In early 2012 Nikon released the Nikon D800. It surprised the DSLR world with 36MP sensor with high dynamic range. I was expecting to get one. However soon it became clear that the unit has some major flaw, no all but a significant number of D800 & D800E had critical focusing issue. To tell the truth I checked quite a number of Nikon D800 & D800E copies, none passed the focus test. So it refrained me from getting the camera I desired. Due to high megapixel it required GOOD photographic skill & very precise focusing to get proper image. Blinded by the high megapixel very few were cable of defining the error. Had the D800 been flawless Nikon never needed a D810. So Nikon D810 confirms the major issues they had in D800/D800E.

When I got my hand on Nikon D810, it give me the sense of confidence I had with D700. Nikon D810 is just how the D800 should have been in the first place. The autofocus system, the accuracy of color and the newly incorporated small details really pleased me.

Look & Feel
As I picked up the camera it felt beefy than my trusty D700. I have average hand size, so if you have a big grip you will find it easy to operate. Unlike entry level DSLR the D810 has a strong built though it came out of the Nikon's Thailand factory. D800 was from Japan. But I don't mind China or Thailand as long as it servers my purpose the way it should be. It shares the same soft rubbery grip which all Nikon Pro bodies have. The material keeps the camera stick to your hand. The memory card door now has a textured finish like rest of the grip which is a good move. The rated shutter life is 200,000. It sounds a lot so long you are only taking still photographs. But as soon as you enter into the world of timelapse photography, you will notice how fast the shutter life is going away. I wish Nikon would have doubled the shutter life for this type of pro camera.

The Nikon D810 body has a pot belly shape in contrast to the other Nikon Pro cameras. Despite this odd appearance it feels well balanced in hand with most Nikkor lenses. A vertical grip is much appreciated but Nikon charges too high for the MB-D12.

Physical Changes
Most of buttons & dials are placed just like Nikon D800 with few changes. On the front side both Preview & function button now has a rounded look just like the old D700 and well spaced.

Newly added Bracketing button on left side close to flash control button. In D800 the bracketing button was on top left dial. The front also has a stereo microphone on either side of pop-up flash.

On the back side of the camera there is a new i-button for quick access of various items. Nikon has moved the Metering selector dial from the back of the camera to the top left dial. This is something I really disliked. With old Metering selector dial around the AF-L/AE-L I could change the metering mode very quickly with right thumb, but now I have to push the top button with left hand and rotate the command dial with right hand to switch metering mode. An ugly decision by Nikon.

The top panel remains almost the same. Little shifting of the shutter release button and a newly added ridge leads to the recording button. The release mode dial now has new Qc (Quite Continuous) option.

Shutter Sound
Shutter sound and vibration generated by shutter mechanism are two section where the D810 has improved significantly. The loud shutter sound is very disturbing in wild life photography as well as in many formal events. D810 gives a very pleasant experience in this regard. I'm really impressed with the soundness of the shutter. On the other hand internal vibration generated by the shutter in long exposure is a major issue camera manufacturers have to tackle in these high megapixel cameras. That's why Canon incorporated a shutter damping system in their newly released Canon 5Ds cameras. The Nikon D810 also address the same with improved components of mirror and shutter.

Viewfinder
Anyone using a Crop / DX camera body for a long time will certainly notice the big jump when looking through the viewfinder of a full frame camera. Compared to my old D700 the Nikon D810 viewfinder looks more natural to me. Most of the Canon camera viewfinder has a bluish cast which I noticed even in film days, while Nikon's tend to be on the Yellow side. Look through the viewfinder of D810 and it feel almost same as you see in naked eye.

Flash
The whole Nikon DSLR line-up has pop-up flash except the D4s. It's such a handy tool. Instead of illuminating the subject with built-in flash, I use it as a commander to control my Nikon SB-800 & SB-900 flash units. With D810 it remains the same regarding the flash.

Connectivity
The connectivity panel on the left side of camera has HDMI, Full size USB-3 port and 3.5 audio jacks. The rubber flap covering these ports now has a hinge which is nice.

Battery Life
Nikon D810 uses EN-EL15 battery, which is a 7v 1900 mAh power source. It's the same battery found in Nikon D7200, D750 and D610. While charging I found it takes more than 2 hour to fully charge the battery - a little surprise for me (too long). If I'm not shooting birds in flight or dolphin in the sea, its really difficult to shoot couple of hundred images in one day (Thoughtful shooting). Nikon says a fully charged battery can take 1200 Normal large jpeg images in single shutter mode & 3860 in continuous mode and 40 minutes of HD video. I have used the camera all day long taking around 400 shot (uncompressed 14bit Raw + Jpeg) and 7 small HD video clips without trouble. The need of extra battery become very much apparent to me when I started In-camera timelapse photography. At 5 second interval the camera operated for 3 hr 30 min (approx.). So if you are shooting timelapse or doing videography for long duration couple of extra battery is a must.

Auto-Focus Performance & buffer
All autofocus issues have been fixed in Nikon D810. It works like a charm. The focus locks on quickly and accurately on the subject even in low light. Out of 51 autofocus point 11 has the ability to focus upto F/8 aperture. The newly added Group area auto-focus has been praised by many. In my regular use it felt just as reliable as the D700 if not better. The continuous shooting buffer has been improved a lot. I used a Lexar 1000x 32GB Compact Flash card which has a write speed 145MB/sec. Normally I shoot uncompressed 14bit RAW + Large fine Jpeg mode, this costs around 100MB per image. A lot of data when shooting birds in flight in continuous high mode, but camera performed decently without any hiccup.  Behind these improvement works the Advanced Multi-CAM 3500FX autofocus sensor module, new EXPEED 4 image-processing engine and doubled buffer memory. However with the increasing number of pixel I feel Nikon needs to improved a lot in focusing module. One important reason is to remember these are high definition camera and a single focusing point still covers a lot of area. So if your subject is small its quite likely that the camera picks up the wrong point and you get an overall sharp image with your main subject out of focus. That's why you may have heard the upcoming Nikon D5 will have 173 autofocus points.

I have added 100% crop version of most sample image.

Image Quality
In the field when shooting with any DSLR and review image in 3'' LCD, we always become delighted looking at the well-lit image. However back home and watching in large monitor takes that delight away. The small 3" LCD most of the time fools us regarding exposure & sharpness. Then we spend a lot of time fixing those issues. With Nikon D810 your mistakes will be more apparent as you watch them in large monitor zooming at 100%. This is a camera that picks up every single mistake you made in the field. In my part of the world now its monsoon. The days are mostly rainy as well as windy. So getting good result has been a real challenge. When reviewed the images in full resolution a lot things become quite clear to me. In short the image you get from the camera is really amazing. It can capture very fine detail. See the compound eye of the dragonfly at 100% magnification or the house in the cock's eye.

ISO Performance
The ISO range extends from 32 to 51200. I liked the ISO 64 most. And my highest limit will be 6400. At 64 ISO the transition from one color to another is buttery smooth. It reminds me of Fuji Velvia 50 film back in film days. The color is rich. Shooting at night at ISO 64 yield excellent result. The chromatic noise and noise in general is greatly reduced if you take the jpeg output from RAW file. The difference between In-camera jpeg and that produced by Capture NX-D is obvious. So I prefer to shoot in RAW.

• See all ISO test sample - Nikon D810 ISO Performance Test