IS power consumption (and a faulty copy)
Discussion
Disappointment. Got my copy of the 70-200 f2.8 IS this morning, but it appears to be faulty 
As soon as I power the camera up, it drains the battery and locks the body up such that I have to remove the backup battery to reset it. With a fresh-off-the-charger battery, it went immediately down to 1 bar on the battery meter, and the AF didn't work.
It has done this on 4 different bodies, so I think that's a fairly compelling case for it being DOA.
Plus it does it with IS and AF switched off, and before you even get as far as a half-press.
I wouldn't expect the IS on this lens to be any more power consuming than my other IS lens (17-55 f2.8), should it? They are the same generation (i.e. 3-stop advantage) IS as far as I know?
I hope I can get it replaced rather than have to send to Canon - it was fresh out of the box.
:grumpysmiley:
DH2
As soon as I power the camera up, it drains the battery and locks the body up such that I have to remove the backup battery to reset it. With a fresh-off-the-charger battery, it went immediately down to 1 bar on the battery meter, and the AF didn't work.
It has done this on 4 different bodies, so I think that's a fairly compelling case for it being DOA.
Plus it does it with IS and AF switched off, and before you even get as far as a half-press.
I wouldn't expect the IS on this lens to be any more power consuming than my other IS lens (17-55 f2.8), should it? They are the same generation (i.e. 3-stop advantage) IS as far as I know?
I hope I can get it replaced rather than have to send to Canon - it was fresh out of the box.
:grumpysmiley:
DH2
i slightly digress here, but a tip worth considering:
any manufacturer is capable of producing less than perfect goods - some faults may be miniscule and some major as per DH2's experience.
i rely on my kit being spot on, straight out of the box, therefore all bodies and lenses go to "Fixation" for check and calibration before they are put to work.
d
any manufacturer is capable of producing less than perfect goods - some faults may be miniscule and some major as per DH2's experience.
i rely on my kit being spot on, straight out of the box, therefore all bodies and lenses go to "Fixation" for check and calibration before they are put to work.
d
So how big are these gyros and where do they sit in the lens? Must be pretty small motors to spin those gyros! 
As I understand, the IS works spinning a small gyroscope which stabilises in one direction (with option 2 for panning mode), or 2 gyros for option 1 to stabilise in 2 directions. They do not have to be large to be effective. Happy to be corrected though, and will wear the cap with a big D on it.
LB
searching has brought up this:
Short answer
"A simplified description of how IS works, taken from Canon's lens brochure:
Optical shake is detected by gyro sensors which provide the data necessary to shift the image-stabilizing lens group in parallel to neutralize the shake. This increases the usable shutter speed range by up to 3 full steps for hand-held shooting.
The "gyro" in their explanation is a gyroscope."
Longer answer:
"Canon started development of IS (Image Stabilizer) technology in 1980s and introduced EF75-300mm f/4-5.6 IS USM in 1995, the world's first interchangeable lens for 35mm SLR with a built-in image stabilizer. The vibration detecting gyro sensor detects the level of camera shake and the actuator moves a part of the optical system (IS lens group) vertically to the optical axis depending on the degree of camera shake, to stabilize the image on the film plane. Normal image stabilizing is suitable for shooting of stationary subject. However, EF300mm f/4 L IS USM has "IS Mode 2" to stabilize finder images at panning shots of moving subjects."
LB
searching has brought up this:
Short answer
"A simplified description of how IS works, taken from Canon's lens brochure:
Optical shake is detected by gyro sensors which provide the data necessary to shift the image-stabilizing lens group in parallel to neutralize the shake. This increases the usable shutter speed range by up to 3 full steps for hand-held shooting.
The "gyro" in their explanation is a gyroscope."
Longer answer:
"Canon started development of IS (Image Stabilizer) technology in 1980s and introduced EF75-300mm f/4-5.6 IS USM in 1995, the world's first interchangeable lens for 35mm SLR with a built-in image stabilizer. The vibration detecting gyro sensor detects the level of camera shake and the actuator moves a part of the optical system (IS lens group) vertically to the optical axis depending on the degree of camera shake, to stabilize the image on the film plane. Normal image stabilizing is suitable for shooting of stationary subject. However, EF300mm f/4 L IS USM has "IS Mode 2" to stabilize finder images at panning shots of moving subjects."
Edited by Luca Brazzi on Thursday 13th December 09:11
LB,
Indeed Gyros do not need to be big to be effective, but a gyro spinning up is a 'relatively' large piece of kit (link to wiki article). There are numerous other gyros (or motion detecting equipment) that do not use spinning discs and are completely motionless, however you mentioned spinning gyros (gimbals etc) and these are definately not in a canon lens. I found this article which also has a link to a dissassembly of a canon 70-200L F2.8.
Indeed Gyros do not need to be big to be effective, but a gyro spinning up is a 'relatively' large piece of kit (link to wiki article). There are numerous other gyros (or motion detecting equipment) that do not use spinning discs and are completely motionless, however you mentioned spinning gyros (gimbals etc) and these are definately not in a canon lens. I found this article which also has a link to a dissassembly of a canon 70-200L F2.8.
ehasler said:
I had a similar problem with my 70-200 lens, and having bought it from a HK based ebay seller, decided to send it back to Canon UK. They fixed it under warranty with no quibbles, and I had it back within a week or so.
Thanks Ed. I'm hoping the vendor will just swap it, but if that doesn't happen, am fairly happy that it can go back to Canon.DH2
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