Full frame vs regular cropped frame?

Ihaveaquestion · Jul 14, 2006

So I was checking out the Nikon D200 and the Canon 5D.

And other than the 2 mega pixel count theres the "Full Frame" issue?

http://www.dpreview.com/reviews/canoneos5d/page12.asp

I dont want to spark the Nikon Canon thing.

I just want to know about the full frame advantage and its main use.

What would I need a full frame camera for?

omeletteman · Jul 14, 2006

Because Full Frame camera's don't have that annoying "crop factor" that normal DSLR's have, lens's will be the same focal length as on a 35mm camera. The main advantage as I see it is that your wide angle lens's will be wider then they would be on a non-full frame camera.

As an example, if you buy a 10mm lens (sweeeeeet) and put it on your Rebel XT it becomes a 16mm lens (not nearly as exciting). If you put it on a 5D or other full frame camera, it's still a 10mm lens.

Of course if you mainly shoot with telephoto lens', this would actually be a disadvantage, because your 1000mm lens would be 1000mm, not 1600mm (I like simple numbers).

The other advantage is image quality, a bigger sensor will record more information then a smaller one.

Big Mike · Jul 14, 2006

That says it pretty well.

A full frame sensor is the same size as 35mm film. Most of the lenses that will fit a DSLR...were designed for 35mm film.

If you like to shoot wide, then a full frame allows you to get a wider FOV than a smaller sensor (with the same focal length). If you like to shoot long...then a smaller sensor may be better for you. You don't actually get more magnification from your lenses (a 1000mm lens will not really become a 1600mm lens) but you will get the same FOV as the longer lens.

One advantage of a smaller sensor, is that it only sees the centre portion of the image projected by the lens (if it's a lens designed for 35mm film). Most lenses will be sharper in the centre...so the smaller sensor is "cutting off" the worst parts of the lens sees.

As mentioned, a bigger sensor should produce less digital noise because the photo receptors are not so densely crowded as they are on a smaller sensor.

markc · Jul 14, 2006

Something to remember is that the digital only lenses, like the Canon EF-S lenses, won't fit on the full-frame cameras.

Iron Flatline · Jul 14, 2006

The crop factor is simply that: a crop factor. It will cut off about a third of your picture around the edges, because the lenses were designed to project light on to a piece of 35 mm film. The typical sensor is simply smaller than a piece of 35mm film - except that of the Canon 5D, and some other high-end cameras. So on a wide-angle camera, you get less of the wide angle. But on a zoom, you don't get more "zoomability." You're not going to get the object any closer, it will simply be cropped.

Uh... basically what Big Mike said.

dsp921 · Jul 14, 2006

"Full frame" (don't like that term, who says 35mm is full frame?), has disadvantages as well. You will have to invest in top quality glass since, as someone said, the worst of the lens isn't cropped out, and the difference between quality glass and cheaper glass will be much more noticeable. Also, wide angle lenses (that take advantage of the full frame) are subject to a pretty high degree of lateral CA. And there is the light fall off at the edges to deal with.
Like most things, there are pluses and minuses, you just have to decide if the pluses are enough so the minuses don't matter.

bigfatbadger · Jul 14, 2006

But if you have a full frame camera, you can get the same effect as the smaller sensors, by simply cropping the middle out in photoshop. So a full frame gives you best of both worlds, except the cheaper Digital lenses

markc · Jul 14, 2006

bigfatbadger said:
But if you have a full frame camera, you can get the same effect as the smaller sensors, by simply cropping the middle out in photoshop. So a full frame gives you best of both worlds, except the cheaper Digital lenses

As long as the pixel count is there. If it's not any higher, then you lose a lot of information.

Unimaxium · Jul 14, 2006

markc said:
As long as the pixel count is there. If it's not any higher, then you lose a lot of information.

Yup, what he said. The 5D has a fewer pixels per millimeter, which means that you will get a higher resolution using the 20D at its full 1.6x than if you were to only use the same amount of space on the 5D.

zedin · Jul 14, 2006

Iron Flatline said:
The crop factor is simply that: a crop factor. It will cut off about a third of your picture around the edges, because the lenses were designed to project light on to a piece of 35 mm film.

Maybe its just me but I hate the term crop factor. It is not really cropping.. it is just the fact the sensor is a different size so a given lens length gives different views. It is like saying a 35mm camera just has a crop factor of whatever vs medium format. A 50mm lens is a 50mm lens but depending on which system you use depends on what the FOV and magnification is. So I don't like 'zoom factor' or 'crop factor' =p It is just a different size so the lens act differently.

markc · Jul 14, 2006

It is cropping, though. A lens is a lens and doesn't act differently based on what's under it. If you take a 35mm neg and put it under a 50mm lens, you get a cropped view of what you would get if you put a 6x6 neg under the same lens at the same lens-to-neg distance.

Big Mike · Jul 14, 2006

I believe Mark is right.

A lens designed for 35mm film will always project an image circle that will cover 35mm film. If the sensor is smaller than 35mm film it only records the centre portion of the projected image...thereby cropping the outsides of the image.

Really, this issue is a very silly thing to discuss. The 'factor' really only comes into play when you are comparing two different cameras. Put a lens on your camera...what you see through the viewfinder is what you get. (well usually it's a little less because non-pro viewfinders are more like 94% coverage...but that's beside the point :roll: )

Alpha · Jul 14, 2006

It actually is quite silly, this whole crop factor thing. It reminds me how cheap so many "prosumer" dslr's are. The whole thing is reminiscent of, oh, I don't know...Advantix

markc · Jul 14, 2006

It's worlds apart in my mind. In the case of APS, disc, and other smaller formats, you are using smaller bits of film that you could otherwise choose and that are readily available. You are giving up quality for the sake of convenience (and are doing the same choosing 35mm over medium format, and medium format over large format).

In the case of digital cameras, there aren't larger sensors that the DSLRs are smaller version of. Sure, there are some MF backs, but those are very rare and expensive and aren't established. This is the leading edge of what's available to most consumers, not a marketing scheme.