Full Frame Fallacy?

[Lee Jay]

i think you are omitting a few things here that should probably be
contested

first,
you are supposing the lenses are out resolved by the sensors, yes?

No.

because if you are, that just isnt so
the lenses in 'that' instance then are not the limiting factor you
would have me believe

This "limiting factor" stuff is largely a myth. The final image MTF is a blend of the sensor's MTF and the lens' MTF.

second,
lets take a look at the usage of those charts
from Luminous Landscape

http://www.luminous-landscape.com/tutorials/understanding-series/understanding-mtf.shtml
"Canon's MTF charts are based on theoretical calculations used in the
design of the lens, while some other manufacturers use actually
measurements. There are valid arguments in favour of both methods. Be
aware though that different manufacturers have different measurement
procedures, and therefore while comparing MTF charts between lenses
in the same line is possible, and is in fact very useful in making a
purchasing decision, doing so between different manufacturer's MTF
charts isn't."

That's true. Are Oly's measured or calculated? I'm guessing they are calculated but I don't know.

so they are theoretical calculations, not actual figures,
and we shouldnt be comparing across systems

On the other hand, the main point I was making is that they need to be compared at the right settings, and Oly is honest enough to do that (using 20 and 60 instead of the 10 and 30 that are the standards for 35mm lenses). That was my point.

from the better respected Photozone.de
http://www.photozone.de/Reviews/overview
Please note that the tests results are not comparable across the
different systems!

I don't respect their tests at all. Most are wrong, all are misleading since they are systems tests, not lens tests. They'll only work well on crummy lenses.

third
IF in any event we were to compare those lenses as lenses when they
are a part of a system, why is one of them a 35-100/2 v/s a 70-200/4
wouldnt that advantage the F4 lens against the faster F2 lens?

The f2 lens isn't faster, it's the same. Both have the same angles-of-view and the same entrance pupil diameters, thus they both collect the same light from the same scene. The final image DOF, noise, and diffraction are dependent on the entrance pupil diameter for a given AOV, not the f-number.

forth
if we forgot about the fact we shouldnt be comparing those lenses as
lenses when they are a part of a system from MTF charts, and that one
is F2 v/s F4 for t'other, lets look at the edge definition on those
MTF charts. Would you agree that the edge definition defined from the
rate of fall on the right of the charts appears better on the Zuiko
examples than the Canon? particularly at higher lpm measurements ?

At the wide end there's a small difference in favor of the twice-as-expensive and twice-as-heavy Oly lens in the last couple of mm, at the tele end they are almost the same at those corners. In the rest of the lens, the smaller, cheaper full-frame lens has the advantage.

Lets keep in mind that the larger system FF has a good deal more
sensor to cover, that this allows for more deviations from the
optimum which is in part the reason d'entre of 4/3rds

The only valid reasons for 4/3 to exist are lower cost and size if you are willing and able to give up speed. Same thing is true of compact cameras. For a given fixed level of performance, a larger-sensor system will usually end up cheaper and smaller, and more performance will be available if you need it.

--
Lee Jay
(see profile for equipment)

 

[joe mama]

Here's 4.5 stops of real IS with the E-3:

http://forums.dpreview.com/forums/read.asp?forum=1022&message=25665477

Obviously not all shots will be in this high of a result but they do
exist and the camera can do it. Olympus also clearly advertises "up
to 5 stops" not "you get 5 stops no matter what."

...is that I could just as easily make the claim that my 5D has over three stops of IS built-in:

Canon 5D + 100mm / 2 @ f / 2, 1/10, ISO 3200

http://www.pbase.com/joemama/image/69352325



Anyway, that's why I'd like a more scientific comparison of the effectiveness of IS, especially as it relates to FL.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[joe mama]

I still don't know what shutter blades are, though. Are they what
hold the mirror?

Wow. I can't quite beleive the author of all these long posts and
articles on equivalence doesn't know what a shutter is. You aren't
pulling our leg are you?

Yeah, as long as that essay is, an essay about what I don't know would be even longer. : )

http://en.wikipedia.org/wiki/Focal_plane_shutter

Not trying to flame or ridicule you Joe, just very suprised.

I went there before I asked the question, but I still didn't get it. I'm off to respond to Rriley's post. I was unaware that there were any moving parts inside a DSLR other than the mirror assembly.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[joe mama]

I still don't know what shutter blades are, though. Are they what
hold the mirror?

i uploaded this for Joseph Wisniewski before



although thats the Copal M8 shutter off a Leica M8, in principle they
are all the same.

Thanks for the illustration, but I still can't figure out what that is and how it works from the picture. It looks like a rectangular hinge arm that rotates.

The blades move both up and down to expose the
sensor, the faster they move the more shutter speeds you have.

If the silver thing in the pic is the blade, I'm not sure how it functions as it does not appear to be large enough to cover the sensor. Is it that not all of the sensor records the image at the same time, and as the shutter moves different lines of the sensor record? Even if that's right, I still don't get how that works. I would have thought that the shutter, per the wikipedia illustration:

http://en.wikipedia.org/wiki/Focal_plane_shutter

would have to be large enough to cover the sensor.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[Ehrik]

As I said initially, I was considering the mass of the mirror. A
lighter mirror can react faster. Especially in a body of constant weight/size.

I think the mirror can react as quickly as the engineers want to make
it react,

Yes, but you need stronger motors, stronger springs and assembly
and more powerful battery and all those things tend to get bigger
to be stronger. Note how all 5fps+ cameras are quite sizable? And
the 8fps+ ones even more so? For a given camera size, a lighter
mirror can be made to move faster, that was my point.

snip

For sure. I'm not sure why FF DSLRs are so large to begin with --
film DSLRs aren't, and it doesn't seem like they should require much
more electronics, certainly not as much as the size differential
suggests. I've often wondered if the size of larger sensor cameras
has to do with spacing things out more for less electronic
interference and better heat dissapation, rather than the actual bulk
of the eqipment.

I think it is more a question of Canon hoping that those who buy a €3,000
camera will buy €3,000 lenses and then a bigger camera will balance those
better. And those who buy a €3,000 camera for bragging rights or to
compensate for something also want a camera of potent size.

snipping shutters since others have provided input and links on that

shorter blackout

For the same shutter speed, isn't the blackout time the same? I
don't know.

Blackout is mirror up time + shutter activation time (which can be
longer than the shutter speed) + mirror down time.

Hmm. So the mirror is up, and there's still a delay before the image
is captured? That's odd. Why is that?

I didn't say that. Shutter speeds higher then approx. the flash synch are
achieved by the second curtain starting to close before the first one is fully
open, thus creating a running gap.

Just my two oere
Erik from Sweden

"the 14 bit modes of the Canon 40D and Nikon D300 are pretty well
a waste of space" -GordonBGood
"In the present generation of technology,
14-bit capture is a marketing ploy." -ejmartin
"You only need 12-bits for base ISO,
and as little as 10 or 9 bits for the highest ISOs." -John Sheehy

 

[tko]

I'm sure you meant well, but sensors and optics follow rigorous rules of physics, and they aren't likely to be any significant breakthroughs. DOF follows optical design, and noise is mostly a function of quantum mechanics and the nature of light (you're actually looking at the noise in the light, not the noise in the sensor.) Believe it or not, there are already sensors out their that can count individual photons, but they have a rather noisy view of the universe, like walking around with your hearing aid cranks up to 500%. So, no magic.

But really, you're behind the times. We already have small sensors that work great for everyday use. They've made 20:1 zooms that work OK with them. 4/3rd works pretty well. Noise on this smaller sensors can be much better than some of the cr*ppy film formats offered to consumers in the last 30 years. So, small sensors do an OK job.

You argument is fundamentally flawed, is that you assumed that there is a "good enough" point that will keep everyone happy. For whatever brilliant small sensor you design, there's a better large sensor lurking around the corner. And if you want certain properties, you go large sensor. No way around it.

 

[marf]

A problem with 4/3 is that all lenses has to have extreme resolution.

No problem - simply scale it down.
As long as we are far away from the diffraction limit this is no problem.
I guess the diffraction limit for 4/3 is at approx. 80 MP.
Full frame lenses will also never reach these MPs because of other problems.

I don't know exactly how this affects other qualities I am looking
for in a good lens. In general I find the bokeh less than stellar for
example.

The bokeh ( the look of te OOF regions ) is very good, but the DOF is less shallow in the same situation.

Well if you cannot get 2 x as far away then FF has a Shallow DOF advantage, thats true, but this is only one point in the many things that matter. If you use the same focal length 4/3 and full frame then the DOF Shallow-ness is approx. the same, but if you use the same field of view then Full frame has an artistic advantage there. On the other hand if you want deep DOF, then 4/3 may be better

regards
Martin

-----------------------------
Typing errors are intended to provide a basis for global amusement.
I am a part time wedding photographer (50% of my income)

 

[S Hess]

Smaller does not always equal better. There becomes a point where you go too small and it starts affecting things. Its nice to find a happy medium and I think people found that out decades ago when they chose the 35mm frame size because it has the best compromises.

In response to previous posts about larger sensors always being
better, hasn't digital technology over the years shown us that things
always get better and "smaller?" Certainly, fabrication and
large-scale integration has no limit with regard to size at all. Look
at microprocessors and chips in general. There should be no reason
why a 4/3 sensor can't outperform an FF.

Given duplicate technology which will be available to both sensor sizes, the larger one will always be better. 4/3 would have to come up with superior technology that a larger sensor manufacturer does not have yet in order to achieve superior performance. Then they need to hope that they don't apply it themselves.

It also amazes me that everyone has fallen for the size and megapixel
marketing ploy so easily, while ignoring the things that 'really'
have to do with image quality...such as color accuracy, processing
algorithms and lens characteristics. I believe the only reason FF
exists is to support 35mm lenses, many of which are still around.
Anyone else share these views?

--
http://www.pbase.com/shhe

 

[gnarayan]

If the silver thing in the pic is the blade, I'm not sure how it
functions as it does not appear to be large enough to cover the
sensor. Is it that not all of the sensor records the image at the
same time, and as the shutter moves different lines of the sensor
record? Even if that's right, I still don't get how that works.

If you look closely you should see an outer black square around the "silver thing." Everything inside that square is the shutter blades - usually two black blades. The silver thing is just paint for the metering system. The two blades part to expose the sensor. It doesn't have to be two blades - there are iris shutters like the aperture blades in any lens and traveling blade shutters that open on one side of the chip and close from the other side.

It isn't actually true that all parts of the sensor record the image at the same time - there is normally some light fall off because of the shutter - the center gets a little bit more exposed than the edges but the profile of the fall off depends on the geometry of the shutter and it s usually such a small effect that you'd never notice it but if you are doing precision photometry you correct for it.

--
C&C always welcome.
Reality must take precedence over public relations, for nature cannot be fooled.
http://www.flickr.com/photos/gnarayan

 

[S Hess]

(1) Imaging sensors continue to get better on a per-square-millimeter
basis, so in the future there will be less need to go bigger in order
to get to some fixed level of quality.

Quality will never be fixed, everyone want more quality on a continuous basis. With current technology being equal on both sizes of sensor, the smaller one will always be inferior. Smaller is not always better given equal technology.

(2) Big sensors are subject to the law of diminishing marginal
returns. A sensor with four times the area does not give four times
the resolution or whatever other quality measurement you are trying
to measure. Partially, this is due to the fact that lenses that
project onto a bigger imaging circle resolve fewer lines per inch.
See point 4 below.

Not if the pixel sites are the same size. You may not get 4 times the resolution but you will get 4 times the pixels.

(3) There's a hassle factor associated with bigger cameras, which is
why people stopped using 8 x 10 cameras.

And people have settled on the 35mm frame size. It has the best compromise in quality, performance and portability. There is a definite point where you can go too small. Oly hasn't got there with their bodies or lenses, they are about the same size as all the others but the sensor is much smaller inhibiting the quality. If it didn't, there wouldn't be constant talk about it on these forums.

(4) There's a cost factor associated with big lenses. Even if big
sensors become cheap, big lenses will always be more expensive than
small lenses. Look how expensive medium format lenses were/are
compared with 35mm lenses.

True, but these lenses don't have to be made to exacting standards to equal the resolution and quality of the 4/3rds lenses. This makes them cheaper to make. 4/3 telecentric lenses are more costly to make and this is why they are even MORE expensive than equivalent FF lenses. That being said you could apply the same features as a 4/3 lens to a FF lens in the future if you wish and improve the image quality beyond what is capable with 4/3.

(5) Because the 4/3 system was designed with telecentric lenses, it
provides better image quality on a per-square-millimeter basis than
any other DSLR system. Every other system is a retrofit of a digital
sensor into a lens system designed for film.

See above. Like I said, they could apply any 4/3 technology to FF but it is not currently needed because of the sensor resolution is not high enough to match lens resolution.

(6) IRONY ALERT - the very same forum posters who say that "we don't
need more megapixels" are the same people who say that the 4/3 sensor
is "too small."

--
http://www.pbase.com/shhe

 

[joe mama]

If you look closely you should see an outer black square around the
"silver thing." Everything inside that square is the shutter blades -
usually two black blades.

The image was so dark on my monitor that I had to save the image and brighten it up considerably to see what was going on. The "silver thing", as I now see it, is not a "thing" at all, but rather a gap between the upper and lower shutter blades.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[Jeff]

Bill,

I don't mean anything personal here, but I'm getting pretty tired of this argument about 'physics'. Sure, physics make a difference on what's possible with a particular format and sensor.

But meeting consumer needs and economics matter more. 4/3's has advantages in these regards. So its possible for multiple formats, to survive in the marketplace. And for folks to be quite satisfied with them all, depending on their needs.

So a one-dimensional argument about 'physics' is really quite beside the point. It's meaningless because it ignores the overriding issue of customer needs, and relative value.

Jeff

that is, the larger individual photocells made possible by a larger
sensor give less noise and a "cleaner" image.

To some degree this can be offset in a sense by better software,
etc - but only in a sense, since the same better software applied to
a larger sensor will still give better results.

That said, the 35 mm so called full frame is an accident of history,
related to no print size, and invariable results in more cropping
than needed.

(The original 35mm camera, which morphed - due to demand - into the
Leica - was designed as a tester for 35mm motion picture film (so
that different runs of film could be "matched" by processing. A
still camera made testing batches of film cheaper and much easier.

But the size we know as 35mm full frame is simply TWICE the size of
the 35mm motion picture frame of the day - entirely an accidental
size.

The ideal larger sensor is probably what is called medium format as
per Hasselblad, etc. Next to this the most logical sensor to use
with 35mm legacy lenses is between APS and 35mm full frame - the
largest between these two that would be a usable format - like 4/3 or
8x10 approximate proportions.

However, of course, this will never happen since the 35 mm full frame
has been unoficcialy canonized.
--
bill wilson

--
Jeff

 

[Lee Jay]

These aren't mine, Joe:

http://www.pbase.com/domotang/image/23234724
http://www.pbase.com/domotang/image/23234976
http://www.pbase.com/domotang/image/23257483

--
Lee Jay
(see profile for equipment)

 

[whispersfromspirit]

Where I live(interior of British Columbia), sales of all Olympus cameras are steadily inscreasing over the last 6 months. Can't talk for everyone, but for me the advantage of the Olympus system is in the longer lenses(love birds and wildlife pics). If I need a 400mm lens then all I have to use is a 200mm lens, due to the 2x from the Oly sensor. The advantage in weight is good for me. The image quality from Olympus is very good and for my purposes(I rarely print) it is more then good enough.

All manufacturers are now re-designing and introducing digital FF
lenses.
The Olympus advantage is being eroded.

You can say that anything you can do to a 4/3 lens can be applied to
a FF lens just like you can with sensors.

While Olympus may have the digital lens advantage now....Nikon,
Canon, Pentax, Sony, Tamron, Tokina, etc... are all introducing
digital compatible lenses and this will eliminate the designed for
digital argument that Olympus has been touting.

The other advantage that Olympus DOES NOT HAVE is that the
competition allows the use of their FF digital lenses on small and FF
sensors. Olympus is painted into a corner with their smaller sensor.

I like 4/3 for now. I got a couple of cheap olympus cameras and
lenses because Olympus is always forced to drop prices when their
sales stall and they are unable to create demand because they have no
money for advertising and they have no discernable marketing
department. Who can beat that value! No one in the market can give
you a 10MP, 2 lens kit with IS at those prices. WOW!!!

Now, when there is a FF camera at a price I can justify, I will dump
4/3 except for my 410 because it is perfect for hiking and gives me
better IQ than a P&S camera.

I keep an open mind and not get let myself get fixated on any fanboy
propaganda.

The other thing to keep in mind about your post is physics,
wavelength, diffraction, etc.... A smaller sensor will have more
problems with this than a larger sensor with larger pixels. And I do
like higher resolution because you get better tonal gradations, you
can crop a 3:2 sensor to 4:3 if you want to and still get high
resolution. And I see more detail at a given enlargement with higher
resolution.

the 410/510 are sweet spots in the industry right now. I can see no
reason for someone not to pick up this great value, just know going
in that you are making some compromises and need to work within the
limits of your camera.

Be happy shoot pictures!

 

[joe mama]

I think the mirror can react as quickly as the engineers want to make
it react,

Yes, but you need stronger motors, stronger springs and assembly
and more powerful battery and all those things tend to get bigger
to be stronger. Note how all 5fps+ cameras are quite sizable? And
the 8fps+ ones even more so? For a given camera size, a lighter
mirror can be made to move faster, that was my point.

Once again, I have to disagree. Film SLRs had those high shutter speeds, too, right? And they were not so large. Or am I mistaken?

For sure. I'm not sure why FF DSLRs are so large to begin with --
film DSLRs aren't, and it doesn't seem like they should require much
more electronics, certainly not as much as the size differential
suggests. I've often wondered if the size of larger sensor cameras
has to do with spacing things out more for less electronic
interference and better heat dissapation, rather than the actual bulk
of the eqipment.

I think it is more a question of Canon hoping that those who buy a
€3,000 camera will buy €3,000 lenses and then a bigger camera will balance
those better.

I would disagree once again. I generally support my camera primarily by the lens, not by the body. The only reason I need size on the body is for the viewfinder, LCD, handgrip, and buttons. Of course, maybe I'm weird in how I hold the camera, but I seem to do all right with my technique.

And those who buy a €3,000 camera for bragging rights or to
compensate for something also want a camera of potent size.

For some, I'm sure this is the case. But it would shock me if that was the reason behind the design of such large bodies.

Hmm. So the mirror is up, and there's still a delay before the image
is captured? That's odd. Why is that?

I didn't say that. Shutter speeds higher then approx. the flash synch
are achieved by the second curtain starting to close before the first one
is fully open, thus creating a running gap.

Yeah, I'm just not sure what all that part is about. Shoot, I only learned about a shutter today (I always thought it was just a mirror)! : )

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[Amin Sabet]

Most here have the tact not to say "You are stupid and I am smart." However, multiple people have said a variation of essentially the same thing - eg "It amazes me that people don't understand X" or "I'm amazed that people still think Y." This inflammatory language does not enhance the rest of one's points and makes one appear every bit as foolish as if he or she had said "You are stupid and I am smart." The core discussion here is interesting, but the intellectual chest beating is tiresome.

 

[joe mama]

These aren't mine, Joe:

http://www.pbase.com/domotang/image/23234724
http://www.pbase.com/domotang/image/23234976
http://www.pbase.com/domotang/image/23257483

I guess since I can't see the sensor when the mirror is down, and I see the sensor when the mirror is up when doing a cleaning, that I never knew that there were shutters that covered the sensor until a pic is taken in normal use.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[joe mama]

(5) Because the 4/3 system was designed with telecentric lenses, it
provides better image quality on a per-square-millimeter basis than
any other DSLR system. Every other system is a retrofit of a digital
sensor into a lens system designed for film.

See above. Like I said, they could apply any 4/3 technology to FF
but it is not currently needed because of the sensor resolution is
not high enough to match lens resolution.

...it's been suggested that the reason for the incredible performance of the Nikon 14-24 / 2.8 is that it uses a telecentric, or semi-telecentric design, and that's why it's so large and heavy compared to the Canon UWAs. But, of course, it's IQ is amazing.

As the pixel densities of 35mm FF approach those of the smaller sensor systems, we may find more and more of this in the new 35mm FF lenses.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[marf]

... and I can tell you, that depends how you define "better".

THe only thing is, if Zuiko lenses would be scaled up 2 times, and the sensor surface also, then the sensitivity is better. Approx. 4 times better. BUT

• Full frame lenses are not scaled up 4/3 lenses, they are compromises between how big they should be and what is hand-holdable.
• The full frame mount is also not a scaled-up 4/3 mount, the full-frame mount is also a compromise. This makes wide angle problems.
• THe scaled-up sensor would not cost 4x as much, it would cost approx 20x as much, because various problems. Because this no customer pay, the sensor is not 4x more sensitive
• The sensitivity is the only advantage. There is no law of physics that the Dynamic Range of bigger sensors is bigger. This depends on the capacity of certain elements, and this capacity is theoreticall independant of sensor surface. Despide that there may be other solutions for the DR problem in the future, like adjusting the ISO and shutter speed of each pixel.
• In-Sensor-Antishake is very much more difficult when we want the same Antishake speed

So your simple physics argument is not true.

--
regards
Martin

-----------------------------
Typing errors are intended to provide a basis for global amusement.
I am a part time wedding photographer (50% of my income)

 

[Lee Jay]

These aren't mine, Joe:

http://www.pbase.com/domotang/image/23234724
http://www.pbase.com/domotang/image/23234976
http://www.pbase.com/domotang/image/23257483

I guess since I can't see the sensor when the mirror is down, and I
see the sensor when the mirror is up when doing a cleaning, that I
never knew that there were shutters that covered the sensor until a
pic is taken in normal use.

Reach into your camera, and flip the mirror up with your finger. You'll see the shutter curtains (if you go slow, you'll see the sub-mirror behind the mirror - it sends the image to the AF sensor at the bottom of the mirror box). When you are in sensor cleaning mode, the camera flips up the mirror and opens the shutter.

--
Lee Jay
(see profile for equipment)