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Old Nov 4, 2005, 10:28 AM   #1
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Just a general question: Is the reason for a smaller image sensor in dSLRs due to economics? If so, if the price of these things drops would manufacturers start making full size image sensors and eliminate the 1.6x issue?
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Old Nov 4, 2005, 12:14 PM   #2
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Its issue for some, its a blessing for many.



imagine people who need a 600mm telephoto....????




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Old Nov 4, 2005, 1:40 PM   #3
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Economics. But, as you said, the price keeps coming down - so now more and more DSLRs are coming out with full frame sensors. It's like any other piece of electronics - starts off big and expensive but competition and innovation allow the component to get smaller and smaller at the same cost - think how big computers used to be just 5 years ago with much less power and memory.

The other thing that will be interesting is how companies that have invested in lenses designed specifically for those smaller sensors handle things. For instance Canon, who in the last year released several EF-S lenses designed specifically for their 1.6 sensors - then come out with the 5d which can't use those lenses. An interesting tightrope for them to walk.
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Old Nov 4, 2005, 2:13 PM   #4
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It is much more difficult (and expensive) to create a larger sensor. Canon is the only company that will have a full frame sensor DSLR on the market. I don't think you'll see the 1.5 (or 1.6 or 2.0 depending on the company) factor going away anytime soon.
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Old Nov 4, 2005, 3:17 PM   #5
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Im not sure that will be any more diffacult for the companys to have Lenses for the full frame DSLR's. They have all had them for years for the 35mm cameras. Just slap a "d" on the name and your good to go.......
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Old Nov 4, 2005, 3:50 PM   #6
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I don't think you understand that a 35mm camera uses a piece of film as its sensor... a DSLR uses a piece of silicon.

The problem with fabricating full frame sensors is yield. It's a lot cheaper to manufacture smaller sensors simply because there are fewer rejects. Once the pixels are programmed in ("installed") on the sensor silicon, it's possible to map out bad pixels, but there's a limit as to how many can be fixed.

VAtechtigger wrote:
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Im not sure that will be any more diffacult for the companys to have sensors for the full frame DSLR's. They have all had them for years for the 35mm cameras. Just slap a "d" on the name and your good to go.......
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Old Nov 4, 2005, 7:53 PM   #7
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Wildman wrote:
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I don't think you understand that a 35mm camera uses a piece of film as its sensor... a DSLR uses a piece of silicon.

The problem with fabricating full frame sensors is yield. It's a lot cheaper to manufacture smaller sensors simply because there are fewer rejects. Once the pixels are programmed in ("installed") on the sensor silicon, it's possible to map out bad pixels, but there's a limit as to how many can be fixed.

VAtechtigger wrote:
Quote:
Im not sure that will be any more diffacult for the companys to have sensors for the full frame DSLR's. They have all had them for years for the 35mm cameras. Just slap a "d" on the name and your good to go.......
Wildman has it right. Yield from a silicon wafer gets lower and lower as the sensor size gets larger. And while yields at all sizes will likely improve in future, they will never be as good for larger sensors as for smaller.

Another thing to consider is this: why the neurotic obsession over the "35mm full frame" in the first place? The format itself is little more than an oddity of history, resulting from the fact that it was the size of easily available movie-film stock when Leica decided to adopt a smaller format in place of the then-current 120 roll and large-format sheet films. Unfortunately, when digital SLRs were first developed, there was a lot of pressure on manufacturers to adopt a format that would be backwards-compatible with the 35mm made-for-film lenses then in circulation, even though those lenses were not designed for the needs of digital photography in terms of resolution and light transmission at the edges.

In any event, this desire to keep using lenses from the past is one reason for the crazy mish-mash of formats we have today. Olympus was the only company that bucked the pressure in the small-camera market, going with the 4/3 format and ground-up development of an entire digital system of bodies and lenses to match the specific image format.

This is only a guess, but I would estimate that the vast majority of photography consumers out there today print 90% of their shots at less than A4 size, and the remainder at no larger than A3--they simply don't need the resolution potential of 35mm and larger sensors, just as the majority of film photographers of the 20th century found the 35mm film format fully satisfactory for their needs--and vastly more convenient than hauling around a medium or large format camera and its huge lenses. With its 3:2 dimension, the 35mm's (24x36mm) format is also frankly inconvenient for printing, since most of the popular paper sizes don't accommodate the 3:2 ratio without wasting material from the end of the sensor (if you fill out the paper sides), or else wasting printing paper on the sides in order to fill out the frame length. Many lenses made for 35mm film cameras also do not operate optimally--particularly at wide angles--when used for digital sensors due to light drop-off at the corners. Sure, there are workarounds for such issues, but you can't call the situation optimal.

One other thing is dust--that "issue" that dare not speak its name. Larger sensors gather dust worse than small sensors do, making sensor cleaning and cloning out dust bunnies a more frequent hassle. Whether canon/nikon develop dust shakers or other countermeasures like Olympus' remains to be seen. Overall, we may find that the so-called "full-frame" (35mm full-frame, that is) sensors come to occupy a relatively small overall role in photography, perhaps equivalent to the role played by medium-format film cameras in the 20th century heyday of 35mm film, since for most photography up to the B4/A3 printing size there is still plenty of potential for high quality with the smaller APS, APS-C, and 4/3 sensor sizes.


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Old Nov 6, 2005, 10:51 AM   #8
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Thanks Norm...that's very interesting stuff! My question/concern goes back to JohnG's point that a person investing in a cache of lenses for a 1.x factor won't find those lenses usable should a full 35mm dimension sensor come to market. On the other hand, given the terrific images these cameras produce, I suppose it's just more of an academic issue than anything else.
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Old Nov 6, 2005, 12:13 PM   #9
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There are actually a few reasons to get a lens made for the smaller-than-35mm sensor.
This is all from my memory, so maybe someone can correct/add to it.

They have less chromatic aboration.
They are easier to correct for edge distortion.
They are cheaper to build (less materials) and therefor should be cheaper to us.
I believe wider angle lenses are easier to build in this size.

My wild guess is that once resolution gets high enough and the ability to produce the sensors gets good enough (the Canon 5D is an example that this is coming sooner than I though) I bet the 1.3x size sensor of the Canon Pro models will go away. I think there will be a 1.6x sensor size for a really long time just because its so much cheaper to make.

Eventually that size sensor will limit resolution, dynamic range & noise. Eventually. I have no idea when, though. And maybe by then something like the Fovon will catch on and we'll start another revolution in sensors.

Eric
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Old Nov 6, 2005, 4:57 PM   #10
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"Full frame" lenses work on all digital SLRs. Lenses made for cameras with less than full frame sensors may not. The so-called "DSLR" lenses like Canon's EF-S lenses work only with specific cameras, the two digital Rebel models and the EOS 20D. You're always safe to buy non-EF-S lenses so if you migrate to a full frame camera, you'll be able to take those leses forward.

Up till now, Canon has't kept the promise of lower prices for its EF-S lenses. There are no "L" class EF-S lenses yet and there may never be.

Canon has opted to develop three classes of DSLRs: Full Frames (1.0 crop), 1.3 crop and the APS-C 1.6 crop. The 1.3 crop class probably stands the best chance (just guessing) of being eliminated. This gives the consumer choice and variety.
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