D7100 Inconsistent Focus Tracking Errors

P

Paganman2

Senior Member
Hi all i am new to the D7100 coming strait from a D90, i am loving the camera as a whole but i am experiencing a frustrating focusing problem when used with my Only lens 70-300 AF-S ED VR.
My background and interest with this camera is Aircraft Spotting and Photography in particular aircraft a few miles up flying between airports, my previous camera - D90 with the same lens tackled this very very well, and i upgraded to the D7100 to give me even better focus accuracy and more room to crop.
Unfortunately i am not seeing this dependable improvement as i am seeing a miss match pattern of - In focus, Out focus, In focus etc with the same aircraft taken at the same time under the same conditions, i am finding that in AF-C mode with either single focus or 9 point dynamic, and varying lock on from long, mid or short/off, what i get is the focus confirmation brackets dancing in and out without locking focus, and even when i had focus priority for the shutter it was firing even though it was obviously hunting for focus.
When i switch to AF-A this improves things from the point that the focus confirm light does come on, and i fire the shutter, but i am just not getting a consistent reliable focus pattern and this seems worse the closer the plane is to me even with using 1000th to 1250th sec shutter speed, the focus has been calibrated and is spot on - anything further away and not traveling towards or over me is also ok and focused nice and sharp, the odd one close and coming over me or to the side is ok as well.
It is annoying as there is no security in getting sharp focus as i used to be able to, i have even checked the contacts and cleaned them but they were ok as i would have expected as it is a mint 400 shutter count second hand camera, the same with my lens, that is perfect also.

Does anyone else have this problem, know what it might be or could offer any ideas please, i'm pulling my hair out over this.

Pag.
 
D

Don Kuykendall_RIP

RIP :(
No problem with my D7100 and lenses listed below.

Post a photo here of one where the focus was not good. Be sure to include the EXIF data.

Follow these direction to add the photo.

Guidelines to adding a photo to your post.

1. Resize photo to 1000px on the long side.
2. Resolution set to 72ppi (Pixels Per Inch)

These guidelines will be good for viewing on a computer but will not be good for printing. This will help safeguard your copyright.







 
P

Paganman2

Senior Member
Ok i will have to convert two of the pics i will have to crop them to fully show what i mean as under normal viewing at full size files its hard to see a difference.
 
P

Paganman2

Senior Member
DSC_1478.jpg


DSC_1479.jpg

These were both taken within a few seconds of each other with exactly the same settings, the only difference was with the first one i just shot the plane without following it with tracking, in the second shot i followed the plane with the center focus bracket on the plane, but as normal it was not locking focus as the focus confirm brackets were dancing like crazy.
Bot these shots are 100% crops direct from Nef files and both have had exactly the same editing done - noise control sharpening etc, so in theory they should look exactly the same.

Any ideas folks please...

Pag.
 
Last edited by a moderator:
P

Paganman2

Senior Member
Eyelight said:
Looks little hazy. Are you experiencing the issue all the time or just on some days?

What size is this crop in pixels?


They are both 1000 x 625 cropped from 6000 x 4000 but changed aspect to 16;10, yep i am getting this in any weather conditions but only planes, my BIF shots are fine, as i said in my op post - i never had this problem with my D90 using the same lens, my keeper rate then was about 85% now its less than evens.
Click to expand...
 
P

Paganman2

Senior Member
PH-BQL.jpg

This is an example of what i am used to it was shot with a very old D200 (remember that dinosaur) lol anyway i was/am expecting much much better focus accuracy with my D7100.

P.
 
E

Eyelight

Senior Member
Was hoping some of the D7100 users would wander by and they may still. Would especially be good if one of them had some experience with the D90 or D200 and could comment specifically comparing the focusing differences.

Can't rule out a problem with the camera until you solve it, but I'm thinking it's just a case of adjusting to the different camera. The D7100 uses a much newer focusing system and it may be that for those particular shots, you just haven't found the sweet spot.

Hard for me to imagine the image in the viewfinder and how many focus points may be in play, but I'm thinking that depending on the distance it may be hard to use 1 point and 9 may not be much help either.

As I type this, I wonder if the D7100 having 51 points is actually sampling a smaller point.

Another thought is that the shots being missed may be due to the path of the subject through the viewfinder. Assuming you are facing the plane as it approaches and holding the camera in landscape fashion, maybe try a few with the camera turned 90 degrees so that the flight path runs the length of the image.
 
J

J-see

Senior Member
If you shot in burst mode with VR enabled, it is possible VR negatively affects the focus of some shots. I'd not be surprised if VR works contra-productive in most shots above a certain shutter even if in single mode.
 
P

Paganman2

Senior Member
Thanks for the replies folks, i look forward to more input over this, i have been thinking thought - as the majority of my problems seem to arise when i hold the camera/lens slightly upwards to fully upwards, i wonder if it is some kind of focus element/VR problem with the weight baring down, i ask this because when the camera/lens is horizontal when taking shots of things following across my horizon, there doesn't seem to be a problem, and i can follow and track things and they are in focus.

Just to reiterate - it is only the Aircraft flying towards me either at about 90 odd degrees to the camera or head on/ direct above me that are causing the problems, and it seems that the closer/larger and faster the plane is to me, the more the focus struggles with locking focus, just to be exact - the focus isn't hunting or visually going in or out of focus its only fine focus i am talking about but its enough as i showed in the two pictures further back, with those two pictures the first and sharp focused one was slightly further back and slightly less angled upwards with the camera, the second shot was slightly closer to going overhead and the camera was angled slightly higher.

The third picture i showed was taken with my old D200 and 55-300Vr lens at the 300mm end, so in comparison with my D7100 set up it should have been far less sharp and not as accurate with focus, but as you can tell the D7100/70-300ED VR is not showing its best for some reason??

P.
 
P

Pretzel

Senior Member
Very odd, as I've shot lots of aircraft, birds in flight, para-sails and the works with the same exact combo (D7100 + 70-300 VR). Overhead, from afar... never a focusing issue to speak of, other than my own unsteady hands. The beast isn't with me today, so I can't tell ya exactly what focus mode it's in, but almost always single spot, often centered but quite often dancing around to my point of choice as well. That and I always use the viewfinder, as I'm not much of a live-view shooter...
 
Top