NikonGear'23

Gear Talk => Camera Talk => Topic started by: Steven Paulsen on March 20, 2017, 16:03:53

Title: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Steven Paulsen on March 20, 2017, 16:03:53
I don't wish to bash any particular camera model, however my headache is my D7100. (I was informed several users gave up, and/or moved on to something else, in a previous thread. My intent is to pool as much info from all members, so it could be a help thread for many to come.

I tried outdoor tripod mounting & compared Live View vs VF focus. At the near edge of infinity focus was marginally close. (!6-85VR/V1.) At approx, 60 feed distance AF fine tune values almost seemed  to be in one inch increments.

Inside, with non scientific variables, my 16-85 & my Tokina 12-24/f4 really fell short of focusing on my 8 feet distance  (I indulge in "home theater" & my flat panel is almost a perfect distance of 8 feet from m "Maxell Man" seat.

Both lenses in auto mode, focused to approx, 5-6 feet. On my wide lens, I had to fine tune it to +10, & the 16-85 to +6. I realize I have to confirm in real world, outdoor tests.

What buggers me...."Why the heck do I have to mess with this & still feel uncomfortable with a camera that has been somewhat problematic, right out of the box. (I suppose that what I get with a silver box, 90 day warranty Nikon.

I can always manual focus & use the confirmation dot at the distance closest to infinity.

Please chime in. I'm somewhat home bound, nursing a bad tooth, hopefully getting pulled tomorrow.

"Do you hear this Nikon? If I send my D7100 back & you get a 100% credit, I'll pony up the difference towards a mid range FX Body." I'm not going to screw someone else selling it only to drop $2K on a more expensive can of worms.

 :P :P :P :P :P :P :P :P :P :P :P :P :P :P :P :P :P :P :P :P

Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: simsurace on March 20, 2017, 16:48:47
This sounds like a case of sending the camera in to Nikon.
I'm assuming that you haven't done this already.
Preferably send them also the 16-85.
At least slow lenses should really be able to focus well. Fast glass is more finicky.
It is painful to give up your equipment for a few days or weeks, but they should be able to make them work together.
When you get back your gear, see whether the other lenses have improved.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Ilkka Nissilä on March 20, 2017, 18:20:41
My D7100 didn't have any notable autofocus issues and although, as usual, I did fine tune it with the lenses I used, the results were in general very good. True, it wasn't quite as consistent as the newer D810, but in general I was very happy with the camera's performance. I mostly missed the group area AF and a larger buffer in the D7100, but I can't really say that the camera body I had any significant faults.

I agree with Simone that your camera should be sent to service. Describe the problems that you are having in detail.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Steven Paulsen on March 20, 2017, 19:27:12
In my "Should I buy a DF thread," a couple people replied & did just that, (Send it to Nikon) & they had the same results. Locally, (I happened to be present at a camera repair/rental shop...... & all I heard were bad experiences, about Nikon service.

Years ago I sent one to Nikon Repair because the inside of the LCD glass fogged & looked smeared on the inside, & when they returned it was the exact same way.

I honestly would like to know the exact methodology of what "AF fine tune" actually is. (Honest millimeters/inches what the -15 -+15 in the cameras function actually are.

Yes, a UPS box to Nikon Service may solve the problem. The big "However" is......I never herd a good story that they ever fixed anything, aside from a lens cleaning or damage. Thank you so far for your advise.

Is there anyone who has had a positive story, about an issue similar to this that had a good "Nikon Service" outcome?

I really need to hear one.

 :) :) :) :) :) :) :) :)
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: David H. Hartman on March 20, 2017, 19:27:33
oLnutJob,

I'm sorry this has happened to you. I read Ilkka's reply and I believe his advice is good. I hope you have success in sending in your camera and 16-85mm Nikkor lens.

If that is the AF-S DX NIKKOR 16-85mm f/3.5-5.6G ED VR a friend has one and I've used it a fair amount. I find the performance of that lens very good to excellent on her D300, my D300s and D800. I do note that, that 16-85mm Nikkor needs to be refocused after zooming. Had I bought a DX lens that is the one I would have bought. All of my Nikkor lenses are FX/35mm coverage as full frame always was my goal.

Dave Hartman

I suppose that what I get with a silver box, 90 day warranty Nikon.

That is probably the case.

---

I strongly recommend that NO ONE buy a refurbished Nikon product refurbished by Nikon USA.

I bought a refurbished AF-S NIKKOR 24-85mm f/3.5-4.5G ED VR lens. The VR didn't work which was almost certainly the reason it was returned to Nikon in the first place. The lens was not refurbished just reboxed and sold.

The problem was reported within 14 days or whatever the limit was to return it for a refund. I made multiple calls to tech support. We exchanged multiple e-mails. I was never able to create an RMA online. The tech support could not do it. Finally someone in management emailed me an RMA and return mailing label. Nikon USA's software for both the customer and tech support had a problem which is why several of us could not create the RMA and management had to step in.

I finally got the product returned and received a full refund. I had an opportunity to rate the Nikon store and tech support. I rated the tech support highly as they were very good to excellent and anything not have to do with the people I communicated with very low. I will never buy another refurbished Nikon product. It is important to note that refurbished Nikon products sold by merchants other than the Nikon USA's online store have the same lousy 90 day warranty.

Really Nikon? Only 90 days? Other major camera makers are offering 1 year.

The 90 day warranty shows that Nikon USA does not have confidence in the refurbished products they are selling. If they did they would offer 1 years as competitors do since if the products were "as good as new" the cost of a 1 year warranty v. 90 days would be very small. I also note that the savings for buying refurbished is quite small and not worth the risk of buying from a company that shows it's not confident in its refurbished products process.

My advice is don't buy refurbished products from Nikon USA or their dealers as the 90 day warranty is as good as an admission that the products not uniformly up to par.

Dave Hartman
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Ilkka Nissilä on March 20, 2017, 19:43:04
I have had nothing but the best experiences with Nikon service, but I live in Finland. It may be different in your region.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: pluton on March 20, 2017, 20:50:09

My advice is don't buy refurbished products from Nikon USA or their dealers as the 90 day warranty is as good as an admission that the products not uniformly up to par.

Dave Hartman
I offer the same advice to those that inquire about buying Nikon USA Refurbs.  There are too many anecdotal reports of defective products to ignore.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Øivind Tøien on March 20, 2017, 22:54:46

I have bought several refurbished Nikon bodies, all happened to be through Cameta. While they were not trouble free, it all ended well:

My D40x came with a lens that did not autofocus - it was promptly replaced. The body had some stuck red pixels - sensor replaced by Nikon. It is still being used as my IR body.

The first D7100 copy I got had too short register distance; I would not have noticed right away unless I had been into manual focus lenses. It was promptly replaced by Cameta (the offer actually included extended warranty to one year without extra cost, whatever that is worth). For both of these bodies AF was spot on (only my 12-24mm required any significant amount of compensation - it is a known problem lens in that respect). At less than $500 price tag, the trouble was well worth it; it is still my main body. My only grudge in general against the D7100 is the well known dark frame fixed pattern noise at low ISO (among the worst in the industry), which very occasionally limits my ability to pull shades.

I bought my D5100 new. It had from the start a severely misaligned mont, which I did not notice right away. I quarreled with Nikon service for 8 months, sending it in 3 times before they finally replaced it with a new one.

I conclude that  one should do some very careful testing right away when receiving a body whether buying new or refurbished, and promptly return it for a replacement if there are any kind of troubles.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Andrea B. on March 20, 2017, 23:19:56
I've bought 2 refurb bodies and 3 refurb lenses from Nikon USA. All worked well. Still using the lenses.

I send something to Nikon service (Melville) about 2 times a year for cleaning, checking or repair. No bad experiences so far. Maybe I'm just lucky, who knows?  :)
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Akira on March 20, 2017, 23:47:10
I've never used D7100, but I've experienced similar problems with three bodies (two D7000's, a D610 and the current D750) and several lenses (35/1.8DX, 50/1.8G and 24/1.8G).

There are two Nikon services in Tokyo, one in Shinjuku and another in Ginza.  The Shinjuku one turned out to be crap, and Ginza one is good.

Anyway, a rep in Ginza explained that the kind of "neutral position" of an AF-S motor will be "off" over time, and then the focusing elements of the lens will fail to stop at the position at which the camera wants them to stop.  That will cause the focusing error, and you cannot correct the error entirely with AF fine tune.  You need to have the lens re-adjusted at the service when the problem emerges.

Also, the in-camera AF fine tune can only adjust the focus at a certain distances.  If you adjust the focus, say, to 5m, that doesn't guarantee the correct focus at infinity.  In order to address the problem mentioned above, you need the service at the proper Nikon facility.

Also, the AF calibration of the body can be off.  If so, again, the AF fine tune won't work properly.  You need to have the body calibrated at the proper Nikon facility.

I've had no AF issues with the re-calibrated bodies and lenses in Ginza.  I've never been in need of even turning on the in-camera fine tune.

Incidentally, as adviced by Erik Lund and a couple of others here in NG, the AF "hit rate" of AF-C mode is higher than AF-S mode, even for the still objects.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Steven Paulsen on March 21, 2017, 01:26:44
I purchased 4, Nikon US Refurb's in the past. A D80, D300, D5200 & the D7100. Only the last one hit the "Sour Grapes," meter, & my thoughts are that any problem has a solution. And yes.....there is always a Lemon in anything one can purchase.

I'll say it again. I'm searching for the correct formula to test & calibrate. If it can never be solved, then I finally have my Digital Nikkormat/FM. A digital camera with an aperture ring & manual focus, only. I have small faith in Nikon Service, in my perspective.

I've found that one can adjust Af fine tune well past infinity & it gave me an idea. There is a bare tree line at least 1/4 mile away. I will try fine tuning the camera/lens to be correct for infinity sharpness at the tree's skyline. Nikon's way of changing how the D7100's rear LCD functions in "Live View," makes it more difficult, so I can review on screen.

I'm prepared that this may have no effect on objects that are much more close, but I'll deal with that later. Wide lenses are going to be a bit more challenging. I have a Snellen, (eye chart,) for 20 feet distances.

I'm also wondering and will ask, "What method or how did you work, modify, or fix the issue in AF fine tuning?"


Also with a chuckle.....If the camera issue is on the top of my problem list, boy do I have a boring life. Alas, the D7100 thing is much closer to being just a moderate annoyance.

I have three Doctor appointments tomorrow & that isn't even concerning that the battery in my pacemaker is going dead.

I want this to be a learning, contribution thread. If you fell for the excuse...."You need to upgrade to better lenses," my condolences for your financial loss.

And again, A Kind, "Thank You."

 :) :) :) :) :) :) :) :) :) :) :) :) :) :)
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Peter Forsell on March 21, 2017, 16:17:38
Hi,
I am not sure if I am of any help. Please feel free to disregard my post.

First of all, focus accuracy testing (and fine tuning) should be done in daylight. It is a known feature of phase detect autofocus that tungsten lighting can cause front focusing issues. Some AF modules are compensated for this better, some worse.

Also using a self illuminated surface (like tv screen) to test focusing is not recommended. It works only if you are using the moiré detection system that Canon uses for fine tuning, but that is a completely different method.

So, if you are fine tuning a lens at different focusing distances, please do yourself a favor and use a similar target all the time. Do not use a far away barn in sunlight, then a tungsten lit target in the house at 20 feet and thirdly a tv screen at 6 feet. You will get nonsense results.

I fine-tuned my TC-20E III for my AFS 300/2.8VR just the other day. I got fine tune values of all 0 with all cameras and at all focusing distances. The target was a white box with black lines out in daylight. As a matter of fact, I have 9 Nikon DSLR bodies and some 30+ lenses and all of them have fine tune values of 0 (not all can be tuned ofc). Either I'm lucky, or blind, or stupid, but at least I am satisfied.  :P

An easy way to do this is to use the green dot method, you don't even have to take any pictures.
http://www.fredmiranda.com/forum/topic/1187247

Here is a picture of my test target. All shots with mirror up, remote control, tripod. Nikkor AFS 300/2.8VR + TC20E III at 600mm f/5.6 (wide open). Perfect focus with fine tuning = 0. Click for full size.

And if you cannot get your camera+lens combo to focus correctly, they need to be repaired by Nikon.

(https://c1.staticflickr.com/3/2849/32728325944_6d44764898_o.jpg) (https://flic.kr/p/RS6e4N)20170313-_D3S5702 (https://flic.kr/p/RS6e4N) by pforsell (https://www.flickr.com/photos/23025889@N03/), on Flickr

Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Andrea B. on March 21, 2017, 18:42:58
Sound advice, Peter. Thanks!

Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Bjørn Rørslett on March 21, 2017, 19:20:06
Isn't OS2/Warp slightly out of focus these days :D (just kidding, haven't seen that logo for years ...)
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Thomas G on March 21, 2017, 21:09:56
It had marvellous rexx. How can it be out of of focus on a small red car?
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Matthew Currie on March 23, 2017, 16:42:19
I would just add that my D7100 appears to be fine, and with the 18-140 lens it came with it was always nice and sharp.  I've used a number of different lenses on it and most appear to be right on without adjustment.  However, the two I've had to adjust were the 50/1.4D, which my wife got years ago for an F100 and which was always disappointing, and the 16-85 DX zoom, which I bought used.  I suspect that perhaps that 16-85, aside from not being as crisp as the 18-140, might be a little more problematic in tuning as well.  A quick and dirty indoor tune came out with considerable improvement at +5, but it is still a little variable depending on distance and zoom, and never killingly sharp.   At some point I'll do a more thorough, outdoor-lit test, but I suspect that comes pretty close.  The 50/1.4 has become rather nice with its new calibration, after years of neglect owing to its disappointing softness.

I'm guessing here, but imagine that the very high acuity of the D7100 might make tiny focus errors show up more readily, at least when you pixel peep, and that some lenses, of which the 16-85 might be one, may just never satisfy at all distances and focal lengths.  But in this case I'm much more inclined to blame the lens, which visibly back focused on the D3200 as well as on the D7100.  Almost every AF lens I've tried on the D7100 has been close enough not to calibrate, and the MF lenses appear to be correctly focused when the dot says they are.  Fortunately, it seems a good bit easier to confirm good focus than to fix it when it's bad. 

Akira's observation about AFC versus AFS seems interesting, and worth further investigation.  On the D3200, I'm pretty sure the opposite applied, as it's noted in the instructions that focus priority in AFC is relaxed and there's an implication, as usual for Nikon never quantified, that the focus itself is a little sloppier.  It's very hard to judge, especially as lenses themselves vary, but it seems, looking at the focus confirmation dot, that the area considered "good enough" is a little wider.  But if the area is the same, I'd expect AFC to work a little better because it keeps adjusting after the initial hit, rather than stopping as soon as it finds that "good enough" spot. 
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Peter Forsell on March 24, 2017, 11:21:00
... Akira's observation about AFC versus AFS seems interesting, and worth further investigation...

@Matthew Currie
Can you provide link to the text re AFC vs AFS please, I didn't find in this thread and I'd like to read.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Akira on March 24, 2017, 12:58:30
@Matthew Currie
Can you provide link to the text re AFC vs AFS please, I didn't find in this thread and I'd like to read.

Peter, please refer to the post #9 of this thread.

Also, you may want to refer to this thread, too.

http://nikongear.net/revival/index.php/topic,5542.msg88782.html#msg88782

That said, my personal experience (better hit rate of AF-C than that of AF-S) might be because of my shaky body.   :o
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Peter Forsell on March 24, 2017, 18:29:34
Thank you, good read.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Matthew Currie on March 26, 2017, 00:03:15
@Matthew Currie
Can you provide link to the text re AFC vs AFS please, I didn't find in this thread and I'd like to read.

The following passage is found on Page 39 of the D3200 manual: "In AF-C mode or when continuous servo AF is selected in AF-A mode, the camera gives higher priority to focus response (has a wider focus range) than in AF-S mode, and the shutter may be released before the in-focus indicator is displayed."

In the corresponding section of the D7100 manual this passage does not appear.  The D3200 manual, as expected, is vague about the extent of this difference.

Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Matthew Currie on March 26, 2017, 00:05:18
The following passage is found on Page 39 of the D3200 manual: "In AF-C mode or when continuous servo AF is selected in AF-A mode, the camera gives higher priority to focus response (has a wider focus range) than in AF-S mode, and the shutter may be released before the in-focus indicator is displayed."

In the corresponding section of the D7100 manual this passage does not appear.  The D3200 manual, as expected, is vague about the extent of this difference.

added note:  this is the PDF manual.  Anyone owning one of these low end cameras should be aware that the printed manual provided is shamefully abridged, and should download the PDF from the accompanying disk or from Nikon's web site.
Title: Re: 4000 X 6000 Dx Megapixels, AF help & comments
Post by: Steven Paulsen on March 27, 2017, 17:14:00
Thanks to all, again. For anyone down the road with similar cameras with similar issues, I hope this will help.

My D7100 with medium to longer lenses, AF focuses usually quite well, especially with a clear, defining target. When I creep into 24mm & shorter focal ranges, the issue manifests.

I'm a victim of old film camera habits. I usually single click at base ISO using the center AF point, only. This worked well until the D7100. A year or so prior, I bought a Refurb, D5200 & my old habits still worked fairly well. I liked the cropping room of 24mp, higher ISO performance. My idea of the D7100 was the easier ability to use older MF glass & an in body focus motor. The other attraction was a camera body to actually grip with all four fingers.

I played a lot with my 16-85VR, focus testing &  fun shooting. 85mm is fine. 16mm was pretty much disappointing. I turned off Vibration Reduction & images improved a great deal. Tripod mounting helped even more. A sub par protective filter, (Name brand filter/But not so good coatings,) was another culprit.

Say, at 16mm with a group of small detailed objects 8-10 feet away, it still misses focus when everything in the frame is small. (All the detail is less than the coverage of any single AF point.) AF-A/AF-C works better especially when Auto or 3D mode is used, but it's not a magic fix.

What helped more was doing some homework & learning the lens's hyperfocal distance and using the correct aperture/distance, manually. My 3rd party 12-24 is rather simple. (7 feet & F4 is easy to remember for 12mm.) The 16-85 is a bit more complicated. I almost wanted to inkjet a small cheat sheet & clear tape it to the lens body but I know sticky tape adhesive on gear or even a carry sack isn't a good idea.

All is improving, as I continue to move foreword.

Thanks Again,
Steve
 ;) ;) ;) ;) ;) ;) ;) ;) ;)