Posted by Paul DeCesare on April 29, 2013 at 1:02 PM
Hi Sandy, I had considered that system when I first got my 5D2 4 years ago, because I now had this nifty feature of Backfocus adjustment. Before I spent the money I thought I'd give it a go Red Green style, pulling it off at home with ordinary household objects and duct tape (although duct tape didn't get all of the dust off of my sensor for some reason).
It turns out that you can get each of your lenses almost dead on without spending any money (yes, I was kidding about the duct tape!). Just pop the camera on a tripod, I've even done it handheld with a couple lenses since that how I would shoot, and grab a box of cereal or some other object with edges. You want an edge with high contrast, so a yellow Cheerios box with a dark background such as a couch or TV with power off across the room works great as an example. Place the box about 10-15 feet away (longer if you're dialing in a long lens like a 300mm or more), and place your AF point on an edge of the box or a corner. I think you shoot Nikon so I don't know how the mark their increments, but I'll tell you from a Canon POV... I shoot at -15, -10, -5 0. ,+5, +10 and +15. With each shot I take I lightly tap the shutter to engage AF (well, backbutton now, but same thing) and make sure it's happy where it's focused. Then, take your shots and then just scroll back and forth through the 7 images on your LCD, zoomed in of course. You'll know it when the sharpest one shows up; in fact, you'll be surprised how off the bad ones are. You may even have two of the seven images that seem nearly identical in focus on a lens or two, and in that case, pick a setting in between the two sharpest. Otherwise, you'll see the sharpest image. When you do, set the camera at that setting for that lens, and you're done! I've done this with all of my lenses, and I couldn't be happier. I have some big improvements I need to make in my image making, but image sharpness is not a problem anymore thankfully!
Discussion
2 replieshttps://store.birdsasart.com/shop/item.aspx?itemid=304
Thanks for any thoughts or reviews.
Sandy
The Simple Solution to Back-Focus and Front-Focus Problems
Carol
It turns out that you can get each of your lenses almost dead on without spending any money (yes, I was kidding about the duct tape!). Just pop the camera on a tripod, I've even done it handheld with a couple lenses since that how I would shoot, and grab a box of cereal or some other object with edges. You want an edge with high contrast, so a yellow Cheerios box with a dark background such as a couch or TV with power off across the room works great as an example. Place the box about 10-15 feet away (longer if you're dialing in a long lens like a 300mm or more), and place your AF point on an edge of the box or a corner. I think you shoot Nikon so I don't know how the mark their increments, but I'll tell you from a Canon POV... I shoot at -15, -10, -5 0. ,+5, +10 and +15. With each shot I take I lightly tap the shutter to engage AF (well, backbutton now, but same thing) and make sure it's happy where it's focused. Then, take your shots and then just scroll back and forth through the 7 images on your LCD, zoomed in of course. You'll know it when the sharpest one shows up; in fact, you'll be surprised how off the bad ones are. You may even have two of the seven images that seem nearly identical in focus on a lens or two, and in that case, pick a setting in between the two sharpest. Otherwise, you'll see the sharpest image. When you do, set the camera at that setting for that lens, and you're done! I've done this with all of my lenses, and I couldn't be happier. I have some big improvements I need to make in my image making, but image sharpness is not a problem anymore thankfully!