----- Original Message ----- 
From: "Mr. Bill" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, October 11, 2005 7:36 PM
Subject: EOS Calibration


> Malcolm,
> Was the calibration done on the body only or do individual lenses need
> to be calibrated too?
> Will a 20D benefit from the calibration or only the 10D (I have a 10D
> and I'd like to see things sharper, but I have a couple of friends who
> are not happy with the sharpness they are getting on their 20D's).
> How much did Canon charge for the calibration and how long did it take?
> Mr. Bill

Hi Mr Bill,

I had just my 10D "calibrated" by Lehmann's (Authorised by Canon etc.),
shortly before the first 12 months was up - in February 2004.  No lenses.
So the cost to me was zero - I'd taken the precaution of having my warranty
and receipt paperwork with me.
I dropped my 10D off at around 11am, had lunch visiting the Harecastle
Tunnel entrance*, and collected my 10D at around 2pm the same day.  They
updated the firmware as well.
* a nostalgia trip from a canal holiday way back in 1956!

Prior to calibration, shots using my EF 35 f2 at f2 and at night weren't
that well focused.
Afterwards, I noticed very little change with my Canon lenses other than my
EF 50 f1.4 which seemed to have lost some of its  purple fringing at f1.4.
(On a black & white bar line test chart.)  The biggest surprise was with my
Sigma 17-35 EX HSM, original model.  Prior to the calibration, this
performed somewhat badly, some would say atrociously, at a variety of
apertures.  Afterwards, it was good enough for me to show other critical
photographers an A3+ glossy print side by side with shots taken using my EF
135 f2 L.  Very strange. I wish I understood what was going on - all I know
for sure is that we can be much more critical with digital pixel peeping
than ever we were with scanned grainy film!  OTOH, some of my 10" x 8"
Cibachrome prints from K64 are very impressive.
I honestly don't know what standards are possible at around full apertures
of around f2 (MTF graphs are usually dire in this area), but I do know that
my 10D, prime Canon EF lenses at moderate apertures, and my Epson 1270
printer are capable of producing critically sharp, and very pleasing, A3+
glossy prints.  I was never able to do that with the same lenses from
scanned slides.  In the old days f1.4s were used with Tri-X etc. for
reportage shots, and any image was better than none, so perhaps we've lost a
bit of perspective with digital?

(The Sigma focus motor has now stopped working yet again....  No other lens
of mine has had so many visits to the repair shop.)

Chuck Westfall (of Canon USA) has written about the calibration procedure,
and from memory they test a body against a workshop tool lens acting as a
standard, and adjust the camera accordingly.  (Search the Fred Miranda or
Luminous Landscape sites.)
If you are going to do some lens tests, use flash with a short shutter speed
to remove the effect of ambient light, and try not to use the built-in
flash.  It gives too much on axis specular reflection which will be mistaken
for a lens fault.

HTH

Malcolm
Milton Keynes, UK
http://www.megalith.freeserve.co.uk/oddimage.htm




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