Resolution, Sensitivity and Image Quality

Sony likely wanted to scoop the industry with the 14.2MP resolution of the entry A350. That plan probably got scrapped by the 14.6MP Samsung CMOS sensor used in the prosumer Pentax K20D. While the A350 doesn't gain bragging rights as the highest res sensor south of $8000 it is still mighty close at 14.2MP. It is also the highest resolution sensor to be found in any current or announced entry-level DSLR.

Pentax went to great lengths to emphasize the greater size of their photoreceptor sites that made sensitivity more akin to the Sony/Nikon 12MP sensor. Pentax also emphasized the expanded sensitivity of their 14.6MP sensor with ISO options to 6400. Sony makes no special claims for the 14.2MP sensor in the A350, but the new sensor still has the option of ISOs to 3200.

We've already discussed how the A350 is easy to use with the best Live View you can find in a DSLR these days. The big remaining question, then, is whether the 14.2MP sensor really makes any difference in image quality.


To answer that question we considered that the most revealing test of sensitivity, noise, and resolution is low tungsten light typical of home interiors. The selected scene was not chosen to be pretty but to be revealing of sensitivity, noise, and image quality. It is a shot of my office stacked with motherboards and other review equipment taken with a standard 50mm f1.4 lens.


We found the APS-C 14.6MP CMOS sensor in the Pentax K20D to be excellent in sensitivity with well-controlled noise. The sensor size and resolution is roughly comparable to the A350, but the camera is much more expensive, uses a CMOS sensor rather than CCD, and it is targeted at the prosumer rather than entry-level. For those reasons, we included the Pentax K20D in these comparison tests.


The Canon 5D is justifiably famous for its incredible resolution with the full-frame 12.2MP CMOS sensor. The larger size sensor creates larger photo sites and the larger pixels are more sensitive to light than smaller APS-C sensors. The larger sensor size means the pixel size is more like an 8MP APS-C than a 12.2MP sensor. That makes for a good comparison to these two 14+MP sensors.

All images used a 50mm f1.4 lens (Pentax 50mm f1.4, Sony/Minolta 50mm f1.4, Canon Ultrasonic 50mm f1.4). Aperture Priority was used with a fixed aperture of f4 at all ISOs on all three cameras.  Shots were taken using a tripod and remote shutter release to prevent shake. High ISO Noise Reduction used the lowest level of high ISO NR that could be selected in each camera. White Balance was manually set to Tungsten on each camera and the only light source is a 100W tungsten bulb. These harsh test conditions should make image noise as severe as you will likely see in each camera short of time-exposure darkness. Images were captured in JPEG format so they could be displayed and downloaded without the requirement for post-processing software.

Live View and the Optical Viewfinder Sony A350 vs. Pentax K20D
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  • strikeback03 - Monday, March 31, 2008 - link

    I didn't think that was possible. Sounds like it falls in the same category as the optical viewfinders some compact cameras have, designed for emergency use only. I can't wait until some owner, blindly going by what is recommended as "best" on the forums, is trying to shoot with a 70-200/2.8 on an A350 held out at arms length.
  • Wesley Fink - Monday, March 31, 2008 - link

    The Olympus E-510 and E-410/E-420 actually have a viewfinder magnification of .92X, but the smaller sensor with the 2X crop factor makes the viewfinder look smaller than competing 1.5x/1.6x APS-C cameras. As mentioned in the review Oly got around this on the E-3 by going to a 1.15X multiplier. The E-3 has a great viewfinder that still needs a bit more eye relief to bbe nearly perfect. By comparison the A350 has a viewfinder magnification of .74x on a 1.5X crop camera.
  • Deadtrees - Monday, March 31, 2008 - link

    As many others have pointed out, the test is just wrong.
    It's so wrong that it even makes me wonder about credibility of computer hardware tests done here in Anandtech. Well, no, I do trust hardware reviews but not this one.

    1.How can you possibly claim that it's the resolution test when Sony camera had its aperture set as f/2 and other set at f/1.4? On 50mm f/1.4 lens, the difference it makes is quite huge. It'd just be retarded to claim that this camera has better or worse resolution when the apeture value is full 1 stop different on a 50mm f/1.4 lens.

    (I checked some pictures' EXIF data and it seems like they have all mixed apeture values. That's just so wrong)

    - Use fixed aperture value.

    2. Do you know that the actual ISO level can be quite often different than the others? For instance, 5D has higer ISO level than the other cameras: ISO 3200 on 5D can be ISO 4000 on the other cameras. Dpreview mentioned it as well.

    - Show at least basic EXIF information regarding exposure setting so that readers can at least think about it.

    3. Why the claimed Sony A350 ISO 1600 shows exif ISO level of 800?
    Also, A350 was set to use manual WB whereas 5D was set to use preset tungsten WB. Based on this, how can you claim "Canon 5D is somewhat warm at the Tungsten preset compared to the cooler and more accurate rendition of the Sony A350."

    Well, I gotta go now so I'll finish here for now.

  • Basilisk - Monday, March 31, 2008 - link

    I understand you're still working out your aperture/f-stop/ISO parameters for testing. When you've decided on those, you might want to increase your available illumination considerably to get shorter exposure times: 1/6 second seemed unnecessarily long, but that is indeed what the EXIF indicated. Or, perhaps you're setup is immune to vibration?

    Unlike an earlier poster, I'm not so sure camera reviews are a natural extension to your other hardware reviews. A few other sites have been doing those pretty well for some time....
  • Wesley Fink - Monday, March 31, 2008 - link

    We have already reshot the K20D and 5D tests using a fixed aperture and remote shutter release. It is not possible to reshoot the A350 since it has already been shipped to another user. Otherwise we would reshoot the entire sequence using f4.0 on the f1.4 leneses. We have talked about the changes that will be made in future reviews and we have definitely listened to comments and suggestions.

    The EXIF information is available (and has always been available) in the full images that can be downloaded by right-clicking any of the crops. You can see those for yourself in the review. Our conclusions were based on analysis of the full images and not the crops. The crops were designed to show details on the web and we agree they don't communicate noise well in theri current form - that's why we're updating procedures. The EXIF for the 5D on H, BTW, reports 3200 ISO. We did check all the EXIF values and we used the latest 1.1.1 BIOS just released a few days ago by Canon.
  • haplo602 - Tuesday, April 1, 2008 - link

    hmm I still get f-stop 1.4 on the pentax 100iso shot (I did not bother to check the others). truth is, I am using the builtin opera image properties option, but it looks like exif data to me ...
  • Deadtrees - Monday, March 31, 2008 - link

    You haven't replied to some of my crucial questions.

    1. What's the point of ISO 1600 comparisons when A350 was set at ISO 800?

    2. A350 had Custom WB setting and 5D had Tungsten WB:

    Given that, how could you possibly claim that "Canon 5D is somewhat warm at the Tungsten preset compared to the cooler and more accurate rendition of the Sony A350"

    3. What's the point of this review when you said "It is not possible to reshoot the A350 since it has already been shipped to another user?" Should readers just suck it up this false review because you can't redo the review? I think it's just better to take it down as this review just makes fool of Anandtech. Oh well, after all, it's the April Fool's day, isn't it?

    BTW, your answer on the second paragraph didn't make any sense. Not only you did not understand what I was saying, you came out with some weird answers for what I haven't asked. Why are you giving me the instruction of how to view EXIF info? Why are you telling me the point of having cropped images and that the conclusion was based on full sized images? I was not talking about those and I didn't say that the review is false because of that.

    Sorry if I'm being harsh but as you and Anandtech Staffs know, this is Anandtech. Though it's not a site about cameras, the credibility you guys gained over the decades does have a deep impact over readers.
    I really think camera reviews should, at least, meet half of hardware reviews.
  • Wesley Fink - Monday, March 31, 2008 - link

    1. The ISO 1600 being an 800 ISO image is an honest mistake. We uploaded over 127MB of full images for the 3 camera comparisons to our servers and that file name was incorrect. I will replace the 1600 with the correct file as soon as this comment is posted.

    2. The A350 ALSO used Tungsten white balance. I just checked the A350 files with OPanda EXIF 2 and the files are indicated as a Tungsten light source and "Custom White Balance".

    The Canon is almost famous for its poor performance on Auto WB in Tungsten lighting. On AWB it was extremely orange in cast. Even on the Tungsten setting it is warmer as we were comparing Tungsten WB to Tungsten WB. A custom light temperature would probably work better on all 3 cameras.

    3. The review is definitely NOT false, and we stand by our conclusions as we looked at many more images than those published here in reaching our conclusions. Our procedures can definitely be improved. We've committed to doing that in future reviews and we have listened carefully to all suggestions. Cameras are not given to us by manufacturers to hold indefinitely, and we generally have to beg manufacturers for a few days of use to review new cameras. That will change in the future, but short of buying the cameras we evaluate we have them for a limited time.
  • strikeback03 - Monday, March 31, 2008 - link

    It's not an EXIF issue, it's that the actual sensitivity of the camera is not what is indicated (when compared to a good light meter).

    http://www.dpreview.com/reviews/canoneos5d/page21....">http://www.dpreview.com/reviews/canoneos5d/page21....

  • qbfx - Monday, March 31, 2008 - link

    Hmm, I thought it was in the same price and performance class as the Canon 450D and the Nikon D300, why are they comparing it to the 5D ?? I still think the 400D and the 450D are better

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