Originally posted by raider Pardon my ignorance...
I understand that with FF you get less sensor noise at high ISO, u get better of everything thing but why would we want this when
1. u will lose the range of using APC-S glass. i mean that expensive 70-200 we buy when on the APC-S body is really a 105-300mm lens on a FF body. On a FF body, that 70-200 is well, a 70-200. Isn't the extra range something?
2. the ultrawide lens like 14mm and 12-24mm (which to me seems to be wide enuf) on a FF body will be well, 14mm and 12-24mm respectively, which would also mean it is necessary to invest in more expensive filters to avoid vignetting issues? Cokin X-Pro series are very expensive. With APC-S body, we can still stick to Z-Pro series for the 12-24 or some people even use the P-series with some minor modifications. Isn't the cost savings worthwhile?
I would welcome the move to FF but at what cost?
I hear what you are saying regarding the long end of things. A 150mm lens on the 35mm format yeilds about 3x magnification. The same lens on APS-C yields about 4.5x. That is quite a bit of difference. I have to admit that it sort of nice to go into the field with something as short as 200mm and get reasonable shots of wild birds.
On the wide end the difference is a little more extreme (from my perspective). I enjoy doing landscapes and some architectural work. My Zenitar 16/2.8 has 180 degrees diagonal on 35mm. On APS-C that is reduced to 110 degrees, the same as a 24mm on 35mm film. This FOV is acceptable, but in order to get it, I have to put up with extra distortion, "interesting" quality, and a choice of zero filters. My only other option is to pony up the big bucks for a Sigma 15 or Pentax 10-17 (or something similar) just to be capable of doing landscape work.
For the 35mm format, the wide angle of choice would be 28mm for most people and 20mm or 24mm for those doing architectural work. Most lenses at those focal lengths have minimal distortion, are fairly fast, and are well-corrected to boot. (Did I mention that they also tend to cost less?). They accept regular filters of reasonable size (my 28mm takes 49mm filters) and are even relatively light and compact. As for the truly short focal lengths, lenses below 20mm are used mostly for special effects if FF land.
The picture gets even more interesting with normal zooms. Instead of paying mucho dinero for a DA* 16-50/2.8 (good as that lens is), one can be very happy with something like the excellent Tamron 28-75/2.8 instead.
Just a few things to consider. On one end you lose. On the other you gain.
Steve