Spyder auto-focus calibration

Spyder have a new product. Having calibrated your screen for colour you can now use their new system to calibrate your lens/AF system.

http://download.datacolor.eu/newsletter/2010-09-01-EN/

Interesting bit of kit, but €49 + VAT? A bit steep I think.


I haven't found any solution to B/F focussing that describes how to correctly adjust the camera when a zoom lens is used. Would you test at max. or min. zoom?

It depends on how well the zoom maintains focus over the range, so I would expect an average is about the best that can be achieved. Zoom lenses are fairly modest apertures, so hopefully Depth of Focus (at the sensor) will be enough to cover any residual error.

Peter,

I have a universal correction of +150um dialed in on my K10, and that serves the zooms just as well as the primes FWIW. The zooms in my case are the 16-45, and the 50-135.

Gwyn,
Will you be taking you camera/lenses for the free callibration
quote from the site;

"If you want to see the SpyderLensCal live, then visit us at Photokina (Hall 4.1 Stand F019/E010) in Cologne, Germany from September 21-26 and we will calibrate the autofocus of your favorite camera/lens combination. We have 100 free tickets for the photokina tradeshow so just drop us an email quickly, as it's first come first serve! "

Regards

A chap in Quebec has developed a lens calibration chart and instructions that are all FREE. Visit pentaxdslrs.blogspot.com for the download. I haven't used it yet so can't comment, but I have purchased one of his e-books and am very pleased.

Regards,

Stephen

If I still had a camera I would

Stephen - there are lots of free calibration charts available, but they are not always easy to use, and depend to a good degree on how good your printer is.

The printer quality hardly is an issue for focus calibration charts, as it is the distance that counts. On the other hand, charts for resolution measurements are different and need quality printout.

Just stand a ruler up at 45deg at the side of a cornflakes box so that it looks similar to the Spyder in the links above. Your focus point is where the ruler passes the front face of the box.

Canon suggest that adjustments should be made at the long end of the zoom range, using a target positioned at a distance of at least 50x the focal length.

Our own (ex-) Richard Day tests at wide, mid and long ends of the zoom range, at long, middle and near distance, then averages the result! He mentioned it in one of his posts.