DPreview of 50D is flawed ..please read

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Archive 2008 · DPreview of 50D is flawed ..please read

makron
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p.1 #1 · DPreview of 50D is flawed ..please read

just like to point out some facts:

Dpreview used the canon 50/1.4 @ f8 (please correct me if i'm wrong)

The MEASURED resolution of the 50mm/1.4 at f8 is 70 line pairs per mm (50% MTF).
here: http://www.wlcastleman.com/equip/reviews/50mm/index.htm
(please read in detail how is this measured)

50D (based on 15Mpixel) resolution is 105 line pairs per mm
40D (based on 10Mpixel) resolution is 86 line pairs per mm

Theoretical (http://www.luminous-landscape.com/tutorials/resolution.shtml)
for f8 is 86 line pairs per mm (50% MTF)

And you don't expect the Canon 50/1.4 @f8 to outresolve the theoretical resolution do you?

You decide for yourself.

update:

Please note that 50% MTF is "perceived image sharpness" as defined in the first link and absolute resolution is higher. The image can be sharpened to "bring out" the details so that it can be "perceived" by human eyes.

one line pairs per mm means one white and one black line per mm.

Update on digital sensor resolution:

(approximately only) In pixel term is 2 pixels per mm (one pixel for white and one pixel for black.
For its accurate treatment please refer to the link in the post
http://www.fredmiranda.com/forum/topic/703015/0#6332889

Edited on Nov 01, 2008 at 02:20 AM · View previous versions

Oct 31, 2008 at 10:59 AM

Beni
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p.1 #2 · DPreview of 50D is flawed ..please read

So as the 50D is outresolving a sharp prime at it's sharpest aperture the test is flawed? Would you have just prefered them to say that the camera is outresolving the canon lens lineup? Oh, they did. What use is a camera that cannot reach it's potential in the real world?

Oct 31, 2008 at 11:01 AM

makron
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p.1 #3 · DPreview of 50D is flawed ..please read

Beni wrote:
So as the 50D is outresolving a sharp prime at it's sharpest aperture the test is flawed? Would you have just prefered them to say that the camera is outresolving the canon lens lineup? Oh, they did. What use is a camera that cannot reach it's potential in the real world?

sharpest for the 50mm is at f4.

DPreview could have used a better (non-canon) 50mm @f4 or f2.8. It was afterall a review and comparison of the camera.

I hope Canon is reading this and very soon we'll have a new improved range of canon primes. hopefully!

Edited on Oct 31, 2008 at 11:23 AM · View previous versions

Oct 31, 2008 at 11:05 AM

Daan B
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p.1 #4 · DPreview of 50D is flawed ..please read

If the 50D will outresolve the 50 1.4 @ f/8 there will be a lot of lenses (even expensive L lenses) that are going to be outresolved by the 50D. The 50 1.4 @ f/8 is equally sharp or in some situations even sharper than many current Canon lenses (like the 24-70L, 24-105L, 50 1.8, 35L, etc). I think it is a good thing that DPreview used a lens like the 50 1.4. This way it will prove the point that you need very, very, very sharp glass to keep up with the 50D. Not to mention higher shutterspeeds to counter camera shake... 15MP on a 1.6x crop sensor is just too much.

Oct 31, 2008 at 11:17 AM

Antje
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p.1 #5 · DPreview of 50D is flawed ..please read

To put a positive twist on it: Now the camera is not the limiting factor anymore. I think that's quite cool, actually.

Antje

Oct 31, 2008 at 11:28 AM

makron
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p.1 #6 · DPreview of 50D is flawed ..please read

Antje wrote:
To put a positive twist on it: Now the camera is not the limiting factor anymore. I think that's quite cool, actually.

Antje

that's right!

Oct 31, 2008 at 11:34 AM

SoundHound
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p.1 #7 · DPreview of 50D is flawed ..please read

YES! Let's hold their feet to the fire for better lenses! Or if you build it (15Mp+ crop sensors) they (better line pair lenses) will come?

Oct 31, 2008 at 11:36 AM

freetime101
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p.1 #8 · DPreview of 50D is flawed ..please read

If the 15mp of the 50D outresolves canons best lenses what do 1Ds and 5D mkII users do with their 21mp?

Oct 31, 2008 at 11:44 AM

Geert Koning
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p.1 #9 · DPreview of 50D is flawed ..please read

freetime101 wrote:
If the 15mp of the 50D outresolves canons best lenses what do 1Ds and 5D mkII users do with their 21mp?

The 50D has a pixel density of 214/mm the 5DII only 156/mm same as the 20D

Oct 31, 2008 at 12:08 PM

Beni
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p.1 #10 · DPreview of 50D is flawed ..please read

makron wrote:
Beni wrote:
So as the 50D is outresolving a sharp prime at it's sharpest aperture the test is flawed? Would you have just prefered them to say that the camera is outresolving the canon lens lineup? Oh, they did. What use is a camera that cannot reach it's potential in the real world?

sharpest for the 50mm is at f4.

DPreview could have used a better (non-canon) 50mm @f4 or f2.8. It was afterall a review and comparison of the camera.

I hope Canon is reading this and very soon we'll have a new improved range of canon primes. hopefully!

Not in my experience. I also find it a whole heck of a lot sharper at f4-5.6 than any of the three 24-70L's I've owned or my 70-200 f4L IS.

I actually prefer a real world test. Yes they could use ZE glass at the optimum aperture but that ain't going to tell you what using the camera with the vast majority of popular canon lenses is going to be like.

Of course if you are quibbling about apertures then to even get close to the expected resolution you better have a very solid tripod, MLU, etc.

I think the conclusion is true, unless you want it as a special needs camera (only the best of the best lenses), don't bother, keep your 40D.

It does put it's price advantage over the D300 into perspective though. It's cheaper but only has better IQ if you pay through the nose for L primes by which point its a lesser spec'd and far more expensive camera with only a marginal resolution advantage.

If you want a camera with better IQ and noise than the 40D - get a 5D mkI. Incredible chip, dirt cheap and will blow your socks off for IQ. According to Canon the AF is better as well!

Oct 31, 2008 at 12:30 PM

RCicala
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p.1 #11 · DPreview of 50D is flawed ..please read

Anyone know of a quick easy (maybe tabular) reference listing the measured resolution of the various Canon lenses?

Oct 31, 2008 at 01:38 PM

n0b0
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p.1 #12 · DPreview of 50D is flawed ..please read

I thought people say a few MP increase makes very little difference? Well the 450D is not that far behind from the 50D in terms of pixel density and I don't think it outresolves any lenses at all, not even the 18-55mm IS kit lens at f/8.

I don't get it... first people say pixel peeping is bad, total sharpness is not everything, etc etc. but now people are complaining about 50D outresolving a sharp lens.

Oct 31, 2008 at 02:20 PM

molson
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p.1 #13 · DPreview of 50D is flawed ..please read

freetime101 wrote:
If the 15mp of the 50D outresolves canons best lenses what do 1Ds and 5D mkII users do with their 21mp?

Thy probably use them to make photographs, and don't waste their time quibbling over nonsensical internet postings...

Oct 31, 2008 at 04:28 PM

calemon
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p.1 #14 · DPreview of 50D is flawed ..please read

freetime101 wrote:
If the 15mp of the 50D outresolves canons best lenses what do 1Ds and 5D mkII users do with their 21mp?

FF "looks through" more of the lens than 1.6 crop.

You need to look at LP/mm and pixel densities to put them on an equal playing field.

Oct 31, 2008 at 04:32 PM

crypt
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p.1 #15 · DPreview of 50D is flawed ..please read

My wife's 50D is doing just great regardless of anyones reviews. I now reach for her camera over my 5D about 1/2 the time. And I don't give a second thought to LP/mm or how well the 40D does for noise. It seems like people are in a gear bashing mood lately. I have to go to the nikon forums to hear someone appreciate canon gear.

Oct 31, 2008 at 04:39 PM

davenfl
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p.1 #16 · DPreview of 50D is flawed ..please read

It is a poor test, flawed in many ways the worst of which is the raw software used. First they used a beta version of ACR 4.6, then reposted with the latest 4.6. Anyone fooling with the 50D knows that ACR needs 5.1 and then it is really still very poor compared to DPP just as ACR couldn't properly handle the 40D for six months after it came out. The lenses is an issue but not the primary one here IMO. People are posting comparisons this morning at DPR of the difference between ACR and DPP and of course they are significant.

Frankly I would rather as MOLSON alluded to look at proper photographs taken by photographers who are after quality and use the right tools available at the moment. Some of the quality 50D pictures I have seen certainly speak for themselves. DPR has become the ultimate bit twitling pixel peeking forum, you have to take it with a box of salt, I would say a pinch but it is way beyond that now.

Oct 31, 2008 at 04:43 PM

bushwacker
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p.1 #17 · DPreview of 50D is flawed ..please read

okay now here's my question... for all you of who did the testing...

AM I TAKING ADVANTAGE IF I BUY A 50D UNIT OVER THE OLD XXD MODELS?

forget about the money\price for now and its handling..let's concentrate on image quality and noise for now.

or WE CAN JUST SAY 50d IS A COMPLETE GARBAGE?

Oct 31, 2008 at 04:56 PM

mdowsing
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p.1 #18 · DPreview of 50D is flawed ..please read

RCicala wrote:
Anyone know of a quick easy (maybe tabular) reference listing the measured resolution of the various Canon lenses?

I second that request, just for curiosities sake.

Oct 31, 2008 at 04:56 PM

bushwacker
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p.1 #19 · DPreview of 50D is flawed ..please read

I think the EYES of EOS III has it... but that's only the MTF charts.

Oct 31, 2008 at 05:08 PM

lexvo
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p.1 #20 · DPreview of 50D is flawed ..please read

Sorry, the DPR test may be flawed, but so is your reasoning

If the lens resolution is 70lp/mm, then the total system resolution can never exceed that value.

In your example, the total resolution of the 50D would be:
1/70 + 1/105 = about 1/42 also a total resolution of: 42 lp/mm

the total resolution of the 40D would be:
1/70 + 1/86 = about 39 lp/mm

That's pretty close or not

The point is that a sensor with more pixels, always will give a higher total resolution, regardless of the lens used. Thus: one can still use the same lens to compare different sensors.

Oh, and one more thing: IIRC, you cannot just derive the sensor resolution from the number of horizontal pixels.

If you want to learn more about resolution see this site:
http://www.normankoren.com/

Oct 31, 2008 at 05:08 PM


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