p.19 #5 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
Hi Can anyone suggest please?
I got a Zeiss manual focus lens for my 5D mark III, and after using the DotTune method, the first steady point is +16 toward the + side, after using the slightly defocus method to workaround, i found the Steady green dot range is 14, so the mid point is 7 and that brings the exact point to be at +16 plus 7 = +23 which is out of the AFMA range.
what shall I do in this case? should I set at +16 or +20 or send the lens back to manufacture to calibrate within the range? but this is a manual focus lens, so, I really dont know what the best option now.
p.19 #6 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
I read ML has DotTune, cant find anything about my 7D having the option in ML. I'm gonna give this a shot to help with my Sig 35mm 1.4 art if not it going back to Amazon
p.19 #7 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
x-box wrote:
Hi Can anyone suggest please?
I got a Zeiss manual focus lens for my 5D mark III, and after using the DotTune method, the first steady point is +16 toward the + side, after using the slightly defocus method to workaround, i found the Steady green dot range is 14, so the mid point is 7 and that brings the exact point to be at +16 plus 7 = +23 which is out of the AFMA range.
what shall I do in this case? should I set at +16 or +20 or send the lens back to manufacture to calibrate within the range? but this is a manual focus lens, so, I really dont know what the best option now.
I helped Henry out over PM. I suggested sending the lens in for calibration if it's under warranty, or otherwise use +20 since that's relatively close to the center of the tuning range.
p.19 #8 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
x-box wrote:
Hi Can anyone suggest please?
I got a Zeiss manual focus lens for my 5D mark III, and after using the DotTune method, the first steady point is +16 toward the + side, after using the slightly defocus method to workaround, i found the Steady green dot range is 14, so the mid point is 7 and that brings the exact point to be at +16 plus 7 = +23 which is out of the AFMA range.
what shall I do in this case? should I set at +16 or +20 or send the lens back to manufacture to calibrate within the range? but this is a manual focus lens, so, I really dont know what the best option now.
Henry-
your writeup is a bit confusing, how did you figure the range is 14 for this manual focus Zeiss? Are you basing it off of other 50mm at the same distance? ANyway, +20 is closer to +23 which would be better than your +16 focus edge. BUT, being that the Zeiss is positioned to work on the Canon with AF confirm, I would suggest sending back to them to better calibrate and tell them that it is naturally and heavily front focusing.
ALSO - one related piece of advice. In Canon AF systems, even for fixed focal length and distance to subject, you will get differenet MFA values under different types of lighting!!! Flourescent will create back focused results while Incandescent will be front focued, and Sunlight in between. ;-(. So, if you sent to Zeiss, consider including description of lighting.
p.19 #9 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
gschlact wrote:
Henry-
your writeup is a bit confusing, how did you figure the range is 14 for this manual focus Zeiss? Are you basing it off of other 50mm at the same distance? ANyway, +20 is closer to +23 which would be better than your +16 focus edge. BUT, being that the Zeiss is positioned to work on the Canon with AF confirm, I would suggest sending back to them to better calibrate and tell them that it is naturally and heavily front focusing.
ALSO - one related piece of advice. In Canon AF systems, even for fixed focal length and distance to subject, you will get differenet MFA values under different types of lighting!!! Flourescent will create back focused results while Incandescent will be front focued, and Sunlight in between. ;-(. So, if you sent to Zeiss, consider including description of lighting. ...Show more →
Very interesting regarding the differenct light conditions, I use one 400W Halogen light to light up the test chat - may give it a try under daytime normal lighting condtion - has to be a weekend, as when I got home weekdays, its completely dark.
p.19 #11 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
I'll test the manual way. How bright of a light setting would be best? Afternoon sun? I'll setup my charts in my year if so. The ML kinda scary with people bricking their bodies.
p.19 #19 · Dot-Tune: Autofocus Fine Tuning in under 5 minutes
bushwacker wrote:
Okay guys... what's the reason why you have to set it at MAX Aperture when doing AF micro-adjustment?
The PDAF system always uses the lens at its maximum aperture when performing phase detection for focusing, so setting the lens to a smaller aperture for the VF confirmation of DotTune will have no effect on the results. If however you use a smaller aperture during the initial CDAF/Live View focus of DotTune then spherical aberration (focus shift) correction will be baked into the tuning result, which most users probably wouldn't want since it will negatively affect the accuracy when shooting wide-open. I actually tune some of my lenses that way so it's a valid technique but only if the photographer understands the implications.
