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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

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

"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?

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
( 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

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.

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/cont...goryNavigation

And

http://www.bhphotovideo.com/bnh/cont...goryNavigation

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

"Stacey" <> 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

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.

David J. Littleboy wrote:

>
> "Stacey" <> 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/cont...goryNavigation

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/cont...goryNavigation

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

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

In article <>, ASAAR
<> 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 ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)