I think the buffer limitation in the D7100 is a serious issue for RAW shooters. But I spend most of my time from April to June shooting warblers and songbirds with fill flash, and neither 6 fps nor the buffer is a limitation for warblers. And who - other than D800 shooters - couldn't use more resolution for warblers? And certainly anyone shooting a D300 like I am can use higher ISOs.
Another thing I want to experiment with is using my 300 f2.8 for birds in flight using the 1.3x crop mode (really micro 4/3rds?). Autofocus should be much faster than using the TC-14E, and if the viewfinder image will be a little small at least it will be bright! And given that DOF will be 2X that of 35mm, I will be able to shoot at f3.5.
And lastly, the obvious point: an extra half an hour at each end of the day. When it's time to pack up my D300 and D300s I can pull out the D7100. It is not the D400, but I look forward to shooting with it.
If you use a DOF chart for micro 4/3rds and 300mm it should be accurate for this camera in 1.3x crop mode. At the same distance, this combination at say f4 will have the same DOF as 600mm f8 in full frame.
You're shooting off in all different directions here! The front element alone determines a lense's light gathering ability - that's why my 300 f2.8 VR with a TC-14E is a 420mm f4. But of course cropping doesn't change the actual focal length: it changes the angle of view. Here's a little light reading for you: http://www.falklumo.com/lumolabs/articles/equivalence/
Sun 24-Feb-13 02:09 PM | edited Sun 24-Feb-13 02:30 PM by Chris Platt
No, there isn't a dof chart for tc's. There isn't a difference between a tc crop factor and a chip crop factor in dof calculations. It is better to think in terms of field of view than focal length.
If you mount a 2x tc and lens on a full frame, you will cut the field of view and the dof in half. If you use the lens without the 2x but cut the sensor size in half you will also cut the field of view and dof in half. This assumes identical dimensions for the final view whether on screen or printed.
For equivalent fields of view (effective focal length) a crop sensor will have a greater dof than a full frame sensor, because you can achieve that equivalent field of view at a greater focus distance or with a shorter focal length lens with a crop sensor.
Conversely, the same focal length lens used on a crop and full size sensor shooting a subject at the same distance will yield a smaller dof on the crop sensor, but the fields of views aren't equivalent.
But warbler season is fast approaching and nowhere do the limitations of the D300 and D300s bother me more than when shooting warblers. I'm not sure that when the D400 does arrive I will like it as well ergonomically as the D300/s. I find the grip and controls on the D800 quite strange as well!
I bought a D300 in 2008. I shoot mostly birds and other wildlife. I've been waiting for a D400 since they started being rumored. I almost bought a D800 in the interim. I just ordered the D7100! More pixels on the bird; higher acceptable ISO; and almost all the other features I've been waiting for (more buffer will occasionally be an issue; dedicated rear focus button easy enough to set up).
But I'd really need to go from my 500 f4 to a 600 f4 VR - I'm a framer, not a cropper. And the problem there for me is more weight than cost. The D7100 should allow me to determine the impact of higher resolution on my images without disrupting the rest of my rig and technique. But I won't be surprised if I discover, for instance, that a 3 series Gitzo is inadequate at 700mm.