Weird Back Focusing issue.

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blutch
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p.2 #1 · Weird Back Focusing issue.

James R wrote:
"I REALLY do not want to be chained to a monopod."

I always try to shoot the 70-200 at 1/300th sec. for best results, and use the back-button focus. In a dark setting, a monopod can make a big difference and getting the shot is what's important. How does the D600 handle ISO 3200 or 6400?

It handles 3200 quite nicely.6400 is usable if you are up close. At this distance the image would have been degraded considerably.

I am using single point focusing here and moving the focus point around quite a bit. I also use the back button to focus. I lock on to the face and carefully take the shot. The focus should not move that much.. certainly not enough to move the focus points two rows back.

I can focus 5-10 feet ahead of the subject and recompose, but that isn't always possible and is a pain in the butt with lots of guess work. I need to get this figured out as I will be using this combination of equipment, in this scenario a lot.

Thanks for the help and ideas. I'm leaning toward sending it in over the holidays while I don't have much work scheduled. I could use help on how to accomplish that.

B

Dec 17, 2012 at 07:06 PM

workerdrone
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p.2 #2 · Weird Back Focusing issue.

I definitely wouldn't try to compensate for it by focusing in front or in back of the subject. I'd rather use live view focus / manual focus.

If it's distance shooting though, you might try just using center point / recompose. This shouldn't throw off focus like it might shooting at F1.4 with a very close subject and a fast portrait lens.

I have not used these guys personally (have never had to repair anything, knock on wood), but I've heard nothing but good things about them

http://nikoncamerarepair.com

Sorry to hear about your frustrations, that's a very expensive lens but I also get the feeling that it's extremely sensitive and complicated gear. If you were nearby you could give mine a test drive, I'm very pleased with my copy and glad I sold my VR1 and didn't buy the Sigma I was looking at - when these are good they're very, very good.

Dec 17, 2012 at 08:40 PM

blutch
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p.2 #3 · Weird Back Focusing issue.

I just got it a month ago, so I shouldn't have to pay for any repairs through Nikon. Are you suggesting sending it through a third party? I can try live view/manual focus, but at that distance i don't think my eyes will be much better. Good idea though! Thanks B

Dec 17, 2012 at 09:28 PM

theSuede
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p.2 #4 · Weird Back Focusing issue.

At least the D7000 has the additional caveat of focusing slightly differently in low WB light temperatures than in daylight temperatures, so be careful in judging the results by one situation only.

This should not have any effect on 200mm vs shorter focal lengths on the zoom - if that's where the problem is.
If you ONLY get back-focus on 200mm (long end of zoom) then there's no other option than to send it in. There's absolutely nothing you can do with manual micro-adjust that won't screw up the other zoom settings. In that case the problem is lens-only, and has nothing to do with the cameras.

Dec 17, 2012 at 09:33 PM

workerdrone
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p.2 #5 · Weird Back Focusing issue.

Oh no, if it's under warranty, by all means let Nikon make it right at their expense. They should not be letting $2k plus lenses go out decentered, unless it took a whack in shipping.

I was suggesting focusing using live view LCD, not MF thru viewfinder, if your subject and yourself are not changing distance dynamically.

Dec 17, 2012 at 09:33 PM

blutch
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p.2 #6 · Weird Back Focusing issue.

Yes. I know WD. I just don't know how well I can focus on such a small target from that distance. I am typically in a balcony or the back of a hall 50-60 yds away. Hard to manual focus in LCD live view as well.

Suede, I don't know what you man about the D7000 focusing different in different light. Please explain if you get a chance.

This lens focuses great at 200 mm if the subject is close enough. The problem occurs when I am a great distance away. B

Dec 17, 2012 at 09:38 PM

sic0048
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p.2 #7 · Weird Back Focusing issue.

Contact Nikon Service through the Nikon Web site. Send the body and the lens in so they can make sure the two are matched as well as possible. You shouldn't need to pay if the lens is under warranty. If you cannot live without the body for a week or two, then you can send the lens only in. But the results will be better when Nikon can adjust the lens for the body.

Dec 18, 2012 at 02:45 AM

blutch
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p.2 #8 · Weird Back Focusing issue.

Thank you, but I have the same problem with both the D600 and the D7000. Going to be tough to send them both in... I don't think this is a body issue, but who knows?

Dec 18, 2012 at 02:59 AM

Grantland
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p.2 #9 · Weird Back Focusing issue.

cltmte wrote:
My monitor may be off a bit but it looks like the three people to her right (our left) are quite sharp and even the gentleman obscured by the conductor is slightly sharper. Maybe "subject" movement?? Just a quick thought.

Mark

i thought the same thing.

Dec 18, 2012 at 04:18 AM

theSuede
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p.2 #10 · Weird Back Focusing issue.

Lenses have built-in EPROM memory of corrections for different focal lengths and distances. In a zoom lens this means a 2-D table, in fixed focal lenses it's "just" an array of values for different distances.

This is not "decentering" in any way. It's a focusing issue.

The D7000 AF module is ever so slightly pushed to hard in the sensitivity, and part of this unfortunately meant they increased the IR sensitivity on the chip. This is easily verifiable if you have the means to change illumination on a target. Very red (WB temperatures below 3500K) light means the D7000 focuses further back with most lenses, depending on how much longitudinal CA they have. Fast short primes are the lenses on which this is most noticeable. The 70-200 would be less sensitive but not immune.

Dec 18, 2012 at 04:27 AM

blutch
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p.2 #11 · Weird Back Focusing issue.

Grantland wrote:
cltmte wrote:
My monitor may be off a bit but it looks like the three people to her right (our left) are quite sharp and even the gentleman obscured by the conductor is slightly sharper. Maybe "subject" movement?? Just a quick thought.

Mark

i thought the same thing.

The soloist is a ful step ahead of those sitting in the row that looks next to her. They are better in focus, but not real sharp. The people in the choir behind them - especially two rows behind - are the most sharp.

B

Dec 18, 2012 at 04:49 AM

NightOwl Cat
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p.2 #12 · Weird Back Focusing issue.

Courthouse steps, maybe, or some sort of building in town that has a lot of steps?

blutch wrote:
Pbraymond,

It is difficult to recreate this scenario in daylight, but I did test it a bit yesterday on a bright day and it didn't seem to back focus. I need to find something "stepped" to shoot that is sort of like that choir, but it doesn't seem to have the problem in real light. B

Dec 18, 2012 at 11:59 AM

trenchmonkey
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p.2 #13 · Weird Back Focusing issue.

I am focused on the woman standing up in the middle with red glasses singing a solo.
She moved

Just LOOK...the guy's cowlick is sharp just off her right shoulder.

Dec 18, 2012 at 12:37 PM

blutch
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p.2 #14 · Weird Back Focusing issue.

TM, she was standing dead still. I have this problem with musicians who are seated and not moving at all. Look how sharp the two rows behind her are.

The guy to her right is not that sharp, plus he is two feet behind her. There was a big space from those seats and she stepped forward into it. He is not nearly as sharp as those in the rows behind her... if you could see it at full resolution and 100% you could see that. I have 10 shots of this exact pose and dozens more in this very situation in different halls and the results are very similar. Otherwise I wouldn't be questioning the lens.

TM - should I be using AF-C in this scenario?? Thanks for the help! B

Dec 18, 2012 at 05:17 PM

Scott Grant
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p.2 #15 · Weird Back Focusing issue.

I noticed how OOF the woman is compared to those surrounding here. I don't think it's an issue with AF.

A misaligned optical element in the lens could account for what you are seeing and also for why the issue is persistent in both bodies.

Dec 18, 2012 at 08:21 PM

blutch
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p.2 #16 · Weird Back Focusing issue.

Scott, thank you for your comments. Why is it that this only occurs at long distances? Up close the thing is dead on.

Keep in mind, she is at her own distance. There is no one to the left or right of her the exact distance away... she is in a row by herself between the seated singers and the back row of the orchestra. There is probably 10 feet in that space. You can't tell from this angle how much space there is. The bald guy behind her looking down is 10-12 feet behind her and he is very sharp.

B

Dec 18, 2012 at 10:12 PM

blutch
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p.2 #17 · Weird Back Focusing issue.

I am pleased to say that although it has been 60 days since I received this lens, Amazon agreed to replace it immediately, no questions asked. When I bought my D600 and this lens at the same time, I got a personal note from Amazon's photography Concierge service... I just wrote back to them and they replaced the lens... even paid for shipping the first one back. Impressive service. I'm glad i purchased through them and will do so in the future.

Dec 29, 2012 at 02:59 AM

blumesan
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p.2 #18 · Weird Back Focusing issue.

So the next question is: Has the new lens solved the problem?

Dec 31, 2012 at 03:36 AM

stevenvh
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p.2 #19 · Weird Back Focusing issue.

blumesan wrote:
So the next question is: Has the new lens solved the problem?

Sorry to dredge up this older thread, but I'd like to hear if the issue was resolved by replacing the lens too.

cheers

Jan 25, 2013 at 04:12 PM

theater_dad
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p.2 #20 · Weird Back Focusing issue.

bumping this thread to see if blutch was able resolve the problem with his new lens.

reason is that i have the exact same problem with a brand new d600 and a VR1. shooting low light at 200mm with long focal lengths. consistently getting the subject out of focus but objects 4 feet or so behind are nearly tack sharp.

any other d600 owners have problems shooting events like this?

i'm very perplexed.....i think i got better focus with my old d60 (but far worse iso performance).......about ready to swap for a d700.

Feb 09, 2013 at 05:37 PM

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