p.4 #1 · Nikon D850 with Sigma Art lens image and resource thread
charles.K wrote:
Hi Paolo. Ideally you want to calibrate the 24-105 via the USB dock with no AFT adjustment on the D850. Hopefully your copy of the 24-105 Art will require no or very little correction via the USB hub. If you have ordered the 24-105 Art make sure you fully test it out. Congrats on the new lens
Hi Charles,
I have usually had to calibrate all the Sigma lenses I have purchased over the years. The only exception was the 35mm ART: on the D800E it required calibration via the USB dock. Instead, for the same lens on the D810 I had to reset everything to default.
However, I still don't understand why you also acted on the calibration of the D850, a secret photographer's trick?
p.4 #2 · Nikon D850 with Sigma Art lens image and resource thread
C.P.G. wrote:
Hi Charles,
I have usually had to calibrate all the Sigma lenses I have purchased over the years. The only exception was the 35mm ART: on the D800E it required calibration via the USB dock. Instead, for the same lens on the D810 I had to reset everything to default.
However, I still don't understand why you also acted on the calibration of the D850, a secret photographer's trick?
Far from it The 24-105 varied quite substantially so I found a AFC on the D850 that gave a reasonable spread of calibration via the USB hub. If I left the D850 on zero, I would not have had enough correction on the 24-105 strange as it may sound.
p.4 #3 · Nikon D850 with Sigma Art lens image and resource thread
charles.K wrote:
Far from it The 24-105 varied quite substantially so I found a AFC on the D850 that gave a reasonable spread of calibration via the USB hub. If I left the D850 on zero, I would not have had enough correction on the 24-105 strange as it may sound.
Now I've understood I hope the contrary, but securely I will expect a long session for calibration.
p.4 #4 · Nikon D850 with Sigma Art lens image and resource thread
hello everyone,
I have a doubt. My 24-105 doesn't suffer from front/back focus, but as you well know, playing with the dock I can sharpen the focus on 16 focal lengths for 16 distances. The fact is that optimizing the focus, for example to 24mm, then continuing with the following focal lengths, often happen to have to go back because some previous adjustments need to be re-calibrated. For me that I'm maybe a bit too precise, it becomes almost a loop with no exit and could last well over 1 day.
In your opinion, is it worth trying to optimize at maximum all 16 values to at 16 distances or am I just wasting time?
p.4 #5 · Nikon D850 with Sigma Art lens image and resource thread
C.P.G. wrote:
hello everyone,
I have a doubt. My 24-105 doesn't suffer from front/back focus, but as you well know, playing with the dock I can sharpen the focus on 16 focal lengths for 16 distances. The fact is that optimizing the focus, for example to 24mm, then continuing with the following focal lengths, often happen to have to go back because some previous adjustments need to be re-calibrated. For me that I'm maybe a bit too precise, it becomes almost a loop with no exit and could last well over 1 day.
In your opinion, is it worth trying to optimize at maximum all 16 values to at 16 distances or am I just wasting time?...Show more →
Do not over think. Do look at the adjustments and then make a judgement call. Ideally you want the 24-105 Art to be sharp at the 4 major FL's and then look at your most common distance near to medium maybe and this has to be sharp as well as at infinity.
p.4 #7 · Nikon D850 with Sigma Art lens image and resource thread
I finished calibrating the 24-105 with the dock. As for infinity calibration, after 2-3 hours of testing I reset infinity to 0. This was because I couldn't get better results at all the focal lengths. In particular, at 50mm whether it increased or decreased the values, sharpness worsened. To put it briefly, I have left everything to 0 at infinity.
I haven't had time to take any real pictures yet. I managed to snatch a shot from my beloved cat, Spenk (he doesn't like to be photographed ). The following shot, the focus is on his left eye with the central point, but the camera was diagonal to both Spenk's eyes, not parallel. What do you think?
p.4 #8 · Nikon D850 with Sigma Art lens image and resource thread
Very nice shot @CPG The 24-105 Art is an excellent lens but can be a pain to calibrate properly. Ideally send it back to Sigma but this is not always possible.
p.4 #9 · Nikon D850 with Sigma Art lens image and resource thread
Thanks Charles. At the infinity the fire is precise, only I tried to make it become a blade, but I could not do it for all focal lengths. Imagine increasing the sharpness with Lightroom or Photoshop, that's what I was trying to do with the dock, probably I had wrong. In fact, at 0 the infinity is in focus correctly, as well as the Nikkor 24-120; I was trying to get more, but evidently there are limits that can not be exceeded.
p.4 #10 · Nikon D850 with Sigma Art lens image and resource thread
Returned my new Sigma 85mm f/1.4 ART lens for AF adjustment. Even in-camera adjustment to the limit was the front focus very prominent.
I have a dock but in fairness is the dock for minor AF adjustments. I friend of mine just got his Sigma back and is now spot on. Seems indeed that the QA is mass production is not under control.
Anyway, I keep faith that after the AF adjustment my lens will simply be a good
