Sign in with
Sign up | Sign in
Your question

Resolution with APS sensor vs. full-frame

Last response: in Digital Camera
Share
Anonymous
September 26, 2005 3:21:11 AM

Archived from groups: rec.photo.digital (More info?)

I'm having difficulty getting my head around the variables with DSLR's.
Would I be correct in thinking that an 8MP APS sensor camera like the
EOS 20D would be just as good for the bird photographer as the 5D
(costing considerably more) with the same lens when the image from the
latter is cropped to the same area as that captured by the former? Or is
it not quite as simple as that - is the resolution better by default
with a full-frame sensor?

I've always considered the 1.5 factor to be a real advantage with my 20D
allowing me to get more magnification for my money. What would I be
gaining by upgrading to the 5D?

--
Paul Flackett
Anonymous
September 26, 2005 3:21:12 AM

Archived from groups: rec.photo.digital (More info?)

Paul Flackett wrote:

> I'm having difficulty getting my head around the variables with DSLR's.
> Would I be correct in thinking that an 8MP APS sensor camera like the
> EOS 20D would be just as good for the bird photographer as the 5D
> (costing considerably more) with the same lens when the image from the
> latter is cropped to the same area as that captured by the former? Or is
> it not quite as simple as that - is the resolution better by default
> with a full-frame sensor?
>
> I've always considered the 1.5 factor to be a real advantage with my 20D
> allowing me to get more magnification for my money. What would I be
> gaining by upgrading to the 5D?
>
5D, 20D comparison:
http://www.dpreview.com/articles/canoneos5d

They way I see it: 20D is 5 frames/sec, 5D is 3.
5D has 8.2 microns pixels versus the 20D 6.2 micron
pixels. The larger pixels will make for better images
in general and sharper images/pixel for a given lens.

The smaller pixels of the 20D will give more pixels per given
cropped area. With processing, I would bet there would be
a slight advantage to the 20D images compared to the
same area cropped 5D, but not as much as the number
of pixels would indicate. For birds, the higher frame
rate could be an advantage with the 20D.

Then the question 5D versus 1Ds Mark II (is the price
increase of the 1dsII worth it over the 5D)? Will the 5D
put pressure to drop the price of the 1DsII?

Roger
September 26, 2005 3:21:12 AM

Archived from groups: rec.photo.digital (More info?)

Paul Flackett wrote:

>I'm having difficulty getting my head around the variables with DSLR's.
>Would I be correct in thinking that an 8MP APS sensor camera like the
>EOS 20D would be just as good for the bird photographer as the 5D
>(costing considerably more) with the same lens when the image from the
>latter is cropped to the same area as that captured by the former? Or is
>it not quite as simple as that - is the resolution better by default
>with a full-frame sensor?

It's not as simple as that.

There are advantages to both imaging sensors, and it depends a lot on
what you want to accomplish. But comparing the 20D and 5D imaging
sensors, you will find the 5D has a larger "receiving area", which
should translate into less noise and a brighter image with the same
lense and same conditions.

>I've always considered the 1.5 factor to be a real advantage with my 20D
>allowing me to get more magnification for my money.

This is a common misconception - it's a crop factor, not any kind of
magnification.

Putting a 200mm lense on a 20D does _NOT_ get you any closer to the
subject than using the same 200mm lense on a full frame camera.

A 200mm lense is a 200mm lense, on a full frame and a 1.6x body. The
difference is _ONLY_ the field of view, or how wide the final image will
appear and how much scenery will be visible around the subject.

To see an example image of what this means, scroll about a quarter of
the way down the following page:

http://www.jimdoty.com/Digital/fov_crop/fov_crop.html

Further down, another example shows the difference between full frame
and 1.6x crop with a 400mm lense and how the zoomed size appears larger.

> What would I be gaining by upgrading to the 5D?

Lots of things related to features and performance, and slightly better
image quality.

I think the biggest advantage would be the full frame sensor that allows
you to use a 28mm lense as it was intended. For wildlife photography,
it's not a major factor.
Related resources
September 26, 2005 5:04:46 AM

Archived from groups: rec.photo.digital (More info?)

Bill wrote:


>
>>I've always considered the 1.5 factor to be a real advantage with my 20D
>>allowing me to get more magnification for my money.
>
> This is a common misconception - it's a crop factor, not any kind of
> magnification.

Actually it changes the FOV which is what also happens when you use a higher
magnification lens. Why people are so hung up on relating everything to
35mm full frame mm of focal length is something I'll never understand. Or
why this "It's works like that mm of lens is suposed to". Focal length and
FOV changes with format whether it's 6X9, 4X5, 4/3 or APS.

FOV is all that really matters. A 90mm lens is a nice wide lens on a 4X5,
should I be upset and demand that any camera should have a wide FOV with a
90mm lens? Of course not, that would be a silly arguement.

>
> Putting a 200mm lense on a 20D does _NOT_ get you any closer to the
> subject than using the same 200mm lense on a full frame camera.

In real use it does. A 200mm lens is a wide angle lens on an 8X10 camera,
doesn't mean it's still a wide angle lens used on a 20D.

Using the same 200mm lens on a 20D will get you closer than that same lens
used on a 35mm camera or a 5D, unless you crop the image of course. Then
you have less MP so it's doubtful the image quality would be as good. And
why pay $3500 to "upgrade" if your going to end up cropping to a smaller MP
final image?

>
> A 200mm lense is a 200mm lense, on a full frame and a 1.6x body. The
> difference is _ONLY_ the field of view,

Which is all that matters, the mm of the lens is a meaningless number. FOV
is all anyone should care about, period! Why people rant about this "A
200mm lens is a 200mm lens" is absurd. From what you're saying, there is no
difference between

http://www.bhphotovideo.com/bnh/controller/home?O=produ...

And

http://www.bhphotovideo.com/bnh/controller/home?O=produ...

except the first has an angle of view of 55 deg and the second of 12 degree
like that's of no real concern to the end user and we should be FOCUSED on
the number of mm the focal length of the lens is..


>
> To see an example image of what this means, scroll about a quarter of
> the way down the following page:
>
> http://www.jimdoty.com/Digital/fov_crop/fov_crop.html
>
> Further down, another example shows the difference between full frame
> and 1.6x crop with a 400mm lense and how the zoomed size appears larger.
>
>> What would I be gaining by upgrading to the 5D?
>
> Lots of things related to features and performance, and slightly better
> image quality.

Not unless he buys new longer/larger/heavier/more expencive lenses so he has
the same FOV across the whole sensor.

--

Stacey
Anonymous
September 26, 2005 6:41:27 AM

Archived from groups: rec.photo.digital (More info?)

On Sun, 25 Sep 2005 17:18:27 -0600, Roger N. Clark (change username
to rnclark) wrote:

> They way I see it: 20D is 5 frames/sec, 5D is 3.
> 5D has 8.2 microns pixels versus the 20D 6.2 micron
> pixels. The larger pixels will make for better images
> in general and sharper images/pixel for a given lens.
>
> The smaller pixels of the 20D will give more pixels per given
> cropped area. With processing, I would bet there would be
> a slight advantage to the 20D images compared to the
> same area cropped 5D, but not as much as the number
> of pixels would indicate. For birds, the higher frame
> rate could be an advantage with the 20D.

I think it would be more than a slight advantage, unless I'm
making a calculation error somewhere. If the 20D's sensor was as
large as the 5D's sensor it would have 6.2 x 1.6 x 1.6, or about
15.9mp. So if the same focal length is used with both sensors, any
subject's image that fits within both sensors (as would be the case
where you can't get close enough to a bird to fill the frame), the
image on the 5D's sensor would utilize 8.2 / 15.9, or 0.52 times the
number of pixels. That is, the image in the 20D would contain
nearly twice the number of pixels. The 5D would have the edge only
if the bird was close enough so that the 20D would have to use a
much shorter focal length than the 5D to keep the bird's image from
exceeding the size of the sensor.
September 26, 2005 7:06:44 AM

Archived from groups: rec.photo.digital (More info?)

ASAAR wrote:


>
> I think it would be more than a slight advantage, unless I'm
> making a calculation error somewhere.

No way, the 5D RULES!!! Don't you know anything? :-)
--

Stacey
Anonymous
September 26, 2005 12:17:56 PM

Archived from groups: rec.photo.digital (More info?)

> Paul Flackett writes ...
>
>Would I be correct in thinking that an 8MP APS sensor camera like the
>EOS 20D would be just as good for the bird photographer as the 5D
>(costing considerably more) with the same lens

Most bird photographers would do better with the 20D due to the 1.6x
crop (actually EVERY pro bird photographer I know who uses Canon gear
uses a 1D Mark II now instead of full frame bodies). I have a 1x
camera (1Ds, 11 Mpix) and a 1.3x camera (1D M II, 8 Mpix) and while I
prefer the image quality of the 1Ds, for birds and wildlife I use the
MII about 8x as often (I usually have both bodies available) because of
the faster AF, higher frame rate and longer "reach" ... we can print
11x14" easily and sometimes 16x20" with these images and that's enough
for bird images.

>I've always considered the 1.5 factor to be a real advantage with my 20D
>allowing me to get more magnification for my money

It is, and I wouldn't upgrade for just birds or bears or other wildlife
shooting where the extra reach is a bonus ...

Bill
Anonymous
September 26, 2005 12:53:18 PM

Archived from groups: rec.photo.digital (More info?)

In article <h84fj1pnl9r3ds3bjekc80ogb0q801h6re@4ax.com>, ASAAR
<caught@22.com> writes
>On Sun, 25 Sep 2005 17:18:27 -0600, Roger N. Clark (change username
>to rnclark) wrote:
>
>> They way I see it: 20D is 5 frames/sec, 5D is 3.
>> 5D has 8.2 microns pixels versus the 20D 6.2 micron
>> pixels. The larger pixels will make for better images
>> in general and sharper images/pixel for a given lens.
>>
>> The smaller pixels of the 20D will give more pixels per given
>> cropped area. With processing, I would bet there would be
>> a slight advantage to the 20D images compared to the
>> same area cropped 5D, but not as much as the number
>> of pixels would indicate. For birds, the higher frame
>> rate could be an advantage with the 20D.
>
> I think it would be more than a slight advantage, unless I'm
>making a calculation error somewhere. If the 20D's sensor was as
>large as the 5D's sensor it would have 6.2 x 1.6 x 1.6, or about
>15.9mp. So if the same focal length is used with both sensors, any
>subject's image that fits within both sensors (as would be the case
>where you can't get close enough to a bird to fill the frame), the
>image on the 5D's sensor would utilize 8.2 / 15.9, or 0.52 times the
>number of pixels.
>
Not quite - you are using the wrong resolution for the 5D, it has
12.9Mp, not 8.2Mp.

Cropped to the same focal plane area, the pixel resolution is simply the
square of the pixel pitch. On the 20D that is 6.4um; on the 5D it is
8.2um, so the 20D will have around 1.64x as many pixels in any given
crop size, including the full APS crop of the 20D.

However, pixel counts isn't everything - all pixels are not equal. Those
smaller pixels demand more performance out of the optic to be properly
resolved - same problem that besets P&S digital cameras, albeit on a
different scale. Even with diffraction limited optic, for anything
above f/11 the actual resolution of the image is determined by the lens
not the 6.4um pixels. For 8.2um. that increases by over a stop. So if
you are shooting at f/16 you won't really be getting 8Mp of information
on the image with the 20D, more than 50% of it is superfluous redundant
data. In addition to which, the larger pixels from the 5D *ought* to be
(since they aren't in general supply yet that is an assumption) more
sensitive and less noisy.

Taking everything into account, what actually matters in these type of
estimates is usually total focal plane area. How it is diced up into
small noisy pixels or large sensitive ones is generally a second or
third order effect as long as the pixel sizes being compared are within
the useful range photographically.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
Anonymous
September 26, 2005 1:17:37 PM

Archived from groups: rec.photo.digital (More info?)

So what your saying is that the 20D and th 1D MII are for the birds! :) 

It seems to me that the answer is application dependent. As a
generalist,
I think someone who has an arsenal of lenses he/she has built up over a
number
of years does not want to have them subjected to a crop or FOV 'shift'
to
accomodate a smaller than full frame sensor.
Anonymous
September 26, 2005 1:20:44 PM

Archived from groups: rec.photo.digital (More info?)

"Paul Flackett" <no_spam@rainow.demon.co.uk> wrote:
> I'm having difficulty getting my head around the variables with DSLR's.
> Would I be correct in thinking that an 8MP APS sensor camera like the EOS
> 20D would be just as good for the bird photographer as the 5D (costing
> considerably more) with the same lens when the image from the latter is
> cropped to the same area as that captured by the former? Or is it not
> quite as simple as that - is the resolution better by default with a
> full-frame sensor?

For the bird photographer, the 64-dollar question is how well does the
(slightly) improved AF tracking (with the 6 extra sensors) work with a 1.4x
TC as opposed to the 20D's AF without the TC.

> I've always considered the 1.5 factor to be a real advantage with my 20D
> allowing me to get more magnification for my money. What would I be
> gaining by upgrading to the 5D?

(1) 25% better linear resolution (using lenses with the same FOV)
(2) Lower noise (should be noticeable at ISO 800 and above)
(3) Better dynamic range (should be noticeable at ISO 100)
(4) Spot meter
(5) Interchangeable focusing screens
(6) Ability to get a 12mm FOV with the Sigma 12-24.
(7) Fisheye
(8) The 24mm TSE acts like a 24mm TSE instead of a 38mm TSE

Note that all of these are enormous for landscape photographers, not bird
photographers.

David J. Littleboy
Tokyo, Japan
Anonymous
September 26, 2005 1:55:04 PM

Archived from groups: rec.photo.digital (More info?)

> Winhag writes ...
>
>So what your saying is that the 20D and th 1D MII are for the birds! :) 

Yep.

>It seems to me that the answer is application dependent

Paul is a very good bird photographer and he asked specifically about a
camera for birds, so I was just answering his "application dependent"
question, which admittedly is a departure from internet newsgroup
tradition :) 

>As a generalist, I think someone who has an arsenal of lenses
>he/she has built up over a number of years does not want to
>have them subjected to a crop or FOV 'shift'

I'm packing for a "generalist" trip right now and the 1Ds is going
along and the 1D Mark II is getting left at home, though it's more
because I prefer 11 MPix over 8 Mpix and won't need 8 fps to photograph
fall foliage than because of the FOV. One really wide lens would fix
that problem quickly enough.

Bill
Anonymous
September 26, 2005 2:14:18 PM

Archived from groups: rec.photo.digital (More info?)

Paul Flackett wrote:

> I've always considered the 1.5 factor to be a real advantage with my 20D
> allowing me to get more magnification for my money. What would I be
> gaining by upgrading to the 5D?

For bird photography, probably nothing. For studio, wide-angle
("landscape"), or macro work, a fair amount. If you are upgrading from
a 20D for wildlife stuff, you should consider a 1DMkII at this time:
the 8fps is _very_ useful.
Anonymous
September 26, 2005 3:07:01 PM

Archived from groups: rec.photo.digital (More info?)

David Dyer-Bennet wrote:
> "Bill Hilton" <bhilton665@aol.com> writes:
>
> > > Winhag writes ...
>
> > >As a generalist, I think someone who has an arsenal of lenses
> > >he/she has built up over a number of years does not want to
> > >have them subjected to a crop or FOV 'shift'
> >
> > I'm packing for a "generalist" trip right now and the 1Ds is going
> > along and the 1D Mark II is getting left at home, though it's more
> > because I prefer 11 MPix over 8 Mpix and won't need 8 fps to photograph
> > fall foliage than because of the FOV. One really wide lens would fix
> > that problem quickly enough.
>
> That last point is key, yes. I finally invested in a new wide lens to
> extend my digital wide end to match what I had on film (Tokina
> 12-24mm). Meanwhile, the much more expensive fast long lenses all get
> a little better :-)
> --
> David Dyer-Bennet, <mailto:D d-b@dd-b.net>, <http://www.dd-b.net/dd-b/&gt;
> RKBA: <http://noguns-nomoney.com/&gt; <http://www.dd-b.net/carry/&gt;
> Pics: <http://dd-b.lighthunters.net/&gt; <http://www.dd-b.net/dd-b/SnapshotAlbum/&gt;
> Dragaera/Steven Brust: <http://dragaera.info/&gt;

But it is not always that simple. For example suppose you like to shoot
on the street with your fast 50mm f/1.4 lens. With the 1.6X factor,
that is now an (has the same FOV of a 35 mm full frame) 80mm lens, not
quite the same beast. I have seen 30mm f/1.4 lenses coming out to
satisfy that need. But I feel you should not have to buy a number of
lenses to compensate for the (probably temporary) high cost of
manufacturing full frame sensors. I am inclined to put the 'extra lens'
money towards something like a 5D and not buy lenses which may lose
their usefullness over just a few years. The argument could go a number
of ways depending on individual needs. In my case, I immediately
cancelled my order for the Canon 10-22mm EF-S lens when I heard the
first rumors of the 5D. Not saying I will go that way, but there was no
way I was going to plunk down that kind of money for a lens I may not
end up needing.
Anonymous
September 26, 2005 4:06:03 PM

Archived from groups: rec.photo.digital (More info?)

>> One really wide lens would fix that problem quickly enough.

>Winhag writes ...
>
>But it is not always that simple.

True, especially if you are talking about fixed focal length lenses
like in your example. But then over 90% of lenses sold are zooms ...

> For example suppose you like to shoot on the street with your fast
>50mm f/1.4 lens. With the 1.6X factor, that is now an (has the same
>FOV of a 35 mm full frame) 80mm lens, not quite the same beast.

Right, it's an 80 mm f/1.4 equivalent, which is a good deal when you
consider the weight and cost of Canon's 85 mm f/1.2 L :)  That's one of
the points David and I were making, whatever you lose at the wide angle
end you gain back at the telephoto end.

In this situation I'd simply use the 35 mm f/2, which is very good
optically and much lighter than the 50 f/1.4, plus is inexpensive (I
have this lens and use it on the street with an 85 mm f/1.8, nice
combination). Now you have a 56 mm equivalent plus a fast 80 mm
equivalent so quit griping. Sure you lose one stop from the f/1.4 (go
to the 28 mm f/1.8 if you really need the speed I guess) but a nice
feature about digital is the ability to bump the iso up a stop when you
need the extra speed.

>But I feel you should not have to buy a number of
>lenses to compensate for the (probably temporary) high cost
>of manufacturing full frame sensors.

Canon will apparently be offering both 1.6 and 1.0x sensors for a while
(plus the 1.3x of the 1D Mark II for a while longer) so pick a sensor
size and stick with it if you're worried about shifting equivalent
focal lengths, I guess. Most of us are coming from the 35 mm world
where all our lenses were effectively 1x previously, so cameras like
the 5D are just bringing us back to where we started, focal-length
wise. So it's no big deal, except for those buying the EF-S lenses ...

Bill
Anonymous
September 26, 2005 4:55:38 PM

Archived from groups: rec.photo.digital (More info?)

"Bill Hilton" <bhilton665@aol.com> writes:

> > Winhag writes ...

> >As a generalist, I think someone who has an arsenal of lenses
> >he/she has built up over a number of years does not want to
> >have them subjected to a crop or FOV 'shift'
>
> I'm packing for a "generalist" trip right now and the 1Ds is going
> along and the 1D Mark II is getting left at home, though it's more
> because I prefer 11 MPix over 8 Mpix and won't need 8 fps to photograph
> fall foliage than because of the FOV. One really wide lens would fix
> that problem quickly enough.

That last point is key, yes. I finally invested in a new wide lens to
extend my digital wide end to match what I had on film (Tokina
12-24mm). Meanwhile, the much more expensive fast long lenses all get
a little better :-)
--
David Dyer-Bennet, <mailto:D d-b@dd-b.net>, <http://www.dd-b.net/dd-b/&gt;
RKBA: <http://noguns-nomoney.com/&gt; <http://www.dd-b.net/carry/&gt;
Pics: <http://dd-b.lighthunters.net/&gt; <http://www.dd-b.net/dd-b/SnapshotAlbum/&gt;
Dragaera/Steven Brust: <http://dragaera.info/&gt;
Anonymous
September 26, 2005 6:46:03 PM

Archived from groups: rec.photo.digital (More info?)

"Stacey" <fotocord@yahoo.com> wrote:
> Bill wrote:
>>
>>> What would I be gaining by upgrading to the 5D?
>>
>> Lots of things related to features and performance, and slightly better
>> image quality.
>
> Not unless he buys new longer/larger/heavier/more expencive lenses so he
> has
> the same FOV across the whole sensor.

Most people will only need one new lens, the longest one. All the others
will work fine. Unless they bet on the wrong horse.

David J. Littleboy
Tokyo, Japan
September 26, 2005 6:46:04 PM

Archived from groups: rec.photo.digital (More info?)

David J. Littleboy wrote:

>
> "Stacey" <fotocord@yahoo.com> wrote:
>> Bill wrote:
>>>
>>>> What would I be gaining by upgrading to the 5D?
>>>
>>> Lots of things related to features and performance, and slightly better
>>> image quality.
>>
>> Not unless he buys new longer/larger/heavier/more expencive lenses so he
>> has
>> the same FOV across the whole sensor.
>
> Most people will only need one new lens, the longest one.

Which will also be the most expencive, heaviest, largest lens they've ever
owned.

If they were using a 200mm f2.8 1.68 pound lens and liked this FOV on the
20D

http://www.bhphotovideo.com/bnh/controller/home?O=produ...

They'd have to get at least a 300 f4 2.6 pound lens at twice the price and a
full stop slower.

http://www.bhphotovideo.com/bnh/controller/home?O=produ...

If they want the same lens speed, add 4.5 pounds to the weight of the 200mm
lens and about $3000 more bucks!

Yea that's nothing for anyone to concern themselves with. Just plop down
$3500 for the body upgrade and $3800 for a new lens to cover the same FOV
at the same speed and haul around 5 -more- pounds of camera.

--

Stacey
Anonymous
September 26, 2005 9:29:51 PM

Archived from groups: rec.photo.digital (More info?)

"Stacey" <fotocord@yahoo.com> wrote in message
news:3ppktcFbnfqfU1@individual.net...
> David J. Littleboy wrote:
>
>>
>> "Stacey" <fotocord@yahoo.com> wrote:
>>> Bill wrote:
>>>>
>>>>> What would I be gaining by upgrading to the 5D?
>>>>
>>>> Lots of things related to features and performance, and slightly better
>>>> image quality.
>>>
>>> Not unless he buys new longer/larger/heavier/more expencive lenses so he
>>> has
>>> the same FOV across the whole sensor.
>>
>> Most people will only need one new lens, the longest one.
>
> Which will also be the most expencive, heaviest, largest lens they've ever
> owned.
>
> If they were using a 200mm f2.8 1.68 pound lens and liked this FOV on the
> 20D
>
> http://www.bhphotovideo.com/bnh/controller/home?O=produ...
>
> They'd have to get at least a 300 f4 2.6 pound lens at twice the price and
> a
> full stop slower.
>
> http://www.bhphotovideo.com/bnh/controller/home?O=produ...
>
> If they want the same lens speed, add 4.5 pounds to the weight of the
> 200mm
> lens and about $3000 more bucks!
>
> Yea that's nothing for anyone to concern themselves with. Just plop down
> $3500 for the body upgrade and $3800 for a new lens to cover the same FOV
> at the same speed and haul around 5 -more- pounds of camera.
>
> --
>
> Stacey

Well, you pays yer money and you take yer choices, don't you?

--
Skip Middleton
http://www.shadowcatcherimagery.com
Anonymous
September 27, 2005 3:17:49 AM

Archived from groups: rec.photo.digital (More info?)

In message <1127753704.834261.119880@z14g2000cwz.googlegroups.com>, Bill
Hilton <bhilton665@aol.com> writes
>> Winhag writes ...
>>
>>So what your saying is that the 20D and th 1D MII are for the birds! :) 
>
>Yep.
>
>>It seems to me that the answer is application dependent
>
>Paul is a very good bird photographer

Why thankee kindly Bill.
>
And thanks everyone for your views. I think I'm going to have to stop
worrying about whether I've bought the right equipment. I've been
beating myself up for ages about about buying the Canon 400 f4 IS DO
instead of the 500 f4 IS but then I just remind myself that it's about
half the weight and I've probably taken it places hanging from my
shoulder when I would have left the 500 at home.

Not being a professional, (in fact I haven't made any money from
photography at all yet) I can only afford one of everything!

--
Paul Flackett
Anonymous
September 27, 2005 6:10:34 AM

Archived from groups: rec.photo.digital (More info?)

In article <1sigj1ldandkc8fcl498ohpgu83vpj9jcn@4ax.com>, ASAAR
<caught@22.com> writes
>On Mon, 26 Sep 2005 08:53:18 +0100, Kennedy McEwen wrote:
>
>
>> However, pixel counts isn't everything - all pixels are not equal. Those
>> smaller pixels demand more performance out of the optic to be properly
>> resolved - same problem that besets P&S digital cameras, albeit on a
>> different scale. Even with diffraction limited optic, for anything
>> above f/11 the actual resolution of the image is determined by the lens
>> not the 6.4um pixels. For 8.2um. that increases by over a stop. So if
>> you are shooting at f/16 you won't really be getting 8Mp of information
>> on the image with the 20D, more than 50% of it is superfluous redundant
>> data. In addition to which, the larger pixels from the 5D *ought* to be
>> (since they aren't in general supply yet that is an assumption) more
>> sensitive and less noisy.
>
> I think you're going a little overboard here in trying to
>emphasize the superiority of FF sensors. The example under
>discussion was of using a long focal length to maximize the size of
>a bird's image. Do nature photographers often use apertures as
>small as f/16? I don't think they carry the excessive weight of a
>really good, large lens only to stop it down to a tiny aperture.

Obviously I don't think I am going overboard at all, otherwise I would
not have made the point. ;-) However, you are reading it with too much
restriction to its meaning. Note that the comparison I made was *even*
with a diffraction limited optic. Whilst most good 35mm lenses will be
close to diffraction limited at f/8 or higher, they generally fall quite
a long way short of that at larger apertures - and those shortfalls will
be just as significant to the small pixels of the 20D as the diffraction
limitations are at higher apertures. So it doesn't matter whether they
carry the excess weight of an f/2.8 or an f/4 to stop it down or not -
the performance limitation will still be more problematic on the smaller
pixel camera.

>And while as you say, the 5D ought to be less noisy, the difference
>in size between the 20D and 5D sensors is much less that the
>difference in size between notoriously noisy P&S sensors and the
>20D's sensor. So if the 5D is less noisy that the 20D, it probably
>won't be by nearly as large margin.
>
It will be at least proportional to the pixel area. In practice it will
probably more than that since some of the architecture of the pixel
itself, eg. tracks and transistor sizes, are fixed, making the ratio of
storage capacitor of each pixel to be greater than the ratio of the
pixel areas themselves. This is normal will all CMOS sensors.

--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
Anonymous
September 27, 2005 6:10:35 AM

Archived from groups: rec.photo.digital (More info?)

On Tue, 27 Sep 2005 02:10:34 +0100, Kennedy McEwen wrote:

>> And while as you say, the 5D ought to be less noisy, the difference
>> in size between the 20D and 5D sensors is much less that the
>> difference in size between notoriously noisy P&S sensors and the
>> 20D's sensor. So if the 5D is less noisy that the 20D, it probably
>> won't be by nearly as large margin.
>
> It will be at least proportional to the pixel area. In practice it will
> probably more than that since some of the architecture of the pixel
> itself, eg. tracks and transistor sizes, are fixed, making the ratio of
> storage capacitor of each pixel to be greater than the ratio of the
> pixel areas themselves. This is normal will all CMOS sensors.

And still much less than the difference multiple-stop difference
between tiny P&S sensors and APS size sensors, as I said. If the 5D
gets you about a one stop noise advantage over the 20D that's nice.
And as I said, for many/most other situations it's a real advantage
over the 20D's sensor. But in cases such as were under discussion
where a particular image produced by one lens would utilize far
fewer pixels with the 5D's sensor, the reduced resolution should be
far more significant than a little extra noise.

It appears to me that you're not disagreeing with what I've said
(nor do I disagree with what you're saying) but you want to find
ways to put the 5D's sensor in the best possible light.

<pun intended>
September 28, 2005 4:45:41 AM

Archived from groups: rec.photo.digital (More info?)

Skip M wrote:


>
> Well, you pays yer money and you take yer choices, don't you?
>

Sure, just seems odd to blow off FOV like it's a non-issue or the "So you
buy a huge 4X more money lens to get the same FOV" comments like it's not
even a consideration.

--

Stacey
September 28, 2005 4:49:15 AM

Archived from groups: rec.photo.digital (More info?)

ASAAR wrote:

>
> I think you're going a little overboard here in trying to
> emphasize the superiority of FF sensors.

Sure he is. If what he posted was a fact, a 20D would have a massive
performance disadvantage vs a 10D. For that matter canon should start
making a 2MP FF sensors again to get giant pixels?

Like I said "5D's rule no matter what!"
--

Stacey
Anonymous
September 28, 2005 11:00:08 AM

Archived from groups: rec.photo.digital (More info?)

If you're a wide-angle shooter it's the other way around. Having a
smaller sensor causes you to spend extra money on a new wide angle
lens.

Stacey wrote:
> Skip M wrote:
>
>
> >
> > Well, you pays yer money and you take yer choices, don't you?
> >
>
> Sure, just seems odd to blow off FOV like it's a non-issue or the "So you
> buy a huge 4X more money lens to get the same FOV" comments like it's not
> even a consideration.
>
> --
>
> Stacey
Anonymous
September 28, 2005 10:33:40 PM

Archived from groups: rec.photo.digital (More info?)

In article <3pulmbFbrgqaU2@individual.net>, Stacey <fotocord@yahoo.com>
writes
>ASAAR wrote:
>
>>
>> I think you're going a little overboard here in trying to
>> emphasize the superiority of FF sensors.
>
>Sure he is. If what he posted was a fact, a 20D would have a massive
>performance disadvantage vs a 10D.

That depends on whether you consider the 1 stop resolution advantage to
be massive or not, doesn't it.

>For that matter canon should start
>making a 2MP FF sensors again to get giant pixels?
>
Using the same flawed logic in your argument, Canon should simply avoid
large format detector completely and furnish their digital SLRs with 8Mp
arrays of 2.5um pixels - approximately 9x6mm frames or around 1/6th of
the APS frame size - since the optical limitations of small pixels are
"not a fact"!! Just think, you could get all of the advantages of a x4
EFL multiplier and have a standard 50mm giving you the FoV that would
require 200mm on a full frame camera - even better than the limited x1.6
of the APS format. There is a reason nobody does that though - it is
because your argument is flawed.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
September 29, 2005 5:17:45 AM

Archived from groups: rec.photo.digital (More info?)

Kennedy McEwen wrote:

> In article <3pulmbFbrgqaU2@individual.net>, Stacey <fotocord@yahoo.com>
> writes
>>ASAAR wrote:
>>
>>>
>>> I think you're going a little overboard here in trying to
>>> emphasize the superiority of FF sensors.
>>
>>Sure he is. If what he posted was a fact, a 20D would have a massive
>>performance disadvantage vs a 10D.
>
> That depends on whether you consider the 1 stop resolution advantage to
> be massive or not, doesn't it.

1 stop resolution? I didn't realize resolution was measured in stops..

>
>>For that matter canon should start
>>making a 2MP FF sensors again to get giant pixels?
>>
> Using the same flawed logic in your argument, Canon should simply avoid
> large format detector completely and furnish their digital SLRs with 8Mp
> arrays of 2.5um pixels - approximately 9x6mm frames or around 1/6th of
> the APS frame size -

Good grief.. Looks like the "full frame guys" are going to be quite
irritating around here. So we go from trying to discuss if a cropped 5D
shot would be lower resolution than a uncropped 20D one to this extream
rant?

--

Stacey
September 29, 2005 5:18:59 AM

Archived from groups: rec.photo.digital (More info?)

winhag@yahoo.com wrote:

> If you're a wide-angle shooter it's the other way around. Having a
> smaller sensor causes you to spend extra money on a new wide angle
> lens.
>

Assuming they already own one plus the APS lens isn't heavier or more
expencive to the same FOV FF one.
--

Stacey
Anonymous
September 29, 2005 10:33:38 AM

Archived from groups: rec.photo.digital (More info?)

"Stacey" <fotocord@yahoo.com> wrote in message
news:3q1bq3Fc4jvnU5@individual.net...
> winhag@yahoo.com wrote:
>
>> If you're a wide-angle shooter it's the other way around. Having a
>> smaller sensor causes you to spend extra money on a new wide angle
>> lens.
>>
>
> Assuming they already own one plus the APS lens isn't heavier or more
> expencive to the same FOV FF one.

No, I think he is right. For your lens array to cover the same effective FOV
it did when you were shooting 35mm or 35mm sensor, you are going to have to
buy one more wider lens to maintain the original widest FOV you had
previously. Otherwise the crop sensor is limiting the capability you already
had (assuming 35mm sensor or emulsion)

Where he is wrong is that he doesn't consider the advantage that brings to
the shooter 1) elimination of glass edges in the WA shot, 2) more effective
reach at the other end of your lens array and 3) the shooter may have needed
a new body plus more reach and decided to buy a camera that granted that
extra reach without having to buy a new telephoto. So spending the extra
money isn't only about maintaining similar capabilities, but also about
improving overall quality and capability across the whole lens array.

My primary reason for excluding any FF body is the edges of the glass in
anything 24mm and wider. It has always been a prohibitive shortcoming in
35mm shooting. It is even worse in FF sensors because at the top of the heap
the sensors are so very good. My preference has been to add reach (without
buying another lens) but to eliminate corners in WA while keeping the same
FOV (by buying a wider lens in order to maintain my previous widest
perspective).

At the top of the dlsr market Canon and Nikon have very different ideas
about sensors and imaging. In Nikon's case they have determined that
eliminating the corners during the compositional stage is an advantage that
some people will find worthwhile. I happen to be in that camp, and so am
shooting a d2x. But I think people who don't shoot 24mm and wider with much
frequency are going to be better of with a FF body like the 1ds mkII.

Pixel count isn't as critical to me as it is to some because at the levels
of 12 and 16 mp it is the software that becomes critical, not the difference
in resolving power. I think the noise issue is way overstated as
well.....but hey, this is a newsgroup!

But of course that is all just my opinion :^)
Anonymous
September 29, 2005 8:46:45 PM

Archived from groups: rec.photo.digital (More info?)

In article <3q1bnpFc4jvnU4@individual.net>, Stacey <fotocord@yahoo.com>
writes
>Kennedy McEwen wrote:
>
>> In article <3pulmbFbrgqaU2@individual.net>, Stacey <fotocord@yahoo.com>
>> writes
>>>ASAAR wrote:
>>>
>>>>
>>>> I think you're going a little overboard here in trying to
>>>> emphasize the superiority of FF sensors.
>>>
>>>Sure he is. If what he posted was a fact, a 20D would have a massive
>>>performance disadvantage vs a 10D.
>>
>> That depends on whether you consider the 1 stop resolution advantage to
>> be massive or not, doesn't it.
>
>1 stop resolution? I didn't realize resolution was measured in stops..
>
It is if you are considering the resolution of the diffraction limit for
a lens. Resolution cut-off in cy/mm at the focal plane of a perfect
lens is 1/(W x f/#), where W is the wavelength of the light being
focussed. A 1 stop advantage in terms of the resolution of a
diffraction limited lens is effectively a x1.4 gain in resolution.

>>
>>>For that matter canon should start
>>>making a 2MP FF sensors again to get giant pixels?
>>>
>> Using the same flawed logic in your argument, Canon should simply avoid
>> large format detector completely and furnish their digital SLRs with 8Mp
>> arrays of 2.5um pixels - approximately 9x6mm frames or around 1/6th of
>> the APS frame size -
>
>Good grief.. Looks like the "full frame guys" are going to be quite
>irritating around here. So we go from trying to discuss if a cropped 5D
>shot would be lower resolution than a uncropped 20D one to this extream
>rant?
>
So using your own flawed logic back at you is a rant is it? In that
case what was your initial response if not an unfounded rant?
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
Anonymous
September 29, 2005 8:53:43 PM

Archived from groups: rec.photo.digital (More info?)

In article <dhgqcj$eqq$1@nnrp.gol.com>, David J. Littleboy
<davidjl@gol.com> writes
>
>"W.E. O'Neil" <we_o@anesthesiaop.net> wrote:
>
>> Where he is wrong is that he doesn't consider the advantage that brings to
>> the shooter 1) elimination of glass edges in the WA shot,
>
>Uh, that doesn't work. Please, think. (a) Lenses get worse overall as they
>get wider and you have to use a "wider" lens on the small sensor (while some
>lenses really do collapse at the far corners (beyond 18mm from the axis),
>most wides get funky either over the whole field or gradualy). (b) You have
>to use more magnification to get to the print from the small sensor (this
>one's a double whammy, because the smaller sensor has a finer pixel pitch
>requiring more resolution: a 35mm lens has a lot easier time providing 40
>lp/mm (5D limiting practical resolution) than a 24mm lens does providing 53
>lp/mm (20D ditto)). (c) What makes wide lenses get funky at the edges is
>that it's hard to make wide lenses without getting funky edges, so you can't
>even redesign for the smaller sensor. (Although redesigning does have the
>advantage of a more modern design.)
>
In addition to which, the shorter focal length necessary to get the same
wide angle FoV will require to have an even higher inverse telephoto
ratio, just to leave room for the SLR mirror. That completely negates
any of the size benefits the shorter focal length would offer, as well
as making the entire design more complex, expensive and prone to
aberrations.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
Anonymous
September 30, 2005 2:31:46 AM

Archived from groups: rec.photo.digital (More info?)

"W.E. O'Neil" <we_o@anesthesiaop.net> wrote:
> "Stacey" <fotocord@yahoo.com> wrote:
>> winhag@yahoo.com wrote:
>>
>>> If you're a wide-angle shooter it's the other way around. Having a
>>> smaller sensor causes you to spend extra money on a new wide angle
>>> lens.
>>
>> Assuming they already own one plus the APS lens isn't heavier or more
>> expencive to the same FOV FF one.
>
> No, I think he is right. For your lens array to cover the same effective
> FOV it did when you were shooting 35mm or 35mm sensor, you are going to
> have to buy one more wider lens to maintain the original widest FOV you
> had previously. Otherwise the crop sensor is limiting the capability you
> already had (assuming 35mm sensor or emulsion)

Just as people with a lens collection they are happy with migrating from
APS-C to full-frame will only have to buy one lens (or one 1.4x TC (see
below)), folks migrating from a filled out 35mm lens collection in their
film days will only have to buy one lens.

Unless you bet on the completely wrong horse, changing horses in mid-stream
isn't all that painful. But people who bet on the completely wrong horse are
going to squawk loudly and obnoxiously about the more sensibly designed
systems. They can be ignored.

> Where he is wrong is that he doesn't consider the advantage that brings to
> the shooter 1) elimination of glass edges in the WA shot,

Uh, that doesn't work. Please, think. (a) Lenses get worse overall as they
get wider and you have to use a "wider" lens on the small sensor (while some
lenses really do collapse at the far corners (beyond 18mm from the axis),
most wides get funky either over the whole field or gradualy). (b) You have
to use more magnification to get to the print from the small sensor (this
one's a double whammy, because the smaller sensor has a finer pixel pitch
requiring more resolution: a 35mm lens has a lot easier time providing 40
lp/mm (5D limiting practical resolution) than a 24mm lens does providing 53
lp/mm (20D ditto)). (c) What makes wide lenses get funky at the edges is
that it's hard to make wide lenses without getting funky edges, so you can't
even redesign for the smaller sensor. (Although redesigning does have the
advantage of a more modern design.)

2) more effective reach at the other end of your lens array

This one's also less than claimed: if a lens is adequately sharp on a 1.6x,
it will be adequately sharp on a FF sensor _with a 1.4x TC_. The extra
sensitivity of the sensor will also exactly make up for the lost speed.

> and 3) the shooter may have needed a new body plus more reach and decided
> to buy a camera that granted that extra reach without having to buy a new
> telephoto.

If you've already got FF, a TC's a better idea than a small sensor. Of
course no one is moving from FF digital to APS-C digital<g>.

> My primary reason for excluding any FF body is the edges of the glass in
> anything 24mm and wider. It has always been a prohibitive shortcoming in
> 35mm shooting. It is even worse in FF sensors because at the top of the
> heap the sensors are so very good.

As before, there's no such thing as a free lunch, and if you see a free
lunch, you should be suspicious. The 'crop off the bad parts' argument reeks
of free-lunch-itis. (Note also that decent telephotos have almost no edge
funkiness to cut off.)

David J. Littleboy
Tokyo, Japan
Anonymous
September 30, 2005 2:31:47 AM

Archived from groups: rec.photo.digital (More info?)

"David J. Littleboy" <davidjl@gol.com> wrote in message
news:D hgvvh$gao$1@nnrp.gol.com...

> I submit that thinking that there's a free lunch is a great way to make
> mistakes.

David, you continue to build straw men and then feel pleased that you have
knocked them down. It doesn't bother me much, but I would prefer not to
waste the time on that type of discussion.

Thanks for the comments.
Anonymous
September 30, 2005 5:21:28 AM

Archived from groups: rec.photo.digital (More info?)

"Kennedy McEwen" <rkm@nospam.demon.co.uk> wrote:
DJL:
>>Uh, that doesn't work. Please, think. (a) Lenses get worse overall as they
>>get wider and you have to use a "wider" lens on the small sensor (while
>>some
>>lenses really do collapse at the far corners (beyond 18mm from the axis),
>>most wides get funky either over the whole field or gradualy). (b) You
>>have
>>to use more magnification to get to the print from the small sensor (this
>>one's a double whammy, because the smaller sensor has a finer pixel pitch
>>requiring more resolution: a 35mm lens has a lot easier time providing 40
>>lp/mm (5D limiting practical resolution) than a 24mm lens does providing
>>53
>>lp/mm (20D ditto)). (c) What makes wide lenses get funky at the edges is
>>that it's hard to make wide lenses without getting funky edges, so you
>>can't
>>even redesign for the smaller sensor. (Although redesigning does have the
>>advantage of a more modern design.)
>>
> In addition to which, the shorter focal length necessary to get the same
> wide angle FoV will require to have an even higher inverse telephoto
> ratio, just to leave room for the SLR mirror. That completely negates any
> of the size benefits the shorter focal length would offer, as well as
> making the entire design more complex, expensive and prone to aberrations.

Uh, but fair is fair: we have to admit that the EF-S lenses don't have that
problem. The made-for-digital lenses from all the other MFRs do, though.

(I'm feeling very pleased with myself that the very first MTF charts I
looked at showed exactly what was expected: individual lens design
differences could, of course, swamp the basic design considerations in
specific cases.)

David J. Littleboy
Tokyo, Japan
Anonymous
September 30, 2005 8:57:33 AM

Archived from groups: rec.photo.digital (More info?)

"W.E. O'Neil" <we_o@anesthesiaop.net> wrote:
> "David J. Littleboy" <davidjl@gol.com> wrote:
>
>> I submit that thinking that there's a free lunch is a great way to make
>> mistakes.
>
> David, you continue to build straw men and then feel pleased that you have
> knocked them down. It doesn't bother me much, but I would prefer not to
> waste the time on that type of discussion.

It's not a straw man: the idea that you can improve corner performance by
using shorter lenses on a smaller sensor is simply wrong. The shorter lens
on the smaller sensor still has to provide the same FOV, and the reason
corners are funky is that it's hard to design lenses to provide a wide FOV.

David J. Littleboy
Tokyo, Japan
!