Quote:
Originally Posted by JohnG Possible dumb question alert here !!
Would cropping the image produced on a FF camera with my 70-300 zoom give me the same sized image of a bird (for example) taken on my 40D with that same lens ? |
It depends. Lets say you use a 10 megapixel camera with a 1.6x crop factor. You'll end up with a nice 10 megapixel image of the bird. Now if you use a 10 megapixel full frame and crop.. it may well be a 5 megapixel image of the bird equivalent. However, if you use a 20 megapixel camera then it'll crop down to maybe around 10 megapixels and not be too different (aside from a little depth of field I think).
If a full frame camera has a "crop mode" then all it's really doing is using the middle bit of it's sensor, roughly half of it and so you lose a lot of the megapixels from the normal mode. This is exactly the same as you taking the photo normally and cropping it yourself. Crop cameras aren't doing anything special to give you that 1.6x zoom though, it's just that they have a smaller sensor so they record less of the image projected into the camera giving the illusion of zoom.
At the end of the day if we end up with full frame cameras that shoot in 20+ megapixels then it'll be no issue at all to crop into them and still be left with a 10 megapixel image and that's likely to become the norm in a few years when they just can't squeeze in as many pixels onto a crop sensor as effectively.