# Using AF Fine Tune with D300 Infinity Focus Problems?



## iflynething (Mar 31, 2009)

I just was able to get a great deal on a 80-200 2.8. Incredible lens and it's super sharp.....so i though.

Many others that I used wondered why they weren't as sharp as I KNOW it should be. Luckily, my new D300 has the AF Fine Tune. I have not tested it on an actual focus chart yet but during a dance compeitioin I messed around with this function. Anyways I got it pretty spot on. I was at another location and found a horizontal rope to look at and just focused on there. I ended up at being at -14 (points, marks?) to make it focus correctly....(as far as I could tell in the viewfinder and from the shots I got)

Having this much front focus and having to correct so much (-14) will it affect how the camera focus at infinity? Will it even be able to focus at infinity?

Also, I was fine tuning at 200mm. Will it make a difference shooting at 80 or will the same parameters be the same for all focal lengths?

~Michael~


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## Sw1tchFX (Mar 31, 2009)

what's the distance?

the 80-200D is known to misfocus and be really soft near it's minimum focus distance.


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## iflynething (Mar 31, 2009)

Sw1tchFX said:


> what's the distance?
> 
> the 80-200D is known to misfocus and be really soft near it's minimum focus distance.



I didn't know that. For the dance photography, it was about 100 feet but what I was doing at the rope was about 10 feet, probably more but I know it wasn't the minimum focus. 

It's pretty spot on right now at the -14 I have it at right now. 

Is there any good technique to focus test other than pointing at a 45 degree angle and going from there?

~Michael~


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## JerryPH (Mar 31, 2009)

I played with this and read up on it.  As far as I can tell, the general results that came out of that for me were that this was not really a means to correct a portion of small focal range of a lens, but the entire range.  

I put on a lens that I knew back focused ever so slightly to the point that it was impossible to see this anywhere else but on a well magnified focus chart and only when set to F/2.8.  This option corrected the back focus everywhere throughout it's entire focal range by using a setting of -1 to perfection through out the entire focal range, and had no effect on focus to infinity that I could tell.

If a lens back focuses, it normally does so everywhere.  The methods provided in the D300, D700 and D3 globally correct this condition to perfection.  But, if you have a mechanical issue where you get a misalignment causing focus issues at different focal lengths, this option is NOT meant to correct for that... and the only solution to that is to send it in to the manufacturer.

Just my 2 cents.


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## JerryPH (Mar 31, 2009)

iflynething said:


> I didn't know that. For the dance photography, it was about 100 feet but what I was doing at the rope was about 10 feet, probably more but I know it wasn't the minimum focus.
> 
> It's pretty spot on right now at the -14 I have it at right now.
> 
> Is there any good technique to focus test other than pointing at a 45 degree angle and going from there?



That -14 seems pretty high to me, suggesting a potential hardware or mechanical issue, but I am no expert.

That focus test chart is pretty much the best way right there.  Also be sure to get as close to 45 degrees as possible, it can have some negative effect on the test results the further off you are away from that angle. If it is less than 45 degrees, it will show less of the error or misfocus.  If it is more than 45 degrees the back focus is amplified and gives greater "wrong" results.


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## iflynething (Mar 31, 2009)

Thanks Jerry...your new avatar really throws me off sometimes.

I too though that -14 was WAY too much but that is just going from what I was shooting and getting an estimate at what it should be set at.  I could tell that when set at 0, it definitly front focused (I believe I"m using it the right way - at 0, the focus point is in front of where it's supposed to be). I just bought this lens and I wasn't able to take it home to test for focusing problems. I guess no lens is going to be perfect. What would I be looking at for a Nikon calibration?

Is there a good way to know if I"m at 45 degrees or not with some lines and a protractor? I only have a small one, so I'm wondering how I'm going to know if I'm set up to 45 or not. 

Thanks alot for the information

~Michael~


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## Garbz (Apr 1, 2009)

Errr why are you even asking us if it will focus at infinity. It's your lens go outside and point it at something on the horizon and tell us if it focused or not.
Also if you just bought the lens it will cost you nothing to get it sent back for correction.


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## JerryPH (Apr 1, 2009)

My local hardware store has a metal ruler with a sliding section that contains a water level that is adjustable.  I set it at 45 degrees and leaned the ruler against the lens and adjusted the tripod until the water level was perfectly level.  then I locked things down, and took the pictures.  Now... some manual adjustment of the paper may be needed, but once that is done, tape the focus test chart down and shoot away.


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## shivaswrath (Apr 1, 2009)

woah, didn't even know the d300 could do that!!! Cool info for those that are considering. . .


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## iflynething (Apr 1, 2009)

Garbz said:


> Errr why are you even asking us if it will focus at infinity. It's your lens go outside and point it at something on the horizon and tell us if it focused or not.
> Also if you just bought the lens it will cost you nothing to get it sent back for correction.



Thats a good point! I bought it used, so I assume it will cost to get calibrated?

~Michael~


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## JerryPH (Apr 1, 2009)

shivaswrath said:


> woah, didn't even know the d300 could do that!!! Cool info for those that are considering. . .



It gets better.  The camera can remember the different settings from several lenses that you calibrated for.


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## iflynething (Apr 2, 2009)

JerryPH said:


> It gets better.  The camera can remember the different settings from several lenses that you calibrated for.



Ha that's one of the cool parts. As far as I know, you have have up to 12 in the main menu and up to 99? Correct me if that number is wrong

~Michael~


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## Garbz (Apr 2, 2009)

Oh used. Sorry didn't realise that. Yeah Nikon may charge you up to a few hundred to get it fixed then if you don't have a warranty slip with it.


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## shivaswrath (Apr 2, 2009)

iflynething said:


> Ha that's one of the cool parts. As far as I know, you have have up to 12 in the main menu and up to 99? Correct me if that number is wrong
> 
> ~Michael~



man, I'm wondering if I should consider the D300 over the D90 now??

I guess I'll wait to hear what Nikon announces on April 14th - that'll either drive the price of the D300/D90 sensors down, or. . .???

Adorama called me this morning and said my D40x is only worth, at the minimum, $250. . .lol, guess that'll stay as my backup!


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## iflynething (Apr 2, 2009)

Garbz said:


> Oh used. Sorry didn't realise that. Yeah Nikon may charge you up to a few hundred to get it fixed then if you don't have a warranty slip with it.



Yeah, I didn't want to spend the money for a new one. I will have to contact the guy and see if he has a warranty slip for it but I'm going to be needing it about every other weekend now, that's why I bought it - so I wouldn't have to keep renting over and over. 



			
				shivaswrath said:
			
		

> man, I'm wondering if I should consider the D300 over the D90 now??
> 
> I guess I'll wait to hear what Nikon announces on April 14th - that'll either drive the price of the D300/D90 sensors down, or. . .???
> 
> Adorama called me this morning and said my D40x is only worth, at the minimum, $250. . .lol, guess that'll stay as my backup!



I can't say for certain whether you should or should go for the 300 or not. I would say though that if you are going to have a 300 as your main body, I think the 90 would be better suited for the backup and not the D40x...although since you already have it, it should be alright. Also, there are plenty of people who would pay you much more money for your used D40x...more so than Adorama. They have to make money too and of course are going to lowball you on their used price offer.

~Michael~


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## Garbz (Apr 2, 2009)

shivaswrath said:


> man, I'm wondering if I should consider the D300 over the D90 now??!



If that's the reason you are thinking of upgrading then the answer is a plain and simple NO. Having proper working equipment is better than spending extra money just for a body that compensates a trip to the repair shop.


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