Canon 50D review out

[The View]

I do show tests. Haven't you noticed? Whenever I make a point and am able to demonstrate that point with tests, because I have the equipment, I usually do so. When I tried RSP a few years ago and found it produced sharper results than the then current version of ACR, I demonstrated the fact with test images on this forum.

Isn't this the whole point of the forum? Seeing is believing. As I mentioned before, there might be many reaosns why someone prefers a particular converter. It might simply be a quicker and easier way of getting the same results, or the controls might be more intuitive for one particular user, but not necessarily another.

Of course, I don't need to do this. I sometimes wonder why I bother. But the fact is, the very process of organising my own test results into a demonstration format, tests which are initially made for my own edification, clarifies the issues in my mind and helps me discover flaws in my methodology. I learn from the process. If I didn't, I would no longer bother.

There's no reason for me to prove ACR's superiority. I'm not making any claims for ACR other than it's probably, on balance, as good as any other converter on the market but has the advantage of being more of an industry standard than any other converter. If someone wishes to make the claim that another converter does a better job than ACR, then let them demonstrate it so we can all benefit. You don't go through life believing everything that everyone says, do you?

If it would be so easy to show what's best, then we'd probably already have an industry standard RAW converter.

But, like with many creative and technical things, there are different approaches to solve each problem, and different solutions can stand next to each other.

So, if someone tests a device, he should test it for all existing approaches. Which would in this case include more RAW converters in the testing.

It's like philosophic systems. There are many of them, and they are contradicting each other, but still the good ones can't cancel each other out. They coexist.

Aesthetic points you can't prove. Judging image quality will always include aesthetic categories.

[Ray]

If it would be so easy to show what's best, then we'd probably already have an industry standard RAW converter.

But, like with many creative and technical things, there are different approaches to solve each problem, and different solutions can stand next to each other.

So, if someone tests a device, he should test it for all existing approaches. Which would in this case include more RAW converters in the testing.

It's like philosophic systems. There are many of them, and they are contradicting each other, but still the good ones can't cancel each other out. They coexist.

Aesthetic points you can't prove. Judging image quality will always include aesthetic categories.

Dynamic range, resolution and accutance are not esthetic issues. They are the easiest factors to compare. You seem to have strayed off the point. The objection in this thread has been raised that Dpreview's choice of ACR to compare the 50D with the 40D, with respect to DR and resolution, was not the best choice.

Is it not reasonable to ask that those who claim that there is a better choice, demonstrate the fact, so we can all judge whether or not they are correct?

Dpreview are quite likely not aware that there is a better alternative, just as I am not. If those who are aware of a better choice would share their knowledge and experience and demonstrate clearly and concisely why their choice of converter should be used in preference to ACR, then we could all benefit.

[DarkPenguin]

My own tests are suggesting, some of which I'm sharing with you, that the real benefit of this very slight resolution advantage of the 50D, is that one can confidently stop down an additional stop without sacrificing any resolution (compared with the 40D at the plane of focus), yet gain the more significant advantage of the greater DoF that stopping down affords.

Now that is interesting.

Have you done any tests with the half size sraw?  Any noise advantages?

[Ray]

Now that is interesting.

Have you done any tests with the half size sraw?  Any noise advantages?

I haven't yet compared 50D noise with 40D noise, but I have compared 50D noise with 5D noise, and the 5D wins, which just goes to show that sensor size is a significant factor regarding noise.

However, there's another way of looking at this. The cropped format has the advantage of greater DoF at any given aperture, and consequent faster shutter speed. When one equalizes DoF and shutter speed, by using a narrower aperture with the 5D and a higher ISO to allow the same shutter speed, then noise appears to be about equal between the two cameras.

[Slough]

We should all know by now that the resolution differences between the 50D and 40D are very slight. My test results in this thread are an exploration of how such slight differences might be of practical value to me.

It has been suggested many times that such high-pixel-density cameras have no benefit at small apertures and that any resolution advantage will only be apparent with exceptionally good lenses at their sharpest apertures.

My own tests are suggesting, some of which I'm sharing with you, that the real benefit of this very slight resolution advantage of the 50D, is that one can confidently stop down an additional stop without sacrificing any resolution (compared with the 40D at the plane of focus), yet gain the more significant advantage of the greater DoF that stopping down affords.

I won't argue with what you say above, but your two example images cannot be compared. In general I find your tests interesting, but in this case you have to compare like with like, to eliminate possible causes of error. Lens resolution usually varies significantly with F stop.

[Ray]

Lens resolution usually varies significantly with F stop.

Lens resolution does not vary significantly with F stop, within a reasonable range, say F5.6 to F16. It seems to vary roughly to the degree of difference between the 40D's and 50D's resolving capability, for each stop of difference. That's my point, a point which I've demonstrated with examples.

There was no error in my test that I'm aware of. Camera was on tripod and focussing was manual with Liveview. The aliasing artifacts at F5.6 are an indication that focussing was very accurate. You don't get aliasing artifacts with misfocussing.

[Ray]

By special request from Slough, the same banknote at F5.6 with both cameras, this time converted with DPP, no sharpening or noise reduction etc.. Notice the significant aliasing.

[attachment=9393:DPP_F5_6...mparison.jpg]

[DarkPenguin]

I haven't yet compared 50D noise with 40D noise, but I have compared 50D noise with 5D noise, and the 5D wins, which just goes to show that sensor size is a significant factor regarding noise.

I would expect that.  Very curious how the 5D mk II fares.

However, there's another way of looking at this. The cropped format has the advantage of greater DoF at any given aperture, and consequent faster shutter speed. When one equalizes DoF and shutter speed, by using a narrower aperture with the 5D and a higher ISO to allow the same shutter speed, then noise appears to be about equal between the two cameras.

I believe that is the equivalency theory.  The question is always can you find fast enough lenses for the crop camera to shrink DOF and is your high ISO clean enough on FF to give you large DOF when you need it.

[Slough]

Lens resolution does not vary significantly with F stop, within a reasonable range, say F5.6 to F16. It seems to vary roughly to the degree of difference between the 40D's and 50D's resolving capability, for each stop of difference. That's my point, a point which I've demonstrated with examples.

Then I think you are misinformed. The expected variation in lens resolution is going to be greater than the small differences that you are looking at. And the difference in going from F11 to F16 is often very significant, as is the drop in contrast, though it does of course depend on the lens. The 50D would exaggerate that difference.

[Slough]

By special request from Slough, the same banknote at F5.6 with both cameras, this time converted with DPP, no sharpening or noise reduction etc.. Notice the significant aliasing.

[attachment=9393:DPP_F5_6...mparison.jpg]

Thanks. The above comparison proves my point.

Actually something very odd is going on as the two 40D F5.6 images (one from each comparison) are quite different, the second being much worse than the first. Just look at the name at bottom right. In the second case it is quite blurred. I don't mean to be rude but I have lost confidence in your comparisons.

[Ray]

Then I think you are misinformed. The expected variation in lens resolution is going to be greater than the small differences that you are looking at. And the difference in going from F11 to F16 is often very significant, as is the drop in contrast, though it does of course depend on the lens. The 50D would exaggerate that difference.

In photographic matters I am informed by what I see. I don't see much difference, or anything I would describe as very significant, at the plane of focus moving from one aperture to the next one, either up or down one stop, within the range where I find most lenses are acceptably sharp and at F stops most often used (by me). It's not a matter for objective argument because the statement 'don't see much difference' is a personal and subjective statement based upon many tests over the years photographing real-world scenes as well as line charts.

Whilst I find there's a significant difference between F5.6 and F16, I find little difference between F5.6 and F8, between F8 and F11 and between F11 and F16, with the Canon 50/1.4. With other lenses and at other apertures, the situation may be different. With the Canon 100-400 at 400mm the difference between F5.6 and F8 is greater than the difference between F8 and F11. The lens is less sharp at F5.6 than I would like.

However, if you are serious and genuine in your assertion that going from F11 to F16 can be very significant, then please show us all a comparison so we can get an idea of your idea of significant.

Edit: I should add, in case anyone is confused by the above, that I concede it might be possible for a lens to have a very significant difference in performance at F11 and F16, but I don't own any such lenses. I imagine such a lens would be an old-fashioned design for large format film cameras, optimised for sharpest results at F16 or F22 and having a maximum aperture of F11.

[Ray]

Actually something very odd is going on as the two 40D F5.6 images (one from each comparison) are quite different, the second being much worse than the first. Just look at the name at bottom right. In the second case it is quite blurred. I don't mean to be rude but I have lost confidence in your comparisons.

Nothing odd there. The earlier comparisons have been converted using ACR 4.6 with default sharpening. For the latest comparison above, I used DPP and turned off all sharpening. I mentioned this fact in the text. You've made an inappropriate comparison. Even Dpreview advise against comparing current tests with previous tests, possibly because different versions of ACR have been used and at different settings, and general testing procedures might vary slightly over time.

All my comparisons (done at the same time) use the same settings, except for levels and exposure adjustments to get contrast and tonality as similar as possible.


Comparing two different converters is a different exercise. The controls and sliders will tend to produce different effects. One converter's default sharpening might be another converter's 'no sharpening' etc etc. I haven't tried to compare converters here.

[ZoltanZZZ]

First of all, I would say that most people don't shoot in RAW mode in any case. If one shoots in RAW mode and therefore has a use for a RAW converter, it's a sign that one is particularly concerned about subtleties of image quality, obtaining maximum detail in highlights and shadows etc and, in my opinion, quite likely that one will be a Photoshop user.

Of course, without extensive market research it's impossible to say whether greater than 50% of all people who shoot in RAW mode use ACR or Lightroom. Some people will use, or at least try out, a number of different converters and find that a particular converter produces more satifying result with certain types of scenes than ACR. I used to prefer RSP myself, for a while until it was bought out by Adobe. However, I found that ACR always did a better reconstruction job of blown highlights.

Is the actual percentage of ACR users really important? Photoshop and accompanying programs like Bridge and ACR are leading industry standards. That's the essential point. It would get very complicated to run through the whole gamut of available converters on the market every time a new camera was tested.

We are in the digital age that means hardware and software work together one cannot function without the other.  You cannot test hardware without optimized software, Canon designed the hardware and they know how to get the most out of it with the software they also created.  We are no longer in the film world were you test the hardware alone the software also has to be tested in the digital age.  To properly test any camera it should be tested with the software that was written for it no matter how awkward the interface is, that is the only way to determine how good it is.  It is irrelevant how many people use ACR since people are wiling to pay for other programs and choose not to use it.  It is also designed to work with different manufactures RAW files it may be the jack of all converters but it is a master of none.  dpreview needs to get their act together and start testing cameras with their intended software to measure output and compare them to other cameras, they can use ACR later for a comparison of raw converters.  Adobe probably would not like it since it may show that ACR needs improvement.

[Ray]

We are in the digital age that means hardware and software work together one cannot function without the other.  You cannot test hardware without optimized software, Canon designed the hardware and they know how to get the most out of it with the software they also created.  We are no longer in the film world were you test the hardware alone the software also has to be tested in the digital age.  To properly test any camera it should be tested with the software that was written for it no matter how awkward the interface is, that is the only way to determine how good it is.  It is irrelevant how many people use ACR since people are wiling to pay for other programs and choose not to use it.  It is also designed to work with different manufactures RAW files it may be the jack of all converters but it is a master of none.  dpreview needs to get their act together and start testing cameras with their intended software to measure output and compare them to other cameras, they can use ACR later for a comparison of raw converters.  Adobe probably would not like it since it may show that ACR needs improvement.

I understand your argument but I see it as flawed. Whatever procedure Dpreview adopts (probably without exception) there will always be disaffected people whose ego is slighted, who don't like the results and who will therefore criticise the methodology and suggest another converter should have been used. This is the very reason why Dpreview have attempted to standardise their procedure by always using ACR if it supports the camera.

If we had a situation where it was widely accepted that the software that shipped with the camera always gave the best results when converting the RAW images from that camera, then your argument would have merit and ACR would probably not exist. Who would want to use ACR if better results could always be obtained from free software that shipped with the camera.

Now, it might well be the case that Canon have lifted its game in recent years with regard to DPP and that the latest versions of DPP have certain advantages over ACR. But one can't assume that such a situation automatically applies to all manufacturers' own converters.

What happens if one particular converter applies a default level of sharpening which one can do nothing about? What happens if another manufacturer's own converter really is poor software and doesn't do as good a job as ACR? Should the hardware then be judged by the performance of the poor software when other software, such as ACR, can do a better job?

In this particular review of the 50D and its comparison with the 40D, it was unfortunate that initially the version of ACR used was a beta. But they corrected that, didn't they? As I understand, the beta version of ACR 4.6 produced a very marginally less detailed result at the extreme pixel-peeping level, didn't it.

[ZoltanZZZ]

I understand your argument but I see it as flawed. Whatever procedure Dpreview adopts (probably without exception) there will always be disaffected people whose ego is slighted, who don't like the results and who will therefore criticise the methodology and suggest another converter should have been used. This is the very reason why Dpreview have attempted to standardise their procedure by always using ACR if it supports the camera.

If we had a situation where it was widely accepted that the software that shipped with the camera always gave the best results when converting the RAW images from that camera, then your argument would have merit and ACR would probably not exist. Who would want to use ACR if better results could always be obtained from free software that shipped with the camera.

Now, it might well be the case that Canon have lifted its game in recent years with regard to DPP and that the latest versions of DPP have certain advantages over ACR. But one can't assume that such a situation automatically applies to all manufacturers' own converters.

What happens if one particular converter applies a default level of sharpening which one can do nothing about? What happens if another manufacturer's own converter really is poor software and doesn't do as good a job as ACR? Should the hardware then be judged by the performance of the poor software when other software, such as ACR, can do a better job?

In this particular review of the 50D and its comparison with the 40D, it was unfortunate that initially the version of ACR used was a beta. But they corrected that, didn't they? As I understand, the beta version of ACR 4.6 produced a very marginally less detailed result at the extreme pixel-peeping level, didn't it.

If the manufacturer cannot write better software than ACR then they should perhaps be looking at another business.  This refers to the output only not user interface which usually leaves a lot to be desired.  The point I am attempting to make is the cameras should be tested with the software that was provided as a total system, the output can then be compared to ACR as a so called standard (not my standard) RAW processor.  That would be a truer test.  The 50D test just brought out the problems in testing in the digital age, you need to test both hardware and software provided by the manufacture to measure camera performance, you cannot pick software provide by a third party to compare output to standardize it, what are you standardizing ACR performance, it does not come with the camera. When you purchase a camera you are also paying for the software the development and manufactures tweak their software and not just cannon Nikon also does it.  If you use ACR thent Adobe sets the standard not the manufacture, in essence you are testing ACR output.

[Ray]

If you use ACR thent Adobe sets the standard not the manufacture, in essence you are testing ACR output.

Writing RAW conversion software is Adobe's business. They are probably more experienced in such matters than camera manufacturers. It is true that in using ACR you are testing to a certain extent the way ACR handles that particular model of camera. That's unavoidable. No matter what converter you use, the same principle applies. The way the software has been written affects the results.

An example of just one reason for using ACR with all cameras would be that one could expect a certain standardisation of the treatment of sharpening of the RAW file. For example, no sharpening means no sharpening, or at least, if there is some degree of built-in sharpening that is not user controllable, it's likely to be consistent across different models of cameras.

Supposing Dpreview adopted the policy of using only the manufacturer's software to convert RAW files, and came across one particular brand of packaged software that appeared to be doing some basic sharpening, like in-camera sharpening of jpegs that couldn't be completely turned off. What do you do then?

I've noticed a few times on this forum in the past, posters asking Michael why a particular RAW file looks so soft in ACR. The answer tends to be, because the manufacturer's converter does not allow all sharpening to be turned off, whereas ACR does.

[ZoltanZZZ]

Writing RAW conversion software is Adobe's business. They are probably more experienced in such matters than camera manufacturers. It is true that in using ACR you are testing to a certain extent the way ACR handles that particular model of camera. That's unavoidable. No matter what converter you use, the same principle applies. The way the software has been written affects the results.

An example of just one reason for using ACR with all cameras would be that one could expect a certain standardisation of the treatment of sharpening of the RAW file. For example, no sharpening means no sharpening, or at least, if there is some degree of built-in sharpening that is not user controllable, it's likely to be consistent across different models of cameras.

Supposing Dpreview adopted the policy of using only the manufacturer's software to convert RAW files, and came across one particular brand of packaged software that appeared to be doing some basic sharpening, like in-camera sharpening of jpegs that couldn't be completely turned off. What do you do then?

I've noticed a few times on this forum in the past, posters asking Michael why a particular RAW file looks so soft in ACR. The answer tends to be, because the manufacturer's converter does not allow all sharpening to be turned off, whereas ACR does.

When you purchase a camera does ACR come with no it does not, manufactures want to tweak their hardware, why do thing DNG has not been accepted by all the manufactures, if it was, Adobe would control the output, only manufactures accepting DNG are the ones that do not want to invest in software development which by the way is very costly.  As far as control goes the raw file coming out of the camera has already been tweaked by the manufacture, you do not believe that you are actually dealing with raw data do you?  The RAW processor just tweaks more the already processed data and the manufacture knows how better to do that then Adobe since they know the entire process.  Have you seen software provided by the manufacture that was worst than ACR, I certainly have seen much better conversions with factory software for both Nikon and Canon than Adobe and C1 certainly does a better job than ACR.  The point I am making is when you purchase a product you test the product hardware and software not just half of it otherwise you are not testing the product you purchased.

[jani]

Perhaps we should flog dcraw instead.

[fike]

There are two different categories of SLR users (of course this is oversimplified):

1) Those who shoot jpg and send their images to a finisher for printing. (80%-90% of users)
2) Those who can explain what a RAW workflow is and who perform post-processing. (most of us at this board)

For people in category 1, the evaluation is simple.  Compare jpgs out of the camera.  
For people in category 2, there are a multitude of divergent approaches to evaluation.  

For this reason, I don't think we can expect to come to consensus on methods of evaluation to determine the 'BEST' camera.  On the other hand, a more productive line of discussion would be to discuss how to get the most out of our camera using specialized tools and workflow.  

There is no such thing as an "Objective Best Camera."  So, let's stop arguing over that kind of stuff.  For that, go to DPReview forums, and please stop ruining these great Luminous Landscape Forums with these ideological debates.

[Guillermo Luijk]

Writing RAW conversion software is Adobe's business. They are probably more experienced in such matters than camera manufacturers. It is true that in using ACR you are testing to a certain extent the way ACR handles that particular model of camera. That's unavoidable. No matter what converter you use, the same principle applies. The way the software has been written affects the results.

Maybe ACR was not the right choice. Adobe is a team with a lot of people working on it, but still is too much work for them to get the best from every camera. I was recently surprised to find out that ACR seems to develop Fuji RAF's with two issues:
1. A wrong consideration of the real saturation point of the camera (R sensor) which produces magenta artifacts in the highlights
2. A wrong consideration of the white balance for the highlights (R sensor again)

In this sample I developed the same RAF file with ACR and -4EV and -2.5EV exposure correction, and compared results to DCRAW. While in the shadows (sensor S) they were almost identical, in the highlights (sensor R), ACR was not optimum in preserving the neutrality and detail of the highlights which appeared magenta, and also the white balance was very greenish.

Bottom left: DCRAW developing sensor R with white balance calculated for that sensor.
Bottom right: DCRAW developing sensor R with the white balance calculated for the S sensor (it gets closer to ACR result but still not so greenish).