The first below was taken with a 70-200 with 1.4 tc.
this is pretty much a 100% crop
ISO 400 f 6.3 1/320 no sharpening
The next image was taken with the 7D and the 100-400
400 mm ISO 400 f5.6 1/500
Again about 100% crop no sharpening
While both shots are very raw as far as post processing, nothing looks totally in focus on the 100-400 shot.
I took about 7 shots of the cormorant from pretty much the same position and they all look about the same.
I haven't micro adjusted and just want the opinion of someone who has spent time doing it, if this is
pretty much what the before looks like.
It would be useful to know the actual focus point on each image.
The 70-200 x 1.4 tc image is super sharp. The focus point on the 100-400 image looks like it's around the eye or auricular feathers (over ear) and I think they look pretty good for a 100% unsharpened crop. It looks like you have less DoF in the 100-400 image which gives an impression of softness. Finally, the IQ from the 100-400 at 400mm improves a lot with a little stopping down.
Without knowing the actual focus point it's hard to comment on whether you need to microadjust the AF of the lens.
Last edited by John Chardine; 03-25-2010 at 08:17 AM.
Dave S the micro adjustment is a feature of the new Canon cameras. I think from the 50D onward
and the MarkIII onward that lets you adjust the focus on individual lens with your camera.
John the focus point on the little blue is right in the middle of the neck where it bends
and on the cormorant its about 3 inches behind the eye (down the neck)
John my biggest concern is, I don't see anything in sharp focus on any of the 7 shots of the cormorant.
Don't get me wrong it's not bad but I have had razor sharp images with this lens
before.
I'll try Arash's method and see if it makes any difference.
Would add it is better to use a target for testing, live subjects not a good idea. Can use any paper with writing (flat) parallel to the film plane. Use sturdy tripod and lock everything down, also enough shutter speed to make sure .. grain is of no importance. Can shoot wide open then stop down to observe the difference.
There is a great thread on adjustment a few posts below ... if you need it !!!
What autofocus mode is being used here? Single point or zone... with or without expansion points enabled? Handheld or tripod? Light looks very harsh would will also affect a contrast-based Autofocus system.
Try the dollar bill test from a tripod in a controlled lighting situation. Autofocus expansion needs to be disabled too.
Does this lens need the micro adjustment
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