Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon EOS dSLR

Reply
 
Thread Tools Search this Thread
Old Aug 26, 2005, 11:14 AM   #1
Member
 
Join Date: May 2004
Posts: 74
Default

A 5D will have a 24x36 mm sensor (864 square mm.) and 12.8 megapixels orabout 14,815 pixels/sq.mm. A 20D has a 22x15 sensor (330 sq. mm.) and 8.2 megapizels or about24,848 pixels/sq. mm.If the DIGIC and otherenhancements allow the 20D to use comparable ISO with low noise,shouldn'ta20Drecordhigherresolutionimages? I heardan analogy with 35mm v2 1/4 butI am not sure that is a valid comparison. Coarse grain or push processed film in a Rolleioften looks bad and Kodachrome in a Nikon looks good. Kodachrome in roll film looks fantastic! Help me understand why more pixels on a bigger sensor is better.
ADSchiller is offline   Reply With Quote
Sponsored Links
Old Aug 26, 2005, 11:43 AM   #2
Senior Member
 
BoYFrMSpC's Avatar
 
Join Date: Apr 2005
Posts: 339
Default

I think one of the main advantage is noise (I don't think the 20D has comparable noise control). You can use much higher ISO speeds without adding too much grain. It's just like a p & S vs a dSLR. The slr sensors are much larger and you see ISO of 800 and 1600 and 3200. on a p & s, when you set the ISO to 100 there's already a lot of grain due to its really really tiny sensor.

I also think the 5D can have ISO 50... pretty nifty...

And though they could potentially put more pixels in the camera ... 1) isn't 12.8 enough? :blah: and 2) they need to make sure they can make future models, right? The pixel race isn't quite dead, yet.

However... I think there are very few reasons why full frames are still around. Probably one of the big reasons is so there's no crop factor.
BoYFrMSpC is offline   Reply With Quote
Old Aug 26, 2005, 10:33 PM   #3
Senior Member
 
Join Date: Sep 2003
Posts: 229
Default

The pixel and sensor size is an interesting race. The Nikon (1.5 factor)at 12 megapixels exhibits more noise that 11 Megapixel Canon with full frame sensor (according the magazines). I think though that the answer may be in the associated processing chip such as the Digic series which cleans up and processes the image. Improvements there may well be the answer to sensor size.

Still, it sure is nice to see a reasonably priced ( as reasonable as $3300 can be?) camera with full frame. Hopefully the prices will continue to improve on a full frame sensor camera so I can justify having one.
Ctrack is offline   Reply With Quote
Old Aug 27, 2005, 9:37 AM   #4
Senior Member
 
SlapNTickleJr's Avatar
 
Join Date: Sep 2004
Posts: 151
Default

Here's the way I understand it. As far as resolution goes, the 5D is obviously the winner; 4368x2912 vs. the 20D's 3504x2336, but also, since the CMOS is larger it has larger photo-site's (by about a third I believe) so therefore it is able to capture more data and more accurate data...specifically luminance data, similar to having a larger maximum aperture on a lens. But just based on resolution, the 5D has roughly 20% more resolution than the 20D.
SlapNTickleJr is offline   Reply With Quote
Old Aug 27, 2005, 4:42 PM   #5
Senior Member
 
Join Date: Sep 2003
Location: Dallas, Texas USA
Posts: 6,483
Default

CTRACK, it may be $3,300 today, but can you remember what the 3 megapixel D30 cost when it came out 4 1/2 years ago? Right at $3,000.

The 5D is just the beginning. 3-5 years from now we'll be looking at the 5D like we view the D30 today. That's my time frame to obtain one of these.
Greg Chappell is offline   Reply With Quote
Old Aug 28, 2005, 10:24 PM   #6
Senior Member
 
Join Date: Sep 2003
Posts: 229
Default

Yep, me too. I don't think I'll be in the market for a new camera for another3-4 years. I get great 13x19s from my 20D and my old DREBEL (old? 2 years). However, I don't think I'll see the life span I saw with by EOS 620 (20years). Its still works, I just haven't used it in 3 years.
Ctrack is offline   Reply With Quote
Old Aug 29, 2005, 1:47 PM   #7
Senior Member
 
Join Date: Apr 2004
Posts: 192
Default

ADSchiller wrote:
Quote:
A 5D will have a 24x36 mm sensor (864 square mm.) and 12.8 megapixels orabout 14,815 pixels/sq.mm. A 20D has a 22x15 sensor (330 sq. mm.) and 8.2 megapizels or about24,848 pixels/sq. mm.If the DIGIC and otherenhancements allow the 20D to use comparable ISO with low noise,shouldn'ta20Drecordhigherresolutionimages? I heardan analogy with 35mm v2 1/4 butI am not sure that is a valid comparison. Coarse grain or push processed film in a Rolleioften looks bad and Kodachrome in a Nikon looks good. Kodachrome in roll film looks fantastic! Help me understand why more pixels on a bigger sensor is better.


Canon has stated that they think that professionals need very usable 1600 ISO, and they didn't think that the 20D's performance in that regard was good enough. I wish that I had more time to be precise about this statement -- I'd suggest searching the web for that information. The gist is that high ISO low noise is something that Canon feels that the pro market insists upon, in general of course. They sited that the DSLR users in the last Olympics were using 1600 ISO as a rule.

This is, I think, the reason that the 1Ds II has larger photo sites and lower pixel density than the 20D. And this is also one of the reasons that the 5D has lower pixel density than the 20D. We could go on talking about how a 5D with the 20D's pixel density would or would not outperform a 1Ds II, and how much it might cost, but I'll leave this issue to talk about whether or not a 5D is better than a 20D.

With a 5D, your images will have around 12.7 MP, with a 20D, around 8.2 MP. So, in a full frame image, the 5D will have more pixels, and more resolution. The pixels will also presumably have better noise performance, so overall image should be of significantly more resolution. You'll be able to make larger prints with the 5D images, and this is historically what is usually meant by having more resolution.

Assuming that you want the same field of view with the two different cameras, you'll have to use a higher magnification lens on the 5D - 60% more magnification; a 80mm lens on the 5D vs. a 50mm lens on the 20D. Then you have the same field of view, more pixels in the 5D image, and slightly more depth of field in the 20D image (because the focal length is shorter).

You can only get confused about this when you consider just the comparable crop of a 5D image which would have the same size as the 20D's sensor. There, the pixel density comes into play, and you have more pixels in the 20D image. But this is an artificial crop of the 5D. Why would you crop that image and throw away the information at the edges and then compare it? If you're going to do this, you're clearly wasting a big part of the 5D's capability -- get a 20D or 350D then. If your answer is "because I need to zoom in very very far and the 1.6x crop factor will help me do that", then you're still confused. Cropping does not give you magnification. It gives you a smaller and cheaper sensor. If your answer is "because I need to zoom in very very far, and the money I save getting a 20D will let me buy a bigger lens and plane tickets", you have valid points. If your answer is "I don't care about the money, but the 28% greater pixel density of the 20D will give me more magnification for the center crop", you also have a valid point. But that's 28% greater magnification -- 255mm vs 200mm, 510mm vs 400mm. It matters, but probably not enough to give up a better camera and more pixels if money is not a concern -- get a lens that exceeds 28% greater magnification (paying for it), and you'll outperform the 20D significantly with a 5D by virtue of the additional pixels and probable higher ISO performance.
Madwand is offline   Reply With Quote
Old Aug 30, 2005, 9:18 AM   #8
Senior Member
 
Join Date: Sep 2003
Posts: 229
Default

I don't know if I'mclear on you point, but if its that the 5D will be better at higher ISOs and allow for larger prints, I think that should be a given. The lens issue is another matter but probably not much of a concern for many of us sincemany of us had non APS-C lenses.

I have purchased 2 APS-C sensor only lenses. One, because of the need forreal wide angle(Tokina 12-24) and the other for a light Macro lens (EF 60mm). However, no more. The furture has to be in 35mm size sensors for that extra noise control and resolution.
Ctrack is offline   Reply With Quote
Old Aug 30, 2005, 12:18 PM   #9
Senior Member
 
Join Date: Jul 2003
Posts: 3,396
Default

The current MF Mamya and Blad have a 36*48mm sensor and output @ 22mp.
And they do it with a 11-stop range:!: The dslr's are still stuck at the 3-4 stop range of slide film.

I've said it before and mailed some manfacturers about it too, but I'd much prefer the dynamic range of the DSLR's to be increased instead of the megapixels. The 6 or 8mp of the current crop produce excellent super-b and larger sized prints, which for most people is about as large as they are going to print at home.

As for the MegaPixel race the current PhaseOne single-shot back is now at 39mp, squeezed onto a 36.8*49.1mm sensor. I suspect you would get 1-3 images to a 1gb card with it.

PhaseOne P45 Tech specs for those that are interested

Dslr's have a long way to go :-)
Imagine trying to process 500+meg image files on a home pc.
and store them when a image is a cd onto itself and your 200gb drive can only hold 400 images or so.

Peter.

ADSchiller wrote:
Quote:
A 5D will have a 24x36 mm sensor (864 square mm.) and 12.8 megapixels orabout 14,815 pixels/sq.mm. A 20D has a 22x15 sensor (330 sq. mm.) and 8.2 megapizels or about24,848 pixels/sq. mm.If the DIGIC and otherenhancements allow the 20D to use comparable ISO with low noise,shouldn'ta20Drecordhigherresolutionimages? I heardan analogy with 35mm v2 1/4 butI am not sure that is a valid comparison. Coarse grain or push processed film in a Rolleioften looks bad and Kodachrome in a Nikon looks good. Kodachrome in roll film looks fantastic! Help me understand why more pixels on a bigger sensor is better.
PeterP is offline   Reply With Quote
Old Aug 30, 2005, 4:58 PM   #10
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,547
Default

PeterP wrote:
Quote:
The current MF Mamya and Blad have a 36*48mm sensor and output @ 22mp.
And they do it with a 11-stop range:!: The dslr's are still stuck at the 3-4 stop range of slide film...
Isn't the Fuji a 10-stop dynamic range dSLR?
http://www.dpreview.com/reviews/fuji...pro/page18.asp
NHL is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 6:17 PM.