the crops represent actual image pixels, the covered area for the crop varies with the resolution changes. On 14.2 and 12.2MP sensors the crop area represents a smaller (more enlarged) portion of the scene than on the 10.1MP crops. This is because there are more pixels in the image area. However, you can view the full-size images by clicking on the crops and the field of view is the same among 1.6x sensors since the crop factor, sensor multiplier, and shooting position is the same.

In all images the tripod is mounted in the same location relative to the scene being photographed. Therefore, any field of view variations are a result of the different sensors and multipliers for each camera.

To eliminate variations in lens quality as much as possible, all images were photographed using the manufacturers 50mm f/1.4 normal lens. All ISO sequences were shot in Aperture Priority with a fixed aperture of f/4.0. Focusing was manual with the crop area as the focus target.  Lighting was a worst-case single 100W tungsten bulb high and to the right of the scene. All cameras were set to the TUNGSTEN white-balance preset so any color variations are a result of the manner in which the camera implements the Tungsten preset.

Links to the full JPEG images are available on each camera sensitivity crop. These files are huge, but they can be downloaded for those who wish to view the actual images or explore EXIF data embedded in each image. A shareware EXIF viewer, Opanda IEXIP 2, is available at for download at Opanda.

Page 8 compares the Canon XSi, XTi, and 40D over each camera's ISO range. Page 9 compares the Canon XSi to the Nikon D60. Page 10 compares the XSi to its most likely competitor, the Sony A350, which has the same street price as the Canon XSi.

Two Live View Modes XSi vs. XTi vs. 40D
Comments Locked

56 Comments

View All Comments

  • pinto4402 - Monday, May 5, 2008 - link

    Your observation about Canon's overly warm/red WB in tungsten lighting is shared by many camera reviewers/users. It's a "problem" that has been noted for a long time. Some people actually prefer the overly warm colors, though. I'm sure this is the reason why Canon has never fixed their WB.

  • Deadtrees - Monday, May 5, 2008 - link

    "Working range AF specifications are the same EV range of -0.5EV to 18EV. However, the 40D adds an additional diagonal cross-type sensor with greater precision for f2.8 lenses, providing better support for fast Canon L lenses."

    - Not trying to be picky or anything but that is somewhat misleading as not all L lenses have aperture values faster than f/2.8.

    -------------------------------------------------------------------

    "Overall, the Sony A350 actually does better against the Canon XSi than we really expected and acquits itself quite well for a higher resolution sensor that should be showing greater noise than the Canon XSi. Resolution and noise control to ISO 1600 on the Sony holds its own against a sensor maker than has been the low-noise standard since DSLRs began."

    - Keep in mind that A350 utilizes quite agressive noise deduction algorithms resulting smudged water color like images. If you think less noise is good no matter what, I guess it's not so bad. But, what about details that are lost? Do you really want over 10mp dslr images to show details as cell phone cameras? Hell, in that case, even point-and-shoot panasonic cameras that are known for crazy noise reduction algorithm can compete head to head with Nikon D3.

    ---------------------------------------------------------------------
    BTW, I really suggest you to change the test subject. It's glossy coated hardboard papers which makes it virtually impossible to see the loss of details caused by insance noise reduction algorithms.



  • Lord 666 - Monday, May 5, 2008 - link

    Wes,

    If you are comparing the XTi vs. XSi vs. 40D, why not include the D300 as well to compare against?
  • Wesley Fink - Monday, May 5, 2008 - link

    We will include the D300 results in Part 2 of our Digital Sensor article. We will be comparing resolution and noise in different sensor categories, such as 14 megapixel, 12 megapixel, and 10 megapixel.

    I did toy with the idea of including the D300 in comparisons in this review, but I figured Canon to past Canon XTi to top Canon prosumer 40D was a bit more logical than a $800 body to a $1800 body. I'll leave that comparison for the digital sensor article.
  • complectus - Monday, May 5, 2008 - link

    Is that a Frank Lloyd Wright house in 2 of the Sample Images?
  • Wesley Fink - Monday, May 5, 2008 - link

    Yes it is Frank Lloyd Wright. I am fortunate that a real Wright house is in my neighborhood. The furniture was also custom built for the rooms in th eWright house, as was typical of many of his home designs.

    It was built in the early 1900's and is contemporary to the other homes in the photographs. I figured someone would catch it.
  • pinto4402 - Monday, May 5, 2008 - link

    For about five minutes, I was interested in the Xsi as a lightweight backup camera body for event photography. However, the lack of a CF card slot completely nixes this idea. It doesn't make any sense for Canon to switch from CF to SD, other than to attract P&S owners who want to migrate to a DSLR. By doing so, however, Canon effectively excluded us existing DSLR owners who already have many of their lenses and who would be more likely to purchase. I can tolerate the Xsi's plastic body, but I'm not going to invest in new storage media just to use this camera.
  • Wesley Fink - Monday, May 5, 2008 - link

    You can buy a 16GB class 6 hi-speed SD card for $55, a 4GB Class 6 for about $20, or an 8GB for around $30. I can't believe that small expense would keep you from buying and using the XSi if you really wanted to.

    Nikon uses SD on the D80 and D60, Pentax uses it on the K20D and K200D. Sony still uses CF, but new Sony lenses cost a lot more than today's cheap SD and CF memory.
  • RDaneel - Monday, May 5, 2008 - link

    I have no problem with AT doing camera reviews, I think it's a valuable perspective for hobbyists and prosumers. Obviously AT isn't going to review $1500 lenses...

    That being said, this review reads more like Canon ad copy than a real comparative review. There isn't any serious examination of the image quality, and it feels like more effort is spent in comparing the number of AF points and megapixels than really looking at the camera as a DSLR system or really talking about IQ. Just kind of a disappointment, normally the objectivity on AT is a bit better. Did the author get to keep the free press sample? ;)
  • Wesley Fink - Monday, May 5, 2008 - link

    There was no Press sample - not even a loaner. We had to buy the XSi that was reviewed. The same goes for the Nikon D60 and Sony A350 that were compared to the XSi. Since we bought them all we owe nothing to any manufacturer.

    The XSi won't replace my D300 or my Pentax K20D, but it is a really superb entry camera.

Log in

Don't have an account? Sign up now