Nikon D7100 Review and user experience - Part 4 - Out in the sunshine with a Sigma 12-24mm zoom - AA filters and the consequence of their removal.

A short spell of sunshine yesterday morning, 20 minutes worth to be exact, allowed me to try out the D7100 with my Sigma 12-24mm zoom.

The lens obviously doubles up as a wide-angle for my D800E, though on the D7100 its the 35mm equivalent of 18mm. This gives an advantage in that the soft corners aren't so prominent, though they are still there. However the lens overall produces nice images with the D7100 and will be very useful in the future. 

The D7100 continues to impress me, and as usual the highest complement I can pay a camera is that I just don't think about it and concentrate on taking pictures. This is why I have nailed my colours very firmly to the Nikon mast and three out the four cameras I'm currently using are Nikons. 

I like Nikons, and always have, because of the basic absence of 'fluff', by which I mean gimmicky nonsense talked up to try and attract cameras to gearheads. It is becoming more and more difficult to avoid wi-fi, apps and all the other associated tech. stuff  that cameras seemingly have to come equipped with these days. Nikon do a good job with this and while you can get wi-fi connectivity it is an extra. I do realise that it is useful for news photographers needing to get their images transferred as quickly as possible, but I'm doing my best to avoid it. I'm particularly puzzled by the cameras that now transfer images to smartphones to upload to social network sites. Having tried this once just to see what it was like, it took so long to happen that I gave up. It seems that you have to shoot small jpgs. for it to work at any decent speed for those of us who don't live in the middle of large cities, which begs the question why not take the picture on your phone in the first place, since at the sizes people upload who's going to tell the difference?

The D7100 is, thankfully. a 'photographers camera' designed to take pictures and I certainly appreciate that. It is somewhat 'old-school' (as am I of course!!) and that dinosaur of the past, soon to disappear, a DSLR. Apart from the fact that DSLR's aren't really going to vanish anytime soon. They may loose sales to mirrorless, but if they still keep turning out cameras like the D7100, then I see no reason that people will stop using them. 

I should mention a couple of things I haven't so far about the D7100. Firstly it has an OLED viewfinder and screen, which means that if like me you need to shoot with polarised sunglasses in bright sunlight, there is no loss of image either horizontally or vertically. Even my D800E doesn't do that. 

Secondly though the removal of the AA filter does add a small amount of crispness to the images, I think its very much the case that this doesn't have as much impact with a CMOS sensor. We now have this camera, the Leica M and the Pentax K-5 iis, which are all minus an AA / Low pass filter and the Nikon D800E has a filter which conteracts it. It seems that the difference is there, but this difference isn't as marked as with the CCD sensor of the Leica M9 for example. Having used the D7100 and D800E and seen raw samples from the Penatx and Leica there isn't that biting sharpness that the M9 and the Sigma DP Merrills have. The Fuji X-Trans sensor cameras also produces much less crisp images than the lack of an AA filter would indicate. 

The reason seems fairly obvious to me. The Sigma's are only really at their best at the base ISO of 100 and above that generate large amounts of noise. The Leica M9 is somewhat better but still pretty poor by todays standards at high ISO's. And indeed so are many of the AA filter less medium format cameras and backs. Its still true that cameras like the Leica CCD cameras, the Sigmas, the Pentax 645D and various Hassleblad and Leaf etc. cameras and backs do produce the sharpest, highest resolution images you can get. But none of them are particularly versatile and capable of the things we expect out cameras to do these days. The D7100 is a very capable modern camera, with decent high ISO performance, and like many CMOS sensors (though not all) is however capable of taking a good deal of non-destructive sharpening for the files it produces, which can make them pretty much the equal of their CCD equivalents.

Here is a 100% blowup from the D7100 with no sharpening.

 Here is the same blowup with some Smart Sharpen added in Photoshop.

Now for all my library needs that's perfectly adequate to produce an image that will reproduce well for any print requirement. It also makes the image look good on the screen. Now I used to be one those people who if asked what I was looking for in a camera / lens combination I would answer 'Sharpness, sharpness and sharpness'. That isn't the case any more, because there is enough crisp, well-defined resolution available for me in cameras that do other things well and are more versatile to use and don't mean I have to spend a lot of time processing their files. 

Now I did like the Sigma DP Merrills, the resolution was spectacular, but they were so restrictive to use and basically dictated to me what kind of pictures I could take. While I was prepared to put up with a certain amount of that, I was of course missing pictures, not being able to shoot what I wanted and I eventually decided that the constraints those cameras put on me were not worth me going 'Wow' every time I looked at the screen. Because that 'Wow' wasn't pleasure that I had got a great image but just me admiring the image quality, and I'd rather be happy with the image itself than how it looks. 

So while I appreciate the removal of the AA filter on the D7100, because of the obvious improvement in CMOS sensors in general, it doesn't seem particularly necessary for the achievement of sharp images. There are however still cameras that have far too strong AA filters, the Nikon D3200 being an obvious example. Why that camera is like that I have no idea, presumably its a different sensor to the one in the D7100 and needs more filtering to keep the noise down. As I wrote before I also found the output from the Nikon D600 I had somewhat soft also, though to be honest the files would sharpen up nicely in post-processing.

So in conclusion, more positive noises about the D7100. I certainly like it better than either the D600 or D3200 I tried and it will be a nice companion camera to the D800E. I like it as it will be particularly useful for landscape work when I'm looking for that extra depth-of-field. Much as I love the D800E I do sometimes struggle to get enough in focus and tend to push the VR in my lenses and my hand-holding steadiness to the limit. When I had it a while ago I always thought and wrote that the D7000 was a great camera and I think the D7100 is a worthy follow-up and an even better camera. And thats no small complement as far as I'm concerned.