Does DLA chart shows that 40D was better than 50D?

[Nicholas]

From Bryan's review on 50D, the 50D has DLA number of f/7.6 while the 40D has f/9.3.


Does this shows that 40D was more versatile than 50D in terms of when using small apertures? Moreover, Bryan mentioned that 50D demands high-quality optics to produce its highest quality images. So 40D allows us to use more range of lenses to produce equally-fine picture as 50D does? (i.e. without requiring L glasses all the time?)


I'm upgrading my camera from rebel series right now, but have a hard time deciding which body. Some says 40D's better, some says 50D's better. I've also looked up to see if AF microadjustment on 50D will be critical to produce sharp images, and whether upgraded 920,000 dots LCD will be essential to have.


Thanks - any responses that helps will be appreciated!

[Daniel Browning]

Does this shows that 40D was more versatile than 50D in terms of when using small apertures?

No. It only shows that the point of diminishing returns starts slightly earlier. (That is, you can expect the full 50% increase at f/7.6, but you will get slightly less increase if you stay at f/9.3; that is, maybe only 48% increase instead of the full 50%.)

Moreover, Bryan mentioned that 50D demands high-quality optics to produce its highest quality images. So 40D allows us to use more range of lenses to produce equally-fine picture as 50D does? (i.e. without requiring L glasses all the time?)

No, it's again just a matter of diminishing returns. With a top notch lens the 50D will give you 50% more resolution (MTF) than 40D. With a middle-of-the-road lens, maybe just 45%. With really junky lenses wide open, maybe only a 30% improvement. The returns are diminished, but the improvement is always there. (If nothing else, it at least reduces the loss of contrast caused by the OLPF and aliasing/demosiac artifacts are moved to higher spatial frequencies.)

Some says 40D's better, some says 50D's better.

The 50D is superior in every way except price. The only people who say otherwise base their opinion on incorrect information or flawed comparisons. For example, the DPReview 50D review has bad data, bad analysis, and incorrect conclusions. One of the flaws is the misunderstanding of resampling, which was exposed in Phil's blog post. Here is a competent rebuttal:


http://forums.dpreview.com/forums/read.asp?forum=1018&message=30190836


Common mistakes are:

• Unequal spatial frequencies.
• Unequal sensor sizes.
• Unequal processing.
• Unequal expectations.

I can go into more detail, but it's off topic for this thread.

I've also looked up to see if AF microadjustment on 50D will be critical to produce sharp images, and whether upgraded 920,000 dots LCD will be essential to have.

To me, both of those features are essential, but the high resolution is a tremendous draw.

[Keith B]

I own a 40D and 5D Mark2. After viewing the 5D's LCD it alone almost makes want to upgrade the 40D. Almost.


The 50D is obviously better but not enough for me to upgrade my second shooter.

[Kyle Webb]

Keith,


I had the 40D for over a year. I upgrade to the 50D and can say without a doubt that the image quality is better and all of the extras that are facilitated by the Digi 4 system make it a much better camera than the 40D. It is worth the upgrade for sure.


Kyle

[Colin]

Just to echo...


Finer pixels regarding the DLA simply reveals the diminshed sharpness on the focal plane sooner. You'll still get all the lens resolution with the higher pixel density sensor at the narrower aperture DLA listed for the lower pixel density sensor. The difference is that you'll get even MORE resolution below that point, until you get lens blur again on the other side of the curve. It's like, Hey, i cleaned my eyeglasses. Now I can see more crap on the windshield