Why no focus issues with D5100 or D3100 compared with D7000

Started Oct 28, 2012 | Discussions thread
dirtdiver82 New Member • Posts: 24
Re: You can find..

phiri wrote:

dirtdiver82 wrote:


Basically saying what I have all along inconsistency in AF and suggests using live view. I just don't think the D7k is that good for AF after owning 2 of them. Some might accept it..I personally do not. I also noted some mirror vibrations at some shutter speeds causing some blur..which I did not on the D90 separate issues but it did show up for me.

I do hope we get beyond the stage of simply saying the AF is complicated, or just settings, users fault of blaming the lenses, pixel density, or limitations of phase detect AF. It's quite possible your idea of decent AF is a million miles away from mine. D7k is IMHO not that good for AF, and I'm not the first person to suggest that either

Totally agreed.

Same here, I also went from the D90 to the D7000 and using the same lens, no matter how I tried ( single AF point, holding my breath ) many of my pics have a little of motion blur quite evident at 100% while the D90 used to have none.

Not to mention that tracking fast moving objects under certain circumstances remained also problematic with the D7000.

Sadly my D7000 has been stoled so I'm thinking on buying a D5100 to keep the same sensor performance until the eventual D7100/D400 shows up, but I'm not considering another D7000.

The D7K feels more responsive than the D90, has better viewfinder, better video, more features, but AFwise, it disappoints me too specially given the 1300€ I paid for it.

Shutter speeds that are adequate to get sharp focus on a low density sensor may not be adequate on a high density sensor. The reason that many people have problems when they upgrade cameras is that people dont want to re-learn the new camera body. Most users take for granted that simply because one gets sharp photos with camera x, one will easily get sharp photos with camera Y. if you google on this forum, there used to be many complaints from people that D40 was way sharper than d90. These similar sentiments have been carried forward in discusiing the d90 vs D7000 and the only similaritiy in the two cases is the increase in number of pixels. I can tell you this, I started with a D40 and then bought the D90. I had just to learn the D90 from its basics. Took me sometime but it was worth it in the end. from then I bought a D700 which I sold after two months simply because it was limiting me in the telephoto shots. I then replaced with a D7000. My first photos with a d7000 were not sharp enough and this is the truth. I practiced a lot trying to understand its usability in different environments. Quickly I got hold of it. Now I can also honestly tell you that the D7000 is truy sharp and just focusses as well even in low light. Of all the cameras I had, the D40 and D700 were the easiest to get sharp results, so this had to with their low pixel counts (the d700 considered low since it was an FF camera). I also shoot mainly in manual mode and spot metering so I know which shutter speeds are adequate for me. With a 50mm f1.8, 1/50 is a minimum shutter speed I use for still objects or for portarits of people that are stable. otherwise it is 1/100s and above for other things. You have to know your comfortable zones with shutters speeds for each focal length.

I'm aware of the higher pixel density of the D7K.

I'm also aware that my Panasonic FT2 has a crappy 1/2,3" 14MP sensor that has a much greater density than the D7K and has much worse colors, DR, etc, BUT you can take a picture with one hand on a sunny day and despite the noise, the poor colors, etc it's tack sharp.

As Barry said, it's not something consistent. Happens with some shutter speeds to different extents and it's more likely due to vibrations caused by the mirror mechanism. For example, in my experience 1/500s many times looked worse than 1/250s ( w/good lighting and low ISO ). It's been discussed here before.

I chose to live with it while I had my D7K and not to pixel peep my pics using the 70-300VR because I knew what I was going to get. I loved the camera, the colors, the DR, the ISO performance but honestly I always thought there was room for improvement. At that price point.

About low light focusing, I had two D7000s (first one was exchanged because of severe backfocus) and even if the second D7000 focused right on most situations, in indoor tungsten/candle lighting it backfocused like crazy. This is a challenging scenario because of the strong IR light emissions disturbing the PDAF sensors but other cameras just handle it better.
Seems Nikon also realized that there were room for improvement with the D7K AF as they released the D600 with the same AF module but revised. The D600 can focus at f/8. The D7K... well, not. At least in my experience.

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