Crop factor and FF crop post processing

[Swiggen]

Forgive my ignorance but here is my question:

If I take a picture with a FF and crop it in Aperture to the same frame size as I would have with a 1.6 ASPC would the resolution /print quality still be the same?

Thanks in advance.

[neuroanatomist]

IQ will be equivalent, but you'll have fewer MP (FF MP divided by 2.56).

[Sporgon]

IQ will be equivalent, but you'll have fewer MP (FF MP divided by 2.56).

Unless you're packing a D800 in which case cropping to APS would be my only use for 36MP 

[Swiggen]

Thanks guys....will the difference be noticeable on a 30x40 print viewed from 3 metres

[neuroanatomist]

Most likely, yes.  Assuming you're talking about a 20-22 MP FF camera, the resulting ~8 MP likely will not do well as a 30x40" print.

[Jackson_Bill]

IQ will be equivalent, but you'll have fewer MP (FF MP divided by 2.56).

Neuro - How are you defining IQ?

[neuroanatomist]

Loosely.    Basically, a combination of sharpness, noise, CA, etc.  From a similar generation (e.g. 5DII vs. 7D), there's little, if any, difference. Cropping a FF image takes away most of the advantages of the larger sensor.  But...if you can live with fewer MP (i.e. you're not making 30x40" prints), there's no downside to cropping the FF image, and a big upside if you don't need to crop.

[PackLight]

Thanks guys....will the difference be noticeable on a 30x40 print viewed from 3 metres

Doubtful it will hold up, although it will depend on your subject
How about this idea, just get a lens 1.6 times longer instead.

[bycostello]

depends on how you print....

[Mt Spokane Photography]

If your cropping a FF image to APS-C, the IQ will not be what it was unless you are printing or displaying small.  It will be somewhat similar to the APS-C image.
Thats why medium format is so popular for very large prints.

[Swiggen]

Many thanks. Very helpful

[Swiggen]

Many thanks. Very helpful

Sorry neglected to say this would be a 5D mk III......so I expect that would have a bearing on it.

My main interests are candid portraits of family and kids (hence low light uses but also interest in reach from crop) and landscapes.

So I am trying to have my cake and eat it or have my reach and high ISO!