East Wind Photography said:
Jack Douglas said:
mistaspeedy said:
This all sounds like my recent (a week ago) upgrade from the Canon 20D (best crop body at the time), to the 1D Mark II (flagship sports camera at the time)... only I'm 13 years out of date
I hope you are enjoying your new setup. I know I am experiencing that more shallow depth of field going from 1.6x crop to 1.3x crop, and the effect you are experiencing must be much more pronounced going all the way to full frame.
I bought the iDX2 before I had intended (prefer not to be an early adopter) since CPW offered a good price and I thought it'll take a while to get up to speed. Well, getting up to speed midwinter is a lot more challenging than I imagined given the often poor light and the restricted shooting opportunities. Couple that with a lot of work/jobs in the shop and it has been very frustrating. I'm now pretty comfortable with the controls and options but still am not confident in my AFMA. I prefer to get outside in good light to do this and at -20C .....

I seem to be getting differing degrees of focus accuracy depending on the mode so maybe it's time to ship to Canon.
Jack
The mode has little to do with afma. It does however impact how the system focuses on various objects. I can tell you also that an incorrect afma can give you very inconsistent results, even when its just marginally off. When it is set correctly, the accuracy goes way up. I wouldnt have thought that was the case but in testing with Focal and looking at the charts i can see the accuracy go way up when its set correctly. Perhaps there is also some kind of phase feedback that doesnt work as it should when afma is off spec. You should also be setting afma using one shot af, not servo. One shot takes the af mode out of the picture and is supposed to be more accurate for stationary subjects.
I can afma wide to short telephotos in the house rather easily but the long teles take more space and are more temperamental. Temperature has a large impact on big teles. I no longer even bother unless the lens has aclimated to the air temp for at least an hour. I would even go as far as saying some may have a different afma at 80 degrees than at 10 degrees.
Thanks for this encouraging reply. As it happens today was somewhat sunny and +4C, so comfortable enough, so I set up the tripod and my targets on my stucco wire fence as illustrated here and ran through a series of shots. I used a distance of about 40 feet (this was 400 DO II X2 III). The targets were at the camera height and perpendicular and based on the wire dimensions, the top closest was 2" ahead, the bottom, furthest was 2" behind. Focused on the center/middle one. I have a fancier target but wanted to try this. It wasn't bright enough so ISO 1250 to keep the shutter at 1/1000. Spot focus and one-shot for all shots.
I think where I've gotten off track is judging the best focus to be somewhat midway when it's not as the three samples show. From all the shots my best value seems to be AFMA = 3 but get this, here is a chickadee taken when I was at +11. That's what has been driving me crazy.
Jack