I just got my Sigma 35mm a few days ago and I am very happy with it. Sharp, nice AF consistency and +0 MA on my 5Diii. However, I couldn't help but to play around with the USB Dock.
With the USB dock and the 35mm, the software allows one to micro-adjust to 4 fixed distances. They are 12", 16", 26" and infinity. WOW, I was surprised that the first 3 distances are within a foot of each other and then you have infinity. So I found that on my "great copy", the sharpest of sharp adjustments are:
+4,+6, +3, +0 for 12", 16", 26" and infinity respectively.
Kind of makes me think that the 5D3 paired with this lens has this focus shift for close range (and maybe most FF canon bodies). I know it is just my lens/ camera pairing, but just wondering if this is the normal trend.
Has anybody else using the USB dock finding that they need more MA for the close up range on the 35mm?
I would like to add that this dock is very valuable. The focus is now very tack sharp and consistently matching live view focus at most distances. It is slightly less sharp at around 3.5 feet but still pretty darn sharp. (maybe I will need to adjust one number by one) I will have to say that this is my sharpest lens below 2.0 while using phase detect AF.
Not surprised at all , I've ma'ed a few lenses that come up with different numbers at different distances . The 3 distances so close together is a surprise though , but I guess sigma know how their lens works .
My results are in the other USB Dock thread, but they are similar. In fact, mine was even higher of a difference from MFD to Infinity (15 steps). And I agree on the sharpness, wow!
The dock seems to work good for every user here. It's only the people that never have used it that complain aout it
Did everyone upgraded the firmware also ?
My lens had shipped with the latest firmware already installed.
So there's a pattern in our data so far that suggests the lenses are nearly spot on at infinity but require significant MFA as you approach MFD. Not surprising, actually, considering how close those focus distances are. I'm glad to see such positive results.
Did you two also observe a 1:1 correlation between the camera body MFA steps and the lens dock MFA steps?
I myself have not noticed any focus shift with mine. In fact at MFD upto infinity my lens was dead on. It's the only lens I own that does not require and microadjustment. I tested my lens at MFD, 24", 5', and infinity. This was based on the distances I tend to shoot the lens at. I will go back and try my tests at each of the focal lengths the dock recommends to see if there is any difference.
p.1 #10 · Sigma USB Dock calibration data for 35mm
austin.grant wrote:
Did you two also observe a 1:1 correlation between the camera body MFA steps and the lens dock MFA steps?
I cannot confirm this, but I did reconfirm the focus after the calibration. I had to adjust the third data by one tick. I guess I can tinker with focus till death, but not nesessary, The lens was sharp enough out of the box at zero MA. The only difference it did was make the close distance shots sharper if you pixel peep. But frickin sharp is nice to have.
My sig35 came a few days ago. So mine had the latest firmware.
p.1 #11 · Sigma USB Dock calibration data for 35mm
mcd0nald wrote:
i think the firmware is just to get the lens recognized the software....
nothing major
I don't think so. But I don't know. Many people that bought the lens early when it arrived on the market, and had inconsistent AF at different focal lengths. Sigma told them to send in the lens for a new firmware.
p.1 #13 · Sigma USB Dock calibration data for 35mm
MikeW wrote:
Does the usb dock allow you to change the adjustment for outer left, centre & right separately?
The copy I had required different amounts of fine tuning making it unusable.
No, the USB Dock doesn't provide that capability. However, that sounds more like a camera issue than a lens issue. Perhaps someone else will chime in with suggestions?
p.1 #14 · Sigma USB Dock calibration data for 35mm
MikeW wrote:
Does the usb dock allow you to change the adjustment for outer left, centre & right separately?
The copy I had required different amounts of fine tuning making it unusable.
seems like your lens requires service. usb dock software only allow ma input at four fixed distances. so it doent.seem.to be the software to fix decentered lens element.
p.1 #15 · Sigma USB Dock calibration data for 35mm
MikeW wrote:
Does the usb dock allow you to change the adjustment for outer left, centre & right separately?
The copy I had required different amounts of fine tuning making it unusable.
Possible decentered or shifted element(s) or a bad mount, meaning you had a screwy focal plane within the lens...either that or a camera problem but maybe another copy would work?
p.1 #17 · Sigma USB Dock calibration data for 35mm
I sent it back, it is a nikon mount, an issue that is proving quite common unfortunately. I guess unless a perfect copy is received it would require sending it in along with the body to be calibrated.
Such a shame, thanks for the replies *sneaks back into nikon forum*
p.1 #18 · Sigma USB Dock calibration data for 35mm
MikeW wrote:
I sent it back, it is a nikon mount, an issue that is proving quite common unfortunately. I guess unless a perfect copy is received it would require sending it in along with the body to be calibrated.
Such a shame, thanks for the replies *sneaks back into nikon forum*
What common issue are you talking about?
And why "unless a perfect copy is received it would require sending it in along with the body to be calibrated"?
p.1 #19 · Sigma USB Dock calibration data for 35mm
because the focus fine tuning is different from left, centre & right. So unless you always shoot with only one focus point you are always front or back focused. For the nikon mount this issue has shown up, I unfortunately got landed with one. Someone has sent the body & lens to sigma & it came back perfect. I wasn't prepared to send in my D4, so I returned the lens.
I was interested in if the dock could fix the problem but it can't so I'll consider a nikon one. Or switch to canon
