Warren,

Theoretically what you are saying about the sweet spot might be true for some lenses, as you suggest, however if you need a particular angle of view with an APS sensor, you will not use the same focal length as you would with a full frame. For instance I was just shooting a full frame dSLR using a 16mm wide angle. To get the same shot with an APS sensor, which I did recently, requires a 12mm lens.

Warren,

There are several factors to consider on this issue. A full-size 24x36mm sensor is more sensitive and has less noise/grain than an APS size sensor, but is larger, harder to make and more expensive. So, we are really talking compromises here. APS size sensors are favored by many dSLR manufacturers because they are smaller, easier to make and lower in cost. The lenses for APS size sensors can be made to be smaller, lighter weight and lower cost because their image circle can be smaller. So, the total APS system is smaller, lighter, easier to produce and lower in cost, but image quality will be slightly less than a comparable full-size system.

If you use a full-size lens with an APS size dSLR, you can expect the image quality to be slightly better because the outer area of the image circle of the lens is not used. It normally is the outer area of the image circle that has the most imperfections like brightness fall-off, distortion, etc. Angle of view will not change: it is determined by the sensor size and lens focal distance. So, using a full-size lens will get you some improvement in image quality, but it comes at a price: money, weight and size and some of the features of your dSLR may not be available with full-size lenses that have not been specifically developed for it.

Frans Waterlander
frans2001@netzero.net

Frans,

What you said about APS versus full-frame chips has been accepted conventional wisdom. However, maybe the goal posts of the game have been moved and the players are scrambling to optimize what they have committed to. The Nikon D2X versus the Canon EOS 5D flies in the face of that conventional wisdom, both with similar megapixel counts, and one (Canon) full-frame and the Nikon APS, and both cameras quite close in price.

Also one thing about lenses you did not take into consideration, that is the optical factors in designing a retrofocus lens for an APS image field size. When designed for a 35mm SLR body and a smaller field coverage the relatively long nodal distance provides the optical designer with a distinct advantage, and is a part of the reason the "digital" lenses like Canon's 18-55mm for the original Digital Rebel performs very well and is also quite inexpensive. In other words, as long as the flange to focus plane distance is the same, when the field coverage is decreased the corrrections needed are much easier to achieve to accomplish a level of performance necessary for the purpose, in this case recording on a digital sensor. And, that requirement is not all that great considering critical resolution is limited by the sensor cell size.

David,

The point that I wanted to make is that, everything else being the same, the APS size system is smaller, lighter in weight, easy to produce and lower in cost; it's also slightly less in image quality because of the higher noise in the smaller photo sites of the APS size sensor. Marketing goals and competitive pressures may cause prices to not reflect these underlying properties.

Frans Waterlander
frans2001@netzero.net

Frans,

You are postulating a hypothesis on the basis of everything else being the same. The only current full-frame chips available now are Canon CMOS, while the APS chips are likely Sony CCD, two distinctly different sensor technologies, so everything cannot be the same by definition.

And as far as cost is concerned, when a company like Canon makes their own chips in-house, is that at all comparable to Nikon which has to buy its chips from an independent manufacturer?

The argument is theoretical speculation and neither of us has access to all of the pertinent objective data. But I will not argue privilege on the basis of a journalist's access to direct sources, so lets just call it an agreement to disagree, unless you have some hard evidence???

David,

I'm not sure what point you are making or what hard evidence you expect me to provide. I hope we can agree that there are definitely advantages and disadvantages to a dSLR system based on a full-size sensor versus one based on an APS sized sensor. Non-brainers are (I hope) size, weight, noise/grain and sensitivity. We can argue about cost till the cows come home, but it is harder to make a full-size sensor and that is somewhere, somehow accounted for in the price we pay. Most dSLR's have an APS size sensor for all the reasons I mentioned.

I also hope we can agree that when one uses a full-size lens on an APS size dSLR, the outer area of the image circle is not used, thereby very likely improving image quality.

When I said "everything else being the same" I refered to things like camera and lens quality, lens field of view and maximum aperture, camera features, warranty period and the like.

Frans Waterlander
frans2001@netzero.net

Frans,

The point I am trying to make is recent developments have moved ahead of the assumptions you have stated. The goal post aren't where they were six months ago.

I am currently shooting a Canon EOS 5D, 12.8 megapixel with a full-frame CMOS chip, that has a list price of $3299. Its closest competition is the Nikon D2X 12.4 megapixel APS size CCD sensor with a list price of $4,900. And I have seen the output of the Nikon directly, a close friend has one.

The Nikon is larger and heavier than the Canon.

Obviously it is maybe not harder and more costly for Canon to make a full-frame 12.8mpx CMOS sensor than it is for Nikon to buy a 12.4mpx APS CCD sensor. The sensitivity is close to the same range. Noise would be hard to compare because unless the two cameras were used side byside there would be too many variable involved that could influence noise generation to make a definitive assessment.

David,

Well, in your example, everything else is not equal. The Nikon has been optimized for maximum frames per second. This may not be important to you and me, but those people that need this feature, like sports photographers, are willing to pay the extra price. The Nikon even has a mode to increase speed at the expense of resolution. You can't compare the prices of these two cameras based on sensor size alone. I bet the cost for the Canon full-size CMOS sensor by itself is higher than the Nikon APS-size CMOS sensor by itself. Also, like I said before, prices are not driven exclusively by what it costs to make the product; competitive pressures and company strategy play major roles.

Frans Waterlander
frans2001@netzero.net

David

Call your friend that has the D2X and have him bring it over for a test. Take both cameras with 50mm f1.4 lenses, a tripod and a newspaper page full of print. Put the paper flat on a wall in a well lit area. Then set up the Canon on the tripod and focus on the newpaper. Mark the four corners
on the newspaper to mark the image as shown in the viewfinder. Make some test shot at different apertures. Then set up the Nikon at a distance that the marked corners
on the newspaper fit into the Nikon viewfinder. Then expose at the same apertures. Then print at 16x20 and test the images. We use to test our lenses that way to see how they performed. Well you get the idea, it is really quick and easy and would help to test the sensors ability to render images. See the ideas I get at 2:00 A.M. in the morning. Please excuse any typing errrrrors one eye keeps falling asleep.

Frans,

Talk about changing the goal posts! You just proved my point. In this day of technology competition convetional wisdom is good for about six months.

Warren,

What your test would be measuring is the effectiveness of sharpening software, not much else.

Warren,

If I understand you correctly, the point you are making is that you may get better image quality when you use a full-size lens on a dSLR with an APS-size sensor. Reason being that you only use the inner part of the image circle or what you call the sweet spot. And basically I agree with you. However, there are some other issues that may or may not be important. In order to get the same field of view, the lens used on the APS-size dSLR needs to be of a shorter focal length. Such lens may have, with the emphasis on may, more imperfections like distortion, abberation, etc. There may be other issues with the APS-size sensor in terms of increased noise/grain and possibly other factors. I don't know if anybody has tried to do a side-by-side comparison but it would be interesting to see the results of such a test.

I know that David Brooks won't agree with me, but I think it is safe to say that in general a dSLR system with an APS-sized sensor is smaller, lighter, easier to manufacture and lower in cost. These are the very reasons why all dSLR's in the price-sensitive market segments (consumer, pro-sumer and lower-end professional) are equipped with APS-size sensors.

Frans Waterlander
frans2001@netzero.net

What I hope to be testing is the companies imaging systems. I would shoot the images in raw with all setting on default. Then using the software that is supplied with the camera I would process the data. There would be no extra processing used, just what is considered to be autofix or default and is supplied by them. I'm trying to keep this test in the realm of photography not the graphic designer using some mega form of photoshop. I realize these are PRO systems and that the word autofix is probably being snickered at. I'm looking for a baseline to compare full frame to the APS. If one of the systems tended to be softer than the other then adjust say the sharpening default menu a setting or two but try to keep it basic. After the setting are decided on then I would make enlargements of the best image from each system until one wins or a point that it doesn't matter. I'm not trying to test software but the basic imaging system.

I'm not trying to make any points yet about anything yet. I'm just asking questions. I've got a lot to learn about digital. As far as making the test shots, I know it worked for film cameras and can work for digital if kept to basics. Adjusting the distance on the cameras will take care of angle of view problems The differewnce in distance won't be that great for this type of testing (seat of pants). May be about a half F-stop or so and you'll probably be using the 1.4, 5.6, and 16 f-stops for the test shots. Yes there are are alot of varialbe that may skew the test but what the h_ll.

Frans,

It is not I that disagree, it is that Canon changed the reality.

>>These are the very reasons why all dSLR's in the price-sensitive market segments (consumer, pro-sumer and lower-end professional) are equipped with APS-size sensors.<<

The new Canon EOS 5D full-frame makes your statement as quoted above untrue.

Warren,

I think you need to read the camera manufacturers documentation that describes what Raw format is. Raw format is intended to involve and requires color correction and image editing processing in applications like Photoshop to make the image file USABLE for final output like printing.

If you want to test on the basis of the citeria you have explained the images should be recorded in the highest quality JPEG format so they go through the cameras on-board ASIC processing chip to result in a finished file.

When saved in Raw the on-board ASIC processing is bypassed.

The functioning of camaera manufacturer software to process Raw is only intended for converting from the proprietary Raw file format to a universal format like TIFF to enable the file information to be accessible by an image editor like Photoshop. The camera manufacturer Raw conversion software is not intended to provide the same auto-adjustment processing as the camera's on-board ASIC processor chip.

David,

A Canon EOS 5D with a list price of $3299 (body only) and a Nikon D2X with a list price of $4,900 (body only) are NOT included in my definition of price-sensitive market segments of consumer, prosumer or low-end professional cameras. With that clarification, I solidly stand behind what I said before:
"I think it is safe to say that in general a dSLR system with an APS-sized sensor is smaller, lighter, easier to manufacture and lower in cost. These are the very reasons why all dSLR's in the price-sensitive market segments (consumer, pro-sumer and lower-end professional) are equipped with APS-size sensors."

I rest my case...

Frans Waterlander
frans2001@netzero.net

Warren,

It may be hard to find people with the knowledge, the interest, the motivation and the means to carry out tests like you outlined. It appears very hard to get objective, useful information related to digital cameras and the digital darkroom in general that is based on facts, figures, science, engineering and objectivity. Sad, but that seems to be the state of affairs in digital country.

Frans Waterlander
frans2001@netzero.net

What I wrote was:
"I would shoot the images in raw with all setting on default. Then using the software that is supplied with the camera I would process the data. There would be no extra processing used, just what is considered to be autofix or default and is supplied by them."
When I bought my Canon 10D 3 years ago it came with Photoshop Elenents 2. "Then using the software that is supplied with the camera I would process the data." maybe that is my fault for ASSUMING that Canon and Nikon would suppy some sort of similiar program for processing the raw data with their PRO cameras. When I started I used Raw and converted directly to JPEG. I also used the default settings until I studied and tested the settings to see what they did. Now I do convert to TIFF. If I just what to take snapshots I'll use JPEG. I read and studied the manual then read several articles on the usage of Raw files and RGB and
sRGB color space technologies for their proper usuage. I ain't got no proper book learning but I am a tryin. The subjects of sRGB and RGB was another subject that nobody seemed to agree on but that is another forum subject. I'll stay out of that one. Right now I'm just trying to decide which system to use in my next endeavor in photography. The cost is getting too high to change my mind in mid stream even though the prices seem to be coming down a little. $3299.00 to $4999.00 is still a lot of money for a camera body but still cheaper than a Bass boat and trailer.

Frans,

Your ploy reminds me of when I was an adolescent just after the 2nd WW ended. During the Christmas season I was shopping for presents and saw the very first ball pen and Polaroid cameras on sale in the department store. I thought it was very exciting new stuff. After hearing what the price of the pen and camera was my parents dismissed my excitement as something that was foolish and the products would not succeed.

You can't tell where the road ahead will take you by looking in the rear view mirror.

Warren,

Software companies very often make deals with hardware companies like digital camera companies to include their "beginners" application as part of the "bundle". The software companies almost give the software away to the hardware company because they want you to become committed and become a long term customer for their more expansive advanced software. With really professional digital cameras the camera company expects a pro, or someone who thinks they are a pro, not to be a digital beginner and will be someone who already has a computer and the needed software, so bundlingsoftware is not a sales incentive.

Regarding the cost of truly professional photogear, it has never been cheap. In the mid 50's when I was headed for photo school after 4 year in the Air Force, I bought a new VW which was about $1,700, and put my photo gear on the backseat with my bags. I had a Rolleiflex F, and 4x5 view camera, 3 lenses for it 2 dozen film holders and a light meter, all added up costing more than the VW.

The new Canon EOS 5D is less than half the price of last year's full frame professional Canon dSLR, and less than 1/10 the cost of the car I drive.

I've been shooting Canon pro cameras now for at least 25 years, and have thousands of slides made with them, many of which I have scanned (at 5400dpi) and printed. (BTW a new Canon EOS F pro 35mm film body is about as much as my '55 VW was new.) The prints I obtain from the scanned 35mm film compared to those made from the new Canon EOS 5D favor the new 5D in just about every dimension of image quality, plus the advantage of the digital camera prints is they are grainless. And, finally even though $3299 is nothing to sneeze at, the difference between that cost and a new film camera is not that much considering at $15 a roll film and processing adds up fast if you actually use the camera very much.

And, on "artificial" tests. They really don't tell you much, that's why Consumer Reports camera ratings are usually so far off the mark. The real proof is in the pudding, the images a camera can reproduce, which requires a skilled photographer to make, not a test engineer. I have been doing "user tests" of photo gear for 30 years on the basis of "if I can make it work, so can you". From the feedback I have obtained from readers over those years I have not misled but a very few photo enthusiasts.

David,

Warren brings up a couple of very good questions. I can't speak for him, but I see the following issues:
1. What are the advantages/disadvantages of a dSLR system with full-size sensor and lens costing around $4,000 and up as compared to a dSLR system with APS-size sensor and lens costing around $1,000 and up?
2. Can you expect better image quality when you use an APS-size dSLR with a full-size lens?

I have made an effort to supply some answers, but feel that Warren may be more confused now than when he asked his original question. And yes, I feel that it would be extremely helpful for someone to conduct objective side-by-side testing to address these questions. Shutterbug could make a significant contribution in this area.

Frans Waterlander
frans2001@netzero.net

David,

Like the Rollieflex F and many other cameras of your time you used I must agree on one point the cost at the time was not much different compared to what the Canon 5D would be now if you look at what incomes are today vs then. My only real thought here is that the Rolleiflex F like many Rollies before are still around. Not only that, they have some face value. Will the Canon 5D be of any value a year or say even two down the road. I do not think so in terms of an investment. Monte Johnson.

Well we've been around this bush so much I think it is dying. I am just trying to get the pros and cons of the two different types of sensors. I was leaning towards the full frame because of the design features. It seems to have better rendering potential of the images. I've been reading a lot of forums that have post on the subject but am not sure of their credentials. Dpreview did a test on the 1Ds-MarkII and a comparison to the D2X. They gave the edge to Canon but questioned if the price increase of the Canon over Nikon was the deal breaker. They did not compare the Canon 5d to the D2X that I found. I'll look again tomorrow, ah, I meant today.

The reason that I am now looking at both is their enlargement potential. Can a APS stay together for a 30x40 print or will the Full Frame hold up better. If I were using film I would use a 6x7 or 4x5. I know I can get very good result with the 6x7. I can shoot those while I take my Sunday snooze. This digital is a little new to me so I'm doing my homework. I would like to do this project with digital.

David I'm eagerly awaiting the CD's I ordered and am following up on the books you recommended. Oh yes, I started using PC computers for Power Plant Design about 20 or so years ago and photography about 5 years ago, they are not to new to me. Just a pain in the _ss at times.

As far as the test I suggested with the newspaper. I got it, I believe, out of Popular Photography or Peterson's Photographic probably 20/25 years ago. It was in an article on lens testing in the real world with macro lenses. Funny it works. They also sold a target test kit through the magizine at that time. I bought that too. But all in all a comparison test of the two camera's, 5D and D2X, abilities would make a great article.

As far as the glass question goes it's 5:20 AM and I'm tired.

Frans,

There are two advantages I have found shooting a full-frame Canon EOS 5D ($3299). One is the camera is fully comparable to using the 35mm equivalent SLR in both use (handling) and lens compatability. Same angle of view as film with full-frame. Also the viewfinder is brighter and easier to see clearly than APS dSLR's. But the main advantage is resolution (image size). At 12.8mpx the 5D produces better 12x18 inch print image quality than 35mm film scans (5400dpi), and if interpolated at Raw level to 16x24 inches much better print image quality from 5D than I can reproduce on a regular basis from scanned 35mm film. As far as I am concerned the proof is in the pudding which is print image quality.

Your second question, which I assume you meant can 35mm SLR lenses produce better results than the "digital" lenses. When I got a first generation Canon Digital Rebel I did a test with its 18-55 kit lens against a 20-35 "L" 2.8 Canon zoom I have used for almost 10 years. Even interpolated 6mpx image files to output 12x18 by 300dpi inch image size prints (Raw format and using Genuine Fractals) all shots done on a tripod, there was no difference of any significance between images made with the Canon 18-55 kit lens and the relatively expensive Canon "L" 2.8 20-35mm.

The Canon 2.8 20-35mm is one of the best short lenses I have ever used, and I just did quite a number of test shots with the 5D with this lens, as well as the newer Canon 16-35mm 2.8. The quality performance advantages of the Canon pro "L" lenses really does not show up at 6mpx, bit it sure does at 12.8mpx.

Monte,

My 50's Rollei TLR 3.5 F was worn out beyond repair and replaced after about 10 years of moderate use. The 2.8F that replaced it was worn out in less than that. The Rollei TLR's from that period that are still around have spent most of their lives in a closet. The main weakness and point of wear was the gearing in the film advance and shutter cock mechanism.

The value of a camera is in what it is able to produce in image quality. The Rollei TLR's were very limited with just a normal lens, no built-in TTL meter, etc. etc.

A 12.8mpx digital SLR with Canon pro body design and construction has a duty cycle of about 100,000 exposures. The only part likely to wear is the shutter. Similar technology sensor chips are used in professional, broadcast television cameras and get years of use amounting to many many thousands of hours of continuous recording.

The investment is in functionality. You don't buy a car as an investment, why should you think of a camera as an investment any more so. You buy these devices for thir functional value. If you want to 'invest' buy a rare version of a Leica never used, in its box, and then never take it out of its box.

Warren,

With the resolution just about the same between the Canon 5D and the Nikon D2X, and with the Canon sensor full-frame and the Nikon APS, the main difference is in the size of each sensor cell. Theoretically the larger the cell size the more light it can gather, and thus the more current it can generate in a signal sent to the A/D converter, which outputs for each cell a numeric digital value represeenting density/exposure. But of courswe there is much more to the technology, well beyond what is revealed to the public in specific information, and more than I could fully comprehend and understand I can assure you.

So, the proof is in the pudding. What are REAL critical users getting in print image quality. Most of those who are using these products are not wasting their time beating their gums on the internet forums. they have better things to do I'm sure. I put some time in here because it's a part of my job, what i do for a living.

As to an answer to your question in terms of print image size and quality, there should be little difference if the megapixel count is the same. But that means that each produces a file that is just information as to the color/density values for each pixel.

Will you find a really objective in-depth head to head comparison made by an expert photographer? Unlikely because the companies are very disinclined to support published comparative reviews. So, sorry I value the access and cooperation I get from the companies whose products I test and report on. In over 30 years I have not done a head to head shoot-out article. I don't favor being the messenger of bad news - then no one likes you.