Of course one can make it work and get shots, folks used to shoot wildlife with Leica manual focus cameras when I was shooting a Canon Eos 1v and they got amazing shots, but not as reliably and the critter had better be immobile. Try at least a Z6ii or Z7ii - the first gen camera will not give you a good sense of what's possible. If you look at mirrorless for wildlife, do yourself a favor though and do not start with the Z7. sensor surpasses the Nikon 24MP sensors in the D610 and. The camera is compatible with both FX and DX lenses, but it has a 1.5x crop factor when using DX lenses. The D750 has a 24.3-megapixel sensor and uses the EXPEED 4 image processor. For maximum resolution of the digitized negatives, you want them to fill the DSLRs sensor area. The popular opinion is that full frame is for professionals and crop sensor is for non-professionals. The Nikon D750 is a full-frame DSLR camera that was released in 2014. In size and stature, it sits between the smallest entry-level crop sensor bodies such as the D3500, and the entry-level full-frame bodies like the D780 with the D7500 weighing in at 1 lb 9.4 oz. Larger pixels are more sensitive to light and appear to show less noise than smaller pixels. If it's just wildlife then D500, if it's the best of all worlds then D850, if it is an affordable all-rounder that's ok to great at everything, then the D750 or the Z6ii (the Z6ii will outperform the D750 on about every aspect but it will not systematically outperform a D500 for pure wildlife applications) Your Nikon d750 has a full frame sensor, meaning its the same size as a 35mm negative frame. This table comparison shows that while the crop sensor is twice the size of the iPhone 14 Pro Max sensor, it doesnt procure a larger image size. Best camera for still-life photography: Sony Alpha A7R II check best price. Best cheap full-frame Pentax DSLR: Pentax K-1 check best price. Best cheap Nikon DSLR: Nikon D750 check best price. Smallest full-frame camera: Sigma fp check best price. The real question then is what do you want to be the main focus (pun intended) for your photography. Best cheap full-frame Panasonic: Panasonic Lumix S5 check best price. The do-it-all in Nikon's line is the D850 and to this day it is Nikon's best high resolution sensor (I would expect the Z9 to best it, it's about time). That said, the limitations mentioned are real - it is more noisy than the D750 and it clips highlights more brutally, so it's not a great all-rounder. For the price you get top fps, top AF performance and top resolution (as in pixel density, not MPx) - you simply cannot go wrong with the D500 for wildlife, and you can find great ones gently used for $1250. The D500 is the most performance / $ you can buy for active wildlife photography of any system (even today, something like 6+ years after launch). I think folks have summarized it very well - I own D500, D750 and D850 and my experience aligns very well with the comments here. No, the Nikon D3400 is not Full Frame Nikon D3400 has a APS-C (23.5 x 15.6 mm) sensor.

Nikon d750 frame crop frame