(please help) expain crop factor for ASPC camera

[Madwand1]

Originally posted by: shocksyde
Explain to me why using a full frame camera with a 400mm lens is better for birding than using a crop camera with a 400mm lens.

OK, for my comparison, I pick a 300D for the crop format, and a 5D 2 for the full frame. The 5D 2 will be optically better in every respect, and have more detail even when cropped down by the 300D's factor.

Your argument confuses pixel density with crop format, and assumes that a crop format camera will always have a materially higher pixel density. This is not true. It's an assumption. It may often be true in practice, but as in my example above, crop format by itself does not get you a materially higher pixel density. It's a separate variable. You won't understand crop format properly if you always confuse it with pixel density, and you showed that you didn't understand this properly when you said that a crop format gets you an optical zoom like a 1.6x teleconverter.

Another way to understand crop format is to look through the viewfinder on a crop format camera vs. a full frame camera, using the same lens. Try it. You can even do this with an old film camera vs. a DSLR. It'll help set your head straight about the differences due to the crop alone.

 

[finbarqs]

I had a sigma 10-20mm, even wider than the 11-16. but the tokina 11-16 has better MTF charts. Anyways, when I hold a camera in my hands, and i'm looking through the view finder, I see my DOF based on my focal length and point of the subject, and I can also see the DOF preview when i hit the DOF preview button. At that point, I want that DOF... I just need more frame coverage. Sure I can zoom out, but it just doesn't look the same!

 

[finbarqs]

here's a PERFECT example of the differences between FF and CROP

here's a 5D MK2 w/ 85mm f/1.2L lens (full frame)

http://farm4.static.flickr.com...86061_043a9c9552_b.jpg

Here's what a 300D (rebel xt) or even 40D would do to take the same exact shot (w/ the same 85mm f/1.2L)

http://gallery.expertreaction.com/Pictures/aps-c.jpg

there you have it.

 

[shocksyde]

Originally posted by: Madwand1

Originally posted by: shocksyde
Explain to me why using a full frame camera with a 400mm lens is better for birding than using a crop camera with a 400mm lens.

OK, for my comparison, I pick a 300D for the crop format, and a 5D 2 for the full frame. The 5D 2 will be optically better in every respect, and have more detail even when cropped down by the 300D's factor.

Your argument confuses pixel density with crop format, and assumes that a crop format camera will always have a materially higher pixel density. This is not true. It's an assumption. It may often be true in practice, but as in my example above, crop format by itself does not get you a materially higher pixel density. It's a separate variable. You won't understand crop format properly if you always confuse it with pixel density, and you showed that you didn't understand this properly when you said that a crop format gets you an optical zoom like a 1.6x teleconverter.

Another way to understand crop format is to look through the viewfinder on a crop format camera vs. a full frame camera, using the same lens. Try it. You can even do this with an old film camera vs. a DSLR. It'll help set your head straight about the differences due to the crop alone.

It's borderline ridiculous that you're using a 5D2 compared to a 300D. Talk about lop-sided.

A 300D may not have a higher pixel density than a 5D2, but a 50D sure as hell does. 5D2 compared to 50D is a much fairer comparison. Newest Canon crop vs. newest Canon FF.

I understand crop format completely. The sensor is 1.6x smaller than a standard 35mm. The image cast onto the sensor by an EF lens is the same for a 1.6x crop sensor and for a FF sensor. Since the 1.6x sensor is smaller, and most likely has a higher pixel density (when comparing new tech to new tech, not old tech to new tech), the resulting image will have "more pixels in the bird" as stated by another poster above.

Also, I never said it gives you an optical zoom. I said it gives an "optical zoom effect." How about this: "It gives a 1.6x zoom effect." Optical may have been the wrong word.

 

[corkyg]

Lots of tangential factoids resulting from semantical variances. Let's get back to basics and answer the question. The "crop factor" is simply the effect of imposing the 35mm standard on digital imaging sensors. This illustrates it very well.

Crop

 

[shocksyde]

Originally posted by: corkyg
Lots of tangential factoids resulting from semantical variances. Let's get back to basics and answer the question. The "crop factor" is simply the effect of imposing the 35mm standard on digital imaging sensors. This illustrates it very well.

Crop

Yeah, that link's a lot better than arguing back and forth.

 

[ilkhan]

There is no situation where a *proportionally scaled MP count* full frame is inferior to a cropped. If the pixel densities differ (and they do), then there is room for debate.

 

[ElFenix]

Originally posted by: shocksyde


I understand crop format completely. The sensor is 1.6x smaller than a standard 35mm.

on canon it's 2.56x smaller, actually. that's why you get a stop and a third less dof and a stop and a third better noise with a 35 mm format camera over an APS-C format camera.

for sony and nikon i'ts 2.25x smaller.