EOS 7D and resolution

18 MP is perhaps a stretch ... about 4 microns per pixel versus about 6
microns, which was recently the low-end limit for a reasonable tradeoff
between SNR and resolution. I like the gapless micro-lenses and the
shrinking of the surrounding support electronics at each photo diode site.
But, is the smaller photo-site size really a good idea?

Then, there are the lenses that we can buy. With 18 MP crammed onto an
APS-C sensor, are available lenses up to the task? Which ones?

As to being feature-rich, the 7D is way up there. However, the issue for
many is dynamic range, low-light performance, and what one can capture with
available lenses.

Any thoughts on this?

The MP race will only be over when it is over.

"Charles" wrote:
18 MP is perhaps a stretch ... about 4 microns per pixel versus about 6
microns, which was recently the low-end limit for a reasonable tradeoff
between SNR and resolution. I like the gapless micro-lenses and the
shrinking of the surrounding support electronics at each photo diode site.
But, is the smaller photo-site size really a good idea?

Then, there are the lenses that we can buy. With 18 MP crammed onto an
APS-C sensor, are available lenses up to the task? Which ones?

Almost all the better FF lenses will be fine, although maybe only when
stopped down a bit. I'd guess a lot of APS-C only lenses would be iffy.

As to being feature-rich, the 7D is way up there.

Lots of very nice features. Two-axis in-viewfinder level! On-demand grid
lines. Better AF, live view, video.

However, the issue for many is dynamic range, low-light performance, and
what one can capture with available lenses.

Dynamic range is a bit overrated. Most color landscape work is shot using
the Velvia films which have nowhere near the dynamic range of a P&S camera,
let alone the 7D.

And if you need dynamic range, you can always noise reduce at the cost of
resolution.

The MP race will only be over when it is over.

And then there's John Sheehy's point: an 18MP camera will always produce
more detailed images (in a print of the same size, for all sizes) than a 9MP
camera. Always. That difference may be marginal, but it's always there.
That's because MTFs combine multiplicatively. The worst of the two
determines the max possible performance of the system and the better of the
two determines how close you get.

--
David J. Littleboy
Tokyo, Japan

On Sat, 26 Sep 2009 08:10:23 +0900, "David J. Littleboy"
wrote:
:
: "Charles" wrote:
: 18 MP is perhaps a stretch ... about 4 microns per pixel versus about 6
: microns, which was recently the low-end limit for a reasonable tradeoff
: between SNR and resolution. I like the gapless micro-lenses and the
: shrinking of the surrounding support electronics at each photo diode site.
: But, is the smaller photo-site size really a good idea?
:
: Then, there are the lenses that we can buy. With 18 MP crammed onto an
: APS-C sensor, are available lenses up to the task? Which ones?
:
: Almost all the better FF lenses will be fine, although maybe only when
: stopped down a bit. I'd guess a lot of APS-C only lenses would be iffy.
:
: As to being feature-rich, the 7D is way up there.
:
: Lots of very nice features. Two-axis in-viewfinder level! On-demand grid
: lines. Better AF, live view, video.

I've always wondered why we couldn't have an in-viewfinder level. I have the
misfortune of being able to immediately see a half-degree horizon error, while
routinely making errors of a degree or more, even with a viewfinder crammed
with grid lines. That feature alone makes me lust for a 7D.

It seems to me that if it lives up to its specs, the 7D raises serious
questions about the future of FF. It halves the MP gap between the 50D and the
5D2 at a price $1000 below the 5D2, and it preserves a user's investment in
APS-C lenses. Unless the price of FF cameras comes down quickly and
dramatically, I suspect that many serious amateurs who might have gone FF
sooner rather than later may simply rethink the whole concept.

How about you, Bret? Would you have still bought a 5D2 if the 7D had been an
option at the time?

Bob

Robert Coe wrote:

It seems to me that if it lives up to its specs, the 7D raises serious
questions about the future of FF.

Really? Such as "is MPix everything?" and "If you need more
MPix, why not upscale your image?"?

It halves the MP gap between the 50D and the
5D2 at a price $1000 below the 5D2,

I'm using a 20D. I don't feel much of a gap. Sure, many P&S
currently out-pixel me. They don't out-image me.

Limits? Of course a 20D has limits. Some of them are clearly
felt, but they mostly relate to low light capability for me.
Too few pixels? Never felt that as a problem.

Yes, I lust after a 5D2, because the pixel size is the same but
the sensor has been much improved. For me, give me larger pixels,
not more.

and it preserves a user's investment in
APS-C lenses.

Kit lenses and their ilk aren't much of an investment, and those
who made investments other than the 10-22mm *knew* they would
stay with crop frames. Me, I like to keep my way to FF open.

Unless the price of FF cameras comes down quickly and
dramatically, I suspect that many serious amateurs who might have gone FF
sooner rather than later may simply rethink the whole concept.

Pixel fixation speaking?

Building a FF with the 7D pixel size would yield 46MPix.
Always remember that the tricks you can do with crop sensors
work just as well on FF.

-Wolfgang

On Sat, 26 Sep 2009 22:53:55 +0200, Wolfgang Weisselberg
wrote:
: Robert Coe wrote:
:
: It seems to me that if it lives up to its specs, the 7D raises serious
: questions about the future of FF.
:
: Really? Such as "is MPix everything?" and "If you need more
: MPix, why not upscale your image?"?
:
: It halves the MP gap between the 50D and the
: 5D2 at a price $1000 below the 5D2,
:
: I'm using a 20D. I don't feel much of a gap. Sure, many P&S
: currently out-pixel me. They don't out-image me.
:
: Limits? Of course a 20D has limits. Some of them are clearly
: felt, but they mostly relate to low light capability for me.
: Too few pixels? Never felt that as a problem.
:
: Yes, I lust after a 5D2, because the pixel size is the same but
: the sensor has been much improved. For me, give me larger pixels,
: not more.
:
: and it preserves a user's investment in
: APS-C lenses.
:
: Kit lenses and their ilk aren't much of an investment, and those
: who made investments other than the 10-22mm *knew* they would
: stay with crop frames. Me, I like to keep my way to FF open.
:
: Unless the price of FF cameras comes down quickly and
: dramatically, I suspect that many serious amateurs who might have gone FF
: sooner rather than later may simply rethink the whole concept.
:
: Pixel fixation speaking?
:
: Building a FF with the 7D pixel size would yield 46MPix.
: Always remember that the tricks you can do with crop sensors
: work just as well on FF.

My 50D is less than a year old, so I have no dog in this hunt. But if I were
in your shoes, with a once excellent APS-C camera that's gone a bit long in
the tooth, I think I might be more likely to replace it with a 7D than with a
5D2.

But that wasn't my point. My point was that a lot of people may feel that way.
And that Canon may have concluded that that's where the future is, at least in
the near term. Your vigorously defensive reaction syggests to me that you may
secretly suspect that I'm right. ;^)

Bob

Rich wrote in
:

The output from this new Canon seems very good, perhaps the best of
the current APS sized sensored cameras. Maybe.

At high ISO, certainly, based on the RAWs available. For base ISO, I've
seen at least one alarmingly poor sample, with an 8-column periodic
blackpoint offset pattern, with an amplitude of almost 20 14-bit ADUs.
Hope that was just a lemon, or an uncalibrated pre-production unit.

Robert Coe wrote:

My 50D is less than a year old, so I have no dog in this hunt. But if I were
in your shoes, with a once excellent APS-C camera that's gone a bit long in
the tooth,

The camera is about as good as it was on the day it was made.
It's even better in my hands than it was there in the beginning
since I have learned a lot about the dos and don'ts with that body.
:-)

So, I have an excellent APS-C camera that is eclipsed by some even
more excellent offerings. Life is good whether I upgrade or not.
Isn't that great? :-)

I think I might be more likely to replace it with a 7D than with a
5D2.

I don't think I represent a majority or important minority.

But that wasn't my point. My point was that a lot of people may feel that way.

It seems a lot of people are, uhm, a bit megapixel crazy.

A chain being only as strong as the weakest link, I feel that
resolution is already being limited by most lenses outside
their best apertures at lower than the present megapixels.
(I don't think you'll get a noticeably better image from a wide
open EF 50mm f/1.4 at 18MPix than at 8MPix + sensible upscaling
(e.g. Lanczos scaling) where needed, for a drastic example.)

And that Canon may have concluded that that's where the future is, at least in
the near term. Your vigorously defensive reaction syggests to me that you may
secretly suspect that I'm right. ;^)

Canon has concluded that they need to sell cameras and to sell
cameras they need to compete in features and marketing numbers.
Megapixel record numbers belong there.

If suddenly a serious part of the camera buyers(!) would decide
cameras needed to look like puppys and smell of burned toast ---
well, Canon would be stupid to not offer them exactly that.

As for *me*, that's not where *my* future lies, yes.

-Wolfgang

"Wolfgang Weisselberg" wrote in message


[...]

Canon has concluded that they need to sell cameras and to sell
cameras they need to compete in features and marketing numbers.
Megapixel record numbers belong there.

Yes and no. They dropped the megapixel count on the G11.

-------- Original Message --------
Subject: EOS 7D and resolution
From: Wolfgang Weisselberg
To:
Date: 29/09/2009 12:33 p.m.

Robert Coe wrote:

My 50D is less than a year old, so I have no dog in this hunt. But if I were
in your shoes, with a once excellent APS-C camera that's gone a bit long in
the tooth,

The camera is about as good as it was on the day it was made.
It's even better in my hands than it was there in the beginning
since I have learned a lot about the dos and don'ts with that body.
:-)

So, I have an excellent APS-C camera that is eclipsed by some even
more excellent offerings. Life is good whether I upgrade or not.
Isn't that great? :-)

I think I might be more likely to replace it with a 7D than with a
5D2.

I don't think I represent a majority or important minority.

But that wasn't my point. My point was that a lot of people may feel that way.

It seems a lot of people are, uhm, a bit megapixel crazy.

A chain being only as strong as the weakest link, I feel that
resolution is already being limited by most lenses outside
their best apertures at lower than the present megapixels.
(I don't think you'll get a noticeably better image from a wide
open EF 50mm f/1.4 at 18MPix than at 8MPix + sensible upscaling
(e.g. Lanczos scaling) where needed, for a drastic example.)

And that Canon may have concluded that that's where the future is, at least in
the near term. Your vigorously defensive reaction syggests to me that you may
secretly suspect that I'm right. ;^)

Canon has concluded that they need to sell cameras and to sell
cameras they need to compete in features and marketing numbers.
Megapixel record numbers belong there.

If suddenly a serious part of the camera buyers(!) would decide
cameras needed to look like puppys and smell of burned toast ---
well, Canon would be stupid to not offer them exactly that.

As for *me*, that's not where *my* future lies, yes.

-Wolfgang

Even if the lens cannot equal the sensor for resolution, the image will
still be better than with fewer pixels. The resultant resolution is
always a function of both lens and sensor. I've pointed this out
several times in the past.

The maximum resolution obtainable in practical photographic work is
limited both by the camera lens and by the film/sensor. The formula
often used to predict the resolution of a camera original is:

1/Rt2 = 1/Rs2 + 1/RL2 (Higgins, G.C.Appl. Opt. 3, v.1, 9, Jan 1964)

Rt = Resolution of the system (lens + sensor)

Rs = Resolution of the sensor

RL = Resolution of the lens

As you can see, system resolution is not just lens resolution alone.

--

Colin D.

-------- Original Message --------
Subject: EOS 7D and resolution
From: Wolfgang Weisselberg
To:
Date: 29/09/2009 12:33 p.m.

Robert Coe wrote:

My 50D is less than a year old, so I have no dog in this hunt. But if I were
in your shoes, with a once excellent APS-C camera that's gone a bit long in
the tooth,

The camera is about as good as it was on the day it was made.
It's even better in my hands than it was there in the beginning
since I have learned a lot about the dos and don'ts with that body.
:-)

So, I have an excellent APS-C camera that is eclipsed by some even
more excellent offerings. Life is good whether I upgrade or not.
Isn't that great? :-)

I think I might be more likely to replace it with a 7D than with a
5D2.

I don't think I represent a majority or important minority.

But that wasn't my point. My point was that a lot of people may feel that way.

It seems a lot of people are, uhm, a bit megapixel crazy.

A chain being only as strong as the weakest link, I feel that
resolution is already being limited by most lenses outside
their best apertures at lower than the present megapixels.
(I don't think you'll get a noticeably better image from a wide
open EF 50mm f/1.4 at 18MPix than at 8MPix + sensible upscaling
(e.g. Lanczos scaling) where needed, for a drastic example.)

And that Canon may have concluded that that's where the future is, at least in
the near term. Your vigorously defensive reaction syggests to me that you may
secretly suspect that I'm right. ;^)

Canon has concluded that they need to sell cameras and to sell
cameras they need to compete in features and marketing numbers.
Megapixel record numbers belong there.

If suddenly a serious part of the camera buyers(!) would decide
cameras needed to look like puppys and smell of burned toast ---
well, Canon would be stupid to not offer them exactly that.

As for *me*, that's not where *my* future lies, yes.

-Wolfgang

Even if the lens cannot equal the sensor for resolution, the image will
still be better than with fewer pixels. The resultant resolution is
always a function of both lens and sensor. I've pointed this out
several times in the past.

The maximum resolution obtainable in practical photographic work is
limited both by the camera lens and by the film/sensor. The formula
often used to predict the resolution of a camera original is:

1/Rt2 = 1/Rs2 + 1/RL2 (Higgins, G.C.Appl. Opt. 3, v.1, 9, Jan 1964)

Rt = Resolution of the system (lens + sensor)

Rs = Resolution of the sensor

RL = Resolution of the lens

As you can see, system resolution is not just lens resolution alone.

--

Colin D.