Seattle photos & Canon’s micro-focus adjustments

Downtown Seattle - 168mm, 1/500, f/5.6, ISO1600

Downtown Seattle – 168mm, 1/500, f/5.6, ISO1600

I took this shot from Hamilton Viewpoint Park in West Seattle.  I had my 10-year-old EF 70-200mm f/4L lens on my new EOS 6D.  The lens itself has a fairly severe back focusing problem (focuses slightly further than what the autofocus point is aimed at). When I first noticed it, I chalked it up to camera shake blur, or I would have returned it and asked for another copy.  The more I used it, I began to notice that an animal’s eyes (which I pointed the AF point at) were a little soft, but the fur on its shoulders was tack sharp.  If my shutter speed was too slow the whole shot would have been soft. Thank goodness for Canon’s MFA (Micro-Focus Adjustment) feature on their newer dSLRs!

My EOS 50D and EOS 7D allowed you to set an autofocus compensation adjustment for each lens, which the AF system would take into account each time you attached a particular lens.  Very handy, but I discovered the 6D actually has separate wide and telephoto MFA settings for each lens.  Awesome!  Especially for troublesome lenses like my 70-200mm.  I’ve tried hooking my 7D to my computer and focusing on a target on the wall halfway across the house to make these settings.  This time I took a more practical, albeit less scientific, approach.

I like using magnified Live View and manually focusing to ensure sharp landscapes.  Action shots or situations which require precise timing and a quick shutter finger can’t take advantage of this technique, but it works for tripod shots of static subjects.  To set my MFA adjustments, I set the camera on a tripod and focused on a subject that was about the distance of most subjects I’d shoot with that particular lens.  For example: at 200mm, I focused on the tree across the road about 300 feet away, and for my 35mm, I focused on a bench about 10 feet away.  Normal working ranges for me at those focal lengths.  Then I magnified Live View 5X or 10X, and manually focused until the details were as sharp as I could get them.  Next I flipped the lens’ AF switch and half-pressed the shutter while carefully watching the distance scale on the lens.  If it moved, I entered an adjustment.

Eventually, I got all my lenses not to move at all from the sharpest I could get using magnified manual focus.  Now I am getting the sharpest images I ever have with my 70-200, thanks to a minus 15 micro-focus adjustment.  Just to put that in perspective, -20 is the farthest you can go, and my other lenses needed only +/- 3 MFA or less.  But look at those buildings!  Very sharp.  Great optics, but a poorly aligned AF motor.

Space Needle - 154mm, 1/500, f/8, ISO800

Space Needle – 154mm, 1/500, f/8, ISO800

Another secret for sharp hand-held images:  My shutter speed was set to 1/500 sec.  The basic rule is to set your shutter speed at, or higher than, your focal length. So at 200mm, your shutter speed should be at least 1/250.  I went a little faster because it was breezy and I know, even bracing my elbows on the fence, I can’t keep the camera completely still. If I have to raise my ISO to get a high enough shutter speed, I do it!  Sharp but grainy photos are more usable than smooth but soft, blurred photos, and software noise reduction actually works surprisingly well.

Seattle Bi-Color - NIK Color Efex Pro 4

Seattle Bi-Color – NIK Color Efex Pro 4

Here is a crazy bi-color filter on one of the photos I took. Now that I look at it inserted into the post, it looks like I jammed a sunset city and mid-afternoon water together in Photoshop, but it really is one photo.  Sometimes it’s fun to just experiment and not be too stuck on “realistic”.

Rainier from Discovery Park

Rainier from Discovery Park

This is a shot from earlier the same day at Discovery Park north of downtown Seattle.  I normally don’t like borders but once it awhile I think it can add to the photo.  If you look at the horizon line just to the right of the mountain, that’s where I went to shoot the other photos in this post.  I used my EF 35mm f/2 lens for this photo at f/13, trying to keep everything in focus from near to far.

I hope you like the photos, and if you have an EOS dSLR and think your lenses might not be autofocusing precisely, this may give you some ideas.


3 thoughts on “Seattle photos & Canon’s micro-focus adjustments

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