Third Party Manufacturers / Re: Which grass is considered greener (do nikonians complain as much as canonians)?« on: September 09, 2014, 07:05:01 PM »
At the moment the big differences are just at low ISO. Low ISO is generally the realm of different kinds of photography, photography where it's difficult to impossible to actually control the lighting, and where dynamic range can easily surpass 11-12 stops...and the differences really are significant. Maybe it's just the number "two" stops of DR. Two is a small number, it doesn't seem all that meaningful. It is a factor of four difference in the range of usable tonal levels. Four is still a "small" number...so when you get right down to it, it's basically the difference between having 12-bit or a 14-bit data...now THAT number is big. That number is 12,288...which is a really big number. That number is a better indication of the differences between a Canon sensor and an Exmor. If we regularly talked about differences in dynamic range with big numbers like that, maybe the real benefit of having "two more doublings" would be more obvious.
Try 3 stops of difference between the 5D3 and the D810. More if you account for FPN.
If you need DR, then I would offer that DR is more than just a nice to have. If you NEED DR, then having more DR is essential. I don't need DR in all my photography...when I do need more DR, I already have some tools that help me resolve the issues with having less...GND filters for example. HDR is another option, albeit one that is imperfect and adds work. More DR is more DR...having two more stops is huge...it's very meaningful, and much more than just a nice to have. It reduces the amount of time I have to spend figuring out which GND filters to use, how many to stack, how to blend across the contrast divide, etc. Instead of three filters, maybe I can get away with just one. With two more stops of DR, I could get away with a heavier shadow lift instead of having to apply an LR/ACR gradient filter in post. More in-camera DR, work. Less work with literal filters, less work in post.
Don't forget that GND filters are *still* useful for Exmor, to combat shot noise. You may or may not care if somewhat noisier shadows (b/c of noise in the sampling of light itself) don't bother you - since they're generally less visible.
The other way to do this for a scene that does fit within the DR of your sensor is to shoot a number of frames where you've exposed for the highlights, and then average them. This decreases shot noise (importantly: in your shadows), and allows you to then process the single averaged image. And image averaging is much easier than HDR merging - I can't stand the results most automated HDR software produce. Hence I do it all by hand. Which can be quite painful.
What I just explained above is a significantly better way to shoot HDR scenes than what I typically had to do with Canon. And the best part is - if you don't care about some shot noise in your shadows (a +3 EV push of ISO 64 shadows on the D810 is pretty much like ISO 500 FF levels of noise, which might be perfectly acceptable), then you just use your single frame.
And btw, I have a feeling the A7s has a slightly different architecture from most other Exmor sensors - giving it slightly more downstream read noise (so a bit of a base ISO DR cost, though nowhere near a Canon DSLR) and very low upstream read noise at higher ISOs (which gives it higher ISO DR). So, in a sense, it's a nice compromise btwn low ISO DR and high ISO performance. Slightly better ISO performance at ISO 25.6k doesn't matter to me, and neither does high ISO DR (since I shoot using ISO-less techniques, which actually gives the A7r more DR at higher, lower - above base ISO - DR, if that makes sense), so I prefer the A7r.