Sigma Dock question

I've purchased a Sigma 135mm Art f1.8 lens. I fine tuned it to -3 on my D850 and it's razor sharp. Is there any benefit to buying the Dock and adjusting it using that? Is there likely to be a D850 firmware update for it soon? 

Thanks for any advice.

I think you only need to use the Dock if you can't dial it in using just the camera. Sounds like you're happy with the calibration from the camera? Besides, you only need to calibrate one focal length, unlike using a zoom with many different focal lengths - which is really time consuming using the Dock, as you have to set 16 calibrations compared to just 4 with a fixed focal length. I did my Sigma 150-600mm S zoom, and it took the better part of all afternoon because of the various focal lengths!

The benefit is that with the dock you calibrate the lens at multiple shooting distances. Doing it with the body only calibrates it at the shooting distance that you performed the calibration at, there are no guarantees at other shooting distances and most lenses do require a somewhat different calibration level between close and far to be absolutely perfect. In the case of your lens, the dock allows you to calibrate the lens near minimum focus, at a typical indoor shooting distance, at a medium shooting distance and at what is essentially infinity. These values are programmed into the lens itself and the lens then calculates the proper offset for distances in between. You set the camera body to zero as all of this is done within the lens itself. It is a vastly superior calibration to just a single distance calibration done in the camera body.

E.J. Peiker wrote:The benefit is that with the dock you calibrate the lens at multiple shooting distances.  Doing it with the body only calibrates it at the shooting distance that you performed the calibration at, there are no guarantees at other shooting distances and most lenses do require a somewhat different  calibration level between close and far to be absolutely perfect.  In the case of your lens, the dock allows you to calibrate the lens near minimum focus, at a typical indoor shooting distance, at a medium shooting distance and at what is essentially infinity.  These values are programmed into the lens itself and the lens then calculates the proper offset for distances in between.  You set the camera body to zero as all of this is done within the lens itself.  It is a vastly superior calibration to just a single distance calibration done in the camera body.

I will get one on order as soon as B&H reopens. 

Can you give me a quick overview of what’s involved in calibrating using the dock please. 

Thanks for the advice guys. 

Sigma has a series of youtube videos on software installation, setup and basic procedures.  I used this review before starting the optimization of my Sigma 150-600mm Sport lens to my Nikon D810.  While it takes more time than just a single 'fine tune' point it was worth the time as I use the full range of this zoom lens.
Ed Hickl

Thanks Ed.

I understand the entering of offsets for the different focal distances to compensate for inaccuracies in the AF due to Camera/Lens tolerances.

What I'm unsure of is the methodology in arriving at these different offset values.

Typically when I fine tune a lens I focus on a Zeiss Test Chart at the most used distance for the particular lens. I'll do it 10 times and average the results and enter that value.

How do you arrive at the offset values to be entered using the USB Dock?

MND wrote:Thanks Ed.

I understand the entering of  offsets for the different focal distances to compensate for inaccuracies in the AF due to Camera/Lens tolerances.

What I'm unsure of is the methodology in arriving at these different offset values.

Typically when I fine tune a lens I focus on a Zeiss Test Chart at the most used distance for the particular lens. I'll do it 10 times and average the results and enter that value.

How do you arrive at the offset values to be entered using the USB Dock?

Do it exactly the same way but for each shooting distance and enter the info into the lens rather than the camera body.  But that results in a lot of mounting and dismounting the lens between camera and computer.  So what I do is I use the in camera numbers I come up with for each shooting distance and then enter those exact numbers into the lens while resetting the camera back to zero.  Then I recheck it and make any tweaks.  One point of change on the in-camera settings is close enough to one point of change on the lens to make that possible.  And then the recheck just finalizes any slight differences between the two.  it is important to turn the camera back to zero though after you enter the values into the lens, otherwise those two adjustments are additive.

Thanks E.J. My USB Dock arrives on Monday so I'll give it a try then.

I'm really liking this lens big though it is.