If you are prepared to “invest” a couple of thousand dollars on a decent lens for your camera, you might expect that the manufacturer would have invested some time in ensuring that the lens was calibrated to a certain standard. Not so when it comes to Canon (or Nikon). The lens may well be “within acceptable tolerances”, but if it is of the type which provides a depth of field of a couple of millimetres at certain settings, then the acceptable tolerances may not prove to be acceptable. If you are focusing on the beautiful eyes of a beautiful lady, and what you get is blurry eyes and a sharp nose, then you tend to get pissed off; as does the beautiful lady, and you should never upset a beautiful lady.
One solution is to take the camera and lens back to Canon (or Nikon, or whoever) and say “calibrate this my man” (or woman or ladyboy, depending on who is serving you). The other solution, if your camera supports it, is to calibrate the lens with the camera by changing some settings. Very useful feature and one I have employed on all my lenses, none of which were completely accurate.
To carry out the calibration, you need something to focus on, and an indicator which shows the amount of front or back focus. I made such a device myself out of cardboard, paper, and a design from the wide, wide world of web. If I was asked to summarise the overall quality, accuracy and robustness of the device, I would say it was rubbish.
It’s difficult to set up with the focus plane vertical, especially as it has been warped with use, misuse and being jumped on by cats. The guide ruler is hard to read and gives different answers on the left to those on the right. But it’s better than nothing. Just
But now there is something better. A clever chap by the name of Michael Tapes has produced a commercial product that is not stuck together with glue and tape, but has magnets and sight holes and is tested with lasers before dispatch (apparently). But it costs considerably more than the 10 baht and an hour of labour the first version cost me. And it’s a device that I would use rarely. In these troubled times it’s impossible to justify such significant expenditure on such a trivial item.
But I have never let common sense interfere with gadget lust, so I picked up my LensAlign Pro from the Post Office this morning.
Now I need to buy some new lenses so I can calibrate them and justify the expense of the LensAlign. Consumerism, it’s such a curse.
Comments 🔗
2009-01-29| The Son saysThe 50D supports AF microadjustment. Oh dear. There goes a weekend of OCD tweaking…
2009-01-30| Spike says50D….? Is there something you haven’t told me?