I have been reading so much lately I am finding it hard to decide if getting the D7100 is the right thing. I have read that DX cameras are great for Birds and Wildlife which I primarily shoot. I see a lot of people on this site are using the high end Pro nikon bodies. I would like to know anything about this before I decide to change from my current D7000. I plan on purchasing the 600mm f/4 with wimberley head so, my budget is a little strapped. I would just like to know whats going to get a better image or if they are pretty much the same if your crafty at getting close to your target. Let me know. Thanks.

If the FX and the DX gives you the same image quality (depends on what you need your images for and how they will be viewed), I'd suggest choose the DX one. That "reach" factor does come in handy a lot of the time. Previously a couple of members suggest that they could just shoot with their full-frame 36 or 24 megapixels cameras from afar and then crop for the final images they want. Well, now that the D7100 also has that many megapixels available, you can do the same with that DX camera.

FWIW, I also use a full-frame body.

I take a different approach - With tons of money invested in prime FX glass and the associated weight of carrying it around - I hate though of wasting all the glass the DX versions don't use. Sad thing is Nikon does not make pro level DX lens - they would cut both cost and weight. One good thing is DX cameras only use center of glass which has its own set of advantages. I use both D800 and D4, I not that familar with new D7100 but both D4 and D800 crush the D7000 due to its small buffer and focus - I know the focus on D7100 is suppose to use same as D800 and D800 in DX about same as D7000 so D7100 has higher resolution at same distance. Hope thisw helps but if D7100 has same small buffer as D7000 it will come up short on BIF and action photos

One of the reasons that many Nikon pros here use FX is because Nikon currently does not have an up-to-date DX pro cameras. They just don't have a choice.

I'd suggest you wait a few weeks to see how good the coming D7100 is. Your lens will never be too long for birds.

Thanks guys! I just know I want the 600mm f/4 and was going to get the 7100 at the same time ( I cant purchase a higher end camera cause of my budget) but I just need to hear some other opinions and from what it sounds like with the new upgrade in pixels and 51 point focus system maybe the 7100 will be good till I can afford a good FX camera. I went with the lens first cause many were telling me glass is very important. Any other info is greatly appreciated I will be purchasing the equipment sometime this month and will post some pics when I get it. I hope I can compete with some of your peoples pictures (there CRAZY nice). Take care.

My advice would be to get the lens and see how you do with your current body. Spec wise, the D7100 appears better but by how much and will you notice? I'm getting real gun-shy with Nikon now, the D800 and then the D600 both had QC problems at release. Add to that some D7000 problems at release and I see a pattern forming that tells me not to be too eager with their new products.
Once you have some experience with your current D7000 and the new lens, you can identify areas that you feel the D7000 may be lacking in and then start looking for a body to fill those shortcomings. Who knows, by then Nikon may announce a D400!

If I were you I would aquire the D600 to use with your lens. FX will always give you the better
image. I have a new D300s and it just sits and is not used. I use a D3 and along with the high
ISO performance my bird images look great. FX is really helpful in northwest Ohio where there is
no sun in the winter. My high ISO settings are between 1250,1600 & 2000.My D300s cannot produce noise
free images unless I have full front sun light and even I'm limited to only 400 ISO.
Next month I'm getting a D600. I'm going FX all the way.

The 17-55/2.8 lens is a pro DX lens. Depending on your standards, the 12-24 DX lens may also be considered pro. Having the 17-55 I can say that's it's not noticeably lighter or smaller than an equivalent FX lens like the 24-70/2.8. It's cheaper by a few hundred bucks though.

Here's a comparison between the D7000 & D7100 specs :

http://nikonrumors.com/2013/02/21/nikon-d7100-vs-nikon-d7000-specifications-comparison.aspx/#more-54482

Doesn't seem like a lot for an upgrade, a few more MP which may or may not give a crop advantage and a few more AF points. To take advantage of the extra pixels you would need to be absolutely steady when shooting. I think. Downside is buffer is smaller 6 images vs 10 in the 7000 (7 vs 11 in 12 bit). I'd be inclined to use your 70000 & save your money for an FX, maybe the D600 as suggested down the road.

Use the 7000 and see how it goes... worst case scenario is that you aren't satisfied and you can pickup a used D7100 from a disastisfied customer for a few hundred $$$ cheaper and sell your 7000 on ebay or something similar.

I was looking at the D600 - but can't afford the reach of a 600mm lens. In the end, I decided on the D7100 because I need that crop factor. I have also just picked up the 12-24 DX lens and it's beautiful - got it used for $600. You can't beat that

Just to chime in one more time - Since you are buying the 600mm - I have that one and it is my go to lens except for hand held action shots ( though some younger and steadier guys do it!!) Like others suggested stay with D7000 see how it works and save cash. Lens hold value - cameras do not even in short run!!!. I did not unload a D2x (pro body) fast enough - probably close to $5000 camera new now it is my 3rd backup since it may fetch all of $700. When Nlikon releases replacement for D4 or D800 their prices will drop quickly and you can pick up one of these for same price as new D7100!!!

A couple of points here:

1.  Yes, I've thought by cropping a D800 image one can effectively lengthen the telephoto lens, by a good amount.  Why not?  And now you mention that one can do the same with this 24 Mpx DX sensor.  Good point.  

NO NIKON PRO GLASS FOR DX FORMAT?
2.  My second point is thrown out there to everyone on the equip forum (i.e. not to DChan specifically) :  Maybe I simply do not understand the DX format's relationship with the FX tele lenses.  I am wondering why all the critique about Nikon not making pro quality DX telephotos.   All one needs to do is attach an existing FX pro tele onto a DX and they effectively lengthen the telephoto and have the image taken with the best part of the lens to boot ?  Excepting for the fact that noise is a factor with these DX sensors in lower light, it seems to me that the Nikon Pro superteles with a high quality DX body is a great solution for the extra reach.  So why the fuss about Nikon not having Pro supertelephoto glass for their DX bodies.  Don't they already have them with these FX lenses ?

Let me ask this in a different way:  What sense does it make for Nikon to come out with pro DX superteles when you already get 50% greater focal length with the existing FX pro superteles on the DX body............and DX pro superteles could only be used on DX bodies?  Why would they do it? Am I missing something?  And that was the basis for my arguments (a few weeks ago) that Nikon IS going to come out with a PRO-QUALITY DX BODY,  beyond the D7100:    Sensor technology is evolving quickly.  When Nikon gets to the point where they have a DX sensor that is what they consider to be of pro quality, then we will see that much-anticipated pro-quality DX body that everyone will love.  

Again, maybe I just do not understand the relationship between DX  bodies and FX glass.  Or maybe the point made by those folks is that Nikon does not have ANY pro-quality DX lenses.  And then I can understand their argument.

1. D800 in DX mode is 15 megapixels, D600 and D3x in DX mode is only 10 megapixels!
2. You don't get the size and weight savings that you would if they had pro-grade DX lenses.

You already have a pro-quality camera that can deliver 15 MP. Its the D800.
DX does not change focal length. It crops the sensor and delivers a image which
taken with a 300mm, but looks like one taken at 450mm. FX lens covers the whole
frame 24x36, DX only cover part of the full frame (1.5)

Right now my camera of choice is a D800 which I use regularly with a 500VR+TC14EII. Given my style of shooting (mostly hand held) I wouldn't want the current 600VR unless it was slimmed down in weight by a several pounds...but I digress. The reason I shoot the D800 is because I have the option of staying wide for an environmental shot or cropping tight for a "closeup" and still retain good IQ (within reason). I also value the D800's decent ISO and AF performance and stellar DR.

But I'd consider buying a D7100 as a second body for the higher sensor density. Assuming it's similar to the D7000, it would be limited to long-distance static shots (e.g. nests) due to the poor build quality, shallow buffer and weak AF. If the D400 is released with a better buffer/AF, then I'll have to take a good look at it, but to tell you the truth right now I really enjoy the flexibility of shooting FX and don't want to return to DX exclusively. The only thing I really miss on the D800 is speed, which I'm hoping might be taken care of by a D4x!

I would keep your D 7000 and use it with your new 600mm f 4.0 when you get it. The limited buffer on the D 7100 makes it a non starter if you shoot NEF or RAW as best as I can tell from the specs. Real world testing will tell us the truth one of these days. I have a D 600 and do not like its relatively low frames per second compared to my D 300s. For most of my bird shooting, like last week, I used my D 300s with my 500mm f 4.0 for two reasons--higher frames per second with added battery pack and its 1.5 crop factor without losing any of the 12 megapixels. If you are going to go FX, I think the D 800 is a better camera if you use it in its crop mode because you end up with more effective pixels as atated above. FWIW, I shoot my D 300s at ISO 1600 a lot and do not see too many problems with noise. Joe Smith

1.  Great!  

I believe 6 mpx is the threshold for a cover or entire page of a paper magazine.  But that is becoming less relevant as the paper medium is rapidly being replaced by the cyber medium.  Still, does 6 mpx not remain the industry threshold ?  Of course we all agree that 6 mpx is something that none of would want today. 

But being able to crop more than 50% of the D800's 36 mpx file and end up with a 15 mpx image excites me.  If I said the D600 I did not mean to.  I was referring to a 24 mpx file (in fact both DX as well as FX) being large enough to be able to crop by 50% to 12 mpx.  It was a short time ago when a 12 mpx image file (DX even) was fine for most of the needs of all of us....excepting maybe decor ambitions.

2.  I may be confused:  

Would these currently-non-existent pro-grade DX lenses we have been discussing, work on FX bodies?  If not, then why would a photog pay twice for a professional-grade supertele line that is already available ?

It does seem to me that there is a reason why Nikon would not produce a pro-grade DX.......the revolutionary D800.  That D800 body does just about everything a photographer could want for.  Clean up the high ISO noise and speed up the data processing for a faster shutter rate and do you not have everything you could want for in a DSLR ?

I used to have a D7000 that i used with a 600f4,I hope you have a battery grip on the D7000 as its very light and wont balance properly with the 600 on a wimberley head without one, Even with one its on its limit and then add a 1.4x and its hard to get a nice balance. I would get the lens first and wait on the body for a few months

D