D7100 Inconsistent Focus Tracking Errors

[Paganman2]

I have been doing a bit of reading up on VR with most Nikkor lenses and when/when not to use it, i did not know it has a bad affect on the image quality if used above 1/500th due to the time it takes for the moving Vr elements to re settle, i believe the optimal shutter speed for Vr to work at its best is around 1/250th as any Vr imperfections are spread evenly over the picture?

So when i have been using my lens with VR on at shutter speeds between 1/1000 - 1/1600 could this have been the reason for slight focus miss match when viewed at cropped ratios?

P.

 

[Don Kuykendall_RIP]

i turned off VR on all my lenses and just use the Reciprocal of Focal Length Shutter Speed Rule. Actually since I shoot DX I always use the effect Focal length instead of the actually length on the lens. Since I started this my Focus results have been much better.

 

[Eyelight]

I have been doing a bit of reading up on VR with most Nikkor lenses and when/when not to use it, i did not know it has a bad affect on the image quality if used above 1/500th due to the time it takes for the moving Vr elements to re settle, i believe the optimal shutter speed for Vr to work at its best is around 1/250th as any Vr imperfections are spread evenly over the picture?

So when i have been using my lens with VR on at shutter speeds between 1/1000 - 1/1600 could this have been the reason for slight focus miss match when viewed at cropped ratios?

P.

This may be a question that has no answer in that the effects are user/camera/lens specific.

I've been playing with VR versus no VR and it obviously helps at slower shutter speeds. But I have yet to see it muck up a shot at a high shutter speed. Not saying it can't or won't happen, but just that I'm not seeing it that I can point to the VR as a root cause.

 

[stmv]

I prefer setting the right speed for the right lens length, and if not, tripod. frankly, I am not happy at all at the obesity of modern
lens between the VR and the focus motor. ugh.. I rather they create compact and really good glass.

 

[Paganman2]

Yep it dawned on me thinking about my airways pictures and why the focus issue i have been getting, and only really visible with cropping or zooming in a fair amount, and why it is more visible on planes and not BIF and after eliminating all the other factors i am left with the VR situation.
I will try it out with VR off above 1/500th on my planes, perhaps even with the mirror delay mode, as i do not shoot in drive mode.

P.

 

[Paganman2]

Just a follow up folks, i came out of using the 1.3 crop mode and am now shooting exclusively in AF-A and 9 section dynamic, and the results i ma getting have improved massively for some reason.
WOW can this baby sing when she gets it right, some of the pics i am getting are so sharp and clear, they are making my eyes bulge out of my head.

P.

 

[Love Nikon]

Paganman..I do not think you will cure this problem ..after many 10s of thousands of perfectly focused D7000 images the D7100 was an instant problem. The problem is a change of focus unit from the 39 point 4800 unit to the 51 point 3500 unit . Basically someone has been told to reduce the cost and weight and the result is inferior .Its a lack of contrast in the image to which the 3500 unit cannot respond. Its a real pig and I have found no solution . Even the AF illuminators dont help.

 

[Paganman2]

Paganman..I do not think you will cure this problem ..after many 10s of thousands of perfectly focused D7000 images the D7100 was an instant problem. The problem is a change of focus unit from the 39 point 4800 unit to the 51 point 3500 unit . Basically someone has been told to reduce the cost and weight and the result is inferior .Its a lack of contrast in the image to which the 3500 unit cannot respond. Its a real pig and I have found no solution . Even the AF illuminators dont help.

What type of difference do you think the central area - say the cluster of nine focus sensors that come into affect in dynamic mode, do you think the D7000 is superior and more reliable in this area?

P.

 

[Horoscope Fish]

Just a follow up folks, i came out of using the 1.3 crop mode and am now shooting exclusively in AF-A and 9 section dynamic, and the results i ma getting have improved massively for some reason.
WOW can this baby sing when she gets it right, some of the pics i am getting are so sharp and clear, they are making my eyes bulge out of my head.

When shooting with my D7100, these are the general things I do ensure sharp focus:

• Stick to the rule of keeping the shutter speed equal to focal length x 1.5; this is a must.
• Use AF-C with Dynamic 9 Point (I also like AF-S Single Point (I'm assuming stills here)).
• Turn off VR when using Nikon lenses (seriously, just shut it OFF!)
• Use Quiet Shutter mode (takes a little getting used to but this really does help in my experience.)

One last thing... There is GOOD shutter button technique and there is BAD shutter button technique. Learn to isolate your shutter button pressing finger from the rest of your hand. It's natural for all the fingers of the hand to want to "squeeze" when you start to move a single finger. Learn NOT to do that. Smooooth, continuous, light pressure until the shutter completes its cycle. Seriously... It's important.
.....

 

[Paganman2]

When shooting with my D7100, these are the general things I do ensure sharp focus:

• Stick to the rule of keeping the shutter speed equal to focal length x 1.5; this is a must.
• Use AF-C with Dynamic 9 Point (I also like AF-S Single Point (I'm assuming stills here)).
• Turn off VR when using Nikon lenses (seriously, just shut it OFF!)
• Use Quiet Shutter mode (takes a little getting used to but this really does help in my experience.)

One last thing... There is GOOD shutter button technique and there is BAD shutter button technique. Learn to isolate your shutter button pressing finger from the rest of your hand. It's natural for all the fingers of the hand to want to "squeeze" when you start to move a single finger. Learn NOT to do that. Smooooth, continuous, light pressure until the shutter completes its cycle. Seriously... It's important.
.....

I can relate to the shutter button actuation i do the same - gentle pressing i also do a similar thing with supporting the lens with my left hand, i do not squeeze the barrel with my left hand i just rest the lens on it, but i find for aircraft flying several miles up i do need VR on as i struggle to follow the plane through the viewfinder let alone take a picture of it, i also use AF-A as i find AF-C looses focus quite a lot, i also leave dynamic nine point on.

P.

 

[Love Nikon]

Its simple ..I take tens of thousands in the same locations with a 4800 AF pack with a D7000 and change to a D7100 ..all the same ,same lens etc and it wont focus.. This has been discussed on the three main Nikon forums without solution .Change the VR, change the single to 9 do what you like the 3500 unit is not as good as the 4800. What it says is that 51 focus points sells more cameras than 39 but the only one we want to use in the center is not as good on low contrast scenes ...Dont fight it you wont change it and dont buy another Nikon until you are sure its sorted.

 

[J-see]

I can relate to the shutter button actuation i do the same - gentle pressing i also do a similar thing with supporting the lens with my left hand, i do not squeeze the barrel with my left hand i just rest the lens on it, but i find for aircraft flying several miles up i do need VR on as i struggle to follow the plane through the viewfinder let alone take a picture of it, i also use AF-A as i find AF-C looses focus quite a lot, i also leave dynamic nine point on.

P.

If the plane is that high up, isn't it easier to shoot AF-S single point with trigger on focus only?

 

[Horoscope Fish]

I can relate to the shutter button actuation i do the same - gentle pressing i also do a similar thing with supporting the lens with my left hand, i do not squeeze the barrel with my left hand i just rest the lens on it, but i find for aircraft flying several miles up i do need VR on as i struggle to follow the plane through the viewfinder let alone take a picture of it, i also use AF-A as i find AF-C looses focus quite a lot, i also leave dynamic nine point on.

D-9 should be plenty to keep track of any plane that high up, assuming you're panning your shots of course. If your panning technique is really, really good VR will be of some benefit; any slop in that department and VR will be of no use at best, and will foul shots at worst. VR is definitely a double-edged sword in my experience.

When you tried using AF-C did you have your shutter release-priority set to Focus Lock? Because not doing so would certainly account for a lot of out-of-focus shots. I find AF-C, D-9 with shutter priority set to Focus Lock covers 99% of anything that moves with any degree predictability. Still, ya gotta go with what works for you.
...

 

[J-see]

I was shooting some small plane miles away today and it's not really challenging to get it into focus since it's at infinity. Once I got it into focus, I don't track and can just fire away. If however I keep the AF-C pressed, I create focus issues myself.

 

[Paganman2]

These are what i can get when it all comes together...

P.



And closer up...

 

[J-see]

Mine today was too far to get a good shot. Fine layers of mist affect the quality pretty fast. But I was even surprised to get this out of it.



It looks like the pilot is sticking his hands outside the window but it's probably something else. Or maybe it's a "look mommy, without hands" thing.

 

[Woodyg3]

Its simple ..I take tens of thousands in the same locations with a 4800 AF pack with a D7000 and change to a D7100 ..all the same ,same lens etc and it wont focus.. This has been discussed on the three main Nikon forums without solution .Change the VR, change the single to 9 do what you like the 3500 unit is not as good as the 4800. What it says is that 51 focus points sells more cameras than 39 but the only one we want to use in the center is not as good on low contrast scenes ...Dont fight it you wont change it and dont buy another Nikon until you are sure its sorted.

Honestly, that is the first time I've read or heard such a notion. can you post links to the discussions you speak of? Thanks.

 

[Paganman2]

D-9 should be plenty to keep track of any plane that high up, assuming you're panning your shots of course. If your panning technique is really, really good VR will be of some benefit; any slop in that department and VR will be of no use at best, and will foul shots at worst. VR is definitely a double-edged sword in my experience.

When you tried using AF-C did you have your shutter release-priority set to Focus Lock? Because not doing so would certainly account for a lot of out-of-focus shots. I find AF-C, D-9 with shutter priority set to Focus Lock covers 99% of anything that moves with any degree predictability. Still, ya gotta go with what works for you.
...

Yep i follow through with the lens and follow the planes smoothly, i also use focus priority, it is a strange coincidence that i was seeing more out of focus when i was using the built in 1.3 crop mode, compared to using it full DX.

P.

 

[Love Nikon]

I previouly commented on poor AF performance particularly in AF-S mode on the D7100 . Many seem to think that its a matter or adjustment but an analysis of the modules gives the reason .
D7100/7200 at f8 1 cross sensor in use
D610/D7000 at f8/5.6 7 cross sensors in use
D750/D8xx at f8 11 cross sensors in use

So we see why in my case an upgrade from a D7000 to a D7100 was such a disaster for me and that a move to a D7200 would make no improvement.
With the bottom two cameras in lower light and low contrast the assisting sensors can find sufficient detail to make a focus but the poor old 7100 cannot .
Where to go from here ?? D610 but then I must buy two and two 28-300mm. This is not good for cashflow. Clearly the marketing value of 51 points outweighs the functionality of the 39 system.
I feel very disapointed ..I pay for an upgrade and get a downgrade but I dont feel a Canon comming on .

 

[J-see]

I previouly commented on poor AF performance particularly in AF-S mode on the D7100 . Many seem to think that its a matter or adjustment but an analysis of the modules gives the reason .
D7100/7200 at f8 1 cross sensor in use

That's effective aperture not selected. I don't see how that is a problem with faster lenses? I'm not familiar with the D7000 but I'd be surprised if it can focus at f/8 (effective aperture) even when only using the center.

The others are FX so you can't really compare them.

I checked Nikon to see which cams can AF up to f/8:

Df, D4, D4S, D600, D610, D750, D800, D800E, D810, D7100.

As you see, the D7100 is actually an improvement on the D7000.