D800 focus with 1.4 prime lenses is very variable and inaccurate

Started Jan 20, 2013 | Discussions thread
inasir1971 Veteran Member • Posts: 3,609
Re: D800 focus with 1.4 prime lenses is very variable and inaccurate

primeshooter wrote:

inasir1971 wrote:

Which lenses are you having trouble with apart from the 50 1.8G and what distances (in meters/feet)?

24mm 1.4g

50mm 1.4g

85mm 1.4d

variable distance, I do not know exactly but see photos.

I have tried my D800 at variable distances (from 2.5m to several hundred meters) with my Nikon AF primes in AF-C and they are as follows (wide open):

35 1.4G - very consistent. The only time where it was giving me unreliable AF was after an extended period in -7 C temperatures which may have been affecting it.

85 1.4G - quite consistent but less so than the 35 1.4G but this may to be expected given the greater demands on AF accuracy.

50 1.8G - acceptable consistency but noticeably less so than the 35 or 85. Say 80%.

135/2 DC - hopeless. couldn't hit the broad side of a barn on a good day.

With all, accuracy does drop somewhat with distances of say several hundred meters.

AF-S has not been consistent as I posted in your earlier thread. In AF-C the 'G' lenses continually make small adjustments (audible) till settling while the 135 DC does not. I would guess that in AF-C as focusing remains closed loop for much longer the 'G' lenses are able to achieve good focus. The 135 DC does not exhibit this behavior of small adjustments and arrives at its final position very quickly.

I haven't checked low light performance in controlled conditions but my gut feeling is that they take a bit longer. I usually initiate AF and wait a second or so before depressing the shutter.

Tracking is an entirely different issue and they all perform poorly.

 inasir1971's gear list:inasir1971's gear list
Sony RX1R II Nikon D4 Nikon D850
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