Advantages of using full frame?

[Mfranquelo]

Dear all,

Could anybody point me to any link, or has a personal experience on using full frame cameras for face scanning ?

- Is worth the advantage of price / quality ?
- Would it be a good idea to place full frame cameras on the front of the subject to acquire better quality on this area, and the 1.6x crop cameras on the sides ?

Thank you community! 

[Marcel]

Fullframe cameras:

Slightly higher resolution,  which is good.
Less ISO noise (but with studio lights ISO should not be a big problem in the first place)
Wider field of view for the same lens
More shallow depth of field (you need to use a higher aperture and that means more light is needed)

So I'm not sure if it useful to switch to full frame cameras.

I think Lee from Infinite Realities uses a mix of mostly cropped and a few full frame cameras,  maybe he can tell you more.

[David Cockey]

Resolution depends on the sensor in the camera. Some full frame cameras have less resolution than some crop frame cameras.

[Mfranquelo]

I know very well how full frame camera works  but i was wondering if anyone had any experiences using them for face scanning and if its worth the difference of the price, for the quality.

[Mr_Curious]

I know very well how full frame camera works  but i was wondering if anyone had any experiences using them for face scanning and if its worth the difference of the price, for the quality.

I've got a bunch of 5D MK II's in my rig and I don't really see that much of a difference to be quite honest.  I think full frame might just be overkill for purposes of scanning and I don't think the cost differential warrants any marginal difference in quality (IMHO). I'd rather spend the cost savings purchasing more cameras with quality lenses.... but that's just me :-)

Cheers,

MC

[Andrew]

Keep in mind that shallower DOF on full frame requires higher f-stop, most likely higher than f13, at which point (well, from f11 onwards) light diffraction significantly reduces image sharpness. This effectively nullifies IQ advantage over crop cameras.

Andrew

[David Cockey]

An interesting discussion with test results of how much diffraction actually affects sharpness, and what happens as sensor resolution increases.  http://www.lensrentals.com/blog/2013/03/overcoming-my-fentekaphobia

[Andrew]

Very interesting read, thanks for the link David!

What I always wondered but never had the time to investigate, is whether one really needs to keep entire face in sharp focus to get awesome face scans? Perhaps sticking to pin-sharp f8 and masking out OOF areas (that will get their sharp photo coverage from other cameras) would produce better quality scans? My gut feeling is that its not worth the hassle, maybe only for the most pale/smooth skins out there

[Marcel]

I know very well how full frame camera works  but i was wondering if anyone had any experiences using them for face scanning and if its worth the difference of the price, for the quality.

But that is my point with my list, there is not much quality to be gained:

- you are using controlled lighting, so ISO noise is not an issue
- you need more light to get the same depth of field (getting everything in focus us a big issue in scanning)
- instead of cheap 50mm lens (99$) you'll need a more expensive 85mm (400$) lens for the same field of view

So apart from the slightly higher resolution, you won't gain much.