Posted by Peter Cross on March 23, 2014 at 11:20 PM
Outdoor Photographer has a short piece about aligning your camera and lens so that the focus is at the image plane (sensor) of the camera and not in front of or behind it. Seems like a reasonable thing to get squared away. But I'm wondering if this is an issue in reality or they are just trying to sell another piece of expensive gear. Does anyone have any experience with this issue and/or the instrument called a LensAlign? There are others.
I assume this refers to lens calibration. It is a common practice, since some individual lenses or even lens + TC combos don't "ideally" focus with certain bodies. Newer bodies can save calibration settings for a variety of lenses.
Some people use systems like Lens Align, while others may set up a bunch of objects to shoot (I know someone that puts beer cans on a fence) as a DIY method.
Max
Posted by Frederic Hore on March 24, 2014 at 11:24 AM
I use the Focus Pyramid, which is sloped at 45 degrees, with a printed scale on it for target shooting and aligning your lenses. Very effective to confirm how your lenses are performing, and to see if they meet "spec."
When it first came out, I read there were problems with some batches of the Nikkor 70-200 f/2.8 AFS being slightly out of alignment, resulting is soft images when using AF. Using the focus pyramid, confirmed mine was OK. Easy to use under controlled lighting conditions, it cost all of $20.
Other things to consider when calibrating a lens is that it will calibrate differently at close focus distance than at further away or infinity. So if you have a temporary need to do some close focusing as I do using a 70-200 lens for dragonflys and butterflys, you will need to calibrate for that distance and note the setting for that lens + tc or extension tube. Then also calibrate for the more common distances you may be using the lens for and use the appropriate setting for that use. If using the LensAlign system, Michael Tapes explains these issues on his website Support-Knowledge base. It's truly another learning curve.
Posted by Rick Cloran on March 26, 2014 at 2:06 PM
Peter, I have done some micro focus adjustments for several of my lenses (500, 100-400) and different bodies. There are several devices that will supposedly help with the problem. The LensAlign is one, Focus Pyramid and Spyder LensCal are others. From my experience the trick is to make sure that you are lined up parallel to the target so that your evaluation of the resulting test shots is valid.
I found the scales hard to be certain of, so I changed my target to a crisp new five dollar bill mounted dead flat against the target surface. When you see the detail in the portrait pop, you know you have focus. I have a friend who uses one of the large size bar codes from a shipping label. If you do try to do this I found a key to be manually putting the lens out of focus in a different direction each time to be necessary. Anything will lock on if you keep bumping the focus once it is very close. When you start well out of focus, you get a real sense of whether the adjustment actually helps. I found that the same lens might need an adjustment on one body, but not on another. Where I did do an adjustment, I feel I do get a higher percentage of good focus locks on the first pass.
Posted by Peter Cross on March 26, 2014 at 3:32 PM
Thanks everyone for the great input on this. I definitely will try it out when I can. Based on what I had read, I thought my camera was new enough that it would allow this to be done. Nope. A Canon EOS 60D is apparently not high enough in the Canon pecking order. When I up grade to a new, and higher level camera, I expect it to be there.
Discussion
6 repliesSome people use systems like Lens Align, while others may set up a bunch of objects to shoot (I know someone that puts beer cans on a fence) as a DIY method.
Max
When it first came out, I read there were problems with some batches of the Nikkor 70-200 f/2.8 AFS being slightly out of alignment, resulting is soft images when using AF. Using the focus pyramid, confirmed mine was OK. Easy to use under controlled lighting conditions, it cost all of $20.
More here: http://focuspyramid.com/free-ebook/
Cheers,
Frederic
http://www.bobrockefeller.com/2011/12/22/the-focus-pyramid/
Sandy
http://photographylife.com/how-to-calibrate-lenses#ixzz2wWUkiEu5
Other things to consider when calibrating a lens is that it will calibrate differently at close focus distance than at further away or infinity. So if you have a temporary need to do some close focusing as I do using a 70-200 lens for dragonflys and butterflys, you will need to calibrate for that distance and note the setting for that lens + tc or extension tube. Then also calibrate for the more common distances you may be using the lens for and use the appropriate setting for that use. If using the LensAlign system, Michael Tapes explains these issues on his website Support-Knowledge base. It's truly another learning curve.
I found the scales hard to be certain of, so I changed my target to a crisp new five dollar bill mounted dead flat against the target surface. When you see the detail in the portrait pop, you know you have focus. I have a friend who uses one of the large size bar codes from a shipping label. If you do try to do this I found a key to be manually putting the lens out of focus in a different direction each time to be necessary. Anything will lock on if you keep bumping the focus once it is very close. When you start well out of focus, you get a real sense of whether the adjustment actually helps. I found that the same lens might need an adjustment on one body, but not on another. Where I did do an adjustment, I feel I do get a higher percentage of good focus locks on the first pass.