D700 AF Queries

[FortyNine]

juz did a simple test this morning. ISO 400 f4 1/60, focus at infinity. One on a white HDB wall, another on a red HDB brick wall, 3rd a green tree

At 100mm, the AF consistently cannot lock onto white, yet can lock onto the red ( high contrast ). It locks onto a green tree at infinity also ( very low contrast )

At 35mm, it locks on 100% of the time ( both white and red and green)

AF chip is colour sensitive.

My interim solution. Focus at 35mm and zoom in.

 

[musicpls]

I'm a new user of D700, a very interesting thread indeed. Now I do noticed some focusing issue too, quite a number of miss or am I due to psychological effect

Let me also do some tests tonight to see if i do also face this problem.

 

[Redsun]

hmm i was thinking of getting a d700 to replace my d300
but this issue is bothering me
hopefully there'll be a firmware release to fix this

 

[daftone]

My temp workaround is to use the D700 with a flash indoors to help with the AF. In using the flash's AF assist which is not as intrusive as the D700's, I have better AF accuracy and faster lock on. Still Nikon needs to do something about the AF issue, a 3.5K equipment should not have this issue, or at least be rectified faster.

 

[lsisaxon]

My interim solution. Focus at 35mm and zoom in.

That's provided the lens is parfocal. Is it? I don't have that lens but I have the impression that nowadays, zooms are no longer made as parfocal as one point in time before.

 

[lsisaxon]

I'm a new user of D700, a very interesting thread indeed. Now I do noticed some focusing issue too, quite a number of miss or am I due to psychological effect

Let me also do some tests tonight to see if i do also face this problem.

Actually this situation was very similar for D200 when it was first released. AF on the D200 was quite terrible and especially with the 17-55/2.8DX... uncannily similar, huh? I felt that even D70s was better. Luckily this did not happen for D300 probably because it was supposed to replace D2X as the DX flagship.

But hang in there, I'm sure they will fix it with a firmware after a period of time when they feel that the D3 has sold enough or there is a replacement model. ;p

 

[chisiang]

juz did a simple test this morning. ISO 400 f4 1/60, focus at infinity. One on a white HDB wall, another on a red HDB brick wall, 3rd a green tree

At 100mm, the AF consistently cannot lock onto white, yet can lock onto the red ( high contrast ). It locks onto a green tree at infinity also ( very low contrast )

At 35mm, it locks on 100% of the time ( both white and red and green)

AF chip is colour sensitive.

My interim solution. Focus at 35mm and zoom in.

I don't wanna flame but can't help to detest that your test is fundamentally and technically flawed (due to probably inadequate understanding of how AF works maybe?), especially the 'focus at 35mm and zoom' in recommendation. Some, if not most, lenses' focus changes with focal length.

 

[FortyNine]

" don't wanna flame "

no offense taken. And I like to hear technical insights.

I'm simply testing on different colour subjects cos of Nikon's claim "Precise color information for outstanding AF accuracy: The D700's precise color information readouts deliver auto focus subject identification and tracking performance that no other camera maker can imitate"

I still feel D700's reading both the colour info and the AF info could interfere with its ability to acquire AF.

Its assuming parfocal. I think my shooting at f4 depth of field can negate the focus shift. And I feel a shot captured is still better than one missed with the AF hunting.

 

[lsisaxon]

" don't wanna flame "

no offense taken. And I like to hear technical insights.

I'm simply testing on different colour subjects cos of Nikon's claim "Precise color information for outstanding AF accuracy: The D700's precise color information readouts deliver auto focus subject identification and tracking performance that no other camera maker can imitate"

I still feel D700's reading both the colour info and the AF info could interfere with its ability to acquire AF.

Its assuming parfocal. I think my shooting at f4 depth of field can negate the focus shift. And I feel a shot captured is still better than one missed with the AF hunting.

Just to clarify, the phase detecion AF module doesn't read colour. The colour information is from the 1005 segment 3D matrix metering module and making use of that colour information to select the 51 point for AF tracking. If you use single AF point there should be no colour information involved.

 

[chisiang]

" don't wanna flame "

no offense taken. And I like to hear technical insights.

I'm simply testing on different colour subjects cos of Nikon's claim "Precise color information for outstanding AF accuracy: The D700's precise color information readouts deliver auto focus subject identification and tracking performance that no other camera maker can imitate"

I still feel D700's reading both the colour info and the AF info could interfere with its ability to acquire AF.

Its assuming parfocal. I think my shooting at f4 depth of field can negate the focus shift. And I feel a shot captured is still better than one missed with the AF hunting.

what I felt is that there were simply too many variables to consider in order to provide a impartial test.

A basic test should involves 2xD700 1xD3 1xD300/D200 using the same lenses in similar conditions.

- If 2xD700 cannot focus on wall while D3 and D300 can focus, then the D700 AF system maybe flawed

- If 2xD700 and 1xD3 cannot focus on wall while D300 can focus, then the shared AF system of D700 and D3 is flawed.

- If 1xD700 cannot focus on wall, while 1xD700, D3, and D300 can focus, then the AF system on the particular D700 could be faulty

- If all cannot focus on wall then it is not a ideal condition

- And also we need a larger sample population, ie out of 100 focuses on the wall, only 10 tries cannot be focused correctly, is it consider acceptable? And what kind of percentage is considered acceptable? etc

etc etc

 

[FortyNine]

Perhaps Nikon tripped over their feet, rolling out the D700 so fast to compete with Canon 5dII. Its frustrating when AF reliability is taken for granted.

With this AF issue, I blame Canon !

 

[Redsun]

Perhaps Nikon tripped over their feet, rolling out the D700 so fast to compete with Canon 5dII. Its frustrating when AF reliability is taken for granted.

With this AF issue, I blame Canon !

:bsmilie:

 

[FortyNine]

and since Canon is the culprit, I'm sure they're behind D700 imperfect auto white balance as well. sorry OT here.

 

[CanonEOS]

Perhaps Nikon tripped over their feet, rolling out the D700 so fast to compete with Canon 5dII. Its frustrating when AF reliability is taken for granted.

With this AF issue, I blame Canon !

What does Canon have to do with this issue? ;p I must well blame the 1D issue on the D3 :bsmilie:

 

[kktan88]

make sure u set to "s" or "m"

sure can lock.

 

[An drew]

Actually this situation was very similar for D200 when it was first released. AF on the D200 was quite terrible and especially with the 17-55/2.8DX... uncannily similar, huh? I felt that even D70s was better. Luckily this did not happen for D300 probably because it was supposed to replace D2X as the DX flagship.

But hang in there, I'm sure they will fix it with a firmware after a period of time when they feel that the D3 has sold enough or there is a replacement model. ;p

Agree. My D200 did miss some shots occasionally but my D700 consistently miss shots if there is insufficient contrast. I actually trust my D40X's AF more than my D700's. I would not upgrade from a D300 to the D700 with the AF issue. I would wait for its replacement unless the problem can be fixed via firmware or part replacement.

 

[yyD70S]

It is said that the D700 uses the same Multi-CAM 3500 FX AF module as the D3. I don't think Nikon 'purposely' crippled the D700. But the D700 (and I'm sure it's the same for the D3) does have problems locking focus when shooting in the portrait (vertical) orientation as they are "more" gaps at the "top" and "bottom" of the frame.

Currently I am still not sure if this is a one off problem or will it come back and haunt me again as I cant seem to recreate the same issue again. I am thinking that the ISO might also play a part.

Recently, I find that the 9pt focus in Dynamic area mode also took quite a bit to hunt even tho I was using a clear contrast area. I can see and feel the lens shifting its focus even tho I was aiming at the eye and nose area. Took me 2-3 times to get the AF lock. If this is going to be the case I might as well go for the D3, at least it didnt give me the same problems when I tried it.

 

[TMC]

It is said that the D700 uses the same Multi-CAM 3500 FX AF module as the D3. I don't think Nikon 'purposely' crippled the D700. But the D700 (and I'm sure it's the same for the D3) does have problems locking focus when shooting in the portrait (vertical) orientation as they are "more" gaps at the "top" and "bottom" of the frame.

You mean areas where the cross sensors are not available is it? I used a D3 in really low light and fast action before. It has yet to fail me so far, so I am wondering why did my D700's AF give me so much probs.

 

[musicpls]

happily did some test shots tonight, mainly paparazzi wannabe shot. Testing the speed of focus, near shot, infinite shot, landscape, portrait, contrast shot, just anyhow shoot.

Meddling around with the metering and different focus type...guess what? I don't find large fault with my D700 only very occasionally miss focus maybe due to unsteady hand holding or wrong focus point, other than that i can't find fault.

On the other hand beside my very old manual camera which do no autofocus, i have no other camera to do a A-B test so my test might not be absolute right.

Or someone has a way to recreate the issue, i will be happy to try it out again. Anyway, i don't think such a reputable company will compromise such a important feature of the semi pro level camera on purpose.

I say happy shooting, D700 band of brothers.

 

[lsisaxon]

It is said that the D700 uses the same Multi-CAM 3500 FX AF module as the D3. I don't think Nikon 'purposely' crippled the D700. But the D700 (and I'm sure it's the same for the D3) does have problems locking focus when shooting in the portrait (vertical) orientation as they are "more" gaps at the "top" and "bottom" of the frame.

D3's AF is noticeably faster than D300's and if D300's is noticeably better than D700 and D700 is using the same sensor as D3, then someone probably didn't do his job well or it's intentionally crippled.