Well, Yes, I will spend $6800 on a lens but refuse to pay $79 on a device to fine tune the autofocus of my camera lens combo. After carefully reading Neuro's tips on AFMA and Bryan's review of one of the two competing AFMA targets I figured that I could do just as good for less than 10 bucks. Now one of those production targets is made of cardboard (high quality of course) and one is made of plastic. Each have a ruler attached to them and each have a high resolution target, and one even has a targeting system designed to drive any obsessive/compulsive (which most of us are) over the edge.

One of the problems I had was that I am trying to AFMA a 500L, and the recommended distance from sensor plane to target is 25-50x the focal length, or the approximate distance you will be shooting from; this equates to 37.5 feet to 75 feet, or I figured the distance I normally shoot from with this lens is over 100 feet---Unfortunately, both of the production targets are too small to cover a significant portion of the frame or sensor field. So I thought a larger target would be more appropriate.

My second thought was the targeting system of the more expensive unit---I have to ask why? How many subjects are at exactly the right distance and exactly level and exactly perpindicular to to the sensor plane?---My guess would be all of them or none of them--depending on your perspective---So, regarding targeting level, distance etc, well close should be good enough.

Next, I needed a good, high resolution target and found a full resolution download on the internet and printed it off @ 8.5x11 in, in high resolution and on satin paper to limit reflection.

I used a couple of scrap boards from the garage (one for the base and one for the target) and I used an old quick release plate to screw on to the bottom so I could attach it to an old tripod.

Finally, I needed a long ruler (with high resolution print) to finish this beast.

Cost:
$2.29 for the ruler (metal, 3 ft long, fairly high resolution print)
$2.50 for two board feet of pine, if you don't have any laying around the garage
$1.00 for the print (ink and paper included)
I used an old lens plate, but you could just as easily use an inset nut for $.29

total cost: $5.79

here is the end result:

Click image for larger version.  Name: AFMA Target.jpg  Views: 93  Size: 34.4 KB  ID: 160

Do you think it will work?

I haven't had a chance to test it yet, weather has been windy and cloudy this week, but When I do test it I will be sure and report out the results-----Note: I shot this hand held from an elevated angle, but even so, you can see that I need some AFMA with this camera lens combo.